Vehicle control system

Abstract

To suppress a vehicle from slipping down when returning from creep cut control.SOLUTION: A control part 22 performs creep cut control of decreasing output torque of an MG30 in a state where a vehicle stops and a brake is turned on, and when determining that the brake is turned off while decreasing the output torque of the MG30, performs return-time control of increasing the output torque of the MG30 on the basis of a torque value calculated by feedback control so that vehicle speed of the vehicle matches predetermined creep speed V1.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a vehicle control device.

Background Art

[0002] Patent Document 1 describes a technique for controlling a drive source based on a creep driving force set so that a vehicle does not slip down when the vehicle stops on a slope road, and reducing the driving force when the braking force generated based on the driver's braking operation is greater than the creep driving force.

[0003] Further, Patent Document 2 describes a technique for changing the torque amount during parking according to the inclination amount of the road surface acquired by a road surface state acquisition means (G sensor) when a brake operation is detected while the vehicle is in a stopped state.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] Although Patent Document 1 describes reducing the driving force generated by a motor when a braking force that prevents the vehicle from slipping down is generated, it does not describe the control when the brake is released and the driving force generated by the motor is restored. Therefore, the technique described in Patent Document 1 may cause the vehicle to slip down when the brake is quickly released while the vehicle is stopped on a slope road.

[0006] Furthermore, the technology described in Patent Document 2 retains creep torque corresponding to the amount of inclination (angle of inclination) when a slope is detected, which may suppress the vehicle from sliding backward even when the brakes are released, but it has the drawback of increasing the vehicle's energy consumption. In addition, sensors that detect the amount of road surface gradient (e.g., G sensors) have variations in the detected values, and if the amount of road surface gradient detected by the sensor is smaller than the actual amount of road surface gradient, there is a risk that the vehicle may slide backward significantly if the brakes are released quickly.

[0007] This disclosure is made in consideration of the above facts, and aims to provide a vehicle control device that can suppress the occurrence of vehicle rollback when returning from creep-cut control. [Means for solving the problem]

[0008] The vehicle control device according to the first embodiment includes a control unit that performs creep-cut control to reduce the output torque of the motor, which is the drive source of the vehicle, when the vehicle is stopped and the brakes are applied, and when it is determined that the brakes have been turned off while the output torque is being reduced, it performs recovery control to increase the output torque based on a torque value calculated by feedback control so that the vehicle speed matches a predetermined creep speed. Furthermore, in the recovery control, the control unit controls the output torque to a torque equivalent to the result of adding a guaranteed gradient equivalent torque, which is set to prevent the vehicle from sliding down on an uphill road with a predetermined road surface gradient, to the torque value calculated in the feedback control. If the recovery control determines that the vehicle has been sliding down, the control unit increases the output torque at a higher rate than when it is not determined that the vehicle has been sliding down, using a gain calculated from the road surface gradient amount detected by the gradient detection sensor that detects the road surface gradient amount. It is.

[0009] In the first embodiment, when the vehicle is stopped and the brakes are applied, creep-cut control is performed to reduce the output torque of the motor, which is the driving source of the vehicle. This improves the vehicle's energy efficiency. In the first embodiment, if it is determined that the brakes have been released while the motor's output torque is being reduced, recovery control is performed to increase the motor's output torque based on a torque value calculated by feedback control so that the vehicle's speed matches a predetermined creep speed. This suppresses the vehicle from sliding backward when recovering from creep-cut control.

[0010] Furthermore, in the first embodiment, during recovery control, the output torque is controlled to a torque equivalent to the result of adding a guaranteed gradient equivalent torque, which is set to prevent the vehicle from sliding down on an uphill road with a predetermined road surface gradient, to the torque value calculated by feedback control. As a result, during recovery control, the vehicle speed can be matched to a predetermined creep speed earlier compared to when the guaranteed gradient equivalent torque is not added.

[0011] moreover, The 1 In this configuration, when it is determined during the recovery control that the vehicle has slipped backward, the motor's output torque is increased at a higher rate than when it is not determined that the vehicle has slipped backward, using a gain calculated from the road surface gradient detected by a gradient detection sensor that detects the road surface gradient. As a result, when the vehicle slips backward, the rate at which the motor's output torque increases is greater, and the amount of vehicle slippage can be reduced.

[0012] The 2 manner Vehicle control device related to teeth, The control unit includes a control unit that performs creep-cut control to reduce the output torque of the motor, which is the drive source of the vehicle, when the vehicle is stopped and the brakes are applied, and when it is determined that the brakes have been released while the output torque is being reduced, it performs recovery control to increase the output torque based on a torque value calculated by feedback control so that the vehicle speed matches a predetermined creep speed. If the control unit determines that the vehicle has rolled down during the recovery control after the creep-cut control has been performed, it stores the roll-down history in the storage unit, and if the creep-cut control is performed again within the same trip period while the vehicle's ignition remains on, it increases the output torque during the recovery control or the standby torque during the creep-cut control when the roll-down history is stored in the storage unit compared to the output torque during the recovery control or the standby torque during the creep-cut control when the roll-down history is not stored.

[0013] In the second embodiment, when the vehicle is stopped and the brakes are applied, creep-cut control is performed to reduce the output torque of the motor, which is the driving source of the vehicle. This improves the vehicle's energy efficiency. Furthermore, in the first embodiment, if it is determined that the brakes have been released while the motor's output torque is being reduced, recovery control is performed to increase the motor's output torque based on a torque value calculated by feedback control so that the vehicle speed matches a predetermined creep speed. This suppresses the vehicle from sliding backward when recovering from creep-cut control. Also, The 2 In this configuration, if it is determined during the recovery control that the vehicle has shifted backward, the shift history is stored in the memory unit. Furthermore, if creep-cut control is performed again within the same trip period, the motor output torque during the recovery control when the shift history is stored in the memory unit is increased compared to the motor output torque during the recovery control when the shift history is not stored. This makes it possible to suppress the occurrence of further shifting within the same trip period if the vehicle shifts backward due to the vehicle's weight or other reasons. [Effects of the Invention]

[0014] The present disclosure has an effect of suppressing the occurrence of vehicle creep when returning from creep cut control.

Brief Description of the Drawings

[0015] [Figure 1] It is a block diagram showing a schematic configuration of a vehicle control device according to an embodiment. [Figure 2] It is a flowchart showing creep cut / return control processing executed by the HEV ECU. [Figure 3] It is a timing chart showing the rising rate of the output torque of the MG and the like. [Figure 4] It is a functional block diagram showing control by the control unit. [Figure 5] It is a diagram showing an example of the relationship between the road surface gradient amount and the rising rate of the MG output torque.

Modes for Carrying Out the Invention

[0016] Hereinafter, an example of an embodiment of the present disclosure will be described in detail with reference to the drawings. A vehicle equipped with the vehicle control device 10 shown in FIG. 1 is a hybrid electric vehicle (HEV) equipped with an engine (not shown), a motor generator (hereinafter referred to as "MG") 30 that operates as a motor for driving the vehicle or as a generator, and a high-voltage battery (not shown). The vehicle control device 10 includes a brake ECU 18, a power control unit (hereinafter referred to as "PCU") 26 including a HEV ECU (Electronic Control Unit) 20, an MG ECU 28, and the MG 30. Note that the MG 30 is an example of the motor in the present disclosure.

[0017] The MG30 and the aforementioned high-voltage battery are connected to the PCU26. The PCU26 includes an inverter capable of converting AC power to DC power and converting DC power to AC power. When the MG30 operates as a motor, power is supplied from the high-voltage battery to the MG30 via the PCU26. When the MG30 operates as a generator, the power generated by the MG30 is supplied to the high-voltage battery via the PCU26, thereby charging the high-voltage battery.

[0018] The MG ECU28 includes a CPU (Central Processing Unit), memories such as a ROM (Read Only Memory) and a RAM (Random Access Memory), a non-volatile storage unit such as an HDD (Hard Disk Drive) and an SSD (Solid State Drive), and an I / F (InterFace) unit. When the MG30 operates as a motor, the MG ECU28 receives a torque command value from the HEV ECU20 and controls the operation of the MG30 so that the output torque from the rotating shaft of the MG30 matches the received torque command value. Also, the MG ECU28 receives the rotational speed (rotation speed) of the rotating shaft of the MG30 from a rotation detection sensor 32 built into the MG30 and outputs the received rotational speed of the rotating shaft of the MG30 to the HEV ECU20.

[0019] On the other hand, the brake ECU18 includes a CPU, memories such as a ROM and a RAM, a non-volatile storage unit such as an HDD and an SSD, and an I / F unit. The brake ECU18 is connected to a G sensor 12 mounted on the vehicle and a brake device 14 including a hydraulic pressure sensor 16. The detection value of the G sensor 12 is used to calculate the detection value of the road surface gradient amount θ. The G sensor 12 is an example of the gradient detection sensor in the present disclosure.

[0020] The hydraulic pressure sensor 16 detects the hydraulic pressure P of the brake fluid in the master cylinder of the brake system 14. The brake ECU 18 performs hill hold control to maintain the brakes on when the brakes are released while the vehicle is stopped on an uphill road where the road surface gradient θ is greater than or equal to the second threshold θth2. The second threshold θth2 is related to the first threshold θth1 (described later) in the relationship θth2 > θth1, and is, for example, a road surface gradient of about 7%. The brake ECU 18 is connected to the HEV ECU 20 and outputs the detected values ​​of the G sensor 12 and the hydraulic pressure sensor 16 to the HEV ECU 20.

[0021] The HEV ECU20 includes a CPU, memory such as ROM and RAM, a non-volatile storage unit such as an HDD or SSD, and an I / F unit. The HEV ECU20 is connected to a shift position sensor 24 that detects the vehicle's shift position. The HEV ECU20 also stores a control program in its memory. The HEV ECU20 functions as a control unit 22 when the control program is read from the memory and loaded into the memory, and then executed by the CPU. The control unit 22 then performs creep cut / recovery control processing (described later) while the vehicle's ignition is on.

[0022] The control unit 22 performs creep-cut control to reduce the output torque of the MG30 when the vehicle is stopped and the brakes are applied. Furthermore, if the control unit 22 determines that the brakes have been released while the output torque of the MG30 is being reduced, it performs recovery control to increase the output torque of the MG30 based on a torque value calculated by feedback control so that the vehicle speed matches a predetermined creep speed. Note that the control unit 22 is an example of a control unit in this disclosure.

[0023] Next, as an explanation of the operation of this embodiment, the creep cut / recovery control process performed by the control unit 22 while the vehicle ignition is on will be described with reference to Figure 2.

[0024] In step 100, the control unit 22 clears the memory. As described later, the memory stores information about the vehicle's sliding history when it slides backward. In the next step 102, the control unit 22 determines whether the conditions for implementing creep-cut control have been met. Examples of conditions for implementing creep-cut control include, as shown by arrow A in Figure 3, when the rotation speed of the MG30 detected by the rotation detection sensor 32 becomes 0, the brake is turned on and the brake flag switches to a value indicating brake on, and the detected value of the road surface gradient amount θ is less than the first threshold θth1. The first threshold θth1 is the road surface gradient amount corresponding to the maximum value of the variation in the detection of the road surface gradient amount θ by the G sensor 12, and as an example, it is a road surface gradient amount of about 3.5%.

[0025] If the determination in step 102 is affirmative, the process proceeds to step 104, in which the control unit 22 determines whether or not the vehicle's sliding history information is stored in memory. If the determination in step 104 is negative, the process proceeds to step 108.

[0026] In step 108, the control unit 22 switches the creep cut control flag (see Figure 3) to a value indicating that creep cut control is in progress, and performs a first creep cut control to reduce the output torque (standby torque) of the MG30. In the first creep cut control, the output torque of the MG30 may be set to 0, or the output torque of the MG30 may be set to a value that is smaller than the output torque before the start of the first creep cut control and greater than 0, for example, a value corresponding to the detected road surface gradient θ. By performing this first creep cut control, the vehicle's energy efficiency can be improved.

[0027] When the first creep-cut control is performed in step 108, the process proceeds to step 110. In step 110, the control unit 22 determines whether the brakes have been turned off. For example, it is preferable to determine that the brakes have been turned off when the rate of change of the brake fluid pressure P detected by the hydraulic pressure sensor 16 becomes greater than or equal to a first predetermined value, or when the absolute value of the brake fluid pressure P falls below a second predetermined value. For example, if the brakes are turned off quickly, the rate of change of the brake fluid pressure P becomes greater than or equal to the first predetermined value, allowing for early determination that the brakes have been turned off when the brakes are turned off quickly. Also, if the brakes are turned off slowly, the absolute value of the brake fluid pressure P falls below a second predetermined value, allowing for appropriate determination that the brakes have been turned off even when the brakes are turned off slowly.

[0028] However, step 110 is not limited to determining brake off using the hydraulic pressure P of the brake fluid; for example, brake off may be determined based on whether or not a brake switch, which is turned on or off in conjunction with the on / off status of the brakes, has been turned off.

[0029] If the determination in step 110 is affirmative, the brake flag is switched to a value indicating brake off, and the creep cut control flag is switched to a value indicating that creep cut control is not in operation (see also arrow B in Figure 3), before proceeding to step 112. Then, recovery control is performed from step 112 onward.

[0030] In other words, in step 112, the control unit 22 determines whether or not the vehicle's sliding history information is stored in memory. If the determination in step 112 is negative, the process proceeds to step 114.

[0031] In step 114, the control unit 22 performs a first control by outputting a torque command value to the MG ECU 28 so that the output torque of the MG 30 is the sum of a guaranteed gradient equivalent torque set so that the vehicle does not slide down on an uphill road with a road surface gradient of a first threshold θth1, and a torque value calculated by feedback control so that the vehicle speed matches a predetermined creep speed V1.

[0032] More specifically, the control unit 22 functionally includes a feedforward controller 40, a subtraction unit 42, a feedback controller 44, and an addition unit 46, as shown in Figure 4. When the target vehicle speed (a predetermined creep speed V1) is input to the feedforward controller 40, it outputs a guaranteed gradient equivalent torque. The subtraction unit 42 calculates a vehicle speed deviation Error by subtracting the actual vehicle speed calculated from the MG rotation speed from the target vehicle speed (a predetermined creep speed V1). The feedback controller 44 calculates a torque value based on the vehicle speed deviation Error calculated by the subtraction unit 42 using a predetermined control gain (a control gain whose output torque increase rate is equal to the reference torque rate A (see Figure 3)). The addition unit 46 then adds the guaranteed gradient equivalent torque output from the feedforward controller 40 and the torque value output from the feedback controller 44, and outputs the sum to the PCU 26 as the manipulated amount of the MG 30's output torque.

[0033] The first control described above combines feedforward control and feedback control to ensure that the output torque of the MG30 is zero, thereby suppressing vehicle rollback when returning from creep-cut control. Furthermore, compared to the case without feedforward control, the actual vehicle speed can be matched to the predetermined creep speed V1 earlier.

[0034] In the next step 118, the control unit 22 determines whether the rotation of the MG30's rotation axis has been detected in the rotation detection sensor 32, that is, whether the vehicle has slipped backward. If the determination in step 118 is negative, the process proceeds to step 124. In step 124, the control unit 22 determines whether to terminate the return control by determining whether the termination conditions for the return control have been met, for example, the vehicle has moved forward. If the determination in step 124 is negative, the process returns to step 118, and steps 118 and 124 are repeated.

[0035] Furthermore, if vehicle sliding occurs, the determination in step 118 is affirmed, and the sliding determination flag is switched to a value indicating the occurrence of sliding (see also arrow C in Figure 3), before proceeding to step 120. In step 120, the control unit 22 changes the control gain in the feedback control by the feedback controller 44 to a value obtained by multiplying a predetermined control gain by a gain Gain_f(θ) corresponding to the detected road surface gradient amount θ, which is higher than when it is not determined that vehicle sliding has occurred. This control reduces the amount of vehicle sliding by increasing the output torque from the MG30 to a value greater than the reference torque rate A and at an increase rate corresponding to the detected road surface gradient amount θ (sliding determination rate = A × Gain_f(θ): see Figure 3).

[0036] The gain Gain_f(θ) corresponding to the detected road surface gradient θ should be determined such that the rate of increase in output torque is higher when the detected road surface gradient θ is greater than or equal to a predetermined value compared to when the detected road surface gradient θ is less than a predetermined value.

[0037] Specifically, as shown in Figure 5(A), for example, the gain Gain_f(θ) may be determined so that the gain Gain_f(θ) increases in steps with increasing detected road gradient θ. Alternatively, as shown in Figure 5(B), for example, the gain Gain_f(θ) may be determined so that the gain Gain_f(θ) increases linearly with increasing detected road gradient θ. Furthermore, as shown in Figure 5(C), for example, the gain Gain_f(θ) may be determined so that the gain Gain_f(θ) increases quadratically with increasing detected road gradient θ. This makes it possible to reduce the amount of vehicle sliding down when the road gradient θ is relatively large.

[0038] After performing the control in step 120, the process proceeds to step 122. In step 122, the control unit 22 stores the vehicle's sliding history information, indicating that the vehicle has slid backward, in memory, and then proceeds to step 124. If the determination in step 124 is affirmative, in step 126, the process of outputting the normal creep torque from the MG30 is performed, and then the process returns to step 102. The normal creep torque is, for example, the torque at which the vehicle's creep speed reaches a predetermined value (for example, around 5-10 km / h) when the vehicle is parked on a flat road.

[0039] On the other hand, if the creep cut condition is met and the determination in step 102 is affirmed after the vehicle has rolled backward once or more within the same trip period while the vehicle's ignition remains on, the determination in step 104 is affirmed and the system proceeds to step 109. Causes of vehicle rollback include, for example, a heavier-than-normal vehicle weight due to a large number of passengers. If the cause is a heavy vehicle weight, there is a possibility that the vehicle may roll backward again within the same trip period. Therefore, in step 109, the control unit 22 performs a second creep cut control that increases the standby torque output from the MG30 compared to the first creep cut control, and then proceeds to step 110.

[0040] Furthermore, in the second creep-cut control in step 109, increasing the standby torque compared to the first creep-cut control can be achieved, for example, by calculating the standby torque T2 using the following equation (1), where T2 is the standby torque in the second creep-cut control and T1 is the standby torque in the first creep-cut control. T2 = T1 + Addition term …(1) The additive term in equation (1) is a torque value corresponding to the maximum amount of sliding when sliding occurs. This additive term can be determined, for example, by pre-registering the relationship between the amount of sliding and the additive torque value in a table, and deriving the additive torque value corresponding to the maximum amount of sliding when sliding occurs from the table. As described above, by making the standby torque T2 in the second creep-cut control larger than the standby torque T1 in the first creep-cut control, it is possible to suppress the occurrence of sliding again during creep-cut control within the same trip period when sliding of the vehicle occurs due to the weight of the vehicle, etc.

[0041] Furthermore, if the vehicle rolls backward once or more within the same trip period while the vehicle's ignition remains on, and then a second creep-cut control is performed in step 109, and the brake is subsequently released and the determination in step 110 is affirmed, the determination in step 112 is affirmed and the system proceeds to step 116. In step 116, the control unit 22 performs a second control that increases the output torque from the MG30 compared to the first control, and then proceeds to step 118.

[0042] Furthermore, in the second control in step 116, increasing the output torque from MG30 compared to the first control can be achieved, for example, by changing the target vehicle speed to a predetermined creep speed V2 (where V2 > V1). Alternatively, it can be achieved by making the torque value output from the feedforward controller 40 greater than the guaranteed gradient equivalent torque. It can also be achieved by making the gain Gain_f(θ) multiplied by a predetermined control gain in the feedback control by the feedback controller 44 a value corresponding to the detected road surface gradient amount θ, and greater than during the first control. This makes it possible to suppress the recurrence of vehicle slippage within the same trip period if it occurs due to the vehicle's weight or the like.

[0043] Furthermore, in the determination in step 102, if the detected value of the road surface gradient amount θ is greater than or equal to the first threshold θth1, the process returns to step 102 via step 126.

[0044] As described above, in this embodiment, when the vehicle is stopped and the brakes are applied, the control unit 22 performs creep-cut control, which reduces the output torque of the MG30, the drive source of the vehicle. Furthermore, if the control unit 22 determines that the brakes have been released while the output torque of the MG30 is being reduced, it performs recovery control, which increases the output torque of the MG30 based on the torque value calculated by feedback control so that the vehicle speed matches a predetermined creep speed V1. This makes it possible to suppress the vehicle from sliding backward when recovering from creep-cut control.

[0045] Furthermore, in this embodiment, when the control unit 22 determines that the vehicle has slipped during the return control, it uses the gain Gain_f(θ) calculated from the road surface gradient θ detected by the G sensor 12 to increase the output torque of the MG30 at a higher rate than when it is not determined that the vehicle has slipped. As a result, when the vehicle slips, the rate at which the motor's output torque increases is greater, and the amount of vehicle slippage can be reduced.

[0046] Furthermore, in this embodiment, if the control unit 22 determines that the vehicle has rolled backward after performing creep-cut control, it stores the roll-down history in memory. Also, if the control unit 22 performs creep-cut control again within the same trip period while the vehicle's ignition remains on, it increases the output torque of the MG30 during the recovery control or the standby torque during creep-cut control when the roll-down history is stored in memory compared to the output torque of the MG30 during the recovery control or the standby torque during creep-cut control when the roll-down history is not stored in memory. This makes it possible to suppress the occurrence of further roll-down within the same trip period if the vehicle has rolled backward due to the vehicle's weight or other reasons.

[0047] In the above embodiment, the vehicle equipped with the vehicle control device 10 was described as an HEV (Hybrid Electric Vehicle), but the vehicle equipped with the vehicle control device 10 may also be an EV (Electric Vehicle).

[0048] Furthermore, although the above embodiment describes a method of detecting vehicle slippage by the reverse rotation of the MG30's rotation axis, this disclosure is not limited thereto, and vehicle slippage may also be detected by the reverse rotation of the vehicle's wheels. Alternatively, vehicle slippage may be detected by a GNSS (Global Navigation Satellite System) sensor or the like.

[0049] Furthermore, in the above embodiment, a method was described in which a second control is performed in which the output torque from the MG30 is increased compared to the first control when a history of vehicle sliding is stored in memory during recovery control, but this disclosure is not limited thereto. For example, in the second control, the torque output from the MG30 may be increased as the number of times the vehicle slides increases. Also, for example, creep cut control may be not performed when a history of vehicle sliding is stored in memory, or when the number of times the vehicle slides exceeds a predetermined value.

[0050] The following additional information is disclosed regarding the embodiments described above.

[0051] (Note 1) A vehicle control device including a control unit that performs creep-cut control to reduce the output torque of the motor, which is the drive source of the vehicle, when the vehicle is stopped and the brakes are applied, and when it is determined that the brakes have been released while the output torque is being reduced, performs recovery control to increase the output torque based on a torque value calculated by feedback control so that the vehicle speed matches a predetermined creep speed.

[0052] (Note 2) The vehicle control device according to Appendix 1, wherein the control unit determines that the vehicle has slipped during the return control, and increases the output torque at a higher rate than when it is not determined that the vehicle has slipped, using a gain calculated from the amount of road surface gradient detected by a gradient detection sensor that detects the amount of road surface gradient.

[0053] (Note 3) The vehicle control device according to Appendix 1, wherein the control unit determines that the vehicle has rolled down during the recovery control after the creep cut control has been performed, stores the roll history in the storage unit, and if the creep cut control is performed again within the same trip period while the vehicle's ignition remains on, the output torque during the recovery control or the standby torque during the creep cut control when the roll history is stored in the storage unit is increased compared to the output torque during the recovery control or the standby torque during the creep cut control when the roll history is not stored.

[0054] (Note 4) The vehicle control device according to Appendix 1, wherein the control unit controls the output torque in the return control to a torque equivalent to the result of adding a guaranteed gradient equivalent torque set to prevent the vehicle from sliding down on an uphill road with a predetermined road surface gradient to the torque value calculated by the feedback control. According to the embodiment described in Appendix 4, the vehicle speed can be matched to a predetermined creep speed earlier compared to the case where the guaranteed gradient equivalent torque is not added.

[0055] (Note 5) The vehicle control device described in Appendix 4, wherein the predetermined road surface gradient amount is a road surface gradient amount corresponding to the maximum value of the detection variation in the gradient detection sensor that detects the road surface gradient amount. According to the embodiment described in Appendix 5, even when the detection variability of the gradient detection sensor is relatively large, the motor can output sufficient torque to suppress the vehicle from sliding downwards.

[0056] (Note 6) The control unit, when the vehicle is stopped and the brakes are applied, does not perform the creep-cut control when the amount of road surface gradient detected by the gradient detection sensor that detects the amount of road surface gradient is equal to or greater than the predetermined amount of road surface gradient. This is the vehicle control device described in Appendix 1. According to the embodiment described in Appendix 6, it is possible to reliably suppress the occurrence of vehicle sliding in areas where the road surface gradient detected by the gradient detection sensor for detecting the road surface gradient is greater than or equal to a predetermined road surface gradient. [Explanation of Symbols]

[0057] 10. Vehicle control system 12 G sensor (gradient detection sensor) 20 HEV ECU 22 Control Unit 30 MG 32 Rotation detection sensor

Claims

1. The control unit includes a control unit that performs creep-cut control to reduce the output torque of the motor, which is the drive source of the vehicle, when the vehicle is stopped and the brakes are applied, and when it is determined that the brakes have been released while the output torque is being reduced, it performs recovery control to increase the output torque based on a torque value calculated by feedback control so that the vehicle speed matches a predetermined creep speed. The control unit controls the output torque in the recovery control to a torque equivalent to the result of adding a guaranteed gradient equivalent torque set to prevent the vehicle from sliding down on an uphill road with a predetermined road surface gradient to the torque value calculated in the feedback control, and when it is determined in the recovery control that the vehicle has slid down, it increases the output torque at a higher rate than when it is not determined that the vehicle has slid down, using a gain calculated from the road surface gradient amount detected by a gradient detection sensor that detects the road surface gradient amount.

2. The control unit includes a control unit that performs creep-cut control to reduce the output torque of the motor, which is the drive source of the vehicle, when the vehicle is stopped and the brakes are applied, and when it is determined that the brakes have been released while the output torque is being reduced, it performs recovery control to increase the output torque based on a torque value calculated by feedback control so that the vehicle speed matches a predetermined creep speed. The control unit, when it determines that the vehicle has rolled down during the recovery control after the creep cut control has been performed, stores the roll history in the storage unit, and when the creep cut control is performed again within the same trip period while the vehicle's ignition remains on, increases the output torque during the recovery control or the standby torque during the creep cut control when the roll history is stored in the storage unit compared to the output torque during the recovery control or the standby torque during the creep cut control when the roll history is not stored.

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