WO2022196205A1

WO2022196205A1 - Vehicle control device and vehicle control method

Info

Publication number: WO2022196205A1
Application number: PCT/JP2022/005609
Authority: WO
Inventors: 有樹小澤
Original assignee: 株式会社デンソー; 株式会社J-QuAD DYNAMICS
Priority date: 2021-03-18
Filing date: 2022-02-14
Publication date: 2022-09-22
Also published as: JP2022144077A

Abstract

Provided is a vehicle control device comprising: a sailing control unit (12) that performs sailing control in which the power transmission path between an engine (4) and wheels (2) installed in a vehicle (1) is cut off; and a sailing determination unit (13) that determines the start and end of the sailing control and outputs a determination result to the sailing control unit, wherein the sailing determination unit (13) is provided with first and second conditions as finish conditions for determining to finish the sailing control and determines to finish the sailing control if at least one of the first condition and the second condition is satisfied, the first condition being satisfied when a relative time is shorter than a preset time threshold (THt1), the relative time being determined by the inter-vehicle distance between the own vehicle and the preceding vehicle and the speed or relative speed of the own vehicle, the second condition being satisfied on the basis of the rate of change in the relative time exceeding a preset rate-of-change threshold (THa).

Description

Vehicle control device and vehicle control method

Cross-reference to related applications

This application is based on Patent Application No. 2021-44925 filed in Japan on March 18, 2021, and the content of the underlying application is incorporated by reference in its entirety.

　It relates to a vehicle control device and a vehicle control method, and particularly to a device and method for performing sailing control.

A control called sailing control or coasting control is known. Sailing control is control that interrupts the power transmission path between the engine and the wheels while the vehicle is running. The vehicle runs by inertia by executing the sailing control. When the engine is provided as the prime mover, the engine brake does not operate, and when the motor is provided as the prime mover, the regenerative brake does not operate.

In the device described in Patent Document 1, when the inter-vehicle time becomes short, the coasting mode, which is sailing control, is terminated in order to shift to the deceleration mode. The device described in Patent Document 1 has a rapid deceleration mode and a normal deceleration mode as deceleration modes. The normal deceleration mode is a mode in which only the engine and regenerative generator are operated to decelerate. The rapid deceleration mode is a mode that operates the friction brake. When the inter-vehicle time is relatively long, the normal deceleration mode is set. When the inter-vehicle time is relatively short, the rapid deceleration mode is entered.

JP 2018-34597 A

With the device described in Patent Document 1, even if the preceding vehicle starts to decelerate rapidly, sailing control is continued until the inter-vehicle time becomes smaller than a certain threshold. Therefore, it cannot be said that the start of deceleration is sufficiently early. If the start of deceleration is delayed, it becomes necessary to use the friction brake to rapidly decelerate, which deteriorates the ride comfort. Furthermore, in the case of a vehicle that can use regenerative braking, if the start of deceleration is delayed, the amount of electric power that can be generated by regeneration will decrease.

If the sailing control can be terminated early when the vehicle in front begins to decelerate rapidly, it will be possible to achieve gradual deceleration through engine braking and regenerative braking, which is desirable.

The present disclosure has been made based on this situation, and its object is to provide a vehicle control device and a vehicle control method that can terminate sailing control early when a preceding vehicle starts to decelerate rapidly. to do.

The above object is achieved by the combination of features described in the independent claims, and the subclaims define further advantageous embodiments. Reference numerals in parentheses in the claims indicate correspondence with specific aspects described in embodiments described later as one aspect, and do not limit the disclosed technical scope.

One disclosure related to a vehicle control device for achieving the above object is
a sailing control unit that performs sailing control to cut off a power transmission path between a prime mover mounted on a vehicle and wheels;
A vehicle control device comprising a sailing determination unit that determines the start and end of sailing control and outputs the determination result to the sailing control unit,
The sailing determination unit determines that the sailing control should be terminated as a termination condition,
Established when the relative time determined by the inter-vehicle distance between the vehicle using the vehicle control device and the preceding vehicle and the speed or relative speed of the vehicle is shorter than a preset time threshold. a first condition;
and a second condition that is satisfied based on the fact that the relative time change speed exceeds a preset change speed threshold,
A vehicle control device that determines to end sailing control when at least one of a first condition and a second condition is satisfied.

One disclosure relating to a vehicle control method for achieving the above object is
performing sailing control to cut off a power transmission path between a prime mover mounted on a vehicle and wheels;
determining the start and end of sailing control;
The end condition for judging to end the sailing control is
A first condition that the inter-vehicle distance between the vehicle and the preceding vehicle and the relative time determined by the speed or relative speed of the vehicle is shorter than a preset time threshold;
and a second condition that is satisfied based on the relative time change speed exceeding a preset change speed threshold,
The vehicle control method determines that the sailing control is terminated when at least one of a first condition and a second condition is satisfied.

By providing the first condition as a termination condition for determining that the sailing control should be terminated, the vehicle control device and the vehicle control method described above can determine that the sailing control should be terminated when the relative time becomes shorter. In addition, a second condition is provided as an end condition.

When the vehicle in front suddenly decelerates, the speed of change in relative time is greater than that in relative time. Therefore, by providing the second condition, the sailing control can be terminated early when the preceding vehicle suddenly decelerates.

1 is a configuration diagram of a vehicle provided with a vehicle control device; FIG. The figure which shows the termination conditions of sailing control. The figure which shows the magnitude|size of 2nd time threshold THt2 and 1st time threshold THt1. FIG. 4 is a diagram showing processing executed by a sailing control unit 12 and a sailing determination unit 13;

Hereinafter, embodiments will be described based on the drawings. FIG. 1 is a configuration diagram of a vehicle 1 provided with a vehicle control device (hereinafter referred to as control device) 100 of this embodiment. The vehicle 1 includes a controller 10, wheels 2, a transmission 3, an engine 4, a brake device 5, a sensor 6, and the like.

The wheels 2 are connected to the transmission 3 via axles 7. The transmission 3 rotates the axle 7 and the wheel 2 connected to the axle 7 by the power generated by the engine 4 which is the prime mover. The transmission 3 and axles 7 form a power transmission path between the engine 4 and the wheels 2 . The transmission 3 has a clutch inside. When the clutch is disengaged, the power transmission path is cut off.

The engine 4 generates power to drive the vehicle 1. Power generated by the engine 4 is transmitted to the wheels 2 via the transmission 3 and the axles 7 . The engine 4 produces no power when no fuel is supplied. When the engine 4 does not generate power and the engine 4 and the wheels 2 are connected by the power transmission path, the engine brake is activated.

The brake device 5 is a device that reduces the rotation speed of the wheel 2, and is configured with a friction material and a mechanism that operates the friction material.

A plurality of sensors 6 are provided on the vehicle 1 . The sensors 6 include a vehicle speed sensor, an inter-vehicle distance sensor for measuring the inter-vehicle distance from the preceding vehicle, an accelerator opening sensor, a brake pedal sensor, and the like. The vehicle speed sensor detects the vehicle speed of the vehicle 1, which is the own vehicle. The inter-vehicle distance sensor can use one or more of radar, lidar, and camera. The preceding vehicle is another vehicle located in front of the vehicle 1 and closest to the vehicle 1 in the same lane as the vehicle 1 . A plurality of inter-vehicle distance sensors may be provided in order to calculate the inter-vehicle distance to the preceding vehicle. The accelerator opening sensor detects the depression amount of an accelerator pedal provided in the vehicle 1 . A brake pedal sensor detects whether the brake pedal is depressed.

The control device 10 can be realized by a configuration including at least one processor. For example, the control device 10 can be implemented by a computer including a processor, nonvolatile memory, RAM, I/O, bus lines connecting these components, and the like. A program for operating a general-purpose computer as the control device 10 is stored in the nonvolatile memory. The control device 10 controls the transmission 3 , the engine 4 , and the braking device 5 by the processor executing the program stored in the nonvolatile memory while using the temporary storage function of the RAM.

The control device 10 also operates as an ACC control unit 11, a sailing control unit 12, and a sailing judgment unit 13, as shown in FIG. Execution of these operations means execution of the vehicle control method corresponding to the program. Note that the control device 10 may be composed of a plurality of devices such as a device that controls the engine 4, a device that controls the transmission 3, a device that controls the brake device 5, and the like.

The ACC control unit 11 executes adaptive cruise control. Adaptive cruise control is control that follows the vehicle in front while maintaining a constant inter-vehicle distance from the vehicle in front. Adaptive cruise control maintains the speed of vehicle 1 at a preset speed when there is no vehicle ahead. The ACC control unit 11 starts and ends adaptive cruise control according to a driver's switch operation. The ACC control unit 11 also temporarily or completely terminates the adaptive cruise control when various termination conditions such as depression of the accelerator pedal or the brake pedal are satisfied.

The sailing control unit 12 performs sailing control based on the determination by the sailing determination unit 13. Sailing control is control that blocks the power transmission path between the engine 4 and the wheels 2 . In sailing control, the engine 4 may be in a state where the fuel supply is stopped or in an idling state.

The sailing determination unit 13 determines the start and end of sailing control. The sailing determination unit 13 outputs the determination result to the sailing control unit 12 . Sailing control initiation conditions may be one or more independent conditions. Sailing control start conditions can include a condition that the headway time THW becomes shorter than the start time threshold while following the preceding vehicle. The headway time THW is the headway distance/the speed of the vehicle 1 . The headway time THW is an example of relative time.

Sailing control can be executed even when the vehicle is not following. An example of a condition for starting sailing control when the vehicle is not following is a condition that the difference between the vehicle speed of the vehicle 1 and the target vehicle speed is equal to or less than a certain value. Sailing control can also be performed during manual sailing. An example of conditions for starting sailing control during manual travel is that the speed of the vehicle 1 is within a preset sailing execution speed range, the accelerator pedal and brake pedal are not operated, and the shift position is the D position. is the condition.

Next, the conditions for terminating sailing control will be explained. In this embodiment, the first condition, the second condition, and the third condition shown in FIG. 2 are provided as end conditions for sailing control. The first condition is that the headway time THW is less than or equal to the first time threshold THt1. The first condition is satisfied when the headway time THW is shorter than the first time threshold THt1. The first condition is also satisfied when the headway time THW is equal to the first time threshold THt1.

The second condition has two conditions. Let the first condition be the 2-1 condition, and let the second condition be the 2-2 condition. The second condition is met when both the 2-1 condition and the 2-2 condition are met. The second-1 condition is that the magnitude of the time differential value of the time to collision TTC is greater than or equal to the changing speed threshold THa. The time to collision TTC can be calculated from the inter-vehicle distance/relative speed. The time to collision TTC is also an example of the relative time because it is determined by the distance between the vehicles and the relative speed. The relative speed is positive when the speed of the host vehicle is high. If the magnitude of the time-differentiated value of the collision margin time TTC exceeds the change speed threshold THa, that is, if the magnitude of the time-differentiation value of the collision margin time TTC is greater than the change speed threshold THa, 2-1 condition is satisfied. Condition 2-1 is also established when the magnitude of the time differential value of the time to collision TTC is equal to the change speed threshold value THa.

The 2-2 condition is that the headway time THW is equal to or less than the second time threshold THt2. If the headway time THW is shorter than the second time threshold THt2, the 2-2 condition is met. Condition 2-2 is also satisfied when the headway time THW is equal to the second time threshold THt2.

The second time threshold THt2 is greater than the first time threshold THt1. The range of time headway THW in which the first condition is satisfied and the range of time headway THW in which condition 2-2 is satisfied have the relationship shown in FIG. However, in order to satisfy the second condition, the condition 2-1 must also be satisfied, whereas the first condition is only the headway time THW. Therefore, the second condition is meaningful in that the headway time THW is satisfied between the first time threshold THt1 and the second time threshold THt2.

The 2-1 condition determines the magnitude of the time differential value of the collision margin time TTC. The time differential value of the time to collision TTC can also be said to be the rate of change of the time to collision TTC or relative acceleration. Since the time to collision TTC is the inter-vehicle distance/relative speed, when the preceding vehicle suddenly decelerates, the time differential value of the time to collision TTC changes greatly. The second condition is a condition for terminating the sailing control when the preceding vehicle suddenly decelerates even if the headway time THW is between the first time threshold THt1 and the second time threshold THt2.

The changing speed threshold THa is set to a value that allows it to be determined that the vehicle in front has suddenly decelerated. Also, if the vehicle in front is far away, there is no need to decelerate the vehicle even if the vehicle in front suddenly decelerates. The second time threshold THt2 is set from the viewpoint of whether or not the host vehicle needs to decelerate when the preceding vehicle suddenly decelerates. An example of the second time threshold THt2 is 20 seconds. A first time threshold THt1 shorter than the second time threshold THt2 is, for example, 10 seconds.

The third condition is that the accelerator pedal is depressed, the brake pedal is depressed, etc., and one or more conditions are set. The third condition includes the same condition as the adaptive cruise control end condition.

The sailing determination unit 13 outputs to the sailing control unit 12 that the conditions for terminating the sailing control are satisfied when any one of the first condition, the second condition, and the third condition is satisfied during the execution of the sailing control. do.

FIG. 4 shows a flowchart of the processing executed by the sailing control unit 12 and the sailing determination unit 13. The processing shown in FIG. 4 is periodically executed while the vehicle 1 is running. In step (hereinafter, step is omitted) S1, the sailing determination unit 13 acquires a sensor signal for determining the conditions for starting sailing control. The sensor signal acquired in S1 is, for example, a signal detected by an inter-vehicle distance sensor and a signal detected by a vehicle speed sensor.

In S2, the sailing determination unit 13 determines whether or not the conditions for starting sailing control are satisfied based on the sensor signal acquired in S1. If the determination result of S2 is NO, the process shown in FIG. 4 is terminated. If the determination result of S2 is YES, the process proceeds to S3. In S3, the sailing determination unit 13 outputs to the sailing control unit 12 a signal indicating that the conditions for starting sailing control are met. The sailing control unit 12 starts sailing control when it acquires the signal.

In S4, the sailing determination unit 13 acquires a sensor signal for determining conditions for ending sailing control. The sensor signal acquired in S4 is, for example, the signal detected by the inter-vehicle distance sensor and the signal detected by the vehicle speed sensor.

In S5, the sailing determination unit 13 determines whether or not the conditions for terminating the sailing control are satisfied based on the signal acquired in S4. Sailing control termination conditions include a condition regarding the time to collision TTC. A relative velocity is required to calculate the time to collision TTC. The relative speed is calculated from the change in inter-vehicle distance over time. If the judgment result of S5 is NO, the process returns to S4. If the determination result of S5 is YES, the process proceeds to S6.

In S6, the sailing determination unit 13 outputs to the sailing control unit 12 a signal indicating that the conditions for terminating the sailing control are satisfied. The sailing control unit 12 ends the sailing control when it acquires the signal.

[Summary of embodiment]
As described above, the control device 10 of the present embodiment has the first condition as a condition for ending the sailing control, and thus ends the sailing control when the headway time THW becomes short. In addition, a second condition is provided as an end condition.

When the vehicle in front suddenly decelerates, the rate of change of the time to collision TTC changes more than the time headway THW. Therefore, by providing the second condition, the sailing control can be terminated early when the preceding vehicle suddenly decelerates.

The second condition includes the 2-2 condition that the headway time THW is equal to or less than the second time threshold THt2. Therefore, it is possible to prevent the vehicle 1 from decelerating by ending the sailing control even when the headway time THW is large and deceleration is unnecessary.

In this embodiment, in the second condition, the time to collision TTC is used as the relative time to be time-differentiated. Since the denominator of the time to collision TTC is the relative speed, the value reflects the rapid deceleration of the preceding vehicle rather than the headway time THW, the denominator of which is the speed of the host vehicle. Therefore, the sailing control can be terminated more quickly than when the headway time THW is used as the time-differentiated relative time when the preceding vehicle suddenly decelerates.

On the other hand, under the first condition, the headway time THW is used as the relative time. When the time headway THW is short, if the timing of deceleration control is determined based on the time headway THW, the deceleration control can be started at a deceleration timing close to the deceleration timing when the driver operates the brake by himself/herself. Therefore, the sense of discomfort given to the driver can be reduced.

Although the embodiments have been described above, the disclosed technology is not limited to the above-described embodiments, and the following modifications are also included in the disclosed scope. It can be implemented with various modifications. In the following description, the elements having the same reference numerals as the reference numerals used so far are the same as the elements having the same reference numerals in the previous embodiments unless otherwise specified. Moreover, when only part of the configuration is described, the previously described embodiments can be applied to the other portions of the configuration.

<Modification 1>
In the embodiment, the headway time THW is used in the first condition. However, in the first condition, the time to collision TTC may be used instead of the headway time THW. Further, the time to headway TTC may be used instead of the headway time THW for condition 2-2.

<Modification 2>
In the embodiment, the time to collision TTC is time-differentiated under the 2-1 condition. However, instead of the time to collision TTC, the headway time THW may be time-differentiated.

<Modification 3>
In the first condition, the case where the headway time THW is equal to the first time threshold THt1 may be excluded. That is, the first condition may be that the headway time THW is smaller than the first time threshold THt1. Also, in the 2-1 condition, the case where the change speed threshold value THa is equal may be excluded. In condition 2-2, the case where headway time THW is equal to second time threshold THt2 may be excluded.

<Modification 4>
The 2-1 condition compares the magnitude of the time differential value of the time to collision TTC, that is, the absolute value, with the changing speed threshold THa. However, the time differential value of the time to collision TTC may be compared with the changing speed threshold THa. When the preceding vehicle decelerates, the collision margin time TTC becomes shorter. Therefore, the time differential value of the time to collision TTC when the preceding vehicle decelerates becomes negative. The change speed threshold THa to be compared with the time differential value of the collision time to collision TTC is a negative value, and when the preceding vehicle suddenly decelerates, the time differential value of the collision time to collision TTC changes to be smaller than the change speed threshold THa. exceeds the speed threshold THa.

<Modification 5>
The embodiment has disclosed the vehicle 1 having the engine 4 as the prime mover. However, the technology disclosed in the embodiments can be applied to a vehicle having a motor as a prime mover, or a vehicle having both an engine and a motor as prime movers.

<Modification 6>
The controller and techniques described in this disclosure may be implemented by a special purpose computer comprising a processor programmed to perform one or more functions embodied by a computer program. Alternatively, the controller and techniques described in this disclosure may be implemented by dedicated hardware logic circuitry. Alternatively, the controller and techniques described in this disclosure may be implemented by one or more dedicated computers configured by a combination of a processor executing a computer program and one or more hardware logic circuits. Hardware logic circuits are, for example, ASICs and FPGAs.

Also, the storage medium for storing the computer program is not limited to the ROM, and may be stored in a computer-readable, non-transitional tangible recording medium as instructions executed by the computer. For example, the program may be stored in a flash memory.

Claims

a sailing control unit (12) that performs sailing control to cut off a power transmission path between a prime mover (4) mounted on a vehicle (1) and wheels (2);
A vehicle control device comprising a sailing determination section (13) that determines the start and end of the sailing control and outputs a determination result to the sailing control section,
Said sailing determination unit, as a termination condition for determining that said sailing control should be terminated,
A relative time determined by the inter-vehicle distance between the vehicle in which the vehicle control device is used and the preceding vehicle and the speed or relative speed of the vehicle is longer than a preset time threshold (THt1). A first condition that is satisfied when it is short;
and a second condition that is established based on the change speed of the relative time exceeding a preset change speed threshold (THa),
A vehicle control device that determines to end the sailing control when at least one of the first condition and the second condition is satisfied.
The vehicle control device according to claim 1,
The time threshold included in the first condition is the first time threshold,
The second condition is met when the speed of change of the relative time exceeds the speed-of-change threshold and the relative time is smaller than the second time threshold (THt2). The vehicle control device, wherein the threshold is greater than the first time threshold.
The vehicle control device according to claim 2,
The vehicle control device, wherein the rate of change of the relative time under the second condition is the rate of change of the time to collision.
The vehicle control device according to any one of claims 1 to 3,
The vehicle control device, wherein the relative time included in the first condition is an inter-vehicle time obtained by dividing the inter-vehicle distance by the speed of the host vehicle.
performing sailing control to cut off a power transmission path between a prime mover (4) mounted on a vehicle (1) and wheels (2);
determining the start and end of said sailing control;
End conditions for determining to end the sailing control include:
A first condition that the inter-vehicle distance between the vehicle and the preceding vehicle and the relative time determined by the speed or relative speed of the vehicle is shorter than a preset time threshold (THt1);
a second condition that is established based on the rate of change of the relative time exceeding a preset change rate threshold (THa),
A vehicle control method, comprising determining to end the sailing control when at least one of the first condition and the second condition is satisfied.