JP3912362B2 - Control device for hybrid vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hybrid vehicle that makes its driveability compatible with its fuel efficiency. <P>SOLUTION: In this hybrid vehicle controlling device, a first efficiency index value SOCc1 is selected when the environmental information of a road on which the vehicle travels is detectable, and a second index value SOCc2 when it is not. When the efficiency index value is changed over, a final efficiency index value is calculated by performing a process of making the efficiency index value change continuously from a value before a changeover and correspond to a value after the changeover. Based on a car-speed detection value, braking/driving force command values, and the final efficiency index value, the drive point of an engine and a motor is determined that reduces charging capacity to a battery as the final efficiency index value gets larger. <P>COPYRIGHT: (C)2005,JPO&amp;NCIPI

Description

  The present invention relates to a control device for a hybrid vehicle.

  There is a control device for a hybrid vehicle that obtains road information related to a guidance route from a navigation device in advance and controls an engine and a motor so that the guidance route can be driven with low fuel consumption based on the road information (see Patent Document 1).

  In this prior art, an SOC conversion index SOCc is introduced as a control parameter representing the charge / discharge degree of the battery (= an efficiency index value representing the fuel utilization efficiency), and the fuel consumption and driving force characteristics in the guidance route traveling are improved. I am doing so.

The SOC conversion index SOCc is associated in advance with the operating points of the engine and the motor such that the larger the value, the more the battery discharge amount (less charge amount) and the higher the fuel consumption efficiency of the engine. Therefore, if the SOC conversion index SOCc is set to a large value, an operation point with high fuel consumption efficiency can be realized although the amount of charge to the battery is small (the discharge amount is large), and conversely, the SOC conversion index SOCc is set to a small value. For example, an operating point with low fuel consumption efficiency but with a large amount of charge to the battery (a small amount of discharge) can be realized. In particular, before driving the route, based on the road information of the guidance route obtained from the navigation device, the SOC conversion index SOCc capable of realizing low fuel consumption while maintaining the SOC within a predetermined range is calculated, and the actual accelerator during driving is calculated. By determining the operating points of the engine and the motor based on the opening degree, the actual vehicle speed, and the SOC-converted index SOCc, the fuel consumption at the time of traveling on the guide route is reduced. Further, the fuel consumption reduction effect is further enhanced by repeating the recalculation of the SOC conversion index SOCc during traveling on the guidance route, and the braking / driving force characteristics of the vehicle are determined by determining the SOC conversion index SOCc so that the SOC falls within a predetermined range. Has improved.
JP 2001-298805 A

  However, in the conventional hybrid vehicle control device described above, when the SOC conversion index SOCc is updated, the target operating points of the engine and the motor change discontinuously depending on the SOCc values before and after the update, and the engine and motor There is a possibility that the operating point of the motor changes suddenly, for example, the engine speed increases rapidly. Although such a phenomenon does not affect the braking / driving force of the vehicle, there is room for improvement because it may cause discomfort to the passenger.

  An object of the present invention is to calculate a control parameter based on road information from a navigation device so as to suppress fuel consumption in a travel route to a minimum. It is providing the control apparatus of the hybrid vehicle which suppresses that the driving | running point of a motor changes rapidly. This avoids unnecessary discomfort for the passenger.

The present invention relates to a control apparatus for a hybrid vehicle that uses one or both of an engine and a motor as a braking / driving force source, and transfers power between the motor and a battery. The road environment information of the battery SOC and the travel route of the vehicle is detected. Based on the road environment information of the travel route and the SOC, a first efficiency index value representing the fuel utilization efficiency is calculated. Based on the SOC, the higher the SOC, the larger the efficiency index value (second efficiency index value) When the road environment information of the travel route of the vehicle can be detected, the first efficiency index value is selected. Otherwise, the second efficiency index value is selected, and when the efficiency index value is switched, the efficiency index value is selected. The final efficiency index value is calculated by performing a process of continuously changing the value from the value before switching to match the value after switching . Based on the vehicle speed detection value, the braking / driving force command value, and the final efficiency index value, the operating points of the engine and the motor are determined so that the larger the final efficiency index value, the smaller the charge amount to the battery.
After the vehicle reaches a point where the distance Xr to the end of the travel route set by the navigation is within a predetermined distance, calculation is performed so that the first efficiency index value approaches the second efficiency index value as Xr decreases. .

  In this invention, it can suppress that the operating point of an engine or a motor changes rapidly, and can avoid giving a passenger discomfort.

<< First Embodiment of the Invention >>
FIG. 1 shows the configuration of an embodiment. In the figure, a thick solid line indicates a transmission path of mechanical force, and a thick broken line indicates a power line. A thin solid line indicates a control line, and a double line indicates a hydraulic system. The power train of this hybrid vehicle includes a motor 1, an engine 2, a clutch 3, a motor 4, a continuously variable transmission 5, a speed reducer 6, a differential device 7, and drive wheels 8. A clutch 3 is interposed between the engine 2 and the motor 4, and the output shaft of the motor 1, the output shaft of the engine 2, and the input shaft of the clutch 3 are connected to each other, and the output shaft of the clutch 3 and the motor 4 The output shaft and the input shaft of the continuously variable transmission 5 are connected to each other.

  When the clutch 3 is engaged, the engine 2 and the motor 4 serve as a vehicle propulsion source, and when the clutch 3 is released, only the motor 4 serves as a vehicle propulsion source. The driving force of one or both of the engine 2 and the motor 4 is transmitted to the drive wheels 8 via the continuously variable transmission 5, the speed reducer 6, and the differential device 7. The continuously variable transmission 5 is supplied with pressure oil from the hydraulic device 9, and the belt is clamped and lubricated. An oil pump (not shown) of the hydraulic device 9 is driven by a motor 10.

  The motors 1, 4, and 10 are AC machines such as a three-phase synchronous motor or a three-phase induction motor. The motor 1 is mainly used for engine start and power generation, and the motor 4 is mainly used for vehicle propulsion and braking. The motor 10 is for driving an oil pump of the hydraulic device 9. The motors 1, 4, and 10 are not limited to AC machines, and DC motors can also be used. In addition, when the clutch 3 is engaged, the motor 1 can be used for vehicle propulsion and braking, and the motor 4 can be used for engine starting and power generation.

  The clutch 3 is a powder clutch and can adjust the transmission torque. The clutch 3 may be a dry single plate clutch or a wet multi-plate clutch. The continuously variable transmission 5 is a continuously variable transmission such as a belt type or a toroidal type, and the gear ratio can be adjusted steplessly.

  The motors 1, 4, and 10 are driven by inverters 11, 12, and 13, respectively. In addition, when using a direct current motor for the motors 1, 4, and 10, a DC / DC converter is used instead of an inverter. The inverters 11 to 13 are connected to the main battery 15 via a common DC link 14. The inverter 11 to 13 converts the DC charging power of the main battery 15 into AC power and supplies it to the motors 1, 4, 10. The main battery 15 is charged by converting the AC generated power 4 into DC power. Since the inverters 11 to 13 are connected to each other via the DC link 14, the electric power generated by the motor during the regenerative operation can be directly supplied to the motor during the power running operation without going through the main battery 15. it can. As the main battery 15, various batteries such as a lithium-ion battery, a nickel-hydrogen battery, and a lead battery, and an electric double layer capacitor, so-called power capacitor, can be used.

  The vehicle controller 16 includes peripheral parts such as a microcomputer and a memory. The rotational speed and output torque of the motors 1, 4 and 10, the rotational speed and output torque of the engine 2, the engagement and release of the clutch 3, and the continuously variable transmission 5 The gear ratio is controlled.

  As shown in FIG. 2, the vehicle controller 16 includes a key switch 20, a brake switch 21, an accelerator sensor 22, a vehicle speed sensor 23, a battery temperature sensor 24, a battery SOC detector 25, an engine rotation sensor 26, a throttle sensor 27, and the like. Connected.

  The key switch 20 is turned on (closed) when the vehicle key is set to the ON position or the START position. The brake switch 21 detects the depression state of a brake pedal (not shown), and the accelerator sensor 22 detects the depression amount of the accelerator pedal (hereinafter referred to as accelerator opening). The vehicle speed sensor 23 detects the traveling speed of the vehicle, and the battery temperature sensor 24 detects the temperature of the main battery 15. The battery SOC detection device 25 detects the state of charge (SOC) of the main battery 15, and the engine rotation sensor 26 detects the rotation speed of the engine 2. Further, the throttle sensor 27 detects the throttle valve opening of the engine 2.

  Also connected to the vehicle controller 16 are a fuel injection device 30, an ignition device 31, a throttle valve control device 32, a navigation device 33, and the like of the engine 2. The controller 16 controls the fuel injection device 30 to adjust supply and stop of fuel to the engine 2 and the amount of fuel injection, and also controls the ignition device 31 to ignite the engine 2 and control the throttle valve adjustment device 33. Then, the torque of the engine 2 is adjusted.

  The navigation device 33 is a satellite navigation device that detects the current location and travel route with a GPS receiver, a self-contained navigation device that detects the current location and travel route with a gyrocompass, and a road-to-vehicle communication device that receives traffic information and road information such as VICS. It has a road map database, etc., searches for the optimum route to the destination, and guides passengers along the optimum route.

  The navigation device 33 also includes a route division function 33a, a road environment detection function 33b, and a target SOC determination function 33c realized by microcomputer software. The route division function 33a divides the guidance route to the destination. The road environment detection function 33b detects road curvature radii of divided sections, road gradients, presence / absence of intersections / tunnels / crossings, regulation information such as speed limits, and area information such as city roads and mountain roads. Further, the target SOC determination function 33c determines the target SOC (t_SOC) of the main battery 15 at the destination.

  The vehicle controller 16 includes a traveling condition prediction function 16a, an SOC conversion efficiency index calculation function 16b, and an engine / motor operating point calculation function 16c realized by microcomputer software. The traveling condition prediction function 16a predicts the vehicle speed and braking / driving force command value of each divided section based on the road environment of each divided section.

The SOC-converted efficiency index calculation function 16b calculates an SOC-converted efficiency index SOCc as an efficiency index that represents the fuel utilization efficiency used when determining the engine / motor operating point. The engine / motor operating point calculation function 16c calculates the operating points of the engine 2 and the motors 1 and 4 based on the SOC conversion efficiency index SOCc, the vehicle speed, and the braking / driving force command value.
<< Calculation method of SOC conversion efficiency index SOCc >>
In this embodiment, the engine 2 and the motors 1 and 4 are controlled so that the SOC of the main battery 15 becomes the target value while suppressing the fuel consumption in the guide path to the minimum.

  First, the target SOC (t_SOC) at the destination is set. This target SOC (t_SOC) is the target value of the SOC at the destination, but the SOC of the main battery 15 does not necessarily have to be the target SOC (t_SOC) during the route to the destination. The operating points of the engine 2 and the motors 1 and 4 are not determined based on the target SOC (t_SOC). The target SOC (t_SOC) setting method at this destination includes a method of simply setting a constant value, for example 70%, regardless of the road environment, a method of determining according to the altitude of the destination, for example, the higher the altitude, There is a method of setting a small target SOC (t_SOC) in the hope that the traveling energy at the time of going down can be collected in the main battery 15.

  Next, in this embodiment, in order to set the SOC of the main battery 15 at the destination as the target SOC (t_SOC) while minimizing the fuel consumption in the middle of the route to the destination, An SOC conversion efficiency index SOCc for determining the operating points of the engine 2 and the motors 1 and 4 in the middle of the route is obtained by calculation.

  When this SOC conversion efficiency index SOCc is large, the charging power increase amount Δbat per unit fuel increase amount Δfuel for battery charging is increased, that is, the fuel use efficiency at the time of battery charging is increased. The engine / motor operating point is determined so as to perform charging only, and conversely, when the SOC conversion efficiency index SOCc is small, the engine / motor operating point is determined so that charging is performed even when the fuel utilization efficiency during battery charging is low. .

  With reference to FIG. 3, the calculation method of the SOC conversion efficiency index SOCc will be described. A case where the traveling pattern to the destination is a pattern as shown in FIG. 3A will be described as an example. In FIG. 3a, the route to the destination is divided into n sections way (i) (i = 1, 2,..., N), and the vehicle speed p_vsp is based on the road environment for each section way (i). (I) and the braking / driving force command value p_tTd (i) are predicted. A method for predicting the vehicle speed p_vsp (i) and the braking / driving force command value p-tTd (i) will be described later. 3b to 3d determine the operating points of the engine 2 and the motors 1 and 4 by setting three types of fixed values SOCc_h, SOCc_m, and SOCc_l (where SOCc_h> SOCc_m> SOCc_l) as the SOC conversion efficiency index SOCc, respectively. Shows the minimum fuel consumption, charge / discharge amount, and SOC change.

  As described above, the SOC conversion efficiency index SOCc is an index that represents the fuel use efficiency during battery charging. Therefore, as is apparent from FIGS. 3b to 3d, the final SOC at the destination has the smallest value f_SOCc_h when the maximum value SOCc_h is set in the SOC conversion efficiency index SOCc, and the SOC conversion efficiency index SOCc. The value f_SOCc_l when the minimum value SOCc_l is set is the largest. That is, the actual SOC at the destination becomes smaller as the engine / motor operating point is set so as to charge only when the fuel utilization efficiency is high.

  Some value is set in the SOC conversion efficiency index SOCc, and an engine / motor operation described later is performed based on the predicted vehicle speed p_vsp (i) and the predicted braking / driving force command value p-tTd (i) of each divided section way (i). A temporary operating point of the engine 2 and the motors 1 and 4 is determined by the point determination method. Then, the time integration value p_bat (i) of the charge / discharge power Bat of each divided section way (i) is obtained, and the predicted battery charge / discharge power p_bat () of each divided section way (i) is determined using the current SOC (d_SOC) as an initial value. If i) is integrated over time, the predicted SOC (p_SOC (i)) in each divided section way (i) and the predicted SOC (p_SOC [n]) at the destination can be obtained.

  As described above, if the SOC conversion efficiency index SOCc is increased, the predicted SOC (p_SOC (n)) at the destination is decreased. Therefore, the initial value SOCc_0 is set in the SOC conversion efficiency index SOCc (SOCc = SOCc_0). If the predicted SOC (p_SOC (n)) at the destination is larger than the target SOC (t_SOC) at the destination when the predicted SOC at (p_SOC (n)) is calculated, the SOC conversion efficiency index SOCc is

Reduce and recalculate. Conversely, when the predicted SOC (p_SOC (n)) at the destination is smaller than the target SOC (t_SOC) at the destination, the SOC conversion efficiency index SOCc is

Increase to recalculate.

  When the above calculation is repeated until the predicted SOC (p_SOC (n)) at the destination substantially coincides with the target SOC (t_SOC) at the destination, that is, the difference between the two becomes equal to or less than a predetermined value. SOCc_j (j is an integer of 0 or more) is determined as the final SOC conversion efficiency index SOCc. This calculation is performed when there is a new input or change of the destination, a departure from the guidance route, or a change in the traffic jam situation.

Here, α is a fixed value that does not diverge the repetitive calculation. Alternatively, SOCc_0 may be determined according to traffic information or the like. For example, when the traffic congestion is severe and SOC (d_SOC) is small, SOCc_0 is set to a smaller value. Alternatively, in the case of a route that has traveled before, the initial value is a value that is corrected to be smaller as the current SOC (d_SOC) is smaller based on the SOCc at that time.
<Engine / motor operating point determination method>
Next, a method for determining the engine / motor operating point when the clutch is engaged will be described with reference to FIGS. The operation points A, N, B, C, D, and E in FIG. 4 correspond to the operation points A, N, B, C, D, and E in FIG.

  When the calculation for determining the SOC conversion efficiency index SOCc is being performed, the temporarily set SOCc, the predicted vehicle speed p_vsp (i) and the predicted braking / driving force command value p_tTd (i) for each divided section way (i) Based on the above, temporary operating points of the engine 2 and the motors 1 and 4 are determined. On the other hand, when the determination of the SOC conversion efficiency index SOCc is completed and the vehicle is actually traveling toward the destination, the determined SOC conversion efficiency index SOCc (= SOCc_j), the vehicle speed detection value d_vsp, and the braking / driving force command Based on the calculated value d_tTd of the value, a formal operating point when the engine 2 and the motors 1 and 4 are traveling is determined. The calculation value d_tTd of the braking / driving force command value is obtained by performing a table calculation from a braking / driving force command value table set in advance based on the vehicle speed detection value d_vsp and the accelerator opening detection value.

  In any of the operating point determinations, the operating point is determined so that charging is performed only when the SOC conversion efficiency index SOCc_j or SOCc increases and the fuel use efficiency during battery charging increases.

  FIG. 4 shows the engine / motor operating point when the vehicle speed is 50 km / h and the braking / driving force command value is 1000 N, and FIG. 5 shows the relationship between the engine / motor operating point and the battery charge at the same vehicle speed and braking / driving force command value. Indicates. In FIG. 4, the thick line is the optimum fuel consumption line that connects the operating points at which the fuel consumption is minimized when the same engine output is obtained. The efficiency of the engine 2, the motors 1, 4, and the continuously variable transmission 5 is taken into consideration. It has become a thing. The engine / motor operating point is always set on this bold line. Point A is when the vehicle is driven by the motors 1 and 4 as much as possible (for example, the vehicle is driven by supplying the maximum electric power that can be taken from the main battery 15 to the motors 1 and 4), and the shortage is covered by the output of the engine 2. It is an operating point. On the other hand, the point E is an operating point when the vehicle is driven by the engine 2 and the motors 1 and 4 are driven to generate power in order to increase the charge amount of the battery 15.

  If the fuel supply amount to the engine 2 is increased at the operating point A where the main battery 15 is discharged, the charge / discharge amount of the main battery 15 becomes 0 at the point N, and further points B → C → D → The charge amount of the main battery 15 increases in the order of E. Incidentally, as shown in FIG. 5, the charge amount at point B is c_b (kW), the charge amount at point C is c_c (kW), the charge amount at point D is c_d (kW), and the charge amount at point E is c_e ( kW).

  The relationship between the charging power increase amount Δbat and the charging power Bat with respect to the fuel increase amount Δfuel with reference to the fuel supply amount at the point A is shown in the curve (1) of FIG. Further, the curve (2) is obtained from the curve (1) to obtain the ratio (= Δbat / Δfuel) of the charging power increase amount Δbat to the fuel increase amount Δfuel, and this ratio is called sensitivity S in this specification. These curves (1) and (2) are obtained in advance for each condition of vehicle speed and braking / driving force through experiments or the like.

  As shown in FIG. 5, the larger the SOC conversion efficiency index, the greater the sensitivity S is associated with. In this example, the sensitivity S is s170 for the SOC conversion efficiency index = 70%, the sensitivity S is s150 for the SOC conversion efficiency index = 50%, and the sensitivity S is s130 for the SOC conversion efficiency index = 30%. Respectively.

  Then, an engine / motor operating point that realizes charging power Bat with sensitivity S according to the SOC conversion efficiency index is calculated. For example, when the SOC conversion efficiency index is 70%, a point B1 that satisfies the sensitivity S = s170 on the sensitivity curve (2) is obtained, and the point B on the fuel supply amount curve (1) that realizes the sensitivity s170 is obtained. 4 and the point B in FIG. 4 corresponding to this point B may be the operating point of the engine 2 and the motors 1 and 4. In addition, when there are two points on the curve (2) satisfying the sensitivity S, a point having a large charge power Bat is adopted. In addition, when there is no point satisfying the sensitivity S on the curve (2), that is, when there is no driving point that can be charged with the sensitivity S under the current vehicle speed and braking / driving force conditions, the points in FIG. A is an operating point of the engine 2 and the motors 1 and 4. Since the curves (1) and (2) differ depending on the vehicle speed and braking / driving force conditions, the maximum value of the sensitivity S also varies depending on the vehicle speed and braking / driving force conditions. Therefore, when the SOC conversion efficiency index is large, an operating point that satisfies the sensitivity S can be obtained only under the conditions of limited vehicle speed and braking / driving force. On the other hand, when the SOC conversion efficiency index is small, an operating point that satisfies the sensitivity S can be obtained under a wide range of vehicle speed and braking / driving force conditions.

  As a result, the larger the SOC conversion efficiency index, the fewer the chances of charging the battery. Conversely, the smaller the SOC conversion efficiency index, the more charging opportunities. Further, the larger the SOC conversion efficiency index, the higher the fuel utilization efficiency at the time of charging, and the smaller the SOC conversion efficiency index, the lower the fuel utilization efficiency at the time of charging execution.

  In the above description, the sensitivity S corresponding to the SOC conversion efficiency index is obtained, the charging power Bat for realizing the sensitivity S is obtained, and the engine / motor operating point corresponding to the charging power Bat is obtained. Data that associates the charging power Bat with the SOC conversion efficiency index and the engine / motor operating point may be stored, and the data may be read to obtain the charging power Bat and the engine / motor operating point. This facilitates the calculation of the engine / motor operating point.

  For the characteristic curve (1) in FIG. 5, taking into account the power consumption of the electrical components, the discharge efficiency of the main battery 15 is shown when discharging to the left of the point N, and the charging efficiency is shown when charging to the right of the point N. It is good to relate in consideration of the charging efficiency of the main battery 15.

  The gear ratio of the continuously variable transmission 5 is adjusted to a gear ratio that realizes the vehicle speed and the rotational speed of the engine / motor operating point. Further, the torques of the motors 1 and 4 are distributed in advance, and a value that can realize the target braking / driving force command value by the motors 1, 4 and the engine 2 is calculated.

  The operating points of the clutch 3 are related in advance as shown in FIG. 6, and the engagement and release are controlled according to this relationship. When the clutch is disengaged, the rotational speeds of the engine 2 and the motor 1 coincide with each other, and the torque of the engine 2 and the converted value of the torque of the motor 1 around the engine shaft are constant. The operating points of the engine 2 and the motors 1 and 4 are determined by the method described with reference to FIG.

  In this embodiment, the above-described engine and motor operating point determination method is used for calculation of the SOC conversion efficiency index, and conversely, the above-described SOC conversion efficiency index is used for determination of the engine and motor operating point. Therefore, neither one can be calculated unless one is determined first. Therefore, as described above, in the calculation of the SOC conversion efficiency index SOCc, first, some value is set as the value of SOCc, in the above example, the initial value SOCc_0 is set to obtain a temporary operating point of the engine and the motor, and the SOC ( p_SOC (n)) is predicted. The calculation of the SOC conversion efficiency index SOCc is repeated until the predicted SOC (p_SOC (n)) at the destination matches the target SOC (t_SOC) using Formula 1 and Formula 2 using the predetermined value α, and the calculation has converged. Is determined as the final SOC conversion efficiency index SOCc.

  Then, actual operating points of the engine and the motor are determined based on the determined SOC conversion efficiency index SOCc. First, a braking / driving force command value d_tTd corresponding to the detected vehicle speed d_vsp and the detected accelerator opening d_acc is calculated from a table of braking / driving force command values set in advance based on the vehicle speed and the accelerator opening. Next, based on the SOC-converted efficiency index SOCc, the vehicle speed detection value d_vsp, and the calculated value d_tTd of the braking / driving force command value, a formal operating point when the engine and the motor are traveling is determined. The engine 2 and the motors 1 and 4 are controlled at this operating point.

  As a result, the operating point of the engine 2 and the motors 1 and 4 is determined using the SOC conversion efficiency index SOCc in the guidance route to the destination, and the fuel consumption in the guidance route to the destination is minimized. The SOC of the main battery 15 at the destination can be set to the target value t_SOC.

  7 and 8 are flowcharts showing the vehicle control program, and the operation of the first embodiment will be described with reference to these flowcharts. The vehicle controller 16 executes this control program every predetermined time. In step 1, the current location is detected. In the second and subsequent executions, the position of the divided section way (i) (i = 1 to n) is also detected. In the following step 2, it is confirmed whether or not there is a new input or change of the destination, a departure from the guidance route, or a change in the traffic condition. If there is any, the process proceeds to step 3; Proceed to In addition, the change of the traffic situation is obtained by a road-to-vehicle communication device such as VICS.

  When there is any new input or change of the destination, deviation of the guidance route, or change of the traffic congestion state, the guidance route to the destination is searched in step 3. In subsequent step 4, the guidance route to the destination is divided into n sections way (i) (i = 1 to n). This route division method can be used to classify points with distinctive features in the road environment, such as slope change points, intersections, road type change points, traffic jam start points, traffic jam end points, expressway tollgates, etc. There is a method of dividing the distance to the destination into n equal parts. When the distance to the destination is long, the route may be divided using a passing point on the guidance route to the destination as a temporary destination. In addition, as a method for determining the number of route divisions, there are a method for determining according to the degree of gradient change, the number of intersections, the road type, and a method for determining the number of divisions proportional to the distance to the destination.

  In step 5, road environment such as average gradient, intersection position, radius of curvature, altitude, etc. in each divided section way (i) is detected. In the subsequent step 6, as described above, the target SOC (t_SOC) at the destination is determined based on the road environment of each divided section way (i).

  In step 7, the vehicle speed p_vsp (i) and the braking / driving force command value p_tTd (i) in each divided section way (i) between the current location and the destination are predicted based on the road environment of each divided section way (i). . The vehicle speed p_vsp (i) is predicted as follows, for example. In the guidance route, the road speed limit is used as the predicted value. For example, a vehicle speed p_vsp (i) that predicts a vehicle speed p_vsp (i) such that the vehicle speed becomes 0 at a deceleration of 0.1G and returns to the cruising speed at an acceleration of 0.1G after 3 seconds of stopping at an intersection that makes a right or left turn. The vehicle speed p_vsp (i) is predicted based on the acceleration / deceleration and the passing speed corresponding to the vehicle speed. In addition, when traffic jam information is obtained from a road-to-vehicle communication device such as VICS, the vehicle speed p_vsp (i) is predicted such that the average vehicle speed decreases as the traffic jam in the traffic jam section increases. The braking / driving force command value p_tTd (i) of each divided section way (i) includes the driving force corresponding to the running resistance (air resistance component + rolling resistance component) corresponding to the vehicle speed p_vsp (i) and the speed of the previous section. A braking / driving force that is the sum of the braking / driving force corresponding to the acceleration / deceleration according to the difference and the braking / driving force corresponding to the acceleration / deceleration for absorbing the potential energy change of the vehicle according to the road gradient is set.

  When it is determined in step 14 that will be described later that the deviation between the prediction of the vehicle speed and the braking / driving force command value is large and step 7 is executed, the direction of deviation between the predicted value and the actual value is detected, and the direction of deviation is determined. Taking into account, the vehicle speed p_vsp (i) and the braking / driving force command value p-tTd (i) are re-predicted. For example, when the predicted vehicle speed p_vsp (i) during traveling tends to be higher than the actual vehicle speed, the predicted vehicle speed p_vsp (i) is set to a lower value, and the predicted braking / driving force command value p_tTd (i) during traveling is actually controlled. When it is smaller than the driving force command value, the predicted braking / driving force command value p_tTd (i) is set to a larger value. Alternatively, in the case of a route that the guidance route has taken before, the vehicle speed m_vsp (i) of the route section when the route has passed previously may be set as the predicted vehicle speed p_vsp (i), or the predicted vehicle speed p_vsp (i). And an internal division value of the previous vehicle speed m_vsp (i). However, in that case, it is necessary to store at least the vehicle speed m_vsp (i) in the route section that the vehicle has traveled before.

  In step 8, the current SOC (d_SOC) is detected, and in step 9, the SOC conversion efficiency index SOCc is calculated by the method described above. In the subsequent step 101, the calculated SOCc value is substituted for the first efficiency index value SOCc1.

  In step 10 following step 101, based on the calculated SOC conversion efficiency index SOCc, the predicted vehicle speed p_vsp (i), and the predicted braking / driving force command value p_tTd (i), the SOC (p_SOC ( i)) is predicted. First, based on the SOC conversion efficiency index SOCc, the predicted vehicle speed p_vsp (i), and the predicted braking / driving force command value p_tTd (i), the engine 2 and the motors 1 and 4 in each divided section way (i) as described above. When the temporary operating point is obtained, the predicted battery charge / discharge power p_bat (i) in each divided section is obtained. Accordingly, when the current SOC (d_SOC) is used as an initial value and the predicted battery charge / discharge power p_bat (i) of each divided section way (i) is time integrated, the SOC (p_SOC (i)) of each divided section way (i) is obtained. Can be predicted.

  In step 11, the vehicle speed d_vsp is detected by the vehicle speed sensor 23, and in the subsequent step 12, the accelerator opening d_acc is detected by the accelerator sensor 22. In step 13, a braking / driving force command value d_tTd corresponding to the detected vehicle speed d_vsp and the detected accelerator opening d_acc is calculated from a table of braking / driving force command values set in advance based on the vehicle speed and the accelerator opening.

  In step 14, at the end of each divided section way (i), for example, average vehicle speed d_vsp (i) and average braking / driving force command value d_tTd (i), predicted vehicle speed p_vsp (i) and predicted braking / driving force of each divided section. It is determined whether or not the deviation from the command value p_tTd (i) is larger than each predetermined value. If it is larger, the process returns to Step 7, and if it is smaller than the predetermined value, the process proceeds to Step 15.

  As an index of deviation, for example, there is a method in which the sum ERR_1 of the square error of the vehicle speed and the square error of the braking / driving force command value is used as an index.

  In the above equation, K1 is a constant, and Σ represents the total sum in i from the time when the previous predicted value was updated to the present time.

  Further, there is a method in which the power error exerted on the vehicle has a high correlation with the fuel consumption and charge / discharge power noted in this embodiment, and the square error ERR_2 of the power equivalent value (vehicle speed × braking / driving force) is used as an index. .

  In the above equation, Σ represents the sum in i from the time when the previous predicted value was updated to the present time. If it is determined that the prediction of the vehicle speed and the braking / driving force command value is large and the process proceeds from this step to step 7, the direction of deviation between the predicted value and the actual value is detected, and the direction of deviation is taken into consideration. In step 7, the vehicle speed p_vsp (i) and the braking / driving force command value p_tTd (i) are re-predicted. For example, when the predicted vehicle speed p_vsp (i) during traveling tends to be higher than the actual vehicle speed, the predicted vehicle speed p_vsp (i) is set to a lower value, and the predicted braking / driving force command value p_tTd (i) during traveling is actually When it is smaller than the braking / driving force command value, the predicted braking / driving force command value p_Td (i) is set to a larger value. Alternatively, in the case of a route that the guidance route has passed before, the vehicle speed pattern m_vsp (i) of the route section when the route has passed previously may be set as the predicted vehicle speed p_vsp (i), or the predicted vehicle speed p_vsp (i). ) And the previous vehicle speed m_vsp (i). However, in that case, it is necessary to store at least the vehicle speed m_vsp (i) in the route section that the vehicle has traveled before.

  In step 15, it is determined whether or not the difference between the current SOC (d_SOC) and the predicted SOC (p_SOC (i)) is greater than a predetermined value at the end point of each divided section way (i). Returning to step 111, the process proceeds to step 111 if it is equal to or smaller than the predetermined value. As an index of deviation, for example, there is one as shown in the following equation.

  In step 111, the detected SOC value d_SOC is substituted into the second efficiency index value SOCc2.

  In step 112, it is determined whether or not the SOC value is in the vicinity of upper and lower limit values set in advance for protecting the main battery 15. For example, when the upper limit is 80% and the lower limit is 20%, it is determined that the SOC is near the upper and lower limits when the SOC is 78% or more or 22% or less.

  If it is determined that the SOC detection value is in the vicinity of the upper and lower limit values, the routine proceeds to step 113, where SOCc2 is substituted for the target efficiency index SOCct, and otherwise, the first efficiency index value SOCc1 is set to the target efficiency at step 114. Substitute into the index SOCct. Note that step 112 and step 114 may be omitted, and the SOC value d_SOC may be used as the target efficiency index SOCct.

  In step 115, SOCcf, which is the final SOC conversion efficiency index that is the basis for determining the operating point of the engine or motor in the subsequent stage, is calculated. The SOCcf calculation is performed so that the SOCcf value gradually matches the SOCct. For example, a process of approaching the SOCct by 0.5% per second is performed until it matches the SOCct (SOCcf is initialized to d_SOC by an initialization routine not shown).

  In step 16 following step 115, the formal operation during the running of the engine and the motor is performed based on the final value SOCcf of the SOC conversion efficiency index SOCc, the current vehicle speed detection value d_vsp, and the calculated value d_tTd of the braking / driving force command value. Calculate points. At this time, when the detected SOC (d_SOC) is in the vicinity of the upper and lower limit values set in advance for protecting the main battery 15, the protection of the battery 15 is prioritized and the detected SOC is used instead of the SOC conversion efficiency index SOCc. It is assumed that calculation is performed using (d_SOC).

  In the following step 17, the torque of the engine 2, the torques of the motors 1 and 4, the gear ratio of the continuously variable transmission 5, and the engagement / release of the clutch 3 are controlled so as to realize the engine / motor operating point.

  When the navigation device 33 is not operating or when the destination is not set, steps 8 → 11 → 12 → 13 → 111 → 113 → 115 → 116 → 16 in the flowcharts shown in FIGS. Execute in order of → 17. However, when the destination is not set but the navigation device 33 is operating, it is detected that the vehicle is traveling on a commuting route that has traveled in the past or a route that travels well every day. For example, a destination such as a commuting destination or a supermarket may be specified from the traveling information, and step 3 and subsequent steps may be executed.

  In calculating the SOC conversion efficiency index SOCc, the predicted SOC (p_SOC (i)) of all the divided sections way (i) is calculated, so that the predicted SOC (p_SOC (i)) in step 10 is calculated. As the calculation value, the value of each divided section where SOCc = SOCc_j in step 9 may be used.

  Thus, in the first embodiment, the guide route to the destination is divided, and the vehicle speed p_vsp and the braking / driving force command value p_tTd in each divided section of the guide route are predicted based on the road environment information of the navigation, Based on the predicted vehicle speed p_vsp of each divided section, the predicted braking / driving force command value p_tTd, and the SOC-converted efficiency index SOCc in which the initial value SOCc_0 of the battery SOC is set, the operating points of the engine and the motor with good fuel utilization efficiency are temporarily determined. Next, the SOC at the destination is predicted based on the temporary operation points of the engine and motor in each divided section and the current SOC detection value d_SOC, and the predicted SOC (p_SOC) at the destination is the target SOC (t_SOC) at the destination. The SOC-converted efficiency index SOCc is converged to the convergence value SOCc_j until it substantially coincides with. Then, the braking / driving force command value d_tTd is calculated from a preset braking / driving force command value table based on the vehicle speed detection value d_vsp and the accelerator opening detection value, and the vehicle speed detection value d_vsp and the braking / driving force command value are calculated. Based on the value d_tTd and the convergence value SOCc_j of the SOC conversion efficiency index, the final operating points of the engine and the motor are determined.

  According to the first embodiment, the SOC conversion efficiency index SOCc is introduced, the vehicle speed and the braking / driving force command value of the guidance route are predicted based on the road environment information detected by the navigation device, and at the destination In order to achieve the target SOC, the operating points of the engine and the motor with good fuel utilization efficiency are temporarily determined. Therefore, when the vehicle speed detection value to the destination and the calculated value of the braking / driving force command value match the predicted vehicle speed and the predicted braking / driving force command value, respectively, it is possible to minimize the fuel consumption to the destination. it can. Also, when actually driving with the engine and motor operating points determined, instead of the predicted vehicle speed and predicted braking / driving force command value, the official operating point is calculated using the calculated values of the vehicle speed detection value and braking / driving force command value. Since calculation is performed, even when the predicted vehicle speed and the predicted braking / driving force command value deviate from the actual values, the operating point with poor fuel utilization efficiency is not selected, and the fuel consumption is reduced even when the prediction deviates. The effect can be maintained.

Furthermore, according to the present embodiment, the first efficiency index calculating means for calculating an efficiency index value (equivalent to the SOC conversion index SOCc of the conventional example) representing the fuel use efficiency based on the road environment information and the SOC of the travel route. And a second efficiency index calculating means for calculating the efficiency index value based on the SOC without using the road environment information of the travel route. In addition, when the road environment information of the travel route of the vehicle can be detected (or when the SOCc calculated by the first efficiency index calculation means is near the upper and lower limit values), the first efficiency obtained by the first efficiency index calculation means When the index value SOCc1 cannot be detected (or when the SOCc calculated by the first efficiency index calculating means is not near the upper and lower limit values), the second efficiency index value SOCc2 obtained by the second efficiency index calculating means is selected, When switching the selection, the final efficiency index value is calculated by performing a process of continuously changing from the value before switching to match the value after switching. Therefore, even in the following situations, the final efficiency index value takes a continuous value, it is possible to suppress sudden changes in the operating points of the engine and the motor, and to avoid discomforting the occupant. Became.
-Situations that can be improved-
-By setting the destination in the navigation device, it becomes possible to obtain road environment information of the travel route to the destination, and from the control using the second efficiency index value to the control using the second efficiency index value. When switching
・ When switching from control using the second efficiency index value to control using the second efficiency index value because the road environment information of the subsequent travel route cannot be obtained after arriving at the destination set in the navigation device ,
-Since the vehicle deviates from the driving route guided by the navigation and the road environment information of the driving route becomes inappropriate, the control using the second efficiency index value is changed to the control using the second efficiency index value. When switching.

  In addition, when the efficiency index value calculated from the road information of the travel route and the SOC is updated, the efficiency index value may be calculated by performing a process of continuously changing from the value before the update. Even in this case, since the efficiency index value takes a continuous value, it is possible to suppress a sudden change in the operating point of the engine and the motor, and to avoid giving the passenger discomfort. .

Even when the road environment information of the travel route of the vehicle can be detected, the efficiency index value is switched to the second efficiency index value SOCc2 when the SOC is in the vicinity of the upper and lower limit values set in advance for battery protection. I did it. Thereby, battery protection can be performed reliably. Moreover, it is possible to prevent the unit operating point from changing suddenly at the time of switching, and to avoid discomforting the occupant.
<< Second Embodiment of the Invention >>
Another calculation method of the SOC conversion efficiency index SOCc will be described. The configuration of the second embodiment is the same as the configuration shown in FIGS. 1 and 2, and illustration and description thereof are omitted.

  FIG. 9 and FIG. 10 are flowcharts showing a vehicle control program including another calculation method of the SOC conversion efficiency index. The operation of the second embodiment will be described with reference to these flowcharts. Steps that perform the same operations as those shown in FIG. 7 and FIG. 8 are given the same step numbers, and differences will be mainly described.

  The vehicle controller 16 executes this control program every predetermined time. After the current location is detected in step 1, the current SOC (d_SOC) is detected in step 8. In the following step 2, as described above, it is confirmed whether there is a new input or change of the destination, a departure from the guidance route, or a change in the traffic situation. If any, the process proceeds to step 3 and there is nothing. If so, go to Step 11.

  When there is any new input or change of the destination, deviation of the guidance route, or change of the traffic congestion state, the guidance route to the destination is searched in step 3. Next, in step 4, as described above, the guidance route to the destination is divided into m sections way (j) (j = 1 to m), and each section way (j) is further divided into p sections. Is divided into n (= m · p) sections way (i) (i = 1 to n). In subsequent step 5, road environment such as average gradient, intersection position, radius of curvature, altitude, etc. in each divided section way (j) is detected. In the subsequent step 6, as described above, the target SOC (t_SOC) at the destination is determined based on the road environment of each divided section way (j).

  In step 21, the upper and lower limit values of the SOC corresponding to the road environment for each section way (j) are set in consideration of the power performance of the vehicle. For example, as shown in FIG. 11, when an uphill is expected to continue for 5 km from a certain section way (k) in the middle of the route, the section way ( The SOC lower limit value in k) is set to 50%, and when the uphill continues for 10 km, the SOC lower limit value is set to 60%. In principle, the upper and lower SOC values of each divided section are 80% or less and 20% or more for battery protection as shown in FIG. Further, the upper and lower limit values of the SOC may be set over the entire section, or may be set for each section way (j). Furthermore, you may set with respect to the arbitrary points on a guidance route. Of course, only the upper limit value or only the lower limit value may be set.

  In step 7, as described above, the vehicle speed p_vsp (i) and the braking / driving force command value p_tTd () in each divided section way (i) between the current position and the destination based on the road environment of each divided section way (j). i) is predicted. The vehicle speed p_vsp (i) is predicted as follows, for example. In the guidance route, the speed limit of the section way (j) is set as the predicted value. Also, at an intersection, level crossing, or toll gate that makes a right or left turn, for example, a vehicle speed p_vsp (i) is predicted such that the vehicle speed becomes 0 at a deceleration of 0.1G and returns to the cruising speed at an acceleration of 0.1G after stopping for 3 seconds. In the curved road section, the vehicle speed p_vsp (i) is predicted based on the acceleration / deceleration and the passing speed according to the curvature of the road. In addition, when traffic jam information is obtained from a road-to-vehicle communication device such as VICS, the vehicle speed p_vsp (i) is predicted such that the average vehicle speed decreases as the traffic jam in the traffic jam section increases. On the other hand, the braking / driving force command value p_tTd (i) of each divided section way (i) includes the driving force corresponding to the running resistance (air resistance component + rolling resistance component) corresponding to the vehicle speed p_vsp (i), the previous section, The braking / driving force that is the sum of the braking / driving force corresponding to the acceleration / deceleration according to the speed difference and the braking / driving force corresponding to the acceleration / deceleration for absorbing the potential energy change of the vehicle according to the road gradient is set.

  In step 9, the SOC conversion efficiency index SOCc is calculated by the method described above in the first embodiment. In step 10, based on the calculated SOC conversion efficiency index SOCc, the predicted vehicle speed p_vsp (i), and the predicted braking / driving force command value p_tTd (i), the SOC (p_SOC (i)) of each divided section way (i) is calculated. Predict. First, based on the SOC conversion efficiency index SOCc, the predicted vehicle speed p_vsp (i), and the predicted braking / driving force command value p_tTd (i), the engine 2 and the motors 1 and 4 in each divided section way (i) as described above. When the temporary operating point is obtained, the predicted battery charge / discharge power p_bat (i) in each divided section is obtained. Therefore, when the predicted battery charge / discharge power p_bat (i) of each divided section way (i) is time-integrated using the current SOC (d_SOC) as an initial value, the SOC (p_SOC (i)) of each divided section way (i) is obtained. Can be predicted.

  In step 22, it is confirmed whether the SOC (p_SOC (i)) of each predicted divided section way (i) exceeds the upper and lower limit values set in step 21. If not, go to Step 11. If the predicted SOC (p_SOC (i)) exceeds the upper and lower limit values, a correction calculation of the SOC conversion efficiency index SOCc is performed in step 23. For example, as shown in FIG. 12, when the predicted SOC (p_SOC (i)) exceeds the lower limit at the PA point on the way to the destination (line (1)), the lower limit is not exceeded (( The SOC-converted efficiency index SOCc is corrected by Formula 1 and reduced to the line 2). On the contrary, when the predicted SOC (p_SOC (i)) exceeds the upper limit value, the SOC conversion efficiency index SOCc is corrected by the above formula 2 so as not to exceed the upper limit value. However, if both the upper limit value and the lower limit value are exceeded during the correction process, the SOC predicted value p_SOC (i) closer to the current location of the vehicle (the smaller value of i) is preferentially adopted, The SOC conversion efficiency index SOCc is corrected by Equation 1 or Equation 2 so as to be within the lower limit. In the subsequent step 101, the calculated SOCc value is substituted for SOCc1.

  Next, at step 24, the predicted SOC (p_SOC (i)) of each section way (i) falls within the SOC upper and lower limits, for example, the predicted SOC (p_SOC (i)) as shown in FIG. The point where the change curve is closest to the SOC upper / lower limit value, or the intersection “PA” between the change curve of the predicted SOC (p_SOC (i)) and the SOC upper / lower limit value is stored. At this time, since the predicted SOC (p_SOC (n)) at the destination of the line (2) does not match the target SOC (t_SOC), if the SOC-converted efficiency index SOCc calculated in step 23 is used to the destination, the destination The actual SOC at the ground will not match the target SOC (t_SOC). Therefore, the SOC conversion efficiency index SOCc calculated in step 23 is used until the vehicle reaches the point PA, and after determining in step 26 described later that the vehicle has reached the point PA, the SOC conversion efficiency index is calculated in step 9. By recalculating the SOCc and re-determining the driving point of the vehicle based on the value, the actual SOC at the destination can be substantially matched with the target SOC (t_SOC).

  If there is no new input or change of the destination, departure from the guidance route, or change in the traffic congestion state, the vehicle speed d_vsp is detected by the vehicle speed sensor 23 in step 11, and the accelerator opening d_acc is detected by the accelerator sensor 22 in the following step 12. Is detected. In step 13, a braking / driving force command value d_tTd corresponding to the detected vehicle speed d_vsp and the detected accelerator opening d_acc is calculated from a table of braking / driving force command values set in advance based on the vehicle speed and the accelerator opening.

  In step 14, the average vehicle speed d_vsp (i) and the average braking / driving force command value d_tTd (i), the predicted vehicle speed p_vsp (i) and the predicted braking / driving force command of each divided section at the end point of each divided section way (j). It is determined whether or not the deviation from the value p_tTd (i) is larger than each determination reference value. Recalculate. On the other hand, if the difference between the predicted value of the vehicle speed and the braking / driving force command value and the actual value is equal to or less than the determination reference value, the process proceeds to step 15. As the deviation index, the sum ERR_1 of the square error of the vehicle speed and the square error of the braking / driving force command value shown in Equation 3 is used, or the square error ERR_2 of the power equivalent value shown in Equation 4 is used. be able to. In step 15, it is determined whether or not the difference between the current SOC (d_SOC) and the predicted SOC (p_SOC (i)) is larger than the criterion value at the end point of each divided section way (i). Returning to 9, the SOC conversion efficiency index SOCc is recalculated. On the other hand, if the deviation between the predicted value and the actual value of the SOC is equal to or smaller than the determination reference value, the process proceeds to step 25. Note that, for example, ERR_3 shown in Equation 5 can be used as the deviation index.

  When the difference between the vehicle speed, the braking / driving force command value, and the predicted value of SOC and the actual value is small, the difference between the current SOC (d_SOC) in step 25 and the SOC upper and lower limit values set in step 21 is less than or equal to a predetermined value δSOC Check whether or not. Here, an appropriate value for determining that the SOC has approached the upper and lower limit values is set as the predetermined value δSOC. When the current SOC approaches the upper and lower limit values, the process returns to step 9 to recalculate the SOC conversion efficiency index SOCc. On the other hand, when the current SOC is not close to the upper and lower limit values, the routine proceeds to step 26, where it is confirmed whether or not the vehicle has reached the point PA. Here, the point PA is a point where the current SOC (d_SOC) reaches the SOC upper and lower limit values set in step 21. When the point PA is reached, the process returns to step 9 to recalculate the SOC conversion efficiency index SOCc. On the other hand, when the point PA has not been reached yet, the routine proceeds to step 111.

  In step 111, the detected SOC value is substituted into the second efficiency index value SOCc2.

  In step 112, it is determined whether or not the SOC value is in the vicinity of upper and lower limit values set in advance for protecting the main battery 15. For example, when the upper limit is 80% and the lower limit is 20%, it is determined that the SOC is near the upper and lower limits when the SOC is 78% or more or 22% or less.

  If it is determined that the SOC detection value is in the vicinity of the upper and lower limit values, the routine proceeds to step 113, where SOCc2 is substituted for the target efficiency index SOCct, and otherwise, the first efficiency index value SOCc1 is set to the target efficiency at step 114. Substitute into the index SOCct.

  In step 115, SOCcf, which is the final SOC conversion efficiency index that is the basis for determining the operating point of the engine or motor in the subsequent stage, is calculated. The SOCcf calculation is performed so that the SOCcf value gradually matches the SOCct. For example, a process of approaching SOCct by 0.5% per second is performed until the value matches SOCct (SOCcf is initialized to d_SOC by an initialization routine not shown).

  In step 16 following step 115, the official operation during the running of the engine and the motor is performed based on the final value SOCcf of the SOC conversion efficiency index SOCc, the current vehicle speed detection value d_vsp, and the calculated value d_tTd of the braking / driving force command value. Calculate points. In the following step 17, the torque of the engine 2, the torques of the motors 1 and 4, the gear ratio of the continuously variable transmission 5, and the engagement / release of the clutch 3 are controlled so as to realize the engine / motor operating point.

  As described above, in the second embodiment, the upper and lower limit values of the SOC corresponding to the road environment for each section way (i) are set in consideration of the power performance of the vehicle, and the SOC conversion efficiency index SOCc and each section are set. The predicted SOC (p_SOC (i)) of way (i) is calculated. Then, when the predicted SOC (p_SOC (i)) of each section way (i) exceeds the upper and lower limit values of the SOC, the SOC conversion efficiency index SOCc is recalculated so as to be within the upper and lower limit values, The point PA where the change curve of the predicted SOC (p_SOC (i)) in each section way (i) is closest to the SOC upper / lower limit value, or the intersection PA between the change curve of the predicted SOC (p_SOC (i)) and the SOC upper / lower limit value Remember. When the engine / motor operating point is determined based on the SOC conversion efficiency index SOCc and the vehicle is traveling, if the current SOC (d_SOC) approaches the SOC upper or lower limit value or reaches the point PA, the subsequent SOC conversion The efficiency index SOCc is calculated again, the engine / motor operating point is determined based on the new SOC conversion efficiency index SOCc, and the vehicle continues to travel to the destination. Thereby, the target SOC at the destination can be achieved while improving the fuel utilization efficiency to the destination.

Even in the present embodiment, since the SOC conversion efficiency index SOCc when determining the operating points of the engine and the motor changes continuously, it is possible to suppress sudden changes in the operating points of the engine and the motor. The same effects as in the first embodiment can be obtained.
<< Third Embodiment of the Invention >>
Another calculation method of the SOC conversion efficiency index SOCc will be described. The configuration of the third embodiment is basically the same as the configuration shown in FIGS. 1 and 2, but in the third embodiment, the vehicle speed and braking / driving force in each divided section up to the destination are set. The traveling condition prediction function 16a (see FIG. 2) for predicting the command value is unnecessary.

  FIGS. 13 and 14 are flowcharts showing a vehicle control program including another calculation method of the SOC conversion efficiency index. The operation of the third embodiment will be described with reference to these flowcharts. Steps that perform the same operations as those shown in FIG. 7 and FIG. 8 are given the same step numbers, and differences will be mainly described.

  The vehicle controller 16 executes this control program every predetermined time. In step 1, the current location is detected. In the following step 2, it is confirmed whether or not there is a new input or change of the destination, a departure from the guidance route, or a change in the traffic condition. If there is any, the process proceeds to step 3; Proceed to When there is any new input or change of the destination, deviation of the guidance route, or change of the traffic congestion state, the guidance route to the destination is searched in step 3. In the subsequent step 4, as described above, the guidance route to the destination is divided into m sections way (j) (j = 1 to m) using the characteristic points in the road environment as the dividing points. In step 5, road environment such as average gradient, intersection position, curvature radius, altitude, etc. in each divided section way (j) is detected, and in step 6, as described above, the road in each divided section way (j) detected. A target SOC (t_SOC) at the destination is determined based on the environment.

  Next, in step 8, the current SOC (d_SOC) is detected, and in the following step 31, the SOC conversion efficiency index SOCc is calculated as follows. First, a driving pattern is assumed for each road environment, and the driving pattern is stored in advance in a memory as SOC change amount data (MAP2DSOC) per unit distance when driving with the SOC conversion efficiency index SOCc. Then, the SOC change amount p_dSOC (j) corresponding to the SOC conversion efficiency index SOCc and the road environment for each section way (j) is calculated from this data (MAP2DSOC), and the current SOC (d_SOC) is an initial value. As a result, the predicted SOC (p_SOC (j)) of each section way (j) and the predicted SOC (p_SOC (m)) at the destination are obtained by integrating the SOC change amount p_dSOC (j) of each section way (j). . This calculation is performed until the predicted SOC (p_SOC (m)) at the destination substantially matches the target SOC (t_SOC) at the destination, and the SOC-converted efficiency index when the two are almost the same is obtained as the final index SOCc. To do. In the subsequent step 101, the calculated SOCc value is substituted for the first efficiency index value SOCc1.

  Next, in step 11, the vehicle speed d_vsp is detected by the vehicle speed sensor 23, and in the subsequent step 12, the accelerator opening d_acc is detected by the accelerator sensor 22. In step 13, the braking / driving force command value d_tTd corresponding to the detected vehicle speed d_vsp and the detected accelerator opening d_acc is calculated from a braking / driving force command value table set in advance based on the vehicle speed and the accelerator opening.

  In step 32, it is determined whether or not the error of the SOC change amount (p_dSOC (j)) in each section way (j) is large. That is, for each end point of each section way (j), the actual SOC change amount (d_dSOC (k)) of the section way (k) passed immediately before is compared with the calculated SOC change amount p_dSOC (k). If is large, correct it. For example, a value ERR4 obtained by the following equation can be used as the deviation determination reference value.

  When the deviation is large, the process returns to step 8 to recalculate the SOC conversion efficiency index SOCc, and when the deviation is small, the process proceeds to step 15.

  In step 15, it is determined whether or not the difference between the current SOC (d_SOC) and the predicted SOC (p_SOC (i)) is larger than the determination reference value at the end point of each divided section way (j). Returning to step 9, the process proceeds to step 16 if it is equal to or smaller than the determination reference value. As the determination reference value, the reference value ERR_3 can be used in Equation 3 above. As an index of deviation shown, for example, there is the one shown in the following equation.

  In step 111, the detected SOC value is substituted into the second efficiency index value SOCc2.

  In step 112, it is determined whether or not the SOC value is in the vicinity of the upper and lower limit values set in advance for protection of the main battery 15. For example, when the upper limit is 80% and the lower limit is 20%, it is determined that the SOC is near the upper and lower limits when the SOC is 78% or more or 22% or less.

  If it is determined that the SOC detection value is in the vicinity of the upper and lower limit values, the routine proceeds to step 113, where SOCc2 is substituted for the target efficiency index SOCct, and otherwise, the first efficiency index value SOCc1 is set to the target efficiency at step 114. Substitute into the index SOCct.

  In step 115, SOCcf, which is the final SOC conversion efficiency index that is the basis for determining the operating point of the engine or motor in the subsequent stage, is calculated. The SOCcf calculation is performed so that the SOCcf value gradually matches the SOCct. For example, a process of approaching SOCct by 0.5% per second is performed until the value matches SOCct (SOCcf is initialized to d_SOC by an unillustrated initialization routine).

  In the following step 16, a formal operating point when the engine and the motor are running is calculated based on the final value SOCcf of the SOC conversion efficiency index SOCc, the current vehicle speed detection value d_vsp, and the braking / driving force command value calculation value d_tTd. To do. At this time, when the detected SOC (d_SOC) is in the vicinity of the upper and lower limit values set in advance for protecting the main battery 15, the protection of the battery 15 is prioritized, and the detected SOC is substituted for the SOC conversion efficiency index SOCc. It is assumed that calculation is performed using (d_SOC). In the following step 17, the torque of the engine 2, the torques of the motors 1 and 4, the gear ratio of the continuously variable transmission 5, and the engagement / release of the clutch 3 are controlled so as to realize the engine / motor operating point.

  The road environment information, SOC conversion efficiency index, and SOC change amount of the travel route are stored, and the SOC change amount for each section way (j) is predicted in consideration of the past travel route data. Also good. Thereby, it is possible to predict the SOC change amount for each more accurate section way (j).

  Thus, according to the third embodiment, the SOC change amount data per unit travel distance when driving patterns are assumed for each road environment and the driving patterns are driven with various SOC conversion efficiency indexes. Store in memory beforehand. Then, the SOC change amount p_dSOC (j) corresponding to the SOC conversion efficiency index SOCc and the road environment for each section way (j) is calculated from the SOC change amount data per unit travel distance, and the current SOC is calculated. By integrating the SOC change amount p_dSOC (j) of each section way (j) using (d_SOC) as an initial value, the predicted SOC (p_SOC (j)) of each section way (j) and the predicted SOC (p_SOC) at the destination are integrated. (M)). This calculation is executed until the predicted SOC (p_SOCm) at the destination substantially coincides with the target SOC (t_SOC) at the destination, and the SOC conversion efficiency index when the two almost coincide is set as the final index SOCc. When the engine / motor operating point is determined based on the SOC conversion efficiency index SOCc, the actual SOC change amount d_dSOC (k) of each section way (k) and the calculated SOC change amount p_dSOC (k If the deviation is large, the SOC conversion efficiency index (SOC) is corrected. Further, in each section way (j), the current SOC (d_SOC) is compared with the predicted SOC (p_SOC (i)), and when the deviation is larger than the determination reference value, the SOC conversion efficiency index (SOC) is corrected. . Thereby, the target SOC at the destination can be achieved while improving the fuel utilization efficiency to the destination.

  Even in the present embodiment, since the SOC conversion efficiency index SOCc when determining the operating points of the engine and the motor changes continuously, it is possible to suppress sudden changes in the operating points of the engine and the motor. The same effects as in the first embodiment can be obtained.

  In the above embodiment, the SOC-converted efficiency index value SOCc is used as an efficiency index representing the fuel utilization efficiency. Since the relationship between the SOC conversion efficiency index value SOCc as the efficiency index representing the fuel utilization efficiency is the relationship between the sensitivity S and the SOC conversion efficiency index shown in FIG. 5, the efficiency index value representing the fuel utilization efficiency is continuously expressed. It is added that changing to is the same as changing the SOC conversion efficiency index value SOCc continuously as in the above embodiment.

  Subsequently, as a fourth embodiment, the subsequent processing when the vehicle reaches a position where the distance Xp (km) to the destination is closer than a predetermined distance in the above-described embodiment will be described. The navigation device 33 calculates the distance Xp to the destination from the travel route information (route information) to the destination and transmits it to the vehicle controller 16. The vehicle controller 16 performs the following processing instead of step 114.

  First, the weighting coefficients λ1 and λ2 of the first efficiency index value SOCc1 calculated using the path information and the second efficiency index value SOCc2 calculated without using the path information are set in advance according to the received Xp value. This is determined according to the characteristics shown in FIG. That is, when the distance is smaller than the predetermined value (closer to the destination than the predetermined distance), the weighting coefficient λ1 of the SOCc1 is smaller as the distance to the destination is closer, while the weighting coefficient λ2 of the SOCc2 is smaller than the distance to the destination. The closer the distance is, the larger it is set. Here, the predetermined value MXR is set to 2 km, for example.

  Then, using these weighting coefficients, the target efficiency index SOCct is calculated by the following equation.

  By doing so, it is possible to increase the weighting of the second efficiency index value SOCc2 calculated without using the route information as the vehicle approaches the destination. Therefore, the following problems can be solved. In other words, the SOC conversion index SOCc corresponding to the first efficiency index value is derived in such a conventional technique that the SOC at the destination is derived so as to be a preset target value (hereinafter referred to as t_SOC. For example, SOC = 60%). There were the following problems.

  Problem 1) Assuming that the distance from the departure point to the destination is relatively short (for example, 100 m) and the difference between the current SOC and the t_SOC at the destination is large (for example, the difference is 30%), FIG. There is a case of b). In the case of (a), an operating point in which the fuel consumption efficiency of the engine is remarkably bad is realized although the amount of charge is large so that the SOC at the destination becomes t_SOC. As a result, although the SOC at the destination approaches t_SOC, the total fuel consumption including after passing through the destination is not always good, and there is room for improving the fuel consumption. In the case of (b), the battery power is positively discharged so that the SOC at the destination becomes t_SOC. As a result, although the SOC at the destination approaches t_SOC, the total fuel consumption including after passing through the destination is not always good, and there is room for improving the fuel consumption.

  Problem 2) Even if the road from the departure point to the destination is long, depending on the driving situation of the vehicle (for example, by taking a rest in the service area of the highway, the parking area or a store along the general road) There is a case where the difference between the current SOC and the t_SOC at the destination becomes large (for example, the difference is 30%) at a point where the vehicle approaches the destination (for example, 100 m before). In such a case, the recalculation of the SOC conversion index SOCc has the same problem as the problem 1.

  In other words, the conventional method only considers the destination, and does not consider driving beyond the destination, so there is a problem that the total fuel consumption including the destination is not necessarily improved. It was.

  In this embodiment, since the efficiency index value is gradually shifted from the first efficiency index value to the second efficiency index value as the destination is approached, the above problem can be avoided.

  Furthermore, as a fifth embodiment, a process when the time Tp (s) until the vehicle reaches the destination in the above-described embodiment becomes a predetermined time or less will be described. The navigation device 33 calculates the arrival time Tp (s) to the destination from the travel route information (route information) to the destination, the road type (type of expressway / general road, etc.), and the traffic congestion status, etc. It transmits to the controller 16. The vehicle controller 16 performs the following processing instead of step 114.

  First, according to the received value of Tp (s), the weighting coefficients λ1 and λ2 of the first efficiency index value SOCc1 calculated using the path information and the second efficiency index value SOCc2 calculated without using the path information are set in advance. It is determined according to the set characteristic of FIG. In other words, when the value is smaller than the predetermined value (arriving at the destination in a shorter time than the predetermined time), the weighting coefficient λ1 of the SOCc1 becomes smaller as the arrival time at the destination becomes shorter, while the weighting coefficient λ2 of the SOCc2 becomes smaller. The larger the arrival time at the destination, the larger the setting. Here, the predetermined time MTR is set to 120 seconds, for example.

  Then, using these weighting factors, SOCct is calculated by the following equation.

  By doing so, it is possible to increase the weighting of the second efficiency index value SOCc2 calculated according to the arrival time at the destination without using the route information as the vehicle approaches the destination. Therefore, the same effect as when the weighting of the second efficiency index value SOCc2 is increased according to the distance to the destination described above can be obtained.

  In the above embodiment, the ratio (Δbat / Δfuel) of the charging power increase amount Δbat to the fuel increase amount Δfuel, that is, the sensitivity S is used as the SOC conversion efficiency index, but the SOC conversion efficiency index is limited to the sensitivity S. Not. For example, for a hybrid vehicle that controls power generation when the SOC is low and suppresses power generation when the SOC is high, the SOC itself may be used as the SOC conversion efficiency index. In this case, when there is a downhill of a predetermined distance or more on the traveling path of the vehicle, the target SOC may be corrected to be smaller than the detected SOC. Further, the SOC correction amount may be increased as the difference between the SOC detection value and the target SOC at the destination is larger.

  Note that in the braking / driving force automatic adjustment system that automatically adjusts the braking / driving force of the vehicle according to the situation on behalf of the driver, the “accelerator opening” in the above-described embodiment is controlled by the braking / driving force automatic adjustment system. By replacing the driving force command value, it is possible to obtain the same effect as that of the above-described embodiment.

  Further, in the above-described embodiment, the parallel hybrid traveling is realized by engaging the clutch 3, and the application example to the vehicle that also performs the series hybrid traveling by releasing the clutch 3 is shown. Alternatively, the present invention can be similarly applied to a vehicle that performs only series / hybrid driving.

  Furthermore, in the above-described embodiment, the continuously variable transmission has been described as an example. However, the transmission is not limited to a continuously variable transmission, and may be a stepped transmission. Further, the arrangement of the transmission is not limited to the above-described embodiment.

  Furthermore, the present invention can be applied to vehicles of all drive systems such as front wheel drive, rear wheel drive, and four wheel drive, and all forms of driving front wheels with an engine and driving rear wheels with a motor. It can be applied to a vehicle having a drive source form.

  In the above-described embodiment, the guidance route to the destination is searched, the target SOC (t_SOC) at the destination is set, the predicted SOC (p_SOC) at the destination is obtained, and the predicted SOC (p_SOC) is the target SOC. Although an example of setting the SOC conversion efficiency index SOCc that substantially matches (t_SOC) has been shown, an arbitrary intermediate point in the middle of the guide route is set instead of the destination, and a target SOC at the intermediate point is set At the same time, the predicted SOC at the intermediate point may be obtained, and the SOC conversion efficiency index SOCc may be set such that the predicted SOC at the intermediate point substantially matches the target SOC. In that case, the guidance route to the intermediate point is divided, and the SOC change amount, the predicted SOC, etc. are calculated for each divided route. Note that the above-mentioned “specific point on the travel route” includes the destination of the guide route and an arbitrary intermediate point on the guide route.

  The hybrid vehicle to which the present invention is applied is useful for suppressing a sudden change in the operating point of the engine or motor.

It is a figure which shows the structure of one embodiment. It is a figure which shows the structure of one Embodiment following FIG. It is a figure for demonstrating the calculation method of a SOC conversion efficiency parameter | index. It is a figure which shows the operating point of an engine. It is a figure which shows charging power increase amount (DELTA) bat, charging power Bat, and sensitivity S with respect to engine fuel increase amount (DELTA) fuel. It is a map which sets the operating point of a clutch. It is a flowchart which shows the vehicle control program of 1st Embodiment. It is a flowchart which shows the vehicle control program of 1st Embodiment following FIG. It is a flowchart which shows the vehicle control program of 2nd Embodiment. It is a flowchart which shows the vehicle control program of 2nd Embodiment following FIG. It is a figure for demonstrating the setting method of SOC upper / lower limit value. It is a figure for demonstrating the correction method of a SOC conversion efficiency parameter | index. It is a flowchart which shows the vehicle control program of 3rd Embodiment. It is a flowchart which shows the vehicle control program of 3rd Embodiment following FIG. It is a figure explaining the subject of a prior art. It is a figure explaining 4th Embodiment. It is a figure explaining 5th Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Motor 2 Engine 3 Clutch 4 Motor 5 Continuously variable transmission 6 Deceleration device 7 Differential device 8 Drive wheel 11-13 Inverter 14 DC link 15 Main battery 16 Vehicle controller 16a Running condition prediction function 16b SOC conversion efficiency index calculation function 16c Engine / Motor operating point calculation function 20 Key switch 21 Brake switch 22 Acceleration sensor 23 Vehicle speed sensor 24 Battery temperature sensor 25 Battery SOC detection device 26 Engine rotation sensor 27 Throttle sensor 30 Fuel injection device 31 Ignition device 32 Throttle valve control device 33 Navigation device 33a Route division function 33b Road environment detection function 33c Target SOC determination function

Claims (3)

In a control apparatus for a hybrid vehicle that uses either one or both of an engine and a motor as a braking / driving force source and transfers power between the motor and a battery,
Vehicle speed detection means for detecting the vehicle speed;
Braking / driving force command value setting means for setting a braking / driving force command value to the vehicle;
SOC detection means for detecting the SOC of the battery;
A navigation device that sets a travel route of the vehicle and detects road environment information of the travel route;
First efficiency index calculating means for calculating an efficiency index value representing fuel utilization efficiency based on road environment information and SOC of the travel route;
A second efficiency index calculating means for calculating the efficiency index value to a larger value as the SOC is higher, based on the SOC;
When the road environment information of the travel route of the vehicle can be detected, the first efficiency index value obtained by the first efficiency index computing means is selected, and if not, the second efficiency index value obtained by the second efficiency index computing means is selected. In addition, when the efficiency index value is switched, a final efficiency index calculation is performed in which the efficiency index value is continuously changed from the value before switching to match the value after switching to calculate the final efficiency index value. Means,
Based on the vehicle speed detection value, the braking / driving force command value, and a final efficiency index value, an operating point determination unit that determines an operating point of the engine and the motor that reduces the amount of charge to the battery as the final efficiency index value increases, With
The final efficiency index calculating means calculates the second efficiency from the first efficiency index value as Xr decreases after the vehicle reaches a point where the distance Xr to the end of the travel route set by navigation is within a predetermined distance. A control device for a hybrid vehicle, characterized in that it is a means for calculating so as to approach the index value.   Even when the road environment information of the travel route of the vehicle can be detected, the final efficiency index calculation means selects the second efficiency index value when the SOC is in the vicinity of the upper and lower limit values, and continuously determines the value. The hybrid vehicle control device according to claim 1, wherein the control device is a means for calculating a final efficiency index value so as to match. In a control apparatus for a hybrid vehicle that uses either one or both of an engine and a motor as a braking / driving force source and transfers power between the motor and a battery,
Vehicle speed detection means for detecting the vehicle speed;
Braking / driving force command value setting means for setting a braking / driving force command value to the vehicle;
SOC detection means for detecting the SOC of the battery;
A navigation device that sets a travel route of the vehicle and detects road environment information of the travel route;
First efficiency index calculating means for calculating an efficiency index value representing fuel utilization efficiency based on road environment information and SOC of the travel route;
A second efficiency index calculating means for calculating the efficiency index value to a larger value as the SOC is higher, based on the SOC;
When the road environment information of the travel route of the vehicle can be detected, the first efficiency index value obtained by the first efficiency index computing means is selected, and if not, the second efficiency index value obtained by the second efficiency index computing means is selected. In addition, when the efficiency index value is switched, a final efficiency index calculation is performed in which the efficiency index value is continuously changed from the value before switching to match the value after switching to calculate the final efficiency index value. Means,
Based on the vehicle speed detection value, the braking / driving force command value, and a final efficiency index value, an operating point determination unit that determines an operating point of the engine and the motor that reduces the amount of charge to the battery as the final efficiency index value increases, With
After the vehicle has reached a point where the arrival time Tr to the end of the travel route set by navigation is within a predetermined time, the final efficiency index calculation means calculates the second efficiency from the first efficiency index value as Tr decreases. A control device for a hybrid vehicle, characterized in that it is a means for calculating so as to approach the index value.

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