Vehicle control system

Abstract

To prevent hesitation in the stop control with respect to the stopped preceding vehicle.SOLUTION: A vehicle control device according to the present disclosure, which is a vehicle control device that executes follow-up traveling control for causing a host vehicle to travel while maintaining a constant inter-vehicle distance between the host vehicle and a preceding vehicle, includes: a target acceleration plan calculation unit that, when a stopped preceding vehicle is detected ahead of the host vehicle, calculates a target acceleration having a negative acceleration that converges to zero toward a target stop position; a brake request generation unit that, when the target acceleration becomes equal to or less than a predetermined brake request cancellation threshold value, generates a brake request for braking and stopping the host vehicle; and an acceleration restricting unit that, after the target acceleration becomes equal to or less than the brake request cancellation threshold value, maintains the target acceleration to be equal to or less than the brake request cancellation threshold value.SELECTED DRAWING: Figure 3

Description

Technical Field

[0006] ,

[0001] This disclosure relates to a vehicle control device.

Background Art

[0002] One of the controls in a vehicle is a follow - up driving control (ACC: Adaptive Cruise Control) that drives the host vehicle while maintaining a constant inter - vehicle distance between the host vehicle and the preceding vehicle. In ACC, it is possible to perform a stop control in which the host vehicle decelerates with respect to a stopped preceding vehicle and stops at a target position.

Prior Art Document

Patent Document

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in ACC, it is conceivable to calculate a target inter - vehicle distance based on the current inter - vehicle distance and the actual vehicle speed, calculate a target acceleration corresponding to the target inter - vehicle distance, and perform acceleration / deceleration control based on the target acceleration. In this case, when the host vehicle approaches the target stop position, the calculated acceleration may exceed a predetermined threshold value that determines the on / off of the brake, and the brake may be released. As a result, once the stopped host vehicle may restart and a phenomenon called "creeping up" in which the vehicle approaches the stopped preceding vehicle may occur.

[0005] An object of this disclosure is to provide a vehicle control device that can suppress creeping up in stop control for a stopped preceding vehicle.

Means for Solving the Problems

[0007] According to the vehicle control device described herein, it is possible to suppress siding during stopping control with respect to a preceding vehicle that is stopped. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1 is a block diagram showing an example of the configuration of a vehicle control system according to an embodiment. [Figure 2] Figure 2 is a schematic diagram showing an example of control by a vehicle control system according to an embodiment. [Figure 3] Figure 3 is a graph showing the behavior of the vehicle during stopping control in the vehicle control system according to the embodiment and comparative example. [Figure 4] Figure 4 is a flowchart showing an example of the procedure for controlling the vehicle's stop under ACC application by the SCM-ECU according to the embodiment. [Modes for carrying out the invention]

[0009] Hereinafter, embodiments of the vehicle control device according to this disclosure will be described with reference to the drawings.

[0010] (Example of a vehicle control system configuration) Figure 1 is a block diagram showing an example of the configuration of a vehicle control system 1 according to an embodiment. The vehicle control system 1 of the embodiment is mounted on the vehicle and performs adaptive cruise control (ACC) to drive the vehicle while maintaining a constant distance between the vehicle and the preceding vehicle. The vehicle is, for example, an automobile driven by an engine or drive motor (not shown), which is accelerated by the output of the drive source and decelerated by the braking force of brakes such as friction brakes, and acceleration and deceleration (acceleration and deceleration) are performed by ACC.

[0011] As shown in Figure 1, the vehicle control system 1 of this embodiment includes an SCM-ECU (Electronic Control Unit) 10, a front camera 20, and a VSC (Vehicle Stability Control) 30.

[0012] The front camera 20 is, for example, a stereo camera and is configured to capture images of the area in front of the vehicle. The stereo camera continuously captures still images at a predetermined frame rate and detects the distance to the position of an object in the captured images based on parallax information. The front camera 20 is installed, for example, in the center of the front of the vehicle interior, on the windshield surface behind the rearview mirror, so that it can capture images of the area in front of the vehicle at a wide angle.

[0013] However, the mechanism for monitoring the area in front of the vehicle is not limited to a stereo camera; other sensors such as millimeter-wave sensors, laser radar, and sonar may also be used.

[0014] The SCM-ECU10 is configured as a computer that includes, for example, a CPU (Central Processing Unit), ROM (Read Only Memory), and RAM (Random Access Memory), which are not shown in the diagram.

[0015] The CPU included in the SCM-ECU 10 expands and executes a control program stored in, for example, a ROM or the like in the RAM, thereby realizing, as functional units of the SCM-ECU 10, a target inter-vehicle distance plan calculation unit 11, a target acceleration plan calculation unit 12, an operation determination inter-vehicle distance calculation unit 13, a fixed acceleration request generation unit 14, a predicted stop position calculation unit 15, a brake request generation unit 16, and a storage unit 17.

[0016] The target inter-vehicle distance plan calculation unit 11 calculates a target inter-vehicle distance plan that determines a target value of the inter-vehicle distance between the host vehicle and the preceding vehicle. The target inter-vehicle distance plan is determined based on the actual inter-vehicle distance between the host vehicle and the preceding vehicle and the vehicle speed of the host vehicle so as to be an appropriate inter-vehicle distance.

[0017] Information on the vehicle speed and acceleration of the host vehicle can be obtained from various sensors (not shown) provided in the host vehicle. The actual inter-vehicle distance between the host vehicle and the preceding vehicle can be calculated by analyzing the image of the front camera 20. The vehicle speed and acceleration of the preceding vehicle can be estimated from the image of the front camera and the information on the vehicle speed and acceleration of the host vehicle.

[0018] When there is a stopped preceding vehicle, the target inter-vehicle distance plan calculation unit 11 calculates a target inter-vehicle distance plan such that the host vehicle can stop at the target stop position in front of the stopped preceding vehicle. In this case, the target inter-vehicle distance plan is determined such that the target inter-vehicle distance gradually decreases and finally becomes equal to the distance of the target stop position.

[0019] The presence or absence of a stopped preceding vehicle can be detected, for example, by analyzing the image of the front camera 20. The target stop position is determined in advance such that the host vehicle can stop while maintaining a predetermined inter-vehicle distance from the stopped preceding vehicle.

[0020] The target acceleration plan calculation unit 12 calculates a target acceleration plan that determines a target value of the acceleration of the host vehicle such that the inter-vehicle distance between the host vehicle and the preceding vehicle becomes the target inter-vehicle distance. The target acceleration plan is determined based on the target inter-vehicle distance plan from the actual vehicle speed and acceleration of the host vehicle and the estimated vehicle speed and acceleration of the preceding vehicle.

[0021] Further, when there is a stopped leading vehicle, the target acceleration plan calculation unit 12 calculates a target acceleration plan so as to converge to the distance of the target stop position along the above-described target inter-vehicle distance plan. The target acceleration plan in this case is calculated from the current inter-vehicle distance between the host vehicle and the leading vehicle, the current vehicle speed and acceleration of the host vehicle, and the like.

[0022] The target acceleration plan calculation unit 12 outputs the target acceleration plan calculated to make the host vehicle travel while maintaining a constant inter-vehicle distance between the host vehicle and the leading vehicle, or the target speed plan calculated to stop the host vehicle under ACC application when there is a stopped leading vehicle, etc., to the VSC-ECU 30.

[0023] In the SCM-ECU 10 of the embodiment, in the control to stop the host vehicle under ACC application when there is a stopped leading vehicle, etc., as will be described in detail later, the control is switched from the control according to the target acceleration plan to the control to make the acceleration of the vehicle constant at a predetermined timing. For this reason, a fixed acceleration is set in the SCM-ECU 10 as the acceleration value when the acceleration is made constant.

[0024] The operation determination inter-vehicle distance calculation unit 13 calculates the inter-vehicle distance assumed when the switching to the fixed acceleration is performed at a predetermined timing in the control to stop the host vehicle under ACC application. The assumed inter-vehicle distance is calculated from the distance traveled by the host vehicle at the fixed acceleration predicted from the actual vehicle speed and acceleration of the host vehicle at a predetermined timing, and the actual inter-vehicle distance between the host vehicle and the stopped leading vehicle at a predetermined timing.

[0025] The assumed value of the inter-vehicle distance calculated as described above is called the operation determination inter-vehicle distance.

[0026] The fixed acceleration request generation unit 14, acting as an acceleration suppression unit, generates a fixed acceleration request at a predetermined timing based on the operating determination distance and the actual distance between the vehicle and the vehicle ahead of the vehicle that is stopping. The fixed acceleration request includes an instruction to switch from control according to the target acceleration plan to control using fixed acceleration in the control that stops the vehicle under ACC application.

[0027] Furthermore, after switching to control using fixed acceleration, the fixed acceleration request generation unit 14 monitors the amount of deviation between the predicted stopping position calculated by the predicted stopping position calculation unit 15 (described below) and the predetermined target stopping position. If the amount of deviation between the predicted stopping position and the target stopping position exceeds a predetermined distance, the fixed acceleration request generation unit 14 generates a fixed acceleration adjustment request to adjust the preset fixed acceleration. The adjustment value of the fixed acceleration is determined so that the amount of deviation between the predicted stopping position and the target stopping position is less than or equal to a predetermined distance.

[0028] The fixed acceleration request generation unit 14 outputs to the VSC-ECU 30 a fixed acceleration request calculated based on the operating determination distance and the actual distance between the vehicle and the vehicle ahead of it that has stopped, or a fixed acceleration adjustment request calculated so that the difference between the predicted stopping position and the target stopping position is a predetermined distance.

[0029] The predicted stopping position calculation unit 15 predicts the stopping position of the vehicle after switching to control using fixed acceleration. The predicted stopping position is calculated from the distance the vehicle actually traveled under control using fixed acceleration, and the actual distance between the vehicle and the vehicle ahead that is stopping. The distance the vehicle actually traveled can be calculated based on information from various sensors installed on the vehicle.

[0030] The brake request generation unit 16 generates a brake request when the target acceleration falls below a predetermined brake request release threshold during control to stop the vehicle under ACC application.

[0031] A brake request includes a command to apply the brakes to the vehicle and bring it to a stop. The brake request release threshold is the threshold that determines whether a brake request is generated or released. No brake request is generated while the target acceleration exceeds the brake request release threshold. When the target acceleration falls below the brake request release threshold, a brake request is generated and the vehicle is braked.

[0032] The memory unit 17 stores control programs and control parameters for realizing the functions of the SCM-ECU 10. The memory unit 17 also stores information such as the target stopping position, fixed acceleration, and upper limit value of the deviation between the predicted stopping position and the target stopping position, which are used for controlling the vehicle to stop under ACC.

[0033] The VSC-ECU30 is configured as a computer, for example, equipped with a CPU, ROM, RAM, etc. (not shown), and controls the vehicle's brakes via a hydraulic system to decelerate the vehicle. The hydraulic system consists of an oil tank, pump, piston, cylinder, valve, etc., and generates power through hydraulic pressure.

[0034] When the VSC-ECU30 receives a target acceleration plan from the target acceleration plan calculation unit 12, it adjusts the deceleration rate of the vehicle according to the target acceleration plan. Furthermore, when the VSC-ECU30 receives a fixed acceleration request from the fixed acceleration request generation unit 16, it adjusts the deceleration rate of the vehicle according to the fixed acceleration request instead of the target acceleration plan. Additionally, when the VSC-ECU30 receives a new fixed acceleration adjustment request from the fixed acceleration request generation unit 16, it adjusts the deceleration rate of the vehicle according to the fixed acceleration adjustment request.

[0035] Furthermore, when the VSC-ECU30 receives a brake request from the brake request generation unit 16, it controls the brakes to apply braking force to the vehicle and bring it to a stop.

[0036] (Example of vehicle control system control) Next, using Figures 2 and 3, we will explain the control by the vehicle control system 1 of the embodiment that stops its own vehicle 100 at a target stopping position relative to a preceding vehicle 200 that is stopped. Figure 2 is a schematic diagram showing an example of control by the vehicle control system 1 according to the embodiment.

[0037] As shown in Figure 2(a), when a stationary preceding vehicle 200 is detected in front of the vehicle 100 from the image of the front camera 20, the target inter-vehicle distance planning unit 11 of the SCM-ECU 10 calculates a target inter-vehicle distance plan so that the vehicle 100 can stop at a target stopping position just before the stationary preceding vehicle 200.

[0038] Furthermore, the target acceleration plan calculation unit 12 calculates a target acceleration plan in accordance with the target inter-vehicle distance plan calculated by the target inter-vehicle distance plan calculation unit 11, and outputs it to the VSC-ECU 30. The VSC-ECU 30 starts decelerating its own vehicle 100 according to the target acceleration plan output from the target inter-vehicle distance plan calculation unit 11.

[0039] The brake request generation unit 16 generates a brake request when the target acceleration falls below a predetermined brake request release threshold and outputs it to the VSC-ECU 30. The VSC-ECU 30 controls the brakes according to the brake request output from the brake request generation unit 16 and applies braking to the vehicle 100.

[0040] Meanwhile, when the control to stop the vehicle 100 at the target stopping position relative to the preceding stopped vehicle 200 is initiated, the operation determination distance calculation unit 13 calculates the operation determination distance based on the actual distance between the vehicle 100 and the stopped vehicle 200 at each given moment.

[0041] The fixed acceleration request generation unit 14 generates a fixed acceleration request when the operation determination distance matches the actual distance between the vehicle and the stationary preceding vehicle at a predetermined timing, and outputs it to the VSC-ECU 30. The VSC-ECU 30 continues to decelerate the vehicle 100 according to the fixed acceleration request output from the fixed acceleration request generation unit 14, instead of the target acceleration plan output from the target inter-vehicle distance plan calculation unit 11.

[0042] When a fixed acceleration request is output to the VSC-ECU30 and the VSC-ECU30 begins decelerating the vehicle 100 in accordance with the fixed acceleration request, the predicted stopping position calculation unit 15 calculates the predicted stopping position at appropriate intervals. If the difference between the predicted stopping position calculated by the predicted stopping position calculation unit 15 and the target stopping position exceeds a predetermined value, the fixed acceleration request generation unit 14 generates a fixed acceleration adjustment request adjusted so that the difference between the predicted stopping position and the target stopping position is less than or equal to a predetermined distance, and outputs it to the VSC-ECU30. If the VSC-ECU30 receives a fixed acceleration adjustment request from the target inter-vehicle distance planning calculation unit 11, it continues decelerating the vehicle 100 in accordance with the newly outputted fixed acceleration adjustment request from the fixed acceleration request generation unit 14, instead of the original fixed acceleration request.

[0043] As shown in Figure 2(b), as a result of the control by the vehicle control system 1, the vehicle 100 can be stopped within a predetermined error range from the target stopping position.

[0044] Figure 3 shows the detailed behavior of the vehicle 100 during the stopping control shown in Figure 2, along with the behavior of the vehicle control system of the comparative example.

[0045] Figure 3 is a graph showing the behavior of the vehicle during stopping control in the vehicle control systems according to the embodiment and comparative example. Graphs 3(a) and 3(b) show the distance between the vehicle and the preceding vehicle during stopping control by the vehicle control system 1 of the embodiment, and the acceleration of the vehicle, respectively. Graphs 3(c) and 3(d) show the acceleration of the vehicle during stopping control by the vehicle control system of the comparative example, and the generation and release of brake requests, respectively.

[0046] The horizontal axis in Figures 3(a) to 3(d) all represents time. The vertical axis in Figure 3(a) represents the distance between vehicles, the vertical axis in Figures 3(b) and 3(c) represents acceleration, and Figure 3(d) represents the on / off state of the brake request.

[0047] As shown in Figure 3(c), in the comparative example vehicle control system, control is carried out according to the target acceleration plan until the vehicle comes to a stop at the target stopping position.

[0048] In the target acceleration planning for stop control, a negative acceleration is set to decelerate the vehicle. Furthermore, to improve the vehicle's drivability, the negative acceleration applied to the vehicle is initially determined to decrease gradually, reach a peak value at a predetermined timing, and then gradually increase. In other words, at the start of stop control, the vehicle gradually increases its deceleration, and after reaching the peak value, the deceleration gradually weakens as it approaches the target stopping position.

[0049] This type of control is also consistent with a target inter-vehicle distance plan that smoothly converges toward the target stopping position. That is, near the target stopping position, the difference between the target inter-vehicle distance determined by the target inter-vehicle distance plan and the distance between the vehicle and the stopped vehicle at the target stopping position converges to zero, and consequently, the target acceleration determined by the target acceleration plan also converges to zero.

[0050] A brake release threshold is set in advance for the target acceleration determined in this way. The target acceleration, which is a negative value in order to decelerate the vehicle, follows the target acceleration plan and gradually decreases until, at a predetermined timing, the negative target acceleration falls below the brake release threshold. On the other hand, after reaching the peak value, the negative target acceleration begins to increase and exceeds the brake release threshold at a predetermined timing.

[0051] As shown in Figure 3(d), the brake request generation unit of the comparative example generates a brake request and outputs it to the VSC-ECU when the negative target acceleration, which was initially decreasing gradually, falls below the brake request release threshold. Furthermore, the brake request generation unit of the comparative example releases the brake request when the negative target acceleration, which has increased after reaching a peak value, exceeds the brake request release threshold.

[0052] This can cause a phenomenon called "inching forward," where the brakes are released when the vehicle reaches the target stopping position and its speed drops to 0 km / h, causing the vehicle to restart. This inching forward can cause the vehicle to get too close to the preceding vehicle, potentially preventing it from stopping at the target position.

[0053] As shown in Figure 3(a), in the vehicle control system 1 of this embodiment, the target inter-vehicle distance planning unit 11 calculates a target inter-vehicle distance plan so that the target inter-vehicle distance smoothly converges toward the target stopping position. In addition, the operation determination inter-vehicle distance calculation unit 13 provided in the SCM-ECU 10 of this embodiment calculates the operation determination inter-vehicle distance that is expected when a fixed acceleration is applied at each given timing.

[0054] Initially, when the negative acceleration is close to zero according to the target acceleration plan, the set value of the acceleration is higher than the fixed acceleration, and the inter-vehicle distance for operation determination that would be expected if the fixed acceleration were applied is calculated to be shorter than the target inter-vehicle distance determined in the target inter-vehicle distance plan. As the negative acceleration decreases according to the target acceleration plan, the set value of the acceleration becomes lower than the fixed acceleration, and the inter-vehicle distance for operation determination and the target inter-vehicle distance coincide around the time when the negative acceleration has passed its peak value.

[0055] The timing at which this activation detection distance matches the target distance is the timing at which it is possible to stop the vehicle at the target stopping position by controlling it with a fixed acceleration from that point onward.

[0056] As shown in Figure 3(b), the fixed acceleration request generation unit 14 generates a fixed acceleration request and outputs it to the VSC-ECU 30 at the timing when the activation determination distance and the target distance coincide. In this way, the activation determination distance is used to determine the timing for activating the vehicle's control using fixed acceleration. The timing when the activation determination distance and the target distance coincide is also referred to as the activation timing for activating the vehicle's control using fixed acceleration.

[0057] Furthermore, in this manner, once the timing when the activation detection distance and the target distance coincide, the vehicle is controlled with a constant acceleration using fixed acceleration, rather than following the target acceleration plan. This suppresses the occurrence of swerving, where the brakes are released near the target stopping position because the target acceleration exceeds the brake request release threshold. Since the brake request remains constantly on until the vehicle's speed reaches 0 km / h near the target stopping position, the vehicle is transitioned to a stopped state, allowing for a more reliable stop.

[0058] The predicted stopping position calculation unit 15 calculates the predicted stopping position for the vehicle under control by fixed acceleration. As described above, the control of the vehicle by fixed acceleration is started after determining the timing at which the vehicle can be stopped at the target stopping position using fixed acceleration. However, the actual stopping position may fluctuate due to various disturbances.

[0059] Therefore, after starting control by fixed acceleration, the fixed acceleration request generation unit 14 monitors the difference between the predicted stopping position calculated by the predicted stopping position calculation unit 15 and the target position, and if the difference exceeds a predetermined value, it generates a fixed acceleration adjustment request and outputs it to the VSC-ECU 30 in order to adjust the fixed acceleration.

[0060] External disturbances that affect the stopping position include, for example, road surface conditions and weather conditions such as wind. Furthermore, because the resolution of the front camera 20 is limited, errors may occur in the relative distance to the preceding vehicle that is stopped, as analyzed from the image of the front camera 20. Such errors caused by the resolution of the front camera 20 also contribute to disturbances that cause the stopping position to fluctuate.

[0061] In this way, by monitoring the difference between the predicted stopping position and the target position of the vehicle under control by fixed acceleration, and adjusting the fixed acceleration as needed, the vehicle can be stopped within a predetermined error range from the target stopping position.

[0062] (Example of processing by a vehicle control system) Next, an example of the vehicle stopping control process by the SCM-ECU10 of the embodiment will be described using Figure 4. Figure 4 is a flowchart showing an example of the procedure for vehicle stopping control under ACC application by the SCM-ECU10 according to the embodiment.

[0063] As shown in Figure 4, when a stationary vehicle is detected in front of the vehicle, for example, by image analysis of the front camera 20 (step S101), the target inter-vehicle distance plan calculation unit 11 generates a target inter-vehicle distance plan in which the target inter-vehicle distance converges toward the target stopping position (step S102). In addition, the target acceleration plan calculation unit 12 generates a target acceleration plan in which the target acceleration converges toward the target stopping position according to the calculated target inter-vehicle distance plan, and outputs it to the VSC-ECU 30 (step S103).

[0064] From this point onward, the brake request generation unit 16 begins monitoring the target acceleration. As long as the target acceleration is higher than the brake request release threshold, the brake request generation unit 16 does not generate brake requests. When the target acceleration falls below the brake request release threshold, the brake request generation unit 16 generates a brake request and outputs it to the VSC-ECU 30.

[0065] The operation determination inter-vehicle distance calculation unit 13 calculates the operation determination inter-vehicle distance, which is the possible inter-vehicle distance between the vehicle and the stationary preceding vehicle when fixed acceleration is applied, in order to determine the timing of the operation of fixed acceleration (step S104). The fixed acceleration request generation unit 14 monitors the timing when the calculated operation determination inter-vehicle distance matches the target inter-vehicle distance specified in the target inter-vehicle distance plan (step S105). The fixed acceleration request generation unit 14 continues these monitorings as long as the operation determination inter-vehicle distance and the target inter-vehicle distance do not match (step S105: No).

[0066] When the inter-vehicle distance for operation determination matches the target inter-vehicle distance (Step S105: Yes), the fixed acceleration request generation unit 14 generates a fixed acceleration request and outputs it to the VSC-ECU 30 (Step S106). From this point onward, the predicted stopping position calculation unit 15 appropriately calculates the predicted stopping position of the vehicle under control by fixed acceleration (Step S107).

[0067] The fixed acceleration request generation unit 14 monitors whether the amount of deviation between the predicted stopping position and the target stopping position, which is calculated from time to time, exceeds a predetermined threshold (step S108). If the amount of deviation between the predicted stopping position and the target stopping position exceeds the predetermined threshold (step S108: Yes), the fixed acceleration request generation unit 14 generates a fixed acceleration adjustment request and outputs it to the VSC-ECU 30 (step S109). If the amount of deviation between the predicted stopping position and the target stopping position remains below the predetermined threshold (step S108: No), the fixed acceleration request generation unit 14 does not perform the process in step S109.

[0068] Furthermore, while control of the vehicle based on a fixed acceleration request or fixed acceleration adjustment request continues, the SCM-ECU10 periodically monitors whether the vehicle has stopped or not (step S110). As long as the vehicle has not stopped (step S110: No), the SCM-ECU10 repeats the process from step S107 onwards and continues to adjust the fixed acceleration as necessary. When the vehicle has stopped (step S110: Yes), the SCM-ECU10 terminates its processing.

[0069] With the above steps completed, the process of controlling the vehicle's stopping by the SCM-ECU10 in this embodiment is finished.

[0070] (Overview) In ACC-enabled vehicle stopping control, when the target acceleration falls below the brake request release threshold, a brake request is output to the VSC-ECU, and the vehicle is braked. However, as the target acceleration converges to zero near the target stopping position, it may exceed the brake request release threshold, causing the brake request to be released. This results in the vehicle creeping closer to the vehicle ahead. This makes it difficult to stop at the target stopping position and reduces drivability.

[0071] According to the SCM-ECU10 of this embodiment, when a stationary vehicle is detected in front of the vehicle, it is equipped with a fixed acceleration request generation unit 14 that maintains the target acceleration below the brake request release threshold after the target acceleration has fallen below the brake request release threshold. This suppresses the release of the brake request near the target stopping position and suppresses siding during stopping control relative to the stationary vehicle.

[0072] According to the SCM-ECU10 of this embodiment, the fixed acceleration request generation unit 14 switches the vehicle's control from target acceleration to fixed acceleration control when the target inter-vehicle distance and the operating inter-vehicle distance coincide. In this way, the vehicle's control is activated by determining the operating timing based on the operating inter-vehicle distance, making it possible to stop the vehicle more reliably at a position closer to the target stopping position.

[0073] According to the SCM-ECU10 of this embodiment, when the difference between the predicted stopping position and the target stopping position exceeds a predetermined threshold, the fixed acceleration request generation unit 14 adjusts the value of the fixed acceleration so that the difference between the predicted stopping position and the target stopping position becomes less than or equal to the predetermined threshold. This reduces errors in the stopping position due to disturbances and improves the accuracy of the vehicle's stopping position relative to the target stopping position. [Explanation of symbols]

[0074] 1. Vehicle control system 10 SCM-ECU 11. Target Inter-Vehicle Distance Planning Unit 12 Target Acceleration Planning Unit 13 Operation Determination Inter-vehicle Distance Calculation Unit 14 Fixed acceleration request generator 15 Predicted stopping position calculation unit 16 Brake request generation unit 17 Memory section 20 Front Camera 30 VSC-ECU 100 Own vehicle 200 Stop the preceding vehicle

Claims

1. A vehicle control device that performs follow-driving control to drive the vehicle while maintaining a constant distance between the vehicle and the preceding vehicle, When a stationary vehicle is detected in front of the vehicle, a target acceleration planning calculation unit calculates a target acceleration having negative acceleration that converges to zero toward the target stopping position. The system includes an acceleration suppression unit that switches the control of the vehicle from following the target acceleration to following the fixed acceleration at the timing when the target inter-vehicle distance, which converges toward the target stopping position, coincides with the inter-vehicle distance that may occur between the vehicle and the preceding vehicle when a fixed acceleration having a predetermined constant value is applied to the vehicle. Vehicle control device.

2. When a stationary vehicle is detected in front of the vehicle, the target inter-vehicle distance planning calculation unit calculates the target inter-vehicle distance, The system further includes an operating distance calculation unit that calculates the operating distance as the distance that may occur between the vehicle and the stationary preceding vehicle when the fixed acceleration is applied to the vehicle itself. The vehicle control device according to claim 1.

3. The system further includes a predicted stopping position calculation unit that calculates the predicted stopping position of the vehicle under control according to the fixed acceleration, The acceleration suppression unit is If the difference between the predicted stopping position and the target stopping position exceeds a predetermined threshold, the value of the fixed acceleration is adjusted so that the difference between the predicted stopping position and the target stopping position becomes less than or equal to the predetermined threshold. The vehicle control device according to claim 2.

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