Vehicle control device

Abstract

To suppress the driver's intention of deceleration from deviating from the actual deceleration of a vehicle.SOLUTION: A vehicle control device that controls a deceleration of a vehicle includes: a calculation unit that calculates a basic requested deceleration on the basis of information indicating a surrounding situation of the vehicle; and a support unit that executes deceleration support control when a start condition based on a change amount per unit time of an accelerator opening degree and a requested driving force is satisfied. The start condition refers to a case where, if a driver has returned accelerator pedal the change amount per unit time of the accelerator opening is smaller than a change threshold and the requested driving force is smaller than a deceleration threshold, and the support unit updates the requested deceleration to the basic requested deceleration so as to change the vehicle deceleration if the driver is operating the accelerator pedal in a returning direction during an execution of the deceleration support control, and maintains the requested deceleration so as not to change the vehicle deceleration if the accelerator opening degree does not change during the execution of the deceleration support control.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a vehicle control device. [Background technology]

[0002] Patent Document 1 discloses a vehicle control device that controls the deceleration of a vehicle based on the distance to a preceding vehicle and the accelerator pedal position. In the configuration described in Patent Document 1, the absolute value of the accelerator pedal position is the execution condition for deceleration support control, and when the accelerator pedal is returned to the fully closed position from the fuel cut-off position, deceleration support control is executed so that a predetermined braking force is generated in the braking device. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2001-233085 Summary of the Invention [Problem to be solved by the invention]

[0004] In a configuration in which deceleration assist control is executed when the accelerator pedal is released, the start and end of deceleration assist control may be determined by a unique accelerator pedal position, such as accelerator OFF or accelerator ON (i.e., whether the accelerator pedal position is 0% or other than 0%). In this case, it is possible to execute deceleration assist control even while the driver is operating the accelerator pedal. However, if the start and end of deceleration assist control is determined by a unique accelerator pedal position during accelerator pedal operation, a discrepancy may occur between the driver's intention to decelerate and the actual deceleration of the vehicle, which may cause the driver to feel uncomfortable.

[0005] The present invention has been made in consideration of the above circumstances, and aims to provide a vehicle control device that can prevent the actual deceleration of the vehicle from deviating from the driver's intention to decelerate. [Means for solving the problem]

[0006] The present invention is a vehicle control device that controls the deceleration of the vehicle in accordance with operation of an accelerator pedal by a driver of the vehicle, and includes: an acquisition unit that acquires peripheral information indicating the surrounding conditions of the vehicle; a calculation unit that calculates a basic required deceleration based on the peripheral information; an assistance unit that executes deceleration assistance control that controls the required deceleration to assist in deceleration of the vehicle when a start condition for determining the driver's intention to decelerate is satisfied, the start condition being based on a change in accelerator pedal position per unit time and a required driving force; and a control unit that controls a braking device to generate a braking force corresponding to the required deceleration, wherein the start condition is when the change in accelerator pedal position per unit time is smaller than a predetermined change threshold and the required driving force is smaller than a predetermined deceleration threshold, the change threshold being a negative value; and wherein when the accelerator pedal is being operated in a release direction while the deceleration assistance control is being executed, the assistance unit updates the required deceleration to the basic required deceleration so as to change the deceleration of the vehicle, and when the accelerator pedal position does not change while the deceleration assistance control is being executed, the assistance unit maintains the required deceleration so as not to change the deceleration of the vehicle. [Effects of the Invention]

[0007] The present invention can prevent the actual deceleration of the vehicle from deviating from the driver's intention to decelerate. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a diagram schematically illustrating a vehicle according to an embodiment. [Figure 2] FIG. 2 is a block diagram illustrating a control device. [Figure 3] FIG. 4 is a flowchart showing braking control. [Figure 4] FIG. 4 is a flowchart illustrating deceleration support control. [Figure 5] FIG. 4 is a time chart showing a state in which the deceleration of the vehicle changes when deceleration assist control is executed. [Figure 6] FIG. 10 is a time chart showing a state in which the deceleration of the vehicle changes when deceleration assist control of the comparative example is executed. DETAILED DESCRIPTION OF THE INVENTION

[0009] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A vehicle control device according to an embodiment of the present invention will be specifically described below, but the present invention is not limited to the embodiment described below.

[0010] 1 is a diagram schematically illustrating a vehicle according to an embodiment. The vehicle 1 includes a braking device 3 that applies a braking force to wheels 2, and a control device 10 that controls the deceleration of the vehicle 1. The control device 10 is a vehicle control device.

[0011] The braking device 3 is a device that can decelerate the vehicle 1 and generates a braking force to brake the vehicle 1. For example, the braking device 3 is configured with a hydraulic brake, a regenerative brake, or the like. When the braking device 3 is a hydraulic brake, the braking device 3 is provided on each wheel 2. When the braking device 3 is a regenerative brake, the braking device 3 is realized by an electric motor mounted on the vehicle 1. The vehicle 1 is an electric vehicle equipped with an electric motor as a power source. The braking device 3 is controlled by a control device 10.

[0012] The control device 10 is an electronic control device that controls the braking device 3. The control device 10 includes a microcomputer equipped with a CPU, RAM, ROM, and input / output interface. The control device 10 processes signals according to a program pre-stored in the ROM. Signals are input to the control device 10 from various sensors mounted on the vehicle 1. As shown in FIG. 2, the vehicle 1 is equipped with a vehicle speed sensor 21 that detects the vehicle speed, an accelerator opening sensor 22 that detects the accelerator opening, which is the amount of accelerator pedal operation, and a camera 23 that captures images of the surrounding conditions of the vehicle 1. The control device 10 receives signals from the vehicle speed sensor 21, the accelerator opening sensor 22, and the camera 23. The control device 10 performs various controls based on the signals input from the various sensors.

[0013] The control device 10 calculates a required driving force based on the vehicle speed and the accelerator opening. The control device 10 calculates a required power based on the required driving force and the vehicle speed. The control device 10 controls the torque output from the power source based on the required power.

[0014] The control device 10 executes deceleration assist control that assists in deceleration of the vehicle 1 based on the surrounding conditions of the vehicle 1. The deceleration assist control adjusts the deceleration of the vehicle 1 when the accelerator pedal is operated in the release direction while the brake pedal is not depressed (brake OFF). The control device 10 appropriately adjusts the deceleration of the vehicle 1 in driving situations that require deceleration of the vehicle 1, such as when the vehicle 1 approaches a preceding vehicle or before the vehicle 1 enters a curve, in order to reduce the burden on the driver of the vehicle 1 and improve the sense of security. In this case, the control device 10 controls the deceleration of the vehicle 1 so that it changes while the driver is operating the accelerator pedal, and so that it does not change while the driver is not operating the accelerator pedal. This makes it possible to change the deceleration of the vehicle 1 based on the driver's operation status and the vehicle state, and to adjust the sense of deceleration without causing the driver any discomfort or anxiety.

[0015] As shown in FIG. 2, the control device 10 includes an acquisition unit 11, a calculation unit 12, a support unit 13, and a control unit 14.

[0016] The acquisition unit 11 acquires surrounding information that indicates the surrounding conditions of the vehicle 1. The surrounding information includes information that indicates the distance between the vehicle 1 and the preceding vehicle, information that indicates that the vehicle 1 is about to enter a curve, and information that indicates the radius of the curve ahead. The vehicle 1 is equipped with an acquisition device that can acquire information about the surrounding conditions of the vehicle 1. The acquisition device includes a camera 23, a car navigation device, and the like. The camera 23 captures images of the surrounding conditions including the preceding vehicle traveling in front of the vehicle 1. The camera 23 outputs image data of the area in front of the vehicle 1 to the control device 10. The car navigation device outputs position information and map information that indicate the current position of the vehicle 1 to the control device 10. The acquisition unit 11 acquires surrounding information based on information input from the acquisition device to the control device 10. The acquisition unit 11 acquires information that indicates the distance between the vehicle 1 and the preceding vehicle based on the image data input from the camera 23.

[0017] The calculation unit 12 calculates the basic required deceleration based on the peripheral information. The peripheral information may include information indicating that the distance between the vehicle and the preceding vehicle has become shorter, or may include information indicating that the distance between the vehicle and the preceding vehicle has not changed. The calculation unit 12 calculates a larger basic required deceleration as the distance between the vehicles becomes shorter. The peripheral information may also include information indicating the radius of the curve ahead that the vehicle 1 is planning to enter. In this case, the calculation unit 12 calculates a larger basic required deceleration than when the vehicle 1 is not entering the curve.

[0018] The support unit 13 executes deceleration support control based on the surrounding conditions of the vehicle 1. In the deceleration support control, a basic required deceleration is used to support the deceleration of the vehicle 1. The deceleration support control is executed in driving situations where deceleration of the vehicle 1 is required, such as when a preceding vehicle is driving close to the vehicle 1 or when the vehicle 1 enters a curve ahead. If there is no preceding vehicle close to the vehicle 1, the support unit 13 does not execute the deceleration support control. As a precondition for the deceleration support control, the support unit 13 determines whether the driving situation requires deceleration of the vehicle 1 according to the surrounding conditions. The precondition includes that the accelerator opening is greater than 0%. For example, the support unit 13 determines whether the distance between the vehicle and the preceding vehicle is smaller than a predetermined distance threshold. The distance threshold is a preset value. If the support unit 13 determines that the distance between the vehicle and the preceding vehicle is smaller than the distance threshold, it determines that the driving situation requires deceleration of the vehicle 1.

[0019] The support unit 13 provides deceleration support at an appropriate timing according to the driver's intention to decelerate. When the preconditions for deceleration support control are met, the support unit 13 determines whether the driver intends to decelerate or accelerate. The support unit 13 determines whether the driver intends to decelerate using the amount of change per unit time of accelerator opening and the required driving force. The support unit 13 determines whether the driver intends to accelerate using the required driving force. When the support unit 13 determines that the driver intends to decelerate, it executes deceleration support control. When the support unit 13 determines that the driver intends to accelerate while executing deceleration support control, it terminates the deceleration support control. The conditions for determining the driver's intention to decelerate are the start conditions for deceleration support control. The conditions for determining the driver's intention to accelerate are the end conditions for deceleration support control. Note that in this explanation, the start conditions for deceleration support control may be simply referred to as the start conditions, and the end conditions for deceleration support control may be simply referred to as the end conditions.

[0020] The start condition for deceleration assist control is a condition that uses the change in accelerator opening per unit time and the required driving force. The start condition occurs when the change in accelerator opening per unit time is smaller than a predetermined change threshold and the required driving force is smaller than a predetermined deceleration threshold. The change threshold is a negative value. For example, the deceleration threshold is set to 0 [N]. The start condition occurs when the change in accelerator opening per unit time is a negative value and the required driving force is a negative value. A negative change in accelerator opening per unit time indicates that the accelerator opening is decreasing toward 0%, that is, the driver is releasing the accelerator pedal. The start condition is not met when the accelerator is off (accelerator opening is 0%). For example, the change threshold is set to any value within the range of -30 to -20 [% / s]. A negative required driving force indicates that the vehicle speed is low and the accelerator opening is small.

[0021] The termination condition for the deceleration assist control is a condition using the required driving force. The termination condition is when the required driving force is greater than a predetermined acceleration threshold. The acceleration threshold is a positive value. For example, the acceleration threshold is set to 50 [N].

[0022] When the support unit 13 starts deceleration support control, it updates the requested deceleration to the basic requested deceleration at an appropriate timing according to the driver's intention to decelerate. If the accelerator pedal is being operated in the release direction while deceleration support control is being executed, the support unit 13 updates the requested deceleration to the basic requested deceleration so as to change the deceleration of the vehicle 1. If the accelerator opening does not change while deceleration support control is being executed, the support unit 13 maintains the requested deceleration so as not to change the deceleration of the vehicle 1. If the accelerator opening does not change even if the distance to the preceding vehicle becomes shorter while deceleration support control is being executed, the support unit 13 maintains the requested deceleration so as not to change the deceleration of the vehicle 1. If the accelerator opening starts to decrease further from a state in which the requested deceleration was maintained while deceleration support control is being executed, the support unit 13 resumes updating the requested deceleration to the basic requested deceleration.

[0023] The control unit 14 controls the braking device 3 so as to generate a braking force according to the required deceleration. The control unit 14 controls the braking force generated by the braking device 3 so as to achieve the required deceleration set by the support unit 13. The control unit 14 outputs a command signal to the braking device 3.

[0024] 3 is a flowchart showing braking control, which is repeatedly performed by the control device 10.

[0025] The control device 10 acquires surrounding information indicating the surrounding conditions of the vehicle 1 (step S1). In step S1, the surrounding information is acquired from an acquisition device such as the camera 23. The surrounding information includes information indicating the distance to the preceding vehicle, the radius of the curve ahead, etc.

[0026] The control device 10 calculates the basic required deceleration based on the peripheral information (step S2). In step S2, the basic required deceleration is calculated according to the distance between the vehicle and the preceding vehicle.

[0027] The control device 10 executes deceleration support control (step S3). In step S3, if the preconditions for deceleration support control are met, the deceleration support control is executed. A subroutine showing the processing of step S3 is shown in FIG.

[0028] The control device 10 converts the required deceleration into a required braking force (step S4). In step S4, the required braking force is calculated based on the required deceleration set in step S3. The required braking force is the braking force required for the entire vehicle 1.

[0029] The control device 10 distributes the required braking force to each braking device 3 (step S5). If the braking device 3 is a hydraulic brake, the required braking force is distributed to the braking device 3 provided on each wheel 2. If the braking device 3 includes a regenerative brake and a hydraulic brake, the required braking force is distributed to the electric motor and each hydraulic brake.

[0030] The control device 10 causes the braking devices 3 to perform braking (step S6). In step S6, braking force is generated in each braking device 3 so as to satisfy the braking force distributed in accordance with the required braking force. After the processing of step S6 is performed, this control routine ends.

[0031] 4 is a flowchart showing the deceleration support control. The control shown in Fig. 4 is a control that is executed when the preconditions for the deceleration support control are satisfied, and is the processing that is executed in step S3 shown in Fig. 3.

[0032] The control device 10 determines whether the driver intends to decelerate (step S31). In step S31, it is determined whether a start condition based on the amount of change in accelerator opening per unit time and the required driving force is met, as a condition for determining whether the driver intends to decelerate. The start condition is when the amount of change in accelerator opening per unit time is smaller than a predetermined change threshold and when the required driving force is smaller than a predetermined deceleration threshold. The change threshold is a negative value. The deceleration threshold is zero.

[0033] If it is determined that the driver intends to decelerate (step S31: Yes), the control device 10 starts deceleration assist control (step S32). In step S32, the assist unit 13 updates the required deceleration to a basic required deceleration so as to change the deceleration of the vehicle 1. If the accelerator pedal is being operated in the release direction while the deceleration assist control is being executed, the assist unit 13 updates the required deceleration to a basic required deceleration so as to change the deceleration of the vehicle 1. After the processing of step S32 is performed, this subroutine returns to step S31.

[0034] If it is determined that the driver does not intend to decelerate (step S31: No), the control device 10 determines whether the driver intends to accelerate (step S33). In step S33, it is determined whether an end condition for the deceleration assistance control is met. The end condition is when the required driving force is equal to or greater than a predetermined acceleration threshold. The acceleration threshold is a positive value. The assistance unit 13 determines whether the required driving force is equal to or greater than the acceleration threshold. For example, the acceleration threshold is set to 50 [N].

[0035] If it is determined that the driver intends to accelerate (step S33: Yes), the control device 10 ends the deceleration support control (step S34). In step S34, the support unit 13 ends the deceleration support control. After the processing of step S34 is performed, this subroutine returns to step S31.

[0036] If it is determined that the driver does not intend to accelerate (step S33: No), the control device 10 determines that the driver's intention is to maintain the current state. For example, if the accelerator opening degree does not change while deceleration assist control is being executed, the assistance unit 13 maintains the requested deceleration so as not to change the deceleration of the vehicle 1. If the determination in step S33 is negative, this subroutine returns to step S31. If the determination in step S31 is positive after this return, this means that the accelerator opening degree has started to further decrease from the state in which the requested deceleration was maintained while deceleration assist control was being executed. In this case, the assistance unit 13 resumes updating the requested deceleration to the basic requested deceleration.

[0037] FIG. 5 is a time chart showing how the deceleration of the vehicle changes when deceleration assist control is executed. As shown in FIG. 5, when the vehicle acceleration is a negative value and the accelerator pedal position is maintained, the distance to the preceding vehicle decreases (times t1 to t2). The negative vehicle acceleration represents the deceleration of the vehicle 1. The vehicle state and surrounding circumstances from times t1 to t2 do not satisfy the start condition, so the control device 10 does not start deceleration assist control. The distance to the preceding vehicle stops changing (after time t2). The driver slightly releases the accelerator pedal (time t3). At time t3, it is determined that the start condition is satisfied, and the control device 10 starts deceleration assist control. After deceleration assist control is started, the absolute value of the deceleration of the vehicle 1 is changed to a larger value as the accelerator pedal position decreases (times t3 to t4). If the accelerator pedal position is maintained while deceleration assist control is being executed, the braking force is maintained so as not to change the deceleration (time t4). Then, after deceleration assist control starts (after time t3), while the driver maintains the accelerator pedal depressed (after time t4), vehicle acceleration is controlled not to change even if the distance to the preceding vehicle becomes shorter (times t5 to t6). If the driver subsequently releases the accelerator pedal further, braking force is controlled so that the absolute value of the deceleration of vehicle 1 becomes even larger (times t7 to t8). At time t8, the accelerator is released.

[0038] FIG. 6 is a time chart showing how the deceleration of the vehicle changes when deceleration assist control of the comparative example is executed. Unlike the control device 10, the control device of the comparative example starts deceleration assist control based on the absolute value of the accelerator pedal depression. As shown in FIG. 6, under the vehicle state and surrounding conditions from time t11 to t12, the distance to the preceding vehicle becomes shorter, but the absolute value of the accelerator pedal depression is greater than the start threshold, so the deceleration assist control of the comparative example is not started. When the driver slightly releases the accelerator pedal at time t13, the absolute value of the accelerator pedal depression becomes smaller than the start threshold, so deceleration assist control is started. In the comparative example, if the distance to the preceding vehicle becomes further shorter while deceleration assist control is being executed (after time t13), the deceleration changes so that the absolute value of the vehicle deceleration becomes even greater (times t15 to t16). If the driver maintains the accelerator pedal depressed, the vehicle acceleration changes when the distance to the preceding vehicle becomes shorter. This may result in vehicle behavior that does not match the driver's intention, which may cause the driver to feel uncomfortable.

[0039] As described above, according to the embodiment, by utilizing the driver's operation intention and the driver's driving force request as the start and end conditions for deceleration assist control, it is possible to provide deceleration assist according to the driver's operation situation and the vehicle state. As a result, deceleration assist can be applied at an appropriate timing according to the driver's deceleration intention, allowing the driver to drive without feeling any discomfort, etc.

[0040] The braking device 3 may be either a hydraulic brake or a regenerative brake, or may include both a hydraulic brake and a regenerative brake.

[0041] Furthermore, acquisition devices capable of acquiring information about the surrounding conditions of the vehicle 1 are not limited to the camera 23 and the car navigation device. The acquisition device may include a millimeter wave radar. The vehicle 1 may acquire information indicating the distance to the preceding vehicle using a millimeter wave radar instead of the camera 23. Map information is not limited to being acquired by the car navigation device, and may be acquired via wireless communication with an external device. [Explanation of symbols]

[0042] 1 vehicle 2 wheels 3 Braking device 10 Control device 11 Acquisition Department 12 Calculation section 13 Support Department 14 Control Unit 21 Vehicle speed sensor 22 Accelerator opening sensor 23 Camera

Claims

1. A vehicle control device that controls deceleration of a vehicle in response to operation of an accelerator pedal by a driver of the vehicle, an acquisition unit that acquires surrounding information indicating a surrounding situation of the vehicle; a calculation unit that calculates a basic required deceleration based on the peripheral information; a support unit that executes deceleration support control to support deceleration of the vehicle by controlling a required deceleration when a start condition for determining an intention of the driver to decelerate is satisfied, the start condition being based on a change in accelerator opening per unit time and a required driving force; a control unit that controls the braking device to generate a braking force according to the required deceleration; Equipped with the start condition is when a change in the accelerator opening per unit time is smaller than a predetermined change threshold and when the required driving force is smaller than a predetermined deceleration threshold, the change threshold is a negative value; The support unit When the accelerator pedal is being operated in a release direction during execution of the deceleration assist control, the required deceleration is updated to the basic required deceleration so as to change the deceleration of the vehicle; If the accelerator opening degree does not change during execution of the deceleration assist control, the requested deceleration is maintained so as not to change the deceleration of the vehicle. A vehicle control device characterized by:

2. the surrounding information includes inter-vehicle distance information indicating an inter-vehicle distance to a preceding vehicle traveling ahead of the vehicle, the calculation unit calculates the basic required deceleration to a larger value as the inter-vehicle distance becomes shorter, The support unit maintains the requested deceleration so as not to change the deceleration of the vehicle when the accelerator opening degree does not change even if the inter-vehicle distance becomes shorter during execution of the deceleration support control.

2. The vehicle control device according to claim 1.

3. The support unit resumes updating the requested deceleration to the basic requested deceleration when the accelerator opening degree starts to further decrease from a state in which the requested deceleration is maintained during execution of the deceleration support control.

3. The vehicle control device according to claim 2.

4. an end condition for determining the driver's intention to accelerate, the end condition for the deceleration assist control being when the required driving force is equal to or greater than a predetermined acceleration threshold; the acceleration threshold is a positive value; The support unit ends the deceleration support control when the end condition is satisfied during execution of the deceleration support control.

4. The vehicle control device according to claim 3.

5. The deceleration threshold is set to zero 5. The vehicle control device according to claim 1, wherein the vehicle control device is a control device for controlling a vehicle.

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