JP2006224882A - Vehicle deceleration control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vehicle deceleration control device that performs deceleration control to establish the proper positional relationship between a vehicle and another vehicle ahead in such a manner as to keep the driver from feeling discomfort when losing sight of the vehicle ahead. <P>SOLUTION: The vehicle deceleration control device for subjecting a vehicle to deceleration control in order to establish the proper positional relationship between the vehicle X and another vehicle P ahead has a means for detecting the vehicle ahead. If the driver loses sight of the vehicle ahead (S1-N), deceleration applied to the vehicle is reduced according to a value S5 set according to a parameter that makes it possible to estimate a relative period when the vehicle ahead was lost sight of (S11). The parameter is the curvature or radius of either a corner ahead of the vehicle or a corner where the vehicle is running. When the curvature is great or when the radius is small, the deceleration is decreased at a smaller rate than if the curvature is small or if the radius is great. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a deceleration control device for a vehicle that performs deceleration control of the vehicle in order to make the positional relationship with a front vehicle in front of the vehicle appropriate.

  Japanese Patent Laying-Open No. 2003-267085 (Patent Document 1) describes a vehicular travel control device related to control when a preceding vehicle is lost during the preceding vehicle following travel control. That is, in this device, when the front vehicle is lost while following the front vehicle, the front vehicle position is determined from the front of the host vehicle by the difference between the center of the inter-vehicle distance sensor immediately before the lost vehicle and the front vehicle detection position and the corner R. The amount of deviation is calculated, and the base holding time is calculated from this deviation. A correction coefficient is calculated from the difference between the center of the inter-vehicle distance sensor and the front vehicle detection position, the relative vehicle speed, and the corner R, and the holding time is corrected. Assuming that the relative acceleration immediately before the lost is continued from the previous vehicle lost during the corrected holding time, the relative vehicle speed and the inter-vehicle distance are estimated, and the target deceleration of the own vehicle is calculated from this estimated value and control is performed.

  Japanese Patent Laid-Open No. 11-291788 (Patent Document 2) describes the following vehicle travel control device. In other words, when it is estimated that the front vehicle is lost and turning based on the steering angle during the following vehicle following traveling, the deceleration immediately before the lost is maintained. In addition, when the corner R that can be calculated from the vehicle speed and the steering angle is smaller than that at the time of lost, the vehicle is controlled to the target deceleration calculated from the difference between the recommended vehicle speed determined from the corner R and the current vehicle speed. Implement the appropriate control.

  Japanese Unexamined Patent Publication No. 11-198676 (Patent Document 3) describes the following vehicle travel control device. That is, when the front vehicle is lost during the following vehicle following traveling, the current traveling state is maintained while traveling the distance between the vehicles immediately before the lost vehicle. Thereafter, the corner R currently being traveled is calculated. If the corner R is equal to or greater than a predetermined value, acceleration is permitted. If the corner R is equal to or smaller than the predetermined value, deceleration is continued to the optimum vehicle speed determined by the corner R.

  In the technique of Patent Document 1, the deceleration is maintained or increased until a predetermined time elapses. Especially when the front car is lost when the relative acceleration is large, the deceleration continues to increase. Usually, the driver shifts to steady driving soon after entering the corner. For this reason, the deceleration often does not need to continue to increase. Therefore, in the control for increasing the deceleration even after the front vehicle is lost, the driver feels uncomfortable due to the large deceleration.

  In the techniques of Patent Document 2 and Patent Document 3 described above, after the front vehicle is lost, control is performed at a deceleration that is greater than or equal to the current deceleration. The deceleration does not decrease until the previous vehicle is detected again. However, normally, when the vehicle travels at the corner, the driver decelerates to the corner entrance, maintains the vehicle speed, travels around the corner, and accelerates from the corner exit. For this reason, if the control which maintains deceleration during corner driving is performed, the driver will feel uncomfortable due to the large deceleration.

JP 2003-267085 A Japanese Patent Laid-Open No. 11-291788 JP-A-11-198676

  In deceleration control for making the positional relationship with the front vehicle in front of the vehicle appropriate, it is desired that when the front vehicle is lost, control with less discomfort to the driver is performed.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a deceleration control device for a vehicle that performs deceleration control for making the positional relationship with the front vehicle appropriate, and performs control with less discomfort to the driver when the front vehicle is lost. Is to provide.

  The vehicle deceleration control device of the present invention is a vehicle deceleration control device that performs deceleration control of the vehicle in order to make the positional relationship between the vehicle and the front vehicle ahead of the vehicle appropriate, and detects the front vehicle. Means for reducing the deceleration applied to the vehicle according to a value set based on a parameter capable of estimating a relative timing when the front vehicle is lost. It is characterized by that.

  In the vehicle deceleration control apparatus according to the present invention, the parameter is a curvature or a radius of a corner in front of the vehicle or a corner in which the vehicle is traveling.

  In the vehicle deceleration control device of the present invention, when the curvature is large or the radius is small, the deceleration is gradually decreased at a smaller rate than when the curvature is small or the radius is large. It is said.

  In the vehicle deceleration control apparatus according to the present invention, the parameter is a parameter corresponding to a distance between the front vehicle and the vehicle in a state where a corner is detected in front of the vehicle.

  In the vehicle deceleration control apparatus according to the present invention, when the parameter corresponding to the distance is large, the deceleration is gradually decreased at a smaller rate than when the parameter corresponding to the distance is small.

  In the vehicle deceleration control apparatus of the present invention, the parameter corresponding to the distance is an inter-vehicle time or an inter-vehicle distance.

  The vehicle deceleration control device of the present invention is a vehicle deceleration control device that performs deceleration control of the vehicle in order to make the positional relationship between the vehicle and the front vehicle ahead of the vehicle appropriate, and detects the front vehicle. According to a value set based on a parameter for estimating a change in the distance between the front vehicle and the vehicle that is expected after losing sight of the front vehicle when the front vehicle is lost. The deceleration applied to the vehicle is reduced.

  In the vehicle deceleration control apparatus according to the present invention, the parameter is a difference between a gradient of a road surface ahead of the vehicle and a gradient of a road surface on which the vehicle is traveling.

  In the vehicle deceleration control apparatus according to the present invention, when the climbing slope is represented by a positive value and the descending slope is represented by a negative value, the vehicle travels from the slope of the front road surface. When the difference obtained by subtracting the slope of the road surface is large, the deceleration is gradually decreased at a smaller rate than when the difference is small.

  According to the vehicle deceleration control device of the present invention, deceleration control is performed to make the positional relationship with the front vehicle appropriate, and control with less discomfort to the driver is performed when the front vehicle is lost. .

  Hereinafter, an embodiment of a vehicle deceleration control device of the present invention will be described in detail with reference to the drawings.

(First embodiment)
The first embodiment will be described with reference to FIGS. 1 to 9. The present embodiment relates to a vehicle deceleration control device that performs deceleration control in response to a driver's intention to decelerate in order to make the positional relationship with a vehicle (front vehicle) traveling forward.

  Here, in the deceleration control that makes the positional relationship with the front vehicle appropriate, follow-up running (including follow-up control, including the case where the inter-vehicle distance from the preceding vehicle is a predetermined value or less for some reason) is performed. Vehicle-to-vehicle distance control in the case where the vehicle is moving, and collision prevention control that is performed when the vehicle-to-vehicle distance with the preceding vehicle temporarily decreases.

  In this embodiment, when performing deceleration control using the driver's intention to decelerate as a control start trigger based on a parameter corresponding to the distance between the front vehicle and the host vehicle, when the front vehicle is lost, the corner curvature or radius R The deceleration is gradually reduced by the sweep rate determined based on As a result, when the front vehicle is lost, the deceleration does not drop suddenly or the deceleration does not work excessively, so that it is possible to realize deceleration control that does not give the driver a sense of incongruity.

  As described in detail below, the configuration of the present embodiment includes an inter-vehicle distance sensor such as a millimeter-wave radar, a means for measuring or calculating the inter-vehicle distance and the relative vehicle speed with the preceding vehicle, a millimeter-wave radar, a laser radar, and the like. It is premised on a means for calculating the forward corner R, a means for detecting an accelerator operation, and a means capable of controlling the deceleration of the host vehicle.

  In the above, as means capable of controlling the deceleration of the own vehicle, a brake control device (actuator) for controlling a brake or a regenerative brake (hereinafter simply referred to as a brake), an automatic transmission (AT, CVT, hybrid vehicle) In addition, a shift control device that controls the shift of AT, MMT (manual transmission with automatic shift mode), or a cooperative control device that cooperatively controls the brake and the automatic transmission can be used. In the following example, it is assumed that the means capable of controlling the deceleration of the host vehicle is a brake control device.

  In FIG. 2, reference numeral 10 denotes an automatic transmission, 40 denotes an engine, and 200 denotes a brake device. The automatic transmission 10 is capable of five-speed shifting by controlling the hydraulic pressure by energization / non-energization of the solenoid valves 121a, 121b, and 121c. In FIG. 2, three electromagnetic valves 121a, 121b, and 121c are illustrated, but the number of electromagnetic valves is not limited to three. The solenoid valves 121a, 121b, and 121c are driven by a signal from the control circuit 130.

  An electronic throttle valve 43 is provided in the intake pipe 41 of the engine 40. When an accelerator opening that changes due to an operation of an accelerator pedal (not shown) is detected by an accelerator opening sensor (not shown), the control circuit 130 throttles a throttle valve control command based on the accelerator opening. Output to an opening control device (not shown). The throttle opening control device controls the opening of the electronic throttle valve 43 based on the throttle valve control command.

  The throttle opening sensor 114 detects the opening of the electronic throttle valve 43. The engine speed sensor 116 detects the speed of the engine 40. The vehicle speed sensor 122 detects the rotation speed of the output shaft 120c of the automatic transmission 10 that is proportional to the vehicle speed. The shift position sensor 123 detects the shift position. The pattern select switch 117 is used when instructing a shift pattern.

  The acceleration sensor 90 detects vehicle deceleration (deceleration acceleration). The inter-vehicle distance measuring unit 100 includes a sensor such as a laser radar sensor or a millimeter wave radar sensor mounted on the front part of the vehicle, and measures the inter-vehicle distance from the vehicle ahead. The relative vehicle speed measurement unit 112 includes a sensor such as a millimeter wave radar sensor, and can directly measure the relative vehicle speed between the host vehicle and the vehicle ahead. It can also be calculated from the time lapse rate of the measured inter-vehicle distance. The inter-vehicle distance measuring unit 100 and the relative vehicle speed measuring unit 112 are configured by a single (identical) millimeter wave radar.

  The road gradient measurement / estimation unit 118 can be provided as a part of the CPU 131. The road gradient measurement / estimation unit 118 can measure or estimate the road gradient based on the acceleration detected by the acceleration sensor 90. Further, the road gradient measuring / estimating unit 118 may store the acceleration on the flat road in the ROM 133 in advance and obtain the road gradient by comparing with the acceleration actually detected by the acceleration sensor 90.

  The navigation system device 113 has a basic function of guiding the host vehicle to a predetermined destination, and includes an arithmetic processing device and information necessary for traveling of the vehicle (map, straight road, curve, uphill / downhill, highway) Etc.), a first information detection device including a geomagnetic sensor, a gyrocompass, and a steering sensor, and a current position of the vehicle by radio navigation. It is for detecting a position, road conditions, etc., and is provided with a second information detection device including a GPS antenna and a GPS receiver.

  The control circuit 130 inputs signals indicating detection results of the throttle opening sensor 114, the engine speed sensor 116, the vehicle speed sensor 122, the shift position sensor 123, and the acceleration sensor 90, and changes the switching state of the pattern select switch 117. A signal indicating the measurement result by the relative vehicle speed measurement unit 112, and a signal indicating the measurement result by the inter-vehicle distance measurement unit 100. input.

  The control circuit 130 is configured by a known microcomputer and includes a CPU 131, a RAM 132, a ROM 133, an input port 134, an output port 135, and a common bus 136. The input port 134 includes a signal from each of the above-described sensors 114, 116, 122, 123, 90, a signal from the above-described switch 117, an inter-vehicle distance measuring unit 100, a relative vehicle speed measuring unit 112, and a navigation system device 113. The signal from is input. The output port 135 is connected to the electromagnetic valve driving units 138a, 138b, 138c and the brake braking force signal line L1 to the brake control circuit 230. A brake braking force signal SG1 is transmitted through the brake braking force signal line L1.

  The ROM 133 stores a program in which the operations (control steps) shown in the flowchart of FIG. 1 are described in advance, and a shift map for shifting the gear stage of the automatic transmission 10 and a shift control operation (not shown). Is stored. The control circuit 130 shifts the automatic transmission 10 based on various input control conditions.

  The brake device 200 is controlled by a brake control circuit 230 that receives a brake braking force signal SG1 from the control circuit 130, and brakes the vehicle. The brake device 200 includes a hydraulic control circuit 220 and braking devices 208, 209, 210, and 211 provided on the wheels 204, 205, 206, and 207 of the vehicle, respectively. Each of the braking devices 208, 209, 210, and 211 controls the braking force of the corresponding wheels 204, 205, 206, and 207 when the hydraulic pressure is controlled by the hydraulic control circuit 220. The hydraulic control circuit 220 is controlled by the brake control circuit 230.

  The hydraulic control circuit 220 performs brake control by controlling the braking hydraulic pressure supplied to each braking device 208, 209, 210, 211 based on the brake control signal SG2. The brake control signal SG2 is generated by the brake control circuit 230 based on the brake braking force signal SG1. The brake braking force signal SG1 is output from the control circuit 130 of the automatic transmission 10 and input to the brake control circuit 230. The brake force applied to the vehicle during the brake control is determined by a brake control signal SG2 generated by the brake control circuit 230 based on various data included in the brake braking force signal SG1.

  The brake control circuit 230 is configured by a known microcomputer and includes a CPU 231, a RAM 232, a ROM 233, an input port 234, an output port 235, and a common bus 236. A hydraulic control circuit 220 is connected to the output port 235. The ROM 233 stores an operation for generating the brake control signal SG2 based on various data included in the brake braking force signal SG1. The brake control circuit 230 controls the brake device 200 (brake control) based on each input control condition.

  The operation of this embodiment will be described with reference to FIGS.

[Step S1]
First, as shown in step S <b> 1 of FIG. 1, the control circuit 130 determines whether a vehicle is detected in front of the lane of the host vehicle based on a signal indicating the inter-vehicle distance input from the inter-vehicle distance measuring unit 100. judge. As a result of step S1, when it is determined that the vehicle is detected in front of the lane of the own vehicle (step S1-Y), the process proceeds to step S2. On the other hand, when it is not determined that the vehicle is detected ahead of the lane of the own vehicle (step S1-N), the process proceeds to step S10.

[Step S2]
In step S2, the inter-vehicle distance D and the relative vehicle speed Vd are obtained by the control circuit 130. The inter-vehicle distance D and the relative vehicle speed Vd are directly measured by the millimeter wave radar that constitutes the relative vehicle speed measurement unit 112 together with the inter-vehicle distance measurement unit 100. Step S3 is performed after step S2.

[Step S3]
In step S <b> 3, the target deceleration is obtained by the control circuit 130. The target deceleration is obtained as a value (deceleration acceleration) such that the relationship with the preceding vehicle becomes the target inter-vehicle distance or relative vehicle speed when deceleration control based on the target deceleration is performed on the host vehicle. . A signal indicating the target deceleration is output from the control circuit 130 to the brake control circuit 230 via the brake braking force signal line L10 as the brake braking force signal SG1.

ステップＳ３の次に、ステップＳ４が実行される。 The target deceleration is calculated based on the relative vehicle speed, the inter-vehicle distance, and the acceleration of the front vehicle. The acceleration of the front vehicle is calculated from the time change rate of the vehicle speed of the front vehicle. The vehicle speed of the preceding vehicle is calculated from (own vehicle speed−relative vehicle speed). The target deceleration is calculated based on the following equation, for example.

Following step S3, step S4 is executed.

[Step S4]
In step S4, the curvature or radius R of the front corner is estimated by the control circuit 130. The calculation of the front corner R can be performed, for example, by the following method.

First, as shown in FIG. 3, the trajectory of the front vehicle P is calculated, and then, as shown in FIG. 4, the corner R is calculated based on the trajectory of the front vehicle P.
<1> Trajectory of the front car (Fig. 3)
(1) First, the moving distance of the front vehicle P is calculated from the following equation.
Previous vehicle travel distance = front vehicle speed × scanning time (2) Next, the center change angle Dc of the inter-vehicle distance sensor (inter-vehicle distance measuring unit 100) of the host vehicle X is calculated from the following equation.
Dc = yaw rate × scanning time (3) Next, the center deviation amount Lc of the inter-vehicle distance sensor is calculated from the following equation.
Lc = distance between vehicles × sin (Dc)
(4) Next, the absolute movement amount 301 of the front vehicle is calculated by the following equation.
Absolute travel of the front car 301 = Lc + Measured lateral position

<2> Calculation of corner radius (Fig. 4)
(5) Calculate the locus of the front vehicle P at three points.
(6) Connect the points with straight lines and draw perpendicular lines.
(7) The angle between the perpendiculars is the road turning angle Sd.
(8) The corner R is estimated from the road turning angle Sd and the map shown in FIG.
As shown in FIG. 5, when the road turning angle Sd is 20 °, the corner R is estimated to be 200 [m], and when it is 40 °, it is estimated to be 100 [m].

  As a method for calculating the front corner R, for example, a method described in Japanese Patent Laid-Open No. 2002-12053 can be used instead of the above method. Alternatively, the front corner R can be calculated from the current position and map information by the navigation system device 113. Step S5 is performed after step S4.

[Step S5]
In step S5, the control circuit 130 calculates a sweep rate based on the corner R obtained in step S4. For the calculation, a sweep plate setting map shown in FIG. 6 is used.

  As shown in FIG. 7, the distance that can be measured by the inter-vehicle distance sensor (the inter-vehicle distance measuring unit 100) is determined by the measurable range Rs that the inter-vehicle distance sensor has. When the front vehicle deviates from the measurable range Rs of the inter-vehicle distance sensor of the own vehicle X, the front vehicle is lost (missed). It is assumed that there is a corner C1 with a small corner R and a corner C2 with a large corner R in front of the host vehicle X. The entrances Cin of the corners C1 and C2 are common.

  In FIG. 8, reference numeral 401 indicates a target deceleration when the relative vehicle speed with respect to the front vehicle, the inter-vehicle distance, and the acceleration conditions of the front vehicle have certain values, respectively, and the front vehicle is not lost. Reference numeral 402 indicates a target deceleration when the above-described conditions are the same as those of the reference numeral 401 and the front corner is the corner C1 having a small corner R. Reference numeral 403 indicates a target deceleration when the above-described conditions are the same as those of the reference numeral 401 and the front corner is the corner C2 where the corner R is large. As shown in FIGS. 7 and 8, when the front corner is a corner C1 with a small corner R, the front car is lost earlier than when the corner R is a corner C2. Become.

  In the case of the corner C1 having a small corner R, the front vehicle is lost earlier, and the deceleration control is terminated by the lost. Therefore, it is not possible to secure a sufficient time for the deceleration control compared to the case where the corner R1 is not lost. . Therefore, as shown in FIG. 8, in the case of the corner C1 having a small corner R, the driver is dangerous because the vehicle is not approached suddenly by slowing down the deceleration after the previous vehicle is lost. The feeling is suppressed.

  On the other hand, in the case of the corner C2 having a large corner R, it is possible to ensure a longer time for performing the deceleration control than in the case where the corner R is small. For this reason, when the corner R is large, the driver does not feel uncomfortable due to the effect of the deceleration control too much if the deceleration is quickly removed when the front vehicle is lost compared to when the corner R is small.

  From the above, as shown in FIG. 6, when the corner R of the front corner is small, the deceleration is extracted (weakened) with a gentle slope, and when the corner R is large, the deceleration is steep with a steep slope. Unplug (weaken). In this way, by changing the method of extracting the deceleration according to the corner R, it is possible to achieve both of the sudden drop of the deceleration and the prevention of the excessive effect of the deceleration control. Step S6 is performed after step S5.

[Step S6]
In step S6, the control circuit 130 determines whether or not a deceleration control start condition is satisfied. In the present embodiment, it is assumed that the deceleration control start condition is satisfied when all the following conditions <1> to <4> are satisfied.

<1> Detection of driver's intention to decelerate (accelerator OFF)
With respect to the above <1>, the control circuit 130 determines whether or not the accelerator is in an OFF state (the accelerator opening is in a fully closed state) based on a signal from the throttle opening sensor 114. The driver's intention to decelerate is determined as idle contact ON (= accelerator OFF).

<2> The driver is not operating the brake (brake contact OFF)
<3> The front vehicle is being detected <4> Target deceleration> Predetermined value

  As a result of the determination in step S6, if it is determined that the deceleration control start condition is satisfied, the process proceeds to step S7. From step S7, control for making the positional relationship with the front vehicle appropriate is started. On the other hand, if it is not determined that the deceleration control start condition is satisfied, the process proceeds to step S8.

[Step S7]
In step S7, the control circuit 130 starts control so that the deceleration of the host vehicle becomes the target deceleration. In the present embodiment, the brake control circuit 230 starts brake control. That is, the braking force is applied so that the deceleration of the vehicle becomes the target deceleration. In this case, the braking force can be increased at a predetermined gradient (sweep control) until the target deceleration. The deceleration of the vehicle is measured by the acceleration sensor 90.

  In step S7, the brake control circuit 230 generates a brake control signal SG2 based on the brake braking force signal SG1 input from the control circuit 130, and outputs the brake control signal SG2 to the hydraulic control circuit 220. As described above, the hydraulic control circuit 220 controls the hydraulic pressure supplied to the braking devices 208, 209, 210, and 211 based on the brake control signal SG2, so that the braking force as instructed in the brake control signal SG2 is obtained. generate.

  As described above, instead of the method of increasing the braking force at a predetermined gradient, based on the deviation between the current deceleration of the vehicle and the target deceleration so that the current deceleration of the vehicle becomes the target deceleration. Thus, feedback control of the braking force applied to the vehicle can be performed. In this case, the change rate of the brake control amount can be limited so that the brake control amount does not change abruptly. Further, the deceleration control can be smoothly performed by a method such as performing an annealing process on the target deceleration value. After step S7, this control flow is returned.

[Step S8]
In step S8, the control circuit 130 determines whether or not the deceleration control end condition is satisfied. In the present embodiment, it is assumed that the deceleration control end condition is satisfied when all the following conditions <1> to <3> are satisfied.

<1> Accelerator ON
<2> The driver is operating the brake (brake contact ON)
<3> Target deceleration <Predetermined value

  If it is determined as a result of the determination in step S8 that the deceleration control end condition is satisfied, the process proceeds to step S9. On the other hand, if it is not determined that the deceleration control end condition is satisfied, the process proceeds to step S7.

[Step S9]
In step S9, the control circuit 130 ends the deceleration control. The control circuit 130 outputs a brake braking force signal SG1 to end the deceleration control. Based on the brake braking force signal SG1 input from the control circuit 130, the brake control circuit 230 generates a brake control signal SG2 for reducing the hydraulic pressure supplied to the braking devices 208, 209, 210, and 211 to the brake. The control signal SG2 is output to the hydraulic control circuit 220. Thereby, the braking force as deceleration control is made zero. Following step S9, the control flow is returned.

[Step S10]
In step S10, the control circuit 130 determines whether deceleration control is being performed. As a result of the determination, if the deceleration control is being performed, the process proceeds to step S11, and if not, the process proceeds to step S12.

[Step S11]
In step S11, the control circuit 130 gradually decreases the target deceleration to zero according to the sweep rate obtained in step S5. As a result, when the front vehicle is lost during deceleration control (step S1-N, step S10-Y), the time during which deceleration control estimated by the front corner R can be executed (relative to the previous vehicle lost). Depending on the time), the deceleration can be extracted with different slopes.

[Step S12]
In step S12, the control circuit 130 sets the target deceleration to zero. Following step S12, step S8 is performed.

  As described above, according to the present embodiment, the following effects can be obtained.

  According to the present embodiment, as shown in FIG. 9, when the front vehicle is lost at the timing indicated by the symbol Ta during deceleration control, when the corner R of the front corner is large, the time when the front vehicle is lost is relative. Since the time for performing the deceleration control is considered to be relatively long, the target deceleration is gradually decreased with a relatively steep slope. On the other hand, when the corner R is small, it seems that the time when the front vehicle is lost is relatively early and the time for performing the deceleration control is relatively short, so the target deceleration is gradually decreased with a relatively gentle gradient. As a result, the driver is prevented from feeling uncomfortable feelings such as excessive deceleration and feeling of excessive deceleration. That is, in the present embodiment, the time when the front vehicle is lost (relatively early or late), in other words, as a parameter that can estimate the time during which deceleration control can be performed in a state where the front vehicle is detected, The front corner R is used.

  When the front vehicle is lost during the deceleration control, as in the above prior art (Patent Document 1 to Patent Document 3), the deceleration applied to the vehicle is continued or increased as it is. The driver feels uncomfortable by passing. In addition, when the deceleration control is stopped with respect to the lost vehicle, the driver suddenly approaches the vehicle, and the driver feels dangerous.

  On the other hand, in the present embodiment, a deceleration sweep rate is calculated based on the estimated corner R (step S4) (step S5). When the front vehicle is lost during the deceleration control, the deceleration is gradually reduced by the calculated sweep plate. This suppresses the driver from feeling that the deceleration is excessive. Further, in this case, the deceleration does not suddenly become zero, but gradually decreases, so that it is possible to suppress feeling that the deceleration is insufficient. For these reasons, in the present embodiment, it is possible to realize a deceleration control with less uncomfortable feeling and less dangerous than ever before.

  In step S4, the corner R of the corner in front of the vehicle X is estimated. In step S5, the sweep plate is obtained based on the estimated corner R in front of the vehicle. The corner R of the corner where X is traveling is estimated, and the sweep plate can be obtained based on the estimated corner R.

(Second Embodiment)
Next, a second embodiment will be described.
The second embodiment relates to a vehicle deceleration control device that performs cooperative control of a brake (braking device) and an automatic transmission. In the second embodiment, description of parts common to the first embodiment will be omitted, and only characteristic parts will be described.

  In the second embodiment, the operations of steps S1 to S6 and steps S8 to S12 in FIG. 1 of the first embodiment are common, and the operations of step S7 are different. That is, in the first embodiment, deceleration control is performed using only the brake so that the deceleration acting on the vehicle becomes the target deceleration obtained in step S3 or step S11. In the embodiment, by the cooperative control of the brake and the automatic transmission, the deceleration control is performed so that the deceleration acting on the vehicle becomes the target deceleration obtained in step S3 or step S11.

[Step S7]
In step S7 of the second embodiment, the control circuit 130 performs both shift control and brake control. First, in the following, the shift control will be described as item A, and then the brake control will be described as item B.

A. Shift Control In the shift control in step S7, the control circuit 130 obtains a target deceleration (hereinafter referred to as shift speed target deceleration) by the automatic transmission 10, and based on the shift speed target deceleration, the automatic transmission 10 The gear position to be selected in the shift control (shift down) is determined. Hereinafter, the contents of the shift control in step S7 will be described in terms of (1) and (2).

(1) First, the gear position target deceleration is obtained.
The gear stage target deceleration corresponds to the engine braking force (deceleration acceleration) to be obtained by the shift control of the automatic transmission 10. The gear stage target deceleration is set as a value less than or equal to the maximum target deceleration. The following three methods are conceivable as a method for obtaining the speed target deceleration.

First, a first method for obtaining the speed target deceleration will be described.
The gear stage target deceleration is set as a value obtained by multiplying the target deceleration obtained in step S3 by a coefficient greater than 0 and equal to or less than 1. For example, when the target deceleration is −0.20 G, for example, −0.10 G, which is a value obtained by multiplying a coefficient of 0.5, can be set as the gear stage target deceleration.

Next, a second method for obtaining the shift speed target deceleration will be described.
First, the engine braking force (deceleration G) when the accelerator of the current gear stage of the automatic transmission 10 is OFF is obtained (hereinafter referred to as the current gear stage deceleration). A current gear speed deceleration map (FIG. 10) is registered in the ROM 133 in advance. The current gear speed deceleration (deceleration acceleration) is obtained by referring to the current gear speed deceleration map of FIG. As shown in FIG. 10, the current gear speed deceleration is obtained based on the gear speed and the rotational speed NO of the output shaft 120 c of the automatic transmission 10. For example, when the current gear stage is 5th and the output rotational speed is 1000 [rpm], the current gear stage deceleration is -0.04G.

  Note that the current gear speed deceleration may be corrected by a value obtained from the current gear speed deceleration map according to various conditions such as whether the vehicle is operating an air conditioner or whether a fuel cut is present. In addition, a plurality of current gear speed deceleration maps are prepared in the ROM 133 for each situation such as whether the vehicle is operating an air conditioner or whether a fuel cut is present, and the current gear speed deceleration used according to those situations. You may switch maps.

  Next, the shift speed target deceleration is set as a value between the current gear speed deceleration and the target deceleration. That is, the gear stage target deceleration is obtained as a value that is greater than the current gear stage deceleration and less than or equal to the target deceleration. FIG. 11 shows an example of the relationship between the speed target deceleration, the current gear speed deceleration, and the target deceleration.

The speed target deceleration is obtained by the following equation.
Shift speed target deceleration = (Target deceleration−Current gear speed deceleration) × Coefficient + Current gear speed deceleration In the above formula, the coefficient is a value greater than 0 and 1 or less.

  In the above example, target deceleration = −0.20G, current gear speed deceleration = −0.04G, and calculation is performed with the coefficient set to 0.5, the gear position target deceleration is −0.12G. .

  After the speed target deceleration is obtained once in step S7, it is not set again until the deceleration control is completed. As shown in FIG. 11, the speed target deceleration (value indicated by a broken line) is the same value even if time elapses.

(2) Next, based on the shift speed target deceleration obtained in the above (1), the shift speed to be selected in the shift control of the automatic transmission 10 is determined. Vehicle characteristic data indicating the deceleration G for each vehicle speed at each gear stage when the accelerator is OFF as shown in FIG. 12 is registered in advance in the ROM 133.

  As in the above example, assuming that the output rotational speed is 1000 [rpm] and the gear stage target deceleration is −0.12 G, the output rotational speed is 1000 [rpm] in FIG. It can be seen that the gear stage corresponding to the vehicle speed at the time and the closest speed reduction to the speed target deceleration of -0.12G is the fourth speed. Thus, in the case of the above example, in the shift control in step S7, the gear stage to be selected is determined to be the fourth speed. The shift control in step S7 is performed at a point where the accelerator is turned off.

  Here, the gear stage that is the closest to the gear stage target deceleration is selected as the gear stage to be selected. In this case, the gear stage that is the closest to the gear stage target deceleration may be selected.

B. About Brake Control In the brake control of step S7, the brake control circuit 230 executes brake feedback control so that the actual deceleration acting on the vehicle becomes the target deceleration. The brake feedback control is performed at the point where the accelerator is turned off.

  That is, a signal indicating the target gear position is output from the control circuit 130 to the brake control circuit 230 via the brake braking force signal line L1 as the brake braking force signal SG1 from the point where the accelerator is turned off. The brake control circuit 230 generates a brake control signal SG2 based on the brake braking force signal SG1 input from the control circuit 130, and outputs the brake control signal SG2 to the hydraulic control circuit 220.

  The hydraulic control circuit 220 controls the hydraulic pressure supplied to the braking devices 208, 209, 210, and 211 based on the brake control signal SG2, thereby generating a braking force as instructed in the brake control signal SG2.

  In the feedback control of the brake device 200 in step S8, the target value is the target deceleration, the control amount is the actual deceleration of the vehicle, and the control target is the brake (braking devices 208, 209, 210, 211). The operation amount is a brake control amount (not shown), and the disturbance is mainly a deceleration due to the shift of the automatic transmission 10 by the shift control in step S7. The actual deceleration of the vehicle is detected by the acceleration sensor 90.

  That is, in the brake device 200, the brake braking force (brake control amount) is controlled so that the actual deceleration of the vehicle becomes the target deceleration. That is, the brake control amount is set so as to cause a deceleration that is insufficient for the deceleration due to the shift of the automatic transmission 10 by the shift control in step S7 when the target deceleration is generated in the vehicle.

  In the second embodiment, the example in which cooperative control of automatic braking and downshift control is performed as the deceleration control in step S7 has been described, but the present invention is not limited to this. As the deceleration control in step S7, it is possible to use a braking device for generating a braking force on the vehicle, such as a regenerative brake or an exhaust brake, instead of the brake. Further, as the deceleration control in step S7, control for shifting the transmission (including CVT) to a relatively low speed gear stage or gear ratio can be used. That is, the shift control for determining the downshift amount according to the target deceleration may be performed independently.

(Third embodiment)
Next, a third embodiment will be described with reference to FIGS.
In addition, the description about the content common to the said embodiment is abbreviate | omitted.

  In the present embodiment, based on a parameter corresponding to the distance between the front vehicle and the host vehicle, the vehicle performs deceleration control using the driver's intention to decelerate as a control start trigger. When the front vehicle is lost, it is determined based on the inter-vehicle time. Decrease the deceleration with the swept plate. As a result, when the front vehicle is lost, the deceleration does not drop suddenly or the deceleration does not work excessively, so that it is possible to realize deceleration control that does not give the driver a sense of incongruity.

  The operation of the third embodiment will be described with reference to FIG.

Since [Step S1] to [Step S3] are the same as Step S1 to Step S3 of the first embodiment (FIG. 1), description thereof is omitted.

[Step S4]
In step S4, the control circuit 130 determines whether there is a corner ahead. For the determination, as in step S4 of the first embodiment (FIG. 1), a method for obtaining from the trajectory of the preceding vehicle, a method described in Japanese Patent Laid-Open No. 2002-12053, and the navigation system device 113 are used. A method is mentioned. As a result of the determination in step S4, if it is determined that there is a corner ahead, the process proceeds to step S6, and if not, the process proceeds to step S5.

[Step S5]
In step S5, the control circuit 130 selects a preset sweep plate for straight running. For example, the sweep rate during straight running can be set to -1 m / s ² / s. Following step S5, step S7 is performed.

[Step S6]
In step S6, the sweep rate is calculated by the control circuit 130 based on the inter-vehicle time. In the calculation, a sweep plate setting map shown in FIG. 14 is used. Here, the inter-vehicle time is obtained from (inter-vehicle distance / own vehicle speed).

  FIG. 15 shows points where the preceding vehicle is lost with respect to the inter-vehicle time. In the figure, (1) shows the case where the inter-vehicle time is small, and (2) shows the case where the inter-vehicle time is large. In (1) and (2), the front corner C3 has the same corner R, and the recommended vehicle speed at the corner entrance Cin required to turn the corner at a predetermined lateral G is the same. Reference symbol X indicates the position of the host vehicle when the front vehicle P is lost at each inter-vehicle time. It is assumed that the vehicle speed of the own vehicle X is the same when the front vehicle P is lost in each inter-vehicle time.

  In FIG. 15, symbol A indicates the distance between the host vehicle X and the entrance Cin of the corner C3 when the host vehicle X has lost the front vehicle P when the inter-vehicle time is small, and symbol B indicates a case where the inter-vehicle time is large. The distance from the own vehicle X to the entrance Cin of the corner C3 when the own vehicle X has lost the front vehicle P is shown. In FIG. 16, reference numeral 501 indicates a target deceleration when the inter-vehicle time is large and the front vehicle is not lost, and reference numeral 503 indicates a case where the inter-vehicle time is small and the front vehicle is not lost. The target deceleration is shown. As shown in the above formula 1, when the inter-vehicle time is large, the target deceleration is calculated as a smaller value than when the inter-vehicle time is small.

  When the inter-vehicle time is large, the front vehicle P is lost in a state where the distance to the corner C3 is large as compared with the case where the inter-vehicle time is small. That is, when the inter-vehicle time is large, the front vehicle P is lost at a point farther from the entrance Cin of the corner C3 (reference numeral B in FIG. 15). Therefore, the front car P is lost at an early stage. Therefore, when the host vehicle X is under deceleration control, the vehicle X is lost earlier than the time originally required for executing the deceleration control, so that it is not possible to secure a sufficient time for executing the deceleration control. As described above, when the inter-vehicle time is large, the front vehicle P is lost in a state in which the time for executing the deceleration control cannot be sufficiently secured as compared with the case where the inter-vehicle time is small. In addition, the deceleration is slowly removed. By gradually reducing the deceleration with such a gentle gradient to compensate for the lack of deceleration, it is possible to suppress the host vehicle X from approaching the front vehicle P suddenly and feeling dangerous to the driver.

  On the other hand, when the inter-vehicle time is small, the front vehicle P is lost in the vicinity of the entrance Cin of the corner C3, so that sufficient time for executing the deceleration control can be secured as compared with the case where the inter-vehicle time is large. Therefore, in this case, as indicated by reference numeral 504, the driver is prevented from feeling uncomfortable due to the excessive effect of the deceleration control by quickly removing the deceleration.

  From the above, as shown in FIG. 14, by gradually decreasing the deceleration with different slopes (sweep plates) according to the inter-vehicle time, a sudden deceleration of the front vehicle lost, which was the above-mentioned conventional technique, is achieved. It is possible to suppress the feeling of slipping out and the effect of excessive deceleration. That is, in the present embodiment, the time when the front vehicle is lost (relatively early or late), in other words, as a parameter that can estimate the time during which deceleration control can be performed in a state where the front vehicle is detected, The inter-vehicle time is used.

  In step S6, the sweep rate is calculated based on the inter-vehicle time. This inter-vehicle time has a meaning of an index indicating how much time is available to the vicinity of the entrance of the corner. Therefore, in step S6, the inter-vehicle distance can be used instead of the inter-vehicle time.

  If there is a function capable of detecting the distance to the corner entrance in step S6, the sweep rate can also be calculated using (distance to corner entrance / vehicle speed). When the (distance to the corner entrance / own vehicle speed) is large, the sweep plate can be made small. When the (distance to the corner entrance / vehicle speed) is small, the sweep plate can be made large. Step S7 is performed after step S6.

  [Step S7] to [Step S13] are the same as [Step S6] to [Step S12] of the first embodiment (FIG. 1), respectively, and thus description thereof is omitted.

(Fourth embodiment)
Next, a fourth embodiment will be described with reference to FIGS. 17 and 18.
Note that in the fourth embodiment, descriptions of parts that are common to the above embodiments are omitted.

  In the fourth embodiment, a sweep plate corresponding to the corner R and the inter-vehicle time is used in combination with the first and third embodiments. Thereby, control with less discomfort for the driver is realized.

  As shown in [Step S5] in FIG. 17, the sweep rate is calculated based on the inter-vehicle time and the corner R. As shown in FIG. 18, the sweep plate is set to be larger as the corner R is larger, and the sweep plate is set to be larger as the inter-vehicle time is smaller.

(Fifth embodiment)
The fifth embodiment will be described with reference to FIGS. 19 to 23.
In addition, the description about the content common to the said embodiment is abbreviate | omitted.

  In the present embodiment, when performing the deceleration control using the driver's intention to decelerate as a control start trigger based on the parameter corresponding to the distance between the front vehicle and the host vehicle, when the front vehicle is lost, the current road gradient and the front The deceleration is gradually reduced by a sweep plate determined based on the difference in road surface gradient. As a result, when the front vehicle is lost, the deceleration does not drop suddenly or the deceleration does not work excessively, so that it is possible to realize deceleration control that does not give the driver a sense of incongruity.

  The operation of the fifth embodiment will be described with reference to FIG.

  Since [Step S1] to [Step S3] are the same as Step S1 to Step S3 of the first embodiment (FIG. 1), description thereof is omitted.

[Step S4]
In step S <b> 4, the road gradient at the front position is calculated by the control circuit 130. Here, the front position where the road gradient is calculated is preferably a position where the front vehicle is traveling or a position ahead of the position. For the calculation, as in step S4 of the first embodiment (FIG. 1), a method for obtaining from the trajectory of the preceding vehicle, a method described in Japanese Patent Application Laid-Open No. 2002-12053, and the navigation system device 113 are used. A method is mentioned. At this time, the distance to the front to be used can be obtained from the inter-vehicle distance from the preceding vehicle, own vehicle speed × predetermined value, own vehicle speed × collision time, and the like. After step S4, the process proceeds to step S5.

[Step S5]
In step S5, the control circuit 130 calculates the sweep rate based on the difference between the road surface gradient at the current position and the road surface gradient at the front position. For the calculation, a sweep plate setting map shown in FIG. 20 is used. In FIG. 20, the gradient difference is (road surface gradient at the front position−road surface gradient at the current position).

  FIG. 21 is a diagram for explaining the acceleration state of the front vehicle with respect to the gradient difference. In the figure, (1) shows the case where the forward road slope is a positive value (uphill) and the current road slope is a negative value (downhill), and (2) is the forward road slope. The case where the road surface gradient is a negative value (downhill) and the current road surface gradient is a positive value (uphill) is shown. That is, in the case of (1) in FIG. 21, the gradient difference is a positive value, and in the case of (2), the gradient difference is a negative value.

  As shown in (1) of FIG. 21, when the forward road surface gradient changes with respect to the current road surface gradient, the front vehicle P does not immediately accelerate. This is because the driving force is required for the road surface gradient. Thus, when the front vehicle P is lost in a state where the road gradient on the front is larger than the current road gradient, it is highly likely that the front vehicle P will not accelerate immediately. Therefore, when the own vehicle X immediately ends the deceleration control, the inter-vehicle distance from the front vehicle P is reduced, and the driver feels that the deceleration is insufficient.

  Therefore, as shown in FIGS. 20 and 22, when the gradient difference is large (including the case where the road surface gradient at the current position <the road surface gradient at the front position), the sweep rate is set to be relatively small. In FIG. 22, reference numeral 601 indicates a target deceleration when the front vehicle is not lost, and reference numeral 602 indicates a target deceleration when the front vehicle is lost.

  As shown in (2) of FIG. 21, when the front road surface gradient is changed with respect to the current road surface gradient, particularly when the front vehicle P is lost with the front road surface gradient being negative. The front car P accelerates immediately. This is because acceleration force can be obtained by the road surface gradient. Therefore, if the own vehicle X does not immediately end the deceleration control, the driver feels that the deceleration control is too effective.

  Therefore, as shown in FIGS. 20 and 23, when the gradient difference is small (including the case where the road surface gradient at the current position> the road surface gradient at the front position), the sweep rate is set relatively large. In FIG. 23, reference numeral 603 indicates a target deceleration when the front vehicle is not lost, and reference numeral 604 indicates a target deceleration when the front vehicle is lost.

  From the above, as shown in FIG. 20, by gradually decreasing the deceleration at different gradients (sweep plates) according to the gradient difference, a sudden deceleration at the time of the front vehicle lost, which was the above-mentioned prior art, was achieved. It is possible to suppress the feeling of slipping out and the effect of excessive deceleration. In the present embodiment, the difference in gradient is likely to accelerate immediately after the previous vehicle is lost (whether it accelerates immediately or does not accelerate immediately). More precisely, it is expected after the previous vehicle is lost. It is used as a parameter for estimating a change in the relative positional relationship between the front vehicle and the host vehicle (whether the inter-vehicle distance is wider or narrower than when the front vehicle is lost).

[Step S6] to [Step S12] are the same as [Step S6] to [Step S12] in the first embodiment (FIG. 1), respectively, and thus description thereof is omitted.

(Sixth embodiment)
By combining the contents of the first embodiment and the fifth embodiment, the sweep plate can be set based on the difference between the front corner R and the road surface gradient. Alternatively, by combining the contents of the third embodiment and the fifth embodiment, the sweep rate can be set based on the difference between the inter-vehicle time and the road surface gradient. Alternatively, by combining the contents of the first, third, and fifth embodiments, the sweep rate can be set based on the difference between the front corner R, the inter-vehicle time, and the road surface gradient. As described above, by setting the sweep plate by combining the parameters, it is possible to realize control with less discomfort for the driver.

  In the above description, the deceleration indicating the amount that the vehicle should decelerate has been described using the deceleration acceleration (G), but it is also possible to control based on the deceleration torque.

It is a flowchart which shows operation | movement of 1st Embodiment of the deceleration control apparatus of the vehicle of this invention. It is a schematic block diagram of 1st Embodiment of the deceleration control apparatus of the vehicle of this invention. It is a figure for demonstrating calculation of the locus | trajectory of a front vehicle in 1st Embodiment of the deceleration control apparatus of the vehicle of this invention. It is a figure for demonstrating calculation of corner R in 1st Embodiment of the deceleration control apparatus of the vehicle of this invention. It is a figure which shows the corner R estimation map in 1st Embodiment of the deceleration control apparatus of the vehicle of this invention. It is a figure which shows the sweep plate setting map based on the corner R in 1st Embodiment of the deceleration control apparatus of the vehicle of this invention. It is a figure which shows the inter-vehicle distance sensor measurable range with respect to the corner R in 1st Embodiment of the deceleration control apparatus of the vehicle of this invention. It is a figure which shows the front vehicle lost timing with respect to the corner R in 1st Embodiment of the deceleration control apparatus of the vehicle of this invention. It is a time chart which shows operation | movement of 1st Embodiment of the deceleration control apparatus of the vehicle of this invention. It is a map which calculates | requires the vehicle speed and deceleration for every gear stage in 2nd Embodiment of the deceleration control apparatus of the vehicle of this invention. It is a figure for demonstrating the gear stage target deceleration in 2nd Embodiment of the deceleration control apparatus of the vehicle of this invention. It is a figure which shows the gear stage corresponding to a vehicle speed and deceleration in 2nd Embodiment of the deceleration control apparatus of the vehicle of this invention. It is a flowchart which shows operation | movement of 3rd Embodiment of the deceleration control apparatus of the vehicle of this invention. It is a figure which shows the sweep plate setting map based on the inter-vehicle time in 3rd Embodiment of the deceleration control apparatus of the vehicle of this invention. It is a figure which shows the front vehicle lost point with respect to the inter-vehicle time in 3rd Embodiment of the deceleration control apparatus of the vehicle of this invention. It is a figure which shows the front vehicle lost timing with respect to the inter-vehicle time in 3rd Embodiment of the deceleration control apparatus of the vehicle of this invention. It is a flowchart which shows operation | movement of 4th Embodiment of the deceleration control apparatus of the vehicle of this invention. It is a figure which shows the sweep rate setting map based on the corner R and the inter-vehicle time in 4th Embodiment of the deceleration control apparatus of the vehicle of this invention. It is a flowchart which shows operation | movement of 5th Embodiment of the deceleration control apparatus of the vehicle of this invention. It is a figure which shows the sweep plate setting map based on the gradient difference in 5th Embodiment of the deceleration control apparatus of the vehicle of this invention. It is a figure for demonstrating the gradient difference and acceleration condition of a front vehicle in 5th Embodiment of the deceleration control apparatus of the vehicle of this invention. It is a figure for demonstrating the gradient of the target deceleration when the gradient difference in 5th Embodiment of the deceleration control apparatus of the vehicle of this invention is a negative value. It is a figure for demonstrating the gradient of the target deceleration in case the gradient difference in 5th Embodiment of the deceleration control apparatus of the vehicle of this invention is a positive value.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Automatic transmission 40 Engine 90 Acceleration sensor 100 Inter-vehicle distance measurement part 112 Relative vehicle speed measurement part 113 Navigation system apparatus 114 Throttle opening sensor 115 Relative vehicle speed measurement part 116 Engine speed sensor 117 Pattern selection switch 118 Road gradient measurement and estimation part 122 Vehicle speed sensor 123 Shift position sensor 130 Control circuit 131 CPU
133 ROM
DESCRIPTION OF SYMBOLS 200 Brake apparatus 230 Brake control circuit 301 Absolute moving amount of front vehicle 401 Target deceleration when front vehicle is not lost 402 Target deceleration when front corner is corner with small corner R 402 Front corner is corner Target deceleration when R is a large corner 501 When the inter-vehicle time is large and the target deceleration when the previous vehicle is not lost 502 When the inter-vehicle time is large and the previous vehicle is lost Target deceleration 503 Target deceleration when the inter-vehicle time is small and the previous vehicle is not lost 504 Target deceleration when the inter-vehicle time is small and the front vehicle is lost 601 Road surface at the current position The target deceleration when the road gradient ahead is greater than the gradient and the front car is not lost 602 From the road gradient at the current position Target deceleration when the front road surface slope is large and the front car is lost 603 Target when the front road surface slope is smaller than the road surface slope at the current position and the front car is not lost Deceleration 604 When the road gradient ahead is smaller than the road gradient at the current position, the target deceleration when the front vehicle is lost C1 Corner R is small Corner C2 Corner R is large Corner C3 Corner Cin Corner entrance Dc Center change angle of inter-vehicle distance sensor L1 Brake braking force signal line Lc Center deviation amount of inter-vehicle distance sensor P Front vehicle Rs Measurable range of inter-vehicle distance sensor Sd Road turning angle SG1 Brake braking force signal SG2 Brake control signal X Own vehicle

Claims (9)

A vehicle deceleration control device that performs deceleration control of the vehicle in order to make the positional relationship between the vehicle and the front vehicle ahead of the vehicle appropriate,
Means for detecting the front vehicle,
When losing sight of the front vehicle, the deceleration applied to the vehicle is reduced according to a value set based on a parameter capable of estimating the relative timing of losing sight of the front vehicle. Vehicle deceleration control device. The vehicle deceleration control device according to claim 1,
The vehicle deceleration control device, wherein the parameter is a curvature or a radius of a corner in front of the vehicle or a corner in which the vehicle is traveling. The vehicle deceleration control device according to claim 2,
When the curvature is large or the radius is small, the deceleration is gradually decreased at a smaller rate than when the curvature is small or the radius is large. The vehicle deceleration control device according to claim 1,
The vehicle deceleration control device, wherein the parameter is a parameter corresponding to a distance between the front vehicle and the vehicle when a corner is detected in front of the vehicle. The vehicle deceleration control device according to claim 4,
When the parameter corresponding to the distance is large, the deceleration is gradually decreased at a smaller rate than when the parameter corresponding to the distance is small. In the vehicle deceleration control device according to claim 4 or 5,
The vehicle deceleration control device, wherein the parameter corresponding to the distance is an inter-vehicle time or an inter-vehicle distance. A vehicle deceleration control device that performs deceleration control of the vehicle in order to make the positional relationship between the vehicle and the front vehicle ahead of the vehicle appropriate,
Means for detecting the front vehicle,
When the vehicle loses sight of the front vehicle, the vehicle is in accordance with a value set based on a parameter that estimates a change in the distance between the vehicle and the vehicle that is expected after losing sight of the vehicle. A deceleration control device for a vehicle, characterized by reducing a deceleration to be applied. The vehicle deceleration control device according to claim 7, wherein
The vehicle deceleration control device, wherein the parameter is a difference between a slope of a road surface ahead of the vehicle and a slope of a road surface on which the vehicle is traveling. The vehicle deceleration control device according to claim 8,
The slope is represented when the uphill slope is represented by a positive value and the downhill slope is represented by a negative value.
When the difference obtained by subtracting the slope of the road surface on which the vehicle is traveling is subtracted from the slope of the road surface ahead, the deceleration is gradually reduced at a smaller rate than when the difference is small. A vehicle deceleration control device.

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