JP2019115226A - Control device, control method and control system for electric vehicle - Google Patents

Abstract

To provide a control device, a control method and a control system for an electric vehicle that can suppress operability from becoming worse in parking operation with accelerator operation.SOLUTION: For example, a vehicle body speed is equal to or lower than a low-speed determination speed, a brake manipulated variable is larger than a stop request determination manipulated variable, and a steering manipulated variable is equal to or larger than a parking determination steering manipulated variable. In this case, it is determined that the driver is in parking operation, and creep torque is permitted to be output (S1→S2→S3→S5→S6→S4→S10), and while the driver is in parking operation, the creep torque is permitted to be output during the parking operation even if accelerator operation and brake operation are done (S1→S2→S9).SELECTED DRAWING: Figure 2

Description

  The present invention relates to a control device, a control method, and a control system of an electric vehicle.

  According to Patent Document 1, when the accelerator pedal is depressed more than a predetermined position, the brake pedal is applied while the vehicle is stopped or traveling at low speed in an electric vehicle that performs so-called one-pedal control by applying braking force to the vehicle. A technique is disclosed that outputs creep torque when stepped on. If the accelerator pedal is depressed beyond the predetermined position during the output of the creep torque, the output of the creep torque is prohibited.

JP, 2017-47746, A

In the above-mentioned prior art, when the accelerator pedal is depressed during the parking operation, the output of the creep torque is inhibited, and when the accelerator pedal is depressed thereafter, the vehicle is stopped by the one pedal control. For this reason, in the above-mentioned prior art, there existed a possibility that the operativity at the time of parking which requires accelerator operation might deteriorate.
One of the objects of the present invention is to provide a control device, a control method, and a control system of an electric vehicle capable of suppressing deterioration of operability at the time of parking requiring an accelerator operation.

  The control device for an electric vehicle according to an embodiment of the present invention outputs a command to generate regenerative braking force to the electric motor when a signal regarding depression of the accelerator pedal is input from the accelerator pedal sensor, and a vehicle speed detection sensor When an output value below a predetermined speed is input and an output value above a predetermined steering angle is input from the steering angle detection sensor, a command to generate a creep torque is output to the electric motor.

  Therefore, according to the present invention, it is possible to suppress the deterioration of operability at the time of parking requiring an accelerator operation.

FIG. 1 is a view showing a control system of an electrically powered vehicle of an embodiment 1. 5 is a flowchart showing a flow of creep output permission determination control according to the first embodiment. 7 is a time chart showing an operation of creep output permission determination control of the first embodiment.

Embodiment 1
FIG. 1 is a view showing a control system of the electric-powered vehicle of the first embodiment.
The electrically powered vehicle (hereinafter referred to as a vehicle) is a front wheel drive vehicle and has wheels FL, FR, RL, and RR. The front wheels FL, FR are drive wheels, and the rear wheels RL, RR are driven wheels. A wheel cylinder 1 and a wheel speed sensor (vehicle body speed detection sensor) 2 are attached to each wheel. The wheel cylinder 1 presses a brake pad against a brake rotor that rotates integrally with a tire to generate a frictional braking force. The wheel speed sensor 2 detects the wheel speed of the corresponding wheel. A hydraulic unit 3 is connected to the wheel cylinder 1 via a hydraulic piping 1a. The hydraulic unit 3 has a plurality of solenoid valves, a reservoir and a motor for pump. The hydraulic unit 3 applies a braking force to each wheel by controlling the driving states of the solenoid valves and the pump motor based on the hydraulic pressure command from the brake controller 6. The brake controller 6 outputs a hydraulic pressure command to the hydraulic pressure unit 3 in accordance with a friction braking command from a vehicle controller (control unit) 18 described later.

  The vehicle has a motor / generator (electric motor, hereinafter referred to as a motor) 7 as a power source for driving the front wheels FL, FR. The motor 7 has a resolver 7a that detects a motor rotation angle. The motor 7 is connected to the front wheels FL, FR via the reduction gear mechanism 8, the differential gear 9 and the drive shaft 10. The vehicle has a high voltage battery 11 and a battery controller 12. The high voltage battery 11 supplies electric power to the motor 7 during powering operation of the motor 7 and recovers the generated power of the motor 7 during regenerative operation of the motor 7. An auxiliary battery 14 is connected to the high voltage battery 11 via a DC-DC converter 13. The accessory battery 14 functions as a power supply for driving the hydraulic unit 3. The battery controller 12 monitors the state of the high voltage battery 11 and controls the state of the high voltage battery 11 in accordance with a battery control command from the vehicle controller 18. An inverter 15 is provided between the high voltage battery 11 and the motor 7. The inverter 15 controls the output torque of the motor 7 based on an inverter drive signal from the motor controller 16. The motor controller 16 outputs to the inverter 15 an inverter drive signal according to a torque command from the vehicle controller 18.

  The vehicle controller 18, the brake controller 6, the motor controller 16 and the battery controller 12 communicate via the CAN communication line 17. The vehicle controller 18 includes a steering operation amount signal from a steering angle sensor (steering angle detection sensor) 19, an accelerator opening degree signal from an accelerator opening degree sensor (accelerator pedal sensor) 20, and a brake stroke sensor (brake pedal sensor) 21. Input the brake operation amount signal. The steering angle sensor 19 detects a steering angle of the steering wheel 22 (hereinafter referred to as a steering operation amount). The accelerator opening sensor 20 detects the opening of the accelerator pedal 23 (hereinafter referred to as the accelerator opening). The brake stroke sensor 21 detects an operation amount of the brake pedal 24 (hereinafter referred to as a brake operation amount). The vehicle controller 18 also receives a vehicle speed signal calculated by the brake controller 6 via the CAN communication line 17. The brake controller 6 calculates the vehicle speed based on each wheel speed detected by the wheel speed sensor 2.

  The vehicle controller 18 calculates the required driving force or the required braking force of the vehicle according to each input signal. The required driving force has a larger value as the accelerator opening degree is higher or as the vehicle speed is lower. The vehicle controller 18 sets a torque command for realizing the calculated required driving force. In addition, it is a request that the creep phenomenon of an AT car is simulated and the motor 7 outputs a minute torque as a creep torque while the accelerator opening is 0 and the vehicle speed is, for example, 10 km / h or less. Driving force is calculated. The required braking force has a larger value as the brake operation amount is larger. The vehicle controller 18 sets a torque command and a friction braking command to realize the calculated required braking force. The vehicle controller 18 sets a torque command and a friction braking command such that the sum of the regenerative braking force and the friction braking force becomes the required braking force as the regenerative coordination control. At this time, priority is given to the regenerative braking force over the friction braking force, and the torque command and the friction braking command are set so as to realize the required braking force with only the regenerative braking force as much as possible, thereby improving energy recovery efficiency. In addition, when the brake operation amount is zero and the accelerator opening degree is zero, the required braking force that simulates the engine brake is calculated.

The vehicle controller 18 of the first embodiment applies the braking force to the vehicle to stop the vehicle instead of the output of the creep torque when the accelerator pedal 23 is stepped back and the accelerator opening becomes equal to or less than the predetermined opening. Execute one pedal control. The required braking force at the time of one pedal control increases as the accelerator opening approaches zero, and takes a maximum value when the accelerator opening is zero. The required braking force may be increased as the return speed of the accelerator pedal 23 is higher. The maximum value of the required braking force is appropriately set as the braking force required to stop the vehicle (stopping braking force). The stopping braking force is corrected according to the road surface gradient, the friction coefficient between the tire and the road surface, the vehicle weight, and the like. Although regenerative braking force is given priority even in one pedal control, regenerative braking force can not be generated when the vehicle is stopped, so switching from regenerative braking force to friction braking force is performed just before stopping, and the stopped state is maintained by friction braking force Ru.
With the one-pedal control, the vehicle can be decelerated, the vehicle can be stopped, and the vehicle can be held only by depressing the accelerator pedal 23. However, when the one pedal mode for permitting the one pedal control intervention is ON, the creep torque is not generated, and therefore, the driver is forced to perform complicated operation in a scene in which stopping at low traffic and the like and low speed traveling are alternately repeated. At this time, by switching off the one pedal mode, the mode can be switched to the normal mode for generating the creep torque, but since the manual operation is necessary for the mode switching, the driving load is increased.

On the other hand, even when the one pedal mode is ON, when the brake pedal is depressed while the vehicle is stopped or traveling at low speed, creep torque is output instead of the braking force until the accelerator pedal is depressed. Technology is known. In this prior art, since the vehicle position can be adjusted only by the brake operation, the drivability at the time of traffic congestion can be improved. However, in the above-mentioned prior art, there is a problem in operability at the time of parking requiring an accelerator operation. Describing in detail, when there is a road surface with a large running resistance in the parking path, such as a parking lot or slope on a gravel bed, the driving force is insufficient only with the creep torque, so acceleration by accelerator operation is required. In the above-mentioned prior art, the output of the creep torque is prohibited by the accelerator operation, and the vehicle stops when the accelerator pedal is released. For this reason, in the above-mentioned prior art, every time the driver performs an accelerator operation, the vehicle repeats starting and stopping, which may deteriorate operability.
Therefore, the vehicle controller 18 according to the first embodiment aims to suppress the deterioration of the operability during parking requiring an accelerator operation, and executes the creep output permission determination control as described below when the one pedal mode is ON. Do.

FIG. 2 is a flowchart showing the flow of creep output permission determination control of the first embodiment. This control is repeatedly executed in a predetermined operation cycle when the one pedal mode is ON.
In step S1, it is determined whether the vehicle speed is equal to or less than the low speed determination speed. In the case of YES, the process proceeds to step S2, and in the case of NO, the process proceeds to step S8. The low speed determination speed is an upper limit value of the vehicle body speed assumed during the parking operation, and is, for example, 10 km / h.
In step S2, it is determined whether the driver is in a parking operation. In the case of YES, the process proceeds to step S9, and in the case of NO, the process proceeds to step S3. In this step, when the parking operation flag F1 is set (F1 = 1), it is determined that the parking operation is being performed, and when the reset F1 (= 0) is determined, it is determined that the parking operation is not being performed. Do.
In step S3, it is determined whether there is a driver's stop request. In the case of YES, the process proceeds to step S4, and in the case of NO, the process proceeds to step S5. In this step, it is determined that there is a stop request if the stop request flag F2 is set (F2 = 1), and it is determined that there is no stop request if it is reset (F2 = 0).

In step S4, it is determined whether the steering operation amount is equal to or greater than the parking determination steering angle. In the case of YES, the process proceeds to step S10, and in the case of NO, the process proceeds to step S7. The parking determination steering operation amount is a steering operation amount assumed to be when the vehicle is parked, and is, for example, 90 °.
In step S5, it is determined whether the brake operation amount is larger than the stop request determination operation amount. In the case of YES, the process proceeds to step S6, and in the case of NO, the process proceeds to step S13. The stop request determination operation amount is a brake operation amount assumed to be that the driver is performing a brake operation, and is, for example, a brake operation amount at which the brake lamp is lit.
In step S6, the stop request flag F2 is set (F2 = 1).
In step S7, it is determined whether the accelerator opening is positive (> 0). In the case of YES, the process proceeds to step S11, and in the case of NO, the process proceeds to step S12. In this step, it is determined whether the driver is operating the accelerator.
In step S8, as in step S7, it is determined whether the accelerator opening is positive (> 0). In the case of YES, the process proceeds to step S13, and in the case of NO, the process proceeds to return.

In step S9, the creep torque output is permitted, and the process proceeds to return. When the output of the creep torque is permitted, the required braking force is calculated so that the creep torque can be obtained, for example, to obtain a vehicle speed of 6 to 7 Km / h on a flat road. When the output of the creep torque is permitted, the application of the braking force in the one pedal control is prohibited even if the accelerator pedal 23 is stepped back.
In step S10, the in-parking operation flag F1 is set (F1 = 1), the creep torque output is permitted, and the process proceeds to return.
In step S11, output of creep torque is inhibited, and the vehicle stop request flag F2 is reset (F2 = 0), and the process proceeds to return. When the output of the creep torque is prohibited, the braking force is applied by one pedal control when the accelerator pedal 23 is released.
In step S12, as in step S9, output of creep torque is permitted, and the process proceeds to return.
In step S13, the in-parking operation flag F1 and the stop request flag F2 are reset (F1 = 0, F2 = 0), and the output of the creep torque is inhibited as in step S11, and the process proceeds to return.

Next, the operation and effect of the first embodiment will be described.
FIG. 3 is a time chart showing the operation of the creep output permission determination control of the first embodiment. As a comparative example, the one that prohibits the output of the creep torque when the accelerator pedal is depressed is shown by a broken line.
Before time t1, the vehicle speed is higher than the low speed determination speed, and the accelerator opening degree is 0. Therefore, in the flowchart of FIG. 2, the flow of S1 to S8 is repeated. Since the output of the creep torque is not permitted, the torque command value is the regenerative braking torque in the one pedal control, and the vehicle is decelerated by the braking force (regenerative braking force).
At time t1, since the vehicle speed coincides with the low speed determination speed, in the flowchart of FIG. 2, the flow of S1 → S2 → S3 → S5 → S13 is made, and the application of the regenerative braking torque is continued.
At time t2, the steering operation amount is larger than the parking determination steering operation amount, and the brake operation amount is larger than the stop request determination operation amount. Therefore, in the flowchart of FIG. 2, S1 → S2 → S3 → S5 → S6 → The process proceeds from S4 to S10, the in-parking operation flag F1 is set (ON), and the creep torque output is permitted. Accordingly, the flow of S1 → S2 → S9 is obtained, and the output of the creep torque is permitted. Since the torque command changes from regenerative braking torque to creep torque, the vehicle starts moving.

At time t3, the driver starts the accelerator operation. In the flowchart of FIG. 2, since the flow of S1 → S2 → S9 is maintained, the output of the creep torque is continued. Since the torque command increases in accordance with the accelerator opening, the driver can obtain a desired acceleration.
At time t4, the driver starts the brake operation. In the flowchart of FIG. 2, since the flow of S1 → S2 → S9 is maintained, the output of the creep torque is continued. Since the torque command is a creep torque, the driver can adjust the vehicle position only by the brake operation.
At time t5, the vehicle stops at the parking position.
In the comparative example, since the creep torque output is prohibited at time t3, when the driver depresses the accelerator pedal, the torque command becomes a regenerative braking torque, and the vehicle stops. For this reason, at the time of the parking which requires accelerator operation, a vehicle will repeat start and stop every time of accelerator operation, and a driver is forced to carry out complicated operation.
On the other hand, in the creep output permission determination control of the first embodiment, when it is determined that the vehicle speed is equal to or lower than the low determination speed and parking operation is in progress (the steering operation amount is the parking determination steering operation amount in the previous calculation cycle) In the above case), the creep torque output is permitted regardless of the accelerator operation and the brake operation (S1 → S2 → S9). As a result, the vehicle position can be adjusted only by the brake operation even after the accelerator operation, so that it is possible to suppress the deterioration of operability at the time of parking requiring the accelerator operation. Moreover, since it is not necessary for the driver to turn off the one pedal mode each time the parking operation is performed, it is possible to suppress an increase in driving load.

In the creep output permission determination control of the first embodiment, parking is performed when the vehicle speed is equal to or lower than the low determination speed, the brake operation amount is larger than the stop request determination operation amount, and the steer operation amount is equal to or more than the parking determination steer operation amount. Judging that it is in operation, permitting creep torque output (S1 → S2 → S3 → S5 → S6 → S4 → S10) and permitting parking torque regardless of accelerator operation and brake operation (S1) → S2 → S9). It is possible to more accurately determine whether the parking operation is in progress by looking at the driver's request for stopping in addition to the amount of steering operation.
In the creep output permission determination control of the first embodiment, when the vehicle speed is equal to or lower than the low speed determination speed, the steering operation amount is less than the parking determination steering operation amount, and the accelerator opening is 0, the creep torque output is permitted. (S1 → S2 → S3 → S4 → S7 → S12). That is, even when the parking operation is not being performed, the output of the creep torque is permitted when the accelerator operation is not performed. As a result, since the driver can adjust the inter-vehicle distance only by the brake operation at the time of traffic congestion, it is possible to suppress the deterioration of operability.
In the creep output permission determination control of the first embodiment, the creep torque is output when the vehicle speed is equal to or less than the low speed determination speed, the steering operation amount is less than the parking determination steering operation amount, and the accelerator opening is greater than zero. Are prohibited (S1 → S2 → S3 → S4 → S7 → S11). That is, when it is determined that the driver is not willing to park the vehicle and the driver has an intention to accelerate the vehicle, the output of the creep torque is inhibited to operate the one pedal control. As a result, when the distance to the preceding vehicle is reduced after the distance to the preceding vehicle is separated at the time of traffic congestion, it is possible to realize the stop from the deceleration and the holding of the vehicle only by the stepping back operation of the accelerator pedal 23.

Other Embodiments
As mentioned above, although the embodiment for carrying out the present invention was described, the concrete composition of the present invention is not limited to the composition of the embodiment, and there are design changes within the scope of the present invention. Also included in the present invention.
In the first embodiment, although the accelerator opening sensor 20 for detecting the accelerator opening is used as the accelerator pedal sensor, any sensor may be used as long as the accelerator pedal sensor can detect a physical quantity (depression amount and return amount) related to the stroke of the accelerator pedal. May be used.
In the first embodiment, although the wheel speed sensor 2 (the value obtained from the detection value of the wheel speed sensor 2) for detecting each wheel speed is used as the vehicle body speed detection sensor, the vehicle speed detection sensor can detect any physical quantity related to the vehicle speed. A sensor may be used.
Although the steering angle sensor 19 for detecting the steering angle of the steering wheel 22 is used as the steering angle detection sensor in the first embodiment, any sensor may be used as the steering angle detection sensor as long as it can detect a physical quantity related to the steering angle.
In the first embodiment, the brake stroke sensor 21 for detecting the operation amount of the brake pedal 24 is used as the brake pedal sensor, but the brake pedal sensor is optional as long as it can detect physical quantities (depression amount and return amount) related to the stroke of the brake pedal. Sensors may be used.
The electric vehicle may be a rear wheel drive vehicle or a four wheel drive vehicle.

2 Wheel speed sensor (vehicle speed detection sensor)
7 Motor (electric motor)
18 Vehicle controller (control unit)
19 Steering angle sensor (steering angle detection sensor)
20 accelerator opening sensor (accelerator pedal sensor)
21 Brake stroke sensor (brake pedal sensor)
23 accelerator pedal
24 brake pedals
FL, FR front wheel (wheel)
RL, RR Rear wheels (wheels)

Claims (5)

A control device for an electric vehicle including an electric motor that applies regenerative braking force to wheels of the vehicle,
When a signal relating to depression of the accelerator pedal is input from an accelerator pedal sensor that detects a physical quantity related to a stroke of an accelerator pedal of the vehicle, a command to generate the regenerative braking force is output to the electric motor,
An output value below a predetermined speed is input from a vehicle speed detection sensor that detects a physical quantity related to the vehicle body speed of the vehicle, and an output value that exceeds a predetermined steering angle is input from a steering angle detection sensor that detects a physical quantity related to the steering angle of the vehicle. And a control device for an electric vehicle that outputs a command to cause the electric motor to generate a creep torque. In the control device for an electric vehicle according to claim 1,
An output value below a predetermined speed is input from the vehicle body speed detection sensor, and a signal relating to the depression of the brake pedal is input from a brake pedal sensor that detects a physical quantity related to a stroke of the brake pedal of the vehicle. The control apparatus of the electric vehicle which outputs the instruction | command which makes the said electric motor generate a creep torque, when the output value which exceeds a predetermined steering angle from is input. In the control device for an electric vehicle according to claim 1,
An output value below a predetermined speed is input from the vehicle body speed detection sensor, and an output value below a predetermined steering angle is input from the steering angle detection sensor, and a signal regarding depression of the accelerator pedal is input from the accelerator pedal sensor And a control device for an electric vehicle that outputs a command for prohibiting creep torque to the electric motor. When a signal relating to depression of the accelerator pedal is input from an accelerator pedal sensor that detects a physical quantity related to a stroke of an accelerator pedal of the vehicle, the regenerative braking force is generated in an electric motor that applies regenerative braking force to wheels of the vehicle. Output the command,
An output value below a predetermined speed is input from a vehicle speed detection sensor that detects a physical quantity related to the vehicle body speed of the vehicle, and an output value that exceeds a predetermined steering angle is input from a steering angle detection sensor that detects a physical quantity related to the steering angle of the vehicle. A control method of an electric vehicle, which outputs a command to cause the electric motor to generate creep torque. An electric motor that applies regenerative braking force to the wheels of the vehicle;
An accelerator pedal sensor that detects a physical quantity related to a stroke of an accelerator pedal of the vehicle;
A vehicle speed detection sensor that detects a physical quantity related to a vehicle speed of the vehicle;
When a signal relating to depression of the accelerator pedal is input from the accelerator pedal sensor, a command to generate the regenerative braking force is output to the electric motor, and an output value below a predetermined speed is input from the vehicle body speed detection sensor And a control unit for outputting a command for causing the electric motor to generate creep torque when an output value exceeding a predetermined steering angle is input from the steering angle detection sensor;
Control system of an electric vehicle provided with

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