Pure electric vehicle and escape control method thereof

Abstract

The invention relates to a pure electric vehicle and an escape control method thereof, and belongs to the technical field of electric vehicle control. According to the method, after the vehicle enters the escape control mode, when an accelerator is stepped down, corresponding torque is output according to the opening degree of an accelerator pedal to drive the vehicle forwards; when the accelerator is released, corresponding torque is output according to the rotating speed of the motor to reversely drive the vehicle; and the torque is dynamically adjusted according to the number of times of trying to escape in the reverse driving process of the vehicle. And when the vehicle is out of trouble, the driver is familiar with the front-back swing amplitude and rhythm process of the vehicle, so that most of the drivers can receive the control method.

Description

Technical Field

[0001] The invention relates to a pure electric vehicle and a method for controlling the vehicle to escape from a difficult situation, and belongs to the technical field of electric vehicle control. Background Art

[0002] Heavy commercial vehicles are prone to wheels getting stuck on muddy, unpaved roads. The conventional way to get out of trouble is to release the accelerator, step on the clutch to let the vehicle slide backwards, then release the clutch and step on the accelerator to move the vehicle forward. Frequent switching of releasing the accelerator, stepping on the clutch, and releasing the clutch and stepping on the accelerator to get the vehicle out of trouble is complicated to operate and the effect of getting out of trouble is poor.

[0003] The Chinese patent document with announcement number CN115257690B discloses a vehicle control method, a hybrid power system controller and a vehicle. The method includes: maintaining the gear position of the gearbox unchanged, and when the driving mode of the vehicle is not a pure electric driving mode, switching the driving mode of the vehicle to a pure electric driving mode, and turning off the driving anti-skid function of the vehicle; using a preset positive torque and a preset negative torque to drive the motor cyclically, and in each cycle, first using a preset positive torque to drive the motor, and then using a preset negative torque to drive the motor. This solution uses the characteristics of the motor that can be reversed by using a preset positive torque and a preset negative torque to drive the motor cyclically, avoiding the gear switching and the difficulty of getting out of trouble caused by small inertia during the process of rocking the car out of trouble, achieving the maximum rocking force in the forward and reverse directions, and quickly achieving escape, solving the problem of frequent switching between D gear and R gear to rock the car out of trouble in the prior art, which easily damages the gearbox.

[0004] However, this method has technical defects: poor adaptability to working conditions. If the preset positive / negative torque does not match the actual working conditions, the vehicle may easily move (excessive torque) or be unable to escape (too small torque). The driver cannot actively control the vehicle. No matter how the driver steps on the accelerator, the vehicle responds according to the preset torque. The driver's subjective feelings are not taken into consideration. Once the system intervenes, the vehicle is driven according to the preset torque. The system intervention is abrupt, which may cause discomfort to the driver and has poor acceptability. Summary of the invention

[0005] The purpose of the present invention is to provide a pure electric vehicle and a method for controlling the vehicle to escape from a jam, so as to solve the problem in the existing vehicle control method that the control system intervenes abruptly when the vehicle escapes from a jam, causing discomfort to the driver.

[0006] To achieve the above object, the solution of the present invention includes: A pure electric vehicle escape control method of the present invention, after entering the escape control mode, when the accelerator is stepped on, the corresponding torque is output according to the accelerator pedal opening to drive the vehicle forward; when the accelerator is released, the corresponding torque is output according to the motor speed to drive the vehicle in the reverse direction.

[0007] Furthermore, after entering the escape control mode, when the accelerator is released, the torque output to reversely drive the vehicle increases gradually with the number of times the accelerator is depressed.

[0008] Furthermore, when the accelerator is depressed a number of times reaching a preset value, the torque output to reversely drive the vehicle no longer increases when the accelerator is released.

[0009] Furthermore, the conditions for entering the escape control mode include: the current vehicle speed is less than or equal to the preset escape function activation threshold, the current vehicle gear is in the preset escape function gear, the brake pedal opening is greater than or equal to the preset escape function activation pedal opening threshold and the escape function switch is turned on.

[0010] Furthermore, the conditions for exiting the escape control mode include: the time when the accelerator is pressed to drive the vehicle is greater than or equal to the preset accelerator pressing time, the current vehicle gear is not in the preset escape function gear or the escape function switch is turned off.

[0011] Furthermore, after entering the escape control mode, when the accelerator is released and the reverse driving vehicle running time is greater than or equal to a preset reverse driving time threshold or the brake is applied, the vehicle enters a standby mode with no power output; after entering the standby mode, the accelerator is pressed and the vehicle is driven again in the escape control mode.

[0012] A pure electric vehicle of the present invention includes a controller. When the controller determines that the vehicle is in an escape control mode, when the accelerator is pressed, the controller outputs a corresponding torque according to the accelerator pedal opening to drive the vehicle forward; when the accelerator is released, the controller outputs a corresponding torque according to the motor speed to drive the vehicle backward.

[0013] Furthermore, after entering the escape control mode, when the accelerator is released, the torque output by the controller to reversely drive the vehicle increases gradually with the number of times the accelerator is depressed.

[0014] Furthermore, when the accelerator is depressed a number of times reaching a preset value, the torque output by the controller to reversely drive the vehicle no longer increases when the accelerator is released.

[0015] Furthermore, the conditions for the controller to determine that the vehicle is in an escape control state include: the current vehicle speed is less than or equal to a preset escape function activation threshold, the current vehicle gear is in a preset escape function gear, the brake pedal opening is greater than or equal to a preset escape function activation pedal opening threshold and the escape function switch is turned on.

[0016] Furthermore, the controller determines that the conditions for the vehicle to exit the escape control state include: when the accelerator is pressed to drive the vehicle for a time greater than or equal to a preset accelerator pressing time, the current vehicle gear is not in a preset escape function gear or the escape function switch is turned off.

[0017] Furthermore, after entering the escape control mode, when the accelerator is released and the reverse driving vehicle running time is greater than or equal to a preset reverse driving time threshold or the brake is applied, the vehicle enters a standby mode with no power output; after entering the standby mode, the accelerator is pressed and the vehicle is driven again in the escape control mode.

[0018] The beneficial effects of the present invention are: The present invention is a pioneering invention. A pure electric vehicle escape control method and a pure electric vehicle of the present invention can combine the driver's intention and drive the vehicle in a cycle, and use the rocking force to finally escape from trouble. In the escape control mode, the forward drive outputs the driving torque according to the driver's accelerator opening, taking into account the driver's subjective feelings, giving the driver more control authority, and avoiding discomfort caused by sudden intervention of the system; the reverse drive torque is output according to the motor speed; further, the reverse drive torque is dynamically adjusted according to the number of escape attempts, so that the torque increases each time. Giving the driver a process to familiarize himself with the amplitude and rhythm of the vehicle's front and rear rocking when the vehicle is getting out of trouble helps most drivers accept the control method. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic flow chart of the overall solution of a pure electric vehicle escape control method; Figure 2 It is a schematic diagram of the vehicle escape control process; Figure 3 It is a schematic diagram of the vehicle escape control system. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments.

[0021] The present invention provides a pure electric vehicle escape control method and a pure electric vehicle, the idea is to combine the driver's intention and cyclically drive the vehicle, use the rocking force, and finally achieve escape. In the escape control mode, the forward drive outputs the driving torque according to the driver's accelerator opening, taking into account the driver's subjective feelings, giving the driver more control authority, and avoiding discomfort caused by sudden intervention of the system; further, the reverse drive torque is dynamically adjusted according to the motor speed and the number of escape attempts, and the torque increases each time, giving the driver a process of familiarizing himself with the amplitude and rhythm of the vehicle's front and rear rocking, which helps most drivers accept the control method.

[0022] The terms used in the present invention are explained as follows: Double flash: Hazard warning lights, which means that when the car encounters certain dangers or special situations, all four turn signals of the car will light up and flash to remind other vehicles to avoid or drive carefully, commonly known as double jump lights or double flash; Standard driving mode: refers to the vehicle control system responding normally to the driver's control request, such as stepping on the accelerator to output driving force to drive the vehicle; releasing the accelerator (completely releasing the accelerator) to disconnect the driving force and the vehicle coasts; stepping on the brakes to output braking force and the vehicle slows down; Escape control mode: refers to the vehicle control system responding to the driver's control request according to the escape control method. In this mode, releasing the accelerator means completely releasing the accelerator pedal; Standby state: refers to a state in which the vehicle control system enters a state with no driving force output and no braking force output under certain operation of the driver.

[0023] Method Example: like Figure 1 The overall solution process of a pure electric vehicle escape control method shown is as follows: In the standard driving mode, the vehicle speed, accelerator pedal opening, brake pedal opening, gear position, escape function switch signal and double flash signal are first obtained to determine whether the escape function enabling conditions are met, and then determine whether to enter the escape control mode; after entering the escape control mode, the vehicle will be driven cyclically according to the driver's intention and using the forward and reverse characteristics of the motor; the vehicle is driven forward when the driver steps on the accelerator, and driven reversely when the accelerator is released; if the driver releases the accelerator for a time Tr that reaches a set threshold value T0, the function enters a standby state; during the driving process, if the driver steps on the brake, the function also enters a standby state; after entering the standby state, if the driver steps on the accelerator again, the vehicle starts to be driven in the escape control mode again; if the driver steps on the accelerator to drive the vehicle for a time Td that reaches a set threshold value T1, the escape control mode is exited; after exiting the escape control mode, if the accelerator is stepped on again, the standard driving mode is entered, and the vehicle speed, accelerator pedal opening, brake pedal opening, gear position, escape function switch signal and double flash signal are obtained again to determine whether the escape function enabling conditions are met, and then determine whether to enter the escape control mode again.

[0024] Control process such as Figure 2 As shown, after the vehicle enters the escape control mode based on the driver's control, necessary operation prompts are given during the driver's control process to assist the driver in better using the function; after entering the escape control mode, the driving torque is output based on the driver's control, and the motor can be reversed to drive the vehicle in the reverse direction after the driver releases the accelerator. Furthermore, the torque is gradually increased based on the number of times the accelerator is stepped on; the driver repeatedly steps on and releases the accelerator to cycle and drive the vehicle to achieve the purpose of rapid escape. The specific control method is as follows: 1) First, obtain the vehicle speed, accelerator pedal opening, brake pedal opening, gear position, escape function switch signal and double flash signal.

[0025] 2) When the vehicle signal meets the following conditions, the vehicle is judged to enter the escape control mode: a. V≤V0 (V is the vehicle speed, V0 is the vehicle speed threshold for the escape function to start, V0 is generally set to 0); b. G = G0 (G is the current gear of the vehicle, and G0 is the preset gear for activating the escape function); c. B ≥ B0 (B is the brake pedal opening, B0 is the pedal opening threshold for the escape function); d. The escape function switch signal is valid; e. The double flash signal is effective (to ensure safety, turn on the double flash to alert surrounding vehicles).

[0026] 3) When the escape function switch signal is valid but other conditions for entering the escape control mode are not met, the instrument panel will provide the driver with control prompts based on the actual vehicle conditions, including but not limited to "Please shift the vehicle into the preset gear", "Please step on the brake pedal", etc.

[0027] 4) After entering the escape control mode, the vehicle is driven cyclically according to the driver's intention and by utilizing the forward and reverse rotation characteristics of the motor: a. When the driver steps on the accelerator, the vehicle is driven with the corresponding torque according to the accelerator pedal opening; b. After the driver releases the accelerator, the motor reverses and drives the vehicle in the opposite direction with the corresponding torque according to the motor speed.

[0028] 5) Obtain the number of times the driver steps on the accelerator. The number of times the driver steps on the accelerator indicates the number of current escape attempts, that is, the number of times the accelerator is stepped on N indicates that N escape attempts have been made, and N ≥ 0.

[0029] 6) After the driver releases the accelerator, in order to avoid excessive reverse shaking during the initial intervention control, which may cause discomfort or panic to the driver, the motor response torque is output according to the motor speed; more preferably, in order to better match the driver's actual operation and actual road conditions, the torque will be gradually increased in combination with the number of times the driver steps on the accelerator in step 5), providing the driver with a process to become familiar with the amplitude and rhythm of the vehicle's forward and backward shaking, and finally output the corresponding torque according to the driver's control.

[0030] 7) When the number of escape attempts N reaches the preset value, the reverse motor torque no longer increases.

[0031] 8) Obtaining the reverse driving vehicle running time, that is, obtaining the time the driver drives the vehicle in reverse after releasing the accelerator. When the reverse driving vehicle running time is greater than or equal to the reverse driving time threshold, it is determined that the vehicle enters the standby state.

[0032] 9) In the escape control mode, if the driver steps on the brakes, the vehicle is also determined to have entered the standby state. The method for determining that the vehicle has entered the standby state includes but is not limited to obtaining a brake pedal signal. If the brake pedal signal opening is greater than or equal to a preset value (i.e., the brakes are stepped on), it is determined that the vehicle has entered the standby state.

[0033] 10) After entering the standby state, if the driver steps on the accelerator again, the vehicle will be driven in the escape control mode again.

[0034] 11) Obtain the time the driver steps on the accelerator to drive the vehicle. When the time the driver steps on the accelerator to drive the vehicle is greater than or equal to a preset threshold, it is determined that the vehicle has exited the escape control mode. In addition, turning off the escape function switch, turning off the hazard switch, or the gear is not in the preset gear position will also determine that the vehicle has exited the escape control mode.

[0035] 12) After exiting the escape control mode, it is necessary to re-determine whether to enter the escape control mode according to steps 1) and 2).

[0036] Vehicle Example: This embodiment provides a pure electric vehicle, such as Figure 3 As shown, it includes a signal processing module, a control module and a controller: the signal processing module is used to obtain vehicle signals, which include but are not limited to vehicle speed, accelerator pedal opening, brake pedal opening, gear position, function switch signal and double flash signal, and then output the real-time status of each signal; the control module is used to determine which mode the vehicle is in based on the comparison between the real-time status of relevant signals and the preset threshold, such as escape control mode, standard driving mode and the state in the corresponding mode, and in the corresponding mode, respond to the driver's control instructions according to the control method in the mode; the controller is the hardware carrier of the signal processing module and the control module, and is used to execute instructions to implement the pure electric vehicle escape control method. The pure electric vehicle escape control method has been introduced clearly enough in the method embodiment and will not be repeated here.

Claims

1. A pure electric vehicle escape control method, characterized in that: After entering the escape control mode, when the accelerator is pressed, the corresponding torque is output according to the accelerator pedal opening to drive the vehicle forward; When the accelerator is released, the vehicle is driven in reverse according to the torque output according to the motor speed.

2. The pure electric vehicle escape control method according to claim 1, characterized in that: After entering the escape control mode, when the accelerator is released, the torque output to drive the vehicle in reverse increases with the number of times the accelerator is depressed.

3. The pure electric vehicle escape control method according to claim 2, characterized in that: When the accelerator is depressed a preset number of times, the output torque for driving the vehicle in reverse no longer increases when the accelerator is released.

4. The pure electric vehicle escape control method according to claim 1, characterized in that: The conditions for entering the escape control mode include: the current vehicle speed is less than or equal to the preset escape function start threshold, the current vehicle gear is in the preset escape function gear, the brake pedal opening is greater than or equal to the preset escape function start pedal opening threshold and the escape function switch is turned on; the conditions for exiting the escape control mode include: the time when the accelerator is pressed to drive the vehicle is greater than or equal to the preset accelerator pressing time, the current vehicle gear is not in the preset escape function gear or the escape function switch is turned off.

5. The pure electric vehicle escape control method according to claim 1, characterized in that: After entering the escape control mode, when the accelerator is released and the reverse driving vehicle running time is greater than or equal to the preset reverse driving time threshold or the brake is applied, the vehicle enters a standby mode with no power output; After entering the standby mode, if the accelerator is depressed, the vehicle is driven again in the escape control mode.

6. A pure electric vehicle, characterized in that: A controller is included, and when the controller determines that the vehicle is in an escape control mode, when the accelerator is depressed, the controller outputs a corresponding torque according to the accelerator pedal opening to drive the vehicle forward; When the accelerator is released, the controller outputs a corresponding torque according to the motor speed to drive the vehicle in reverse.

7. The pure electric vehicle according to claim 6, characterized in that: After entering the escape control mode, when the accelerator is released, the torque output by the controller to reversely drive the vehicle increases gradually with the number of times the accelerator is depressed.

8. The pure electric vehicle according to claim 7, characterized in that: When the accelerator is depressed for a number of times reaching a preset value, when the accelerator is released, the torque output by the controller for reversely driving the vehicle no longer increases.

9. The pure electric vehicle according to claim 6, characterized in that: The conditions for the controller to determine that the vehicle is in the escape control state include: the current vehicle speed is less than or equal to the preset escape function activation threshold, the current vehicle gear is in the preset escape function gear, the brake pedal opening is greater than or equal to the preset escape function activation pedal opening threshold and the escape function switch is turned on; the conditions for the controller to determine that the vehicle exits the escape control state include: when the accelerator is pressed to drive the vehicle for a time greater than or equal to the preset accelerator pressing time, the current vehicle gear is not in the preset escape function gear or the escape function switch is turned off.

10. The pure electric vehicle according to claim 6, characterized in that: After entering the escape control mode, when the accelerator is released and the reverse driving vehicle running time is greater than or equal to the preset reverse driving time threshold or the brake is applied, the vehicle enters a standby mode with no power output; After entering the standby mode, if the accelerator is depressed, the vehicle is driven again in the escape control mode.

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