JP5369504B2 - Vehicle travel control device - Google Patents

Description

  The present invention relates to a vehicle travel control device.

Conventionally, a hybrid vehicle that includes an engine and a motor as driving power sources and uses these power sources according to driving conditions is known (for example, see Patent Document 1). In such a hybrid vehicle, there is a vehicle that travels only by a motor without driving an engine when traveling with emphasis on fuel efficiency.
JP 2004-926655 A JP 2001-173773 A

  However, in the prior art, when executing fuel efficiency improvement control with an emphasis on improving fuel efficiency, acceleration according to demand is limited, and the driver has to be prepared to deteriorate drivability. . In the prior art, since fuel efficiency improvement control is selected based on the driver's switch operation, if the driver wants to improve both fuel efficiency and drivability, the driver can operate the switch. This causes a problem that increases and becomes annoying.

  The present invention has been made to solve such problems, eliminates the need for frequent switch operation by the driver, improves fuel consumption performance, and improves response to a driver's request for increased driving force. An object of the present invention is to provide a vehicular travel control device capable of achieving both of the above.

  A vehicle travel control device according to the present invention is a vehicle travel control device that includes a driving force control means for controlling the driving force of the host vehicle, and is a peripheral environment information that acquires peripheral environment information that is information related to the surrounding environment of the host vehicle. And a driving force increase request estimating means for estimating the possibility of a driving force increase request by the driver based on the surrounding environment information acquired by the surrounding environment information acquiring means, and the driving force control means When it is estimated by the driving force increase request estimating means that there is a possibility of requesting an increase in driving force, standby control is prepared to increase the driving force smoothly, and driving by the driving force increase request estimating means is performed. It is characterized in that standby control is suppressed when it is estimated that there is no possibility of a force increase request.

  The vehicle travel control apparatus according to the present invention includes driving force increase request estimation means for estimating the presence or absence of a request for increase in driving force by the driver based on the surrounding environment information related to the surrounding environment of the host vehicle. Therefore, when it is estimated that there is a possibility of an increase in driving force, it is possible to improve the response by executing standby control in preparation for the increase in driving force. When it is estimated that there is no possibility of request, by suppressing standby control, unnecessary power can be reduced and fuel efficiency can be improved. This eliminates the need for conventional switch operation (input operation) by the driver, and can automatically switch ON / OFF of the travel control with an emphasis on improving fuel efficiency. Thus, it is possible to achieve both improvement in response to a request for increase in driving force due to.

  Here, the standby control is control prepared to generate the maximum driving force of the host vehicle, and the surrounding environment information means acquires information on the presence or absence of the preceding vehicle as surrounding environment information, and estimates the driving force increase request. The means estimates that there is no possibility of requesting an increase in driving force when there is a preceding vehicle, and the driving force control means determines that there is no possibility of requesting an increase in driving force. Is preferably discontinued.

  Further, in the vehicle travel control device according to the present invention, the driving force control means includes a driving force limiting means that performs fuel efficiency improvement control that places more emphasis on improving fuel efficiency than usual by limiting the upper limit of the driving force. It is preferable that the apparatus further comprises driving force limit changing means for changing the limit by the driving force limiting means in response to the driver's request to increase the driving force. As described above, in the fuel efficiency improvement control, by setting the limit amount and limiting the upper limit of the driving force, it is possible to realize traveling that emphasizes improvement in fuel efficiency compared to normal traveling.

  Further, it is provided with follow-up control means for executing follow-up control for following the preceding vehicle, and the drive force control means is estimated to have a possibility of requesting an increase in drive force during execution of follow-up control and fuel efficiency improvement control. In this case, it is preferable to cancel the fuel efficiency improvement control before starting the acceleration operation.

  In addition, the time for confirming that the distance between the preceding vehicle and the preceding vehicle is equal to or greater than a predetermined distance is a confirmation time, and the driving force control means waits for the confirmation time to elapse. It is preferable to cancel the fuel consumption improvement control without the need. In normal follow-up control, if a sensor (peripheral environment acquisition means) that detects a preceding vehicle loses sight of the preceding vehicle, a safety margin is secured so that it is not immediately determined that the preceding vehicle has not been detected. ing. Without securing a safety margin for information related to the preceding vehicle (neighboring environment information) (without waiting for the confirmation time to elapse), immediately cancel the setting as the preceding vehicle, and the amount of drive power limit Can be quickly returned to the normal state. Therefore, it is possible to achieve both improvement in fuel efficiency and improvement in driving force response.

  The driving force limit changing means is configured to increase the magnitude of the driving force limit amount by the driving force limiting means when the follow-up control is being executed, compared to when the follow-up control is not being executed. It is preferable to do. When follow-up control is being executed, it is unlikely that a greater driving force will be required. Therefore, while the follow-up control is being executed, the amount of restriction on the drive force is increased to improve fuel efficiency. be able to.

  In addition, the driving force limit changing means is configured to detect an obstacle ahead of the host vehicle while the host vehicle is stopped when it is determined that there is an obstacle ahead of the host vehicle while the host vehicle is stopped based on the surrounding environment information. Compared to the case where it is not determined that there is an object, it is preferable that the amount of restriction of the driving force by the driving force limiting means is increased. If there is an obstacle ahead of the host vehicle when it is stopped, the driver is unlikely to request an increase in driving force, so increasing the amount of driving force limit will improve fuel efficiency. Can be achieved.

  The vehicle further includes an overtaking determination unit that determines whether or not the host vehicle is about to pass another vehicle ahead, and the driving force limit changing unit determines that the other vehicle is overtaking the other vehicle by the overtaking determination unit. In this case, it is preferable to reduce the magnitude of the driving force limiting amount by the driving force limiting means as compared with the case where it is not determined that the vehicle is overtaking another vehicle. As a result, when the host vehicle is about to overtake another vehicle, it is possible to quickly respond to an increase in driving force during overtaking by changing the size of the limit amount of the driving force to be small. Therefore, it is possible to achieve both improvement in fuel consumption and improvement in response to driving force.

  In addition, the host vehicle is a hybrid vehicle that includes a motor and an engine as a drive source, and standby control is performed when the host vehicle is traveling at a set vehicle speed or higher using only the power from the motor. Preferably, engine standby control is performed in which the engine is started in advance in preparation for a force increase request.

  Further, the host vehicle is a hybrid vehicle including a motor and an engine as drive sources, and the standby control is preferably boost control in which the supply voltage to the motor is boosted in advance in preparation for a drive force increase request. .

  According to the present invention, there is provided a vehicular travel control device that eliminates the need for frequent switch operations by a driver, and that can achieve both improvement in fuel efficiency and improvement in response to an increase in driving force by the driver. Can be provided.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of a vehicle travel control device according to the invention will be described with reference to the drawings. In the description of the drawings, the same or corresponding elements are denoted by the same reference numerals, and redundant description is omitted. FIG. 1 is a schematic configuration diagram of a hybrid vehicle equipped with a vehicle travel control device according to an embodiment of the present invention, and FIG. 2 is a block configuration diagram of the vehicle travel control device according to an embodiment of the present invention.

  As shown in FIGS. 1 and 2, the vehicle travel control apparatus 10 according to the present embodiment includes, for example, an engine (internal combustion engine) 12 and an electric motor (electric motor) 14 as power sources that generate driving force for propelling the vehicle. The vehicle 100 is mounted on a hybrid vehicle 100 (hereinafter referred to as “own vehicle”) and controls traveling of the own vehicle 100.

  The host vehicle 100 is provided with a power distribution mechanism 16, a generator 18, a power control unit 20, and a hybrid battery 22 (hereinafter referred to as “HV battery”). The vehicle travel control apparatus 10 includes a hybrid electronic control unit (hereinafter referred to as “electric hybrid unit”) electrically connected to the engine 12, the electric motor 14, the power distribution mechanism 16, the generator 18, the power control unit 20, and the HV battery 22. , “HV-ECU”) 40.

  The engine 12 is, for example, a six-cylinder four-cycle gasoline engine, and throttle control, fuel injection control, ignition timing control, variable valve timing control, and the like are executed by a control signal from an HV-ECU (see FIG. 2). The output is controlled.

  The electric motor 14 is, for example, an AC synchronous motor, and the rotation speed is controlled and the motor output is controlled by a control signal from a motor generator ECU (hereinafter referred to as “MG-ECU”) 34 described later. The electric motor 14 functions as a generator when the host vehicle 100 is decelerated, and the generated electric power is charged in the HV battery 22. Then, the driving force output by the engine 12 and the electric motor 14 is transmitted to the driving wheel 26 via the speed reducer 24 to propel the host vehicle 100.

  The power distribution mechanism 16 is connected to the output shaft of the engine 12 and distributes engine output. One of the distributed engine outputs is used as power for driving the drive wheels 26, and the other engine output is used as power for driving the generator 18. The power distribution mechanism 16 can freely control the power distribution ratio (use ratio).

  The generator 18 is, for example, an AC synchronous generator. As described above, the generator output is transmitted via the power distribution mechanism 16 to generate power. The electric power generated by the generator 18 is supplied to the power control unit 20 and is used as driving electric power for the electric motor 14 and is charged to the HV battery 22.

  The power control unit 20 includes an inverter 28, a boost converter 30, a DC / DC converter 32, and an MG-ECU 34, and is electrically connected to the electric motor 14, the generator 18, the HV battery 22, and the HV-ECU 40. .

  MG-ECU 34 operates inverter 28 and boost converter 30 in accordance with a control signal from HV-ECU 40. Boost converter 30 boosts the inverter input voltage according to the operation status of electric motor 14 in accordance with a request from HV-ECU 40. The inverter 28 converts the input DC voltage into an AC current for the electric motor 14.

  The MG-ECU 34 controls the output of the electric motor 14 in accordance with a control signal from the HV-ECU 40, and sends information necessary for vehicle control such as an output current value from the inverter 28, an inverter temperature, and a voltage to the HV-ECU 40. Send.

  Next, the HV-ECU 40 will be described. The HV-ECU 40 is capable of selecting fuel efficiency improvement control that realizes traveling that emphasizes improvement of fuel efficiency compared to normal traveling. The HV-ECU 40 can automatically switch ON / OFF of the fuel efficiency improvement control according to the surrounding environment of the host vehicle 100. That is, in the host vehicle 100, the driver's switch operation is performed between a fuel efficiency-oriented travel mode that is executed when the fuel efficiency improvement control is in an ON state and a normal travel mode that is executed when the fuel efficiency improvement control is in an OFF state. Without being configured, it can be switched automatically.

  The HV-ECU 40 can detect the vehicle speed sensor 42 for detecting the host vehicle speed and obstacles around the host vehicle 100 in addition to the engine 12, the electric motor 14, the generator 18, the power control unit 20, and the HV battery 22. The millimeter wave radar 44 is electrically connected to various sensors such as a direction indicator detection sensor 46 that detects an operating state of the direction indicator of the host vehicle 100. Further, the HV-ECU 40 is configured to be able to exchange data with each other by being connected to other computers such as a computer that performs brake control by a communication circuit such as CAN (Control Area Network). Yes.

  The HV-ECU 40 obtains an engine output and a motor output corresponding to the driving state of the host vehicle 100 based on the accelerator opening, the shift position, and signals from various sensors, and outputs a required value to each computer, thereby generating the host vehicle 100. To control the driving force.

  In the vehicular travel control device 10, control for mechanically transmitting the power of the engine 12 to the drive wheels 26, control for stopping the engine 12 and traveling using only the power of the electric motor 14, the engine 12 and the electric motor Control that travels by transmitting the power of the motor 14 to the drive wheels 26, control that transmits the power of the engine 12 to the generator 18 to generate power, and control that recovers energy by generating power by the electric motor 14 during deceleration It is said that. In the fuel efficiency improvement control, for example, a control for stopping the engine 12 and using only the power of the electric motor 14 is executed.

  The HV-ECU 40 includes a CPU that performs arithmetic processing, a ROM and a RAM that are storage units, an input signal circuit, an output signal circuit, a power supply circuit, and the like. In the HV-ECU 40, the ambient environment information acquisition unit 52, the follow-up control unit 54, the driving force increase request estimation unit 56, the driving force control unit 58, and the driving force control change unit 62 are executed by executing a program stored in the storage unit. An overtaking determination unit 64, an engine standby control unit 66, and a boost voltage drop control unit 68 are constructed.

  Based on information from the millimeter wave radar 44, the surrounding environment information acquisition unit 52 acquires information about the obstacles that exist around the host vehicle 100 (ambient environment information). The surrounding environment information acquisition unit 52 also determines the position of the obstacle ahead of the host vehicle 100, the relative speed between the obstacle and the host vehicle 100, the obstacle and the host vehicle based on information from the vehicle speed sensor 42 and the millimeter wave radar 44. The surrounding environment information such as the distance to the vehicle 100 is acquired. The “obstacle” referred to here is a thing that may hinder the progress of the host vehicle 100, and includes, for example, other vehicles, pedestrians, and the like.

  The follow-up control unit 54 sets a preceding vehicle to be subject to follow-up control based on the surrounding environment information acquired by the surrounding environment information acquisition unit 52. The follow-up control unit 54 determines whether or not a preceding vehicle setting condition for setting the preceding vehicle is satisfied. If the preceding vehicle setting condition is satisfied, the preceding vehicle is set and set. Follow-up control is performed to follow the preceding vehicle.

The “preceding vehicle setting condition” includes the position of another vehicle and the inter-vehicle distance between the other vehicle and the host vehicle 100. The follow-up control unit 54 sets another vehicle as a preceding vehicle when another vehicle exists within a predetermined setting range. The “preceding vehicle setting condition” includes a temporal element. That is, the other vehicle is set as the preceding vehicle when the other vehicle exists within the set range for a preset time “t ₀ ”.

  The follow-up control unit 54 functions as a preceding vehicle setting canceling unit that cancels the setting as the preceding vehicle when the preceding vehicle setting condition is not satisfied. The follow-up control unit 54 secures temporal hysterism (allowable range for continuing the setting as the preceding vehicle even if the millimeter wave radar loses sight of the preceding vehicle, safety margin; confirmation time) in the normal driving mode, The setting as a preceding car is not released immediately. The follow-up control unit 54 is configured to immediately cancel the setting as the preceding vehicle without waiting for the confirmation time to elapse (without securing a safety margin) in the fuel consumption-oriented travel mode. As a result, the limit amount for limiting the driving force during the follow-up control following the preceding vehicle can be immediately relaxed, and the driving force response performance can be improved while improving the fuel consumption performance during the follow-up control execution. Improvements can be made. That is, it is possible to quickly cancel the fuel consumption improvement control in the follow-up control and quickly respond to the driver's request for increase in driving force.

  Based on the surrounding environment information acquired by the surrounding environment information acquisition unit 52, the driving force increase request estimation unit 56 may be a driving force increase request (hereinafter referred to as “driving force increase request”) by the driver. Presence or absence is estimated. For example, when the inter-vehicle distance from the preceding vehicle is short, it is estimated that there is no possibility of requesting an increase in driving force when there is an obstacle immediately before the host vehicle. In addition, when there is no preceding vehicle, when the distance between the preceding vehicle and the preceding vehicle is sufficiently long, or when it is possible to overtake the preceding vehicle, it is estimated that there is a possibility of a drive force increase request. Further, based on the estimated required driving force, it is possible to estimate the possibility of a driving force increase request.

  When the driving force increase request estimation unit 56 estimates that there is a possibility of a driving force increase request, the driving force control unit 58 selects normal driving control (normal driving mode), while allowing a driving force increase request. When it is estimated that there is no possibility, fuel efficiency improvement control (fuel efficiency-oriented travel mode) is selected. The driving force control unit 58 controls the driving force of the host vehicle 100 by operating the engine 12 and the electric motor 14 in accordance with the selected control (traveling mode). The driving force control unit 58 functions as the driving force control means of the present invention that limits the upper limit of the driving force of the host vehicle 100. The driving force control unit 58 sets a driving force upper limit value in the fuel consumption-oriented travel mode, and executes driving force control so as not to exceed the driving force upper limit value.

  Based on the surrounding environment information acquired by the surrounding environment information acquisition unit 52, the driving force control unit 58 estimates a requested driving force that is a driving force requested by the driver of the host vehicle 100. In the driving force control unit 58, for example, a driving force that does not contact other vehicles / obstacles in front of the own vehicle 100 and does not cause fear to the occupant of the own vehicle 100 when approaching the other vehicles / obstacles ( The maximum value of (necessary driving force) is calculated as the required driving force.

  Further, in the driving force control unit 58, for example, the required driving force is calculated to be a smaller value as the inter-vehicle distance between the preceding vehicle (another vehicle) and the host vehicle 100 is shorter. The required driving force is calculated so as to be a small value. Further, the driving force control unit 58 calculates the required driving force so that the smaller the relative speed with respect to the preceding vehicle (the forward direction of the host vehicle is the positive direction) is, the smaller the value is. Further, the driving force control unit 58 calculates the required driving force so that the closer the lateral position (position in the vehicle width direction) of the preceding vehicle is to the own vehicle 100, the smaller the value is, and the absolute value of the lateral speed of the preceding vehicle is calculated. The required driving force is calculated such that the smaller the value, the smaller the value. When the preceding vehicle moves away from the front of the host vehicle 100, the required driving force is calculated so as to be a larger value.

FIG. 3 is a map showing an example of the relationship between the inter-vehicle distance and the required driving force. In FIG. 3, the horizontal axis indicates the inter-vehicle distance between the host vehicle 100 and the preceding vehicle, the vertical axis indicates the required driving force, and the necessary driving force line G ₁ indicated by a solid line indicates the relationship between the inter-vehicle distance and the required driving force. Show. In the range where the inter-vehicle distance is from 0 to d ₁ , the necessary driving force line G ₁ is proportional to the inter-vehicle distance, and in the range where the inter-vehicle distance exceeds the reference value d ₁ , the necessary driving force line G ₁ is the maximum driving force. F _max . The maximum driving force F _max is the maximum driving force of the vehicle 100.

FIG. 4 is a map showing an example of the relationship between the relative speed and the required driving force. In Figure 4, the horizontal axis shows the relative speed to the preceding vehicle, the vertical axis shows the required driving force, required driving force line G ₂ indicated by a solid line shows the relationship between the relative speed and the required driving force. The relative velocity _{v 1} is less than the range, it required driving force line _{G 2} is, becomes a constant value, in the range of relative velocity to _{v 1 ~v 2 (v 1 <} 0 <v 2), required driving force line G ₂ is proportional to the relative speed, the relative speed is _{v 2} is greater than the range, it required driving force line _{G 2} is, the maximum driving force _{F max.}

  When the required driving force estimated by the driving force control unit 58 has a magnitude that cannot be achieved in the fuel consumption-oriented travel mode, the driving force control change unit 62 temporarily stops execution of the fuel consumption-oriented travel mode, The control content by the driving force control unit 58 is changed based on the force. When the required driving force exceeds the driving force upper limit value, the driving force control changing unit 62 cancels the fuel efficiency improvement control and switches from the fuel efficiency-oriented travel mode to the normal travel mode, and is set in the fuel efficiency-oriented travel mode. The driving force upper limit value is changed to function as the driving force limit changing means of the present invention that changes the control contents so that the required driving force can be achieved.

  Further, the driving force control changing unit 62 increases the magnitude of the driving force limit amount when the follow-up control is being executed, compared to when the follow-up control is not being executed. Thereby, the driving force control unit 58 improves the fuel efficiency performance in the fuel efficiency-oriented travel mode by setting the driving force upper limit value lower than the normal time when the follow-up control is being executed.

  Further, the driving force control change unit 62 is configured such that when the host vehicle 100 is stopped and there is an obstacle in front of the host vehicle 100, the host vehicle 100 is stopped and an obstacle is ahead of the host vehicle 100. Compared to the case where there is no driving force, the limit amount of the driving force is increased. As a result, the driving force control unit 58 improves the fuel efficiency in the fuel consumption-oriented travel mode by setting the driving force upper limit value lower than normal when there is an obstacle ahead of the host vehicle 100 that is stopped. .

  The overtaking determination unit 64 determines whether the host vehicle 100 is about to overtake the preceding vehicle based on information from the direction indicator detection sensor 46. The overtaking determination unit 64 determines that the host vehicle 100 is about to overtake another vehicle when the direction indicator is in an operating state. Note that the overtaking determination unit may perform overtaking determination based on the steering operation.

  In addition, when it is determined that the host vehicle 100 is about to overtake another vehicle, the driving force control change unit 62 reduces the magnitude of the limit amount of the driving force as compared to the case where the own vehicle 100 is not overtaking. Thereby, the driving force control part 58 changes a driving force upper limit value highly according to overtaking operation, and improves a response.

  The engine standby control unit 66 is when the host vehicle 100 is traveling at a set vehicle speed (for example, 65 km / h) or higher that is set using only the power from the electric motor 14 (using power from the HV battery 22). In addition, engine standby control is performed in which the engine 12 is started in advance in preparation for a driving force increase request.

  The engine standby control unit 66 allows the engine standby control to be executed when the driving force increase request estimation unit 56 estimates that there is a possibility of a driving force increase request, while there is no possibility of a driving force increase request. When it is estimated that the engine standby control is stopped (suppressed). For example, when it is estimated that there is no possibility of requesting an increase in driving force during execution of engine standby control (engine startup), the engine 12 is stopped. Thereby, the fuel consumption performance can be improved by reducing unnecessary operations.

  The boost voltage control unit 68 executes boost control in which the supply voltage to the electric motor 14 is boosted in advance in preparation for a drive force increase request. In the boost voltage control unit 68, when it is estimated by the driving force increase request estimation unit 56 that there is a possibility of a driving force increase request, it is possible to execute the boost control, while there is no possibility of a driving force increase request. When estimated, the boost control is suppressed by executing the boost voltage drop control for dropping the boost voltage by the boost control. For example, when it is estimated that there is no possibility of requesting an increase in driving force during the boost control, the boost voltage by the boost converter is lowered. Thereby, the fuel efficiency is improved by reducing the heat loss in the boost converter.

  Next, the control process executed by the vehicle travel control device 10 will be described with reference to the flowcharts of FIGS. FIG. 5 is a flowchart showing the driving force control process according to the embodiment of the present invention, and FIG. 6 is a flowchart showing the driving force upper limit value setting process according to the embodiment of the present invention. First, the HV-ECU 40 receives a signal from the millimeter wave radar 44, for example, and acquires surrounding environment information (S1). The HV-ECU 40 receives signals from various sensors including the vehicle speed sensor 42 and the direction indicator detection sensor 46.

  Next, the HV-ECU 40 determines whether or not it is a fuel consumption-oriented travel mode (S2). Here, based on the acquired surrounding environment information, it is determined whether or not there is a possibility of a driving force increase request by the driver, and when it is determined that there is no possibility of a driving force increase request, If it is determined that there is a possibility of requesting an increase in driving force, it is determined that there is a possibility of requesting an increase in driving force.

  In step 3, the HV-ECU 40 executes a “driving force upper limit value setting process”. Here, the process shown in FIG. 6 is executed. The HV-ECU 40 proceeds to step 11 and determines whether or not the host vehicle 100 is stopped based on information from the vehicle speed sensor 42. When the host vehicle speed is 0 km / h, it is determined that the host vehicle 100 is stopped, and the process proceeds to Step 12. On the other hand, if it is not determined that the host vehicle 100 is stopped, the process proceeds to step 15.

  In step 12, the HV-ECU 40 determines whether an obstacle is detected in front of the host vehicle 100 based on the surrounding environment information. If no obstacle is detected in front of the host vehicle 100, the process proceeds to step 13 where the driving force limit amount L1 is set and the driving force upper limit value T1 is set. On the other hand, if an obstacle is detected in front of the host vehicle 100, the process proceeds to step 14, where a driving force limit amount L2 (> L1) is set and a driving force upper limit value T2 (<T1) is set. That is, when there is an obstacle such as another vehicle in front of the host vehicle 100, the limit amount for limiting the upper limit of the driving force is increased as compared with the case where no obstacle is present (the driving force upper limit value is Set low). The driving force upper limit value may be proportional to the distance between the host vehicle 100 and the obstacle. After steps 13 and 14, the driving force upper limit setting process is terminated, and the process proceeds to step 4 in FIG.

  In step 15, the HV-ECU 40 determines whether or not the host vehicle 100 is executing the follow-up control. If the follow-up control is not being executed, the process proceeds to step 16 to set the driving force limit amount L3 and set the driving force upper limit value T3. On the other hand, if the follow-up control is being executed, the process proceeds to step 17 where the drive force limit L4 (> L3) is set, the drive force upper limit value T4 (<T3) is set, and the process proceeds to step 18. That is, when the own vehicle 100 is executing the follow-up control, the limit amount for limiting the upper limit of the drive force is increased (the drive force upper limit value is set lower) than when the follow-up control is not being executed. . After step 16, the driving force upper limit value setting process is terminated, and the process proceeds to step 4 in FIG.

  In step 18, based on the operating state of the direction indicator of the host vehicle 100, it is determined whether or not it is overtaking the preceding vehicle. If the direction indicator is in the ON state, it is determined that the vehicle ahead is about to be overtaken, and the process proceeds to step 19. If the direction indicator is in the OFF state, the vehicle is overtaking the preceding vehicle. Without determination, the driving force upper limit value setting process is terminated, and the process proceeds to Step 4 in FIG.

  In step 19, the HV-ECU 40 changes the limit amount of the driving force from L4 to L3, and changes the driving force upper limit value from T4 to T3. That is, the HV-ECU 40 improves the driver's response to the driving force increase request by predicting the driving force increase request based on the driving operation by the driver and changing the driving force limit amount small. Let After step 19, the driving force upper limit value setting process is terminated, and the process proceeds to step 4 in FIG.

  Next, the HV-ECU 40 returns to step 4 of the driving force control process of FIG. In step 4, the HV-ECU 40 estimates the required driving force based on the surrounding environment information. Here, for example, the required driving force is calculated according to a map (see FIGS. 3 and 4) stored in the storage unit.

  In subsequent step 5, the HV-ECU 40 determines whether or not the required estimated driving force is larger than the driving force upper limit value. That is, by comparing the request estimated driving force and the driving force upper limit value, it is determined whether or not the driver requests a driving force that cannot be achieved in the fuel consumption-oriented driving mode. If the required driving force> the driving force upper limit value is not satisfied, the process proceeds to step 6. If the required driving force> the driving force upper limit value, the process proceeds to step 7.

  In step 6, the HV-ECU 40 continues the fuel consumption-oriented travel mode and performs driving force control so as not to exceed the driving force upper limit value. In step 7, the HV-ECU 40 selects the normal travel mode and performs driving force control. Here, the normal driving is performed by canceling the setting of the driving force upper limit value in the fuel consumption-oriented driving mode. As a result, when the driver demands a driving force that cannot be achieved in the fuel efficiency-oriented travel mode, the fuel efficiency-oriented travel mode can be temporarily canceled and the driving force control based on the requested driving force can be executed.

  That is, in step 5, the required driving force is estimated based on the surrounding environment information, and whether or not there is a possibility of a driving force increase request is determined according to the estimated required driving force. When the request estimated driving force is greater than the driving force upper limit value, it is determined that there is a possibility of requesting an increase in driving force, and the routine proceeds to step 7 where the fuel efficiency improvement control is canceled and the normal driving mode is selected. On the other hand, if the request estimated driving force is not greater than the driving force upper limit value, it is determined that there is no possibility of requesting an increase in driving force, and the routine proceeds to step 6 where fuel efficiency improvement control is executed.

  Next, the preceding vehicle setting release process in the follow-up control will be described with reference to the flowchart of FIG. First, the HV-ECU 40 determines whether follow-up control is being executed (S21). If the follow-up control is being executed, the process proceeds to step 22. If the follow-up control is not being executed, the preceding vehicle setting release process is terminated.

  In step 22, the HV-ECU 40 determines whether or not the fuel efficiency-oriented travel mode is based on the acquired surrounding environment information. If it is in the fuel efficiency-oriented travel mode, the process proceeds to step 23, and if it is not in the fuel efficiency-oriented travel mode, the process proceeds to step 24.

In step 23, the HV-ECU 40 sets “0” as the setting cancellation time, and in step 24, sets “t ₁ ” as the setting cancellation time, and proceeds to step 25. In step 25, the HV-ECU 40 determines whether the preceding vehicle setting condition is satisfied based on the surrounding environment information. If the preceding vehicle setting condition is satisfied, the preceding vehicle setting canceling process is terminated without canceling the setting as the preceding vehicle. On the other hand, if the preceding vehicle setting condition is not satisfied, the process proceeds to step 26.

  In step 26, the HV-ECU 40 determines whether or not the setting release time set in steps 23 and 24 has elapsed. When the setting cancellation time has elapsed, the process proceeds to step 27 to cancel the setting as the preceding vehicle, and the preceding vehicle setting cancellation processing ends. If the setting cancellation time has not elapsed, the processes of steps 25 and 26 are repeated, and the setting as the preceding vehicle is canceled after the setting cancellation time has elapsed.

  In the preceding vehicle setting cancellation process, when the fuel-consumption-oriented travel mode is selected, the setting cancellation time is set to 0, and the setting as the preceding vehicle is performed without waiting for the confirmation time to elapse (without securing a safety margin). Canceled. Therefore, the driving force upper limit value set in the driving force upper limit value setting process of FIG. 6 is changed from T4 to T3 (the driving force limit amount is changed to be small). Thereby, the response is improved while improving the fuel consumption performance. In step 27, when the setting as the preceding vehicle is cancelled, the limit amount of the driving force may be canceled by changing from the fuel consumption-oriented travel mode to the normal travel mode.

  Next, the engine standby off execution determination process executed by the HV-ECU 40 will be described with reference to the flowchart of FIG. First, the HV-ECU 40 determines whether the vehicle is traveling using only the power of the electric motor 14 (S31). If the host vehicle 100 is traveling only by the electric motor 14, the process proceeds to step 32. If the host vehicle 100 is traveling using the power of the engine 12, the engine standby off execution determination process is terminated. To do.

  In step 32, the HV-ECU 40 calculates the host vehicle speed based on the signal from the vehicle speed sensor 42, and proceeds to step 33. Subsequently, in step 33, the HV-ECU 40 determines whether or not the own vehicle speed is equal to or higher than a set vehicle speed (for example, 65 km / h). If the host vehicle speed is equal to or higher than the set vehicle speed, the process proceeds to step 34. If the host vehicle speed is not equal to or higher than the set vehicle speed, the engine standby off execution determination process is terminated.

  In step 34, the HV-ECU 40 determines whether or not the fuel consumption-oriented travel mode is based on the acquired surrounding environment information. If the mode is not selected, the process proceeds to step 35.

  In step 35, the HV-ECU 40 determines that the engine standby control is to be executed, and executes the engine standby control in which the engine 12 is started in advance in preparation for the driver's driving force increase request. In step 36, the HV-ECU 40 does not determine that the engine standby control is to be executed, and executes an engine standby off control that does not start the engine 12 in advance. After executing Steps 35 and 36, the engine standby off execution determination process is terminated.

  That is, in step 34, it is determined whether or not there is a possibility of a driving force increase request based on the surrounding environment information. For example, when there is no preceding vehicle (when the distance between the preceding vehicle and the preceding vehicle is long), it is determined that there is a possibility of requesting an increase in driving force, and the process proceeds to step 35 to execute engine standby control. On the other hand, if there is a preceding vehicle, it is determined that there is no possibility of requesting an increase in driving force, and the routine proceeds to step 36 where engine standby control is canceled (suppressed).

  Next, the boost voltage drop execution determination process will be described with reference to the flowchart of FIG. The HV-ECU 40 determines whether or not the fuel consumption-oriented travel mode is based on the acquired surrounding environment information (S41). Otherwise, go to step 42.

  In step 42, the HV-ECU 40 sets the boosted voltage V <b> 1 and transmits a control signal to the power control unit 20. The power control unit 20 performs boost voltage control so that the voltage supplied to the electric motor 14 is V1.

  In step 43, the HV-ECU 40 sets V2 (<V1) as the boosted voltage and transmits a control signal to the power control unit 20. The power control unit 20 performs boost voltage drop control so that the voltage supplied to the electric motor 14 is V2.

  That is, in step 41, it is determined based on the surrounding environment information whether there is a possibility of a driving force increase request. If it is determined that there is a possibility of an increase in driving force, the process proceeds to step 42 and boost voltage control is executed. On the other hand, if it is determined that there is no possibility of requesting an increase in driving force, the process proceeds to step 43 to lower the boost voltage.

  Such a vehicular travel control apparatus 10 includes a driving force increase request estimation unit 56 that estimates whether or not there is a possibility of a driving force increase request by the driver based on the surrounding environment information related to the surrounding environment of the host vehicle 100. Therefore, when it is estimated that there is a possibility of an increase in driving force, it is possible to improve response by executing engine standby control and boost voltage control in preparation for an increase in driving force. When it is estimated that there is no possibility of requesting an increase in driving force, unnecessary power can be reduced and fuel efficiency can be improved by suppressing engine standby control and boost voltage control. This eliminates the need for conventional switch operation (input operation) by the driver, and can automatically switch ON / OFF of the travel control with an emphasis on improving fuel efficiency. Thus, it is possible to achieve both improvement in response to a request for increase in driving force due to. According to the vehicle travel control device 10, when there is a preceding vehicle, the fuel efficiency improvement control is automatically selected, and the engine standby control and the boost voltage control can be stopped.

  Further, in the vehicle travel control device 10, when it is estimated that there is a possibility of an increase request for driving force during the execution of the follow-up control and the fuel efficiency improvement control, without waiting for the confirmation time to elapse, Since the fuel efficiency improvement control can be canceled before the acceleration operation is started, the magnitude of the limit amount of the driving force during the execution of the fuel efficiency improvement control can be quickly returned to the normal state. Therefore, it is possible to achieve both improvement in fuel efficiency and improvement in driving force response.

  As mentioned above, although this invention was concretely demonstrated based on the embodiment, this invention is not limited to the said embodiment. For example, in the fuel consumption-oriented travel mode, the driving force for propelling the host vehicle 100 may be generated using only the power of the electric motor 14. The host vehicle 100 may be generated using the power of the engine 12 and the electric motor 14. A driving force for propelling may be generated. In short, in the fuel consumption-oriented travel mode, it is only necessary to be able to execute travel that emphasizes improvement in fuel efficiency compared to normal travel.

  Also, in the estimation of the possibility of a driving force increase request based on the surrounding environment information, when a preceding vehicle is detected, it is estimated that there is no possibility of a driving force increase request when an obstacle is detected in front of the host vehicle. Also good. Further, as the surrounding environment information, for example, the presence or absence of the possibility of a driving force increase request may be estimated based on signal cycle information, traffic jam information, information on other vehicles by inter-vehicle communication, information on road-to-vehicle communication, and the like. Also, based on the surrounding environment information, it is estimated that there is a possibility of requesting an increase in driving force when the host vehicle is in an accelerating state, and the driving force is increased when the host vehicle is in an unaccelerated state. It may be estimated that there is no possibility of request.

  The standby control may be control prepared for generating the maximum driving force of the host vehicle, or may be configured to stop the standby control when there is no possibility of requesting an increase in driving force.

1 is a schematic configuration diagram of a hybrid vehicle equipped with a vehicle travel control device according to an embodiment of the present invention. 1 is a block configuration diagram of a vehicle travel control device according to an embodiment of the present invention. It is a map which shows an example of the relationship between distance between vehicles, and request | requirement driving force. It is a map which shows an example of the relationship between relative speed and request | requirement driving force. It is a flowchart which shows the driving force control process which concerns on embodiment of this invention. It is a flowchart which shows the driving force upper limit setting process which concerns on embodiment of this invention. It is a flowchart which shows the preceding vehicle setting cancellation | release process which concerns on embodiment of this invention. It is a flowchart which shows the engine standby off execution determination processing which concerns on embodiment of this invention. It is a flowchart which shows the boost voltage fall execution determination process which concerns on embodiment of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Vehicle travel control apparatus, 12 ... Engine (internal combustion engine), 14 ... Electric motor (electric motor), 16 ... Power distribution mechanism, 18 ... Generator, 20 ... Power control unit, 22 ... Hybrid battery, 24 ... Deceleration , 26 ... drive wheels, 28 ... inverter, 30 ... boost converter, 32 ... DC / DC converter, 34 ... motor generator ECU, 40 ... hybrid ECU, 42 ... vehicle speed sensor, 44 ... millimeter wave radar, 46 ... direction indicator Detection sensor, 52 ... Ambient environment information acquisition unit, 54 ... Follow-up control unit, 56 ... Driving force increase request estimation unit, 58 ... Driving force control unit, 62 ... Driving force control change unit, 64 ... Overtaking determination unit, 66 ... Engine standby control unit, 68... Boosted voltage control unit, 100.

Claims (7)

In a vehicle travel control device including tracking control means for executing tracking control for tracking a preceding vehicle and driving force control means for controlling the driving force of the host vehicle,
Surrounding environment information acquisition means for acquiring surrounding environment information that is information related to the surrounding environment of the vehicle;
Driving force increase request estimating means for estimating the possibility of an increase request for the driving force based on the surrounding environment information acquired by the surrounding environment information acquiring means, and
The driving force control means includes
When it is estimated by the driving force increase request estimation means that there is a possibility of an increase request for the driving force, a standby control is prepared for preparing to increase the driving force smoothly,
When it is estimated by the driving force increase request estimating means that there is no possibility of an increase request for the driving force, the standby control is suppressed,
The driving force control means includes
Driving force limiting means for performing fuel efficiency improvement control that places more emphasis on improving fuel efficiency than usual by limiting the upper limit of driving power,
A driving force limit changing means for changing the limit by the driving force limiting means in response to a request to increase the driving force;
The follow-up control means is provided on the condition that another vehicle exists within a set range from the own vehicle and a preset confirmation time has passed as a preceding vehicle setting condition for setting the preceding vehicle to be subject to the follow-up control. The other vehicle is set as a preceding vehicle to be subject to the follow-up control, and the follow-up control is executed.
When the preceding vehicle setting condition is not satisfied, the follow-up control means waits for a set time for continuing the setting as the preceding vehicle even if the other vehicle is lost in the normal state, as the preceding vehicle. During the execution of the fuel efficiency improvement control, the setting as the preceding vehicle is canceled without waiting for the set time to elapse,
The driving force control means accelerates the fuel efficiency improvement control when it is estimated that there is a possibility of an increase request for the driving force during execution of the follow-up control and during the execution of the fuel efficiency improvement control. Cancel before starting,
The driving force control means does not wait for the set time to elapse if the preceding vehicle setting condition is not satisfied while the follow-up control is being executed and the fuel efficiency improvement control is being executed. The vehicle travel control device is characterized by canceling. The standby control is a control prepared for generating the maximum driving force of the host vehicle,
The surrounding environment information acquisition means acquires information on the presence or absence of a preceding vehicle as the surrounding environment information,
The driving force increase request estimation means estimates that there is no possibility of the driving force increase request when there is a preceding vehicle,
2. The vehicular travel control apparatus according to claim 1, wherein the driving force control unit stops the standby control when it is estimated that there is no possibility of an increase request for the driving force.   The driving force limit changing means increases the magnitude of the driving force limit amount by the driving force limiting means when the follow-up control is being executed, compared to when the follow-up control is not being executed. The vehicular travel control apparatus according to claim 1 or 2.   The driving force limit changing means is configured to detect an obstacle ahead of the host vehicle while the host vehicle is stopped when it is determined that there is an obstacle ahead of the host vehicle while the host vehicle is stopped based on the surrounding environment information. The vehicle according to any one of claims 1 to 3, wherein the amount of restriction of the driving force by the driving force restriction means is increased compared to a case where it is not determined that there is an object. Travel control device. Provided with an overtaking judging means for judging whether or not the own vehicle is about to overtake another vehicle ahead;
The driving force limit changing means is compared with a case where the overtaking determination means determines that the other vehicle is not overtaken when it is determined that the other vehicle is overtaking. The travel control device for a vehicle according to any one of claims 1 to 4, wherein a magnitude of a limit amount of the driving force by the driving force limiting means is reduced. The host vehicle is a hybrid vehicle including a motor and an engine as a drive source,
The standby control is an engine in which the engine is started in advance in preparation for an increase in the driving force when the host vehicle is traveling at a set vehicle speed or higher using only the power from the motor. The vehicle travel control device according to any one of claims 1 to 5, wherein the vehicle travel control device is standby control. The host vehicle is a hybrid vehicle including a motor and an engine as a drive source,
The vehicle travel control according to any one of claims 1 to 6, wherein the standby control is a boost control in which a supply voltage to the motor is boosted in advance in preparation for a drive force increase request. apparatus.

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