Parking control method, parking control system, and storage medium

Abstract

A parking control method, a parking control system and a storage medium for an electric vehicle. The parking control method comprises: collecting an actual rotating speed of a traction motor; collecting a parking instruction; in the case that the parking instruction exists and the rotating speed value of the actual rotating speed is less than or equal to a first set rotating speed value, performing disturbance observation on the running state of the electric vehicle to obtain a related disturbance observation value, setting the direction value of the target rotating speed of the traction motor according to the disturbance observation value, and setting the rotating speed value of the target rotating speed as a second set rotating speed value. In the case that the parking instruction exists and the rotating speed value of the target rotating speed is set as the second set rotating speed value, a control amount is generated based on the actual rotating speed and the target rotating speed, and the control amount is adjusted according to the direction value of the target rotating speed to generate a control output amount for controlling the traction motor. The present disclosure enables stable parking without relying on mechanical components of the electric vehicle.

Description

Parking control method, parking control system and storage medium Technical Field

[0001] The present disclosure relates to the field of parking control, and in particular to a parking control method, a parking control system, and a storage medium for an electric vehicle. Background Art

[0002] Safety is paramount when parking a vehicle on a slope. Conventional solutions typically utilize mechanical components to achieve parking control on varying slopes. However, improper coordination between vehicle traction and braking force during braking and starting on a slope can lead to potential hazards such as impact or backward movement.

[0003] Unlike traditional fuel vehicles, parking control of electric vehicles usually requires coordinated mechanical components and drive motors. Although this type of parking control can achieve the intended function, problems still exist.

[0004] For example, when electric vehicles frequently start and stop on complex roads, at low speeds, braking force is provided entirely by mechanical components, while driving force is provided entirely by the drive motor. The mechanical components control the caliper preload, while the drive motor controls the rotor's tangential torque. These two control systems operate under different control systems, making them difficult to fully unify in terms of timeliness, resulting in low overall control accuracy. Improper coordination between mechanical component control and drive motor control can lead to potential hazards such as impact or vehicle backward movement. Furthermore, the relationship between caliper preload and braking torque is affected by uncertain factors such as the mechanical brake component's structure, material, and humidity, exhibiting difficult-to-estimate nonlinear characteristics. This further complicates the coordination between the mechanical components and the drive motor. Furthermore, the frequent activation of mechanical components leads to wear and fatigue, reducing the safety and reliability of parking control. Furthermore, coordinated control of the mechanical components and the drive motor requires a high level of vehicle automation, making it difficult to implement on low-cost vehicles.

[0005] Summary of the Invention

[0006] In order to solve the above problems, the present disclosure provides a parking control method, a parking control system and a computer-readable storage medium for electric vehicles, so that stable parking can be achieved without relying on the mechanical components of the electric vehicle, that is, the vehicle can roll down the slope at a constant speed on a steep slope and stop without energy consumption on a gentle slope or flat ground.

[0007] An embodiment of the present disclosure provides a parking control method for an electric vehicle, comprising:

[0008] collecting an actual rotational speed of a traction motor in the electric vehicle;

[0009] Collect parking instructions;

[0010] In a case where the parking instruction is present and the actual speed value of the traction motor is less than or equal to a first set speed value, performing a disturbance observation on the operating condition of the electric vehicle to obtain a disturbance observation value related to the operating condition of the electric vehicle, setting a direction value of the target speed of the traction motor according to the disturbance observation value, and setting the speed value of the target speed of the traction motor to a second set speed value, wherein the disturbance observation value is used to indicate a parking posture of the electric vehicle, and the direction value of the target speed of the traction motor is associated with the parking posture; and

[0011] When the parking instruction exists and the speed value of the target speed of the traction motor is set to a second set speed value, a control amount is generated based on the actual speed and the target speed of the traction motor, and the control amount is adjusted according to the direction value of the target speed to generate a control output amount for controlling the traction motor.

[0012] According to an embodiment of the present disclosure, the parking control method further includes: when the parking instruction exists and the speed value of the actual speed of the traction motor is greater than or equal to the first set speed value, setting the target speed of the traction motor to zero, and generating a control amount based on the actual speed and the target speed of the traction motor, and using the control amount as a control output amount for controlling the traction motor.

[0013] According to an embodiment of the present disclosure, the parking posture includes parking with the front of the vehicle facing up, parking with the front of the vehicle facing down, and parking on flat ground. When the disturbance observation value is greater than or equal to zero, it indicates that the parking posture is parking with the front of the vehicle facing down or parking on flat ground; when the disturbance observation value is less than zero, it indicates that the parking posture is parking with the front of the vehicle facing up or parking on flat ground.

[0014] According to an embodiment of the present disclosure, setting the direction value of the target speed of the traction motor according to the disturbance observation value includes: when the disturbance observation value is greater than or equal to zero, setting the direction value of the target speed of the traction motor to a positive direction value; when the disturbance observation value is less than zero, setting the direction value of the target speed of the traction motor to a negative direction value.

[0015] According to an embodiment of the present disclosure, the second set speed value is a preset slope speed value, and the first set speed value is less than or equal to the second set speed value.

[0016] According to an embodiment of the present disclosure, the control quantity is adjusted according to the direction value of the target speed to generate a control output quantity for controlling the traction motor, including: using the direction value of the target speed to limit the polarity of the control quantity so that the direction value of the target speed is different from the polarity of the control quantity.

[0017] According to an embodiment of the present disclosure, the control quantity is adjusted according to the direction value of the target speed to generate a control output quantity for controlling the traction motor, including: when the direction value of the target speed is a positive direction value, if the control quantity is greater than zero, the control output quantity is set to zero; when the direction value of the target speed is a negative direction value, if the control quantity is less than zero, the control output quantity is set to zero.

[0018] According to an embodiment of the present disclosure, the parking instruction is generated by at least one of the following conditions: the accelerator pedal opening is 0; the brake pedal opening is greater than 0; the handbrake is pulled; the speed gear is in neutral; the steering gear is in neutral.

[0019] An embodiment of the present disclosure provides a parking control system for an electric vehicle, comprising:

[0020] a rotation speed sensor configured to collect an actual rotation speed of a traction motor in the electric vehicle;

[0021] A parking command collection module configured to collect parking commands;

[0022] a parking posture recognition module configured to, when the parking instruction is present and the actual speed value of the traction motor is less than or equal to a first set speed value, perform a disturbance observation on the operating condition of the electric vehicle, wherein the parking posture recognition module obtains a disturbance observation value related to the operating condition of the electric vehicle, sets a direction value of the target speed of the traction motor based on the disturbance observation value, and sets the speed value of the target speed of the traction motor to a second set speed value, wherein the disturbance observation value is used to indicate the parking posture of the electric vehicle, and the direction value of the target speed of the traction motor is associated with the parking posture;

[0023] a disturbance observation module configured to perform the disturbance observation and, when the parking instruction is present and the target speed of the traction motor is set to a second set speed value, generate a control variable based on the actual speed and the target speed of the traction motor;

[0024] an adjustment module configured to adjust the control amount according to a direction value of the target speed to generate a control output amount for controlling the traction motor;

[0025] a current control module configured to generate a power circuit control current for controlling the power circuit according to the control output;

[0026] The power circuit is configured to control the traction motor according to the power circuit control current.

[0027] According to an embodiment of the present disclosure, the disturbance observation module is an active disturbance rejection control module, and the active disturbance rejection control module includes a tracking differentiator, a state observer and an error feedback controller: the input of the tracking differentiator is the target speed, and the output of the tracking differentiator is the transition speed; the input of the state observer is the control output and a first speed difference, the first speed difference is the actual speed minus the speed observation value, and the output of the state observer is the speed observation value and the disturbance observation value; the input of the error feedback controller is a second speed difference and the disturbance observation value, the second speed difference is the transition speed minus the speed observation value, and the output of the error feedback controller is the control quantity.

[0028] According to an embodiment of the present disclosure, when the parking instruction exists and the speed value of the actual speed of the traction motor is greater than or equal to the first set speed value, the parking posture recognition module is configured to set the target speed of the traction motor to zero, and the disturbance observation module is configured to generate a control amount based on the actual speed and the target speed of the traction motor, and use the control amount as a control output amount for controlling the traction motor.

[0029] According to an embodiment of the present disclosure, the parking posture includes parking with the front of the vehicle facing up, parking with the front of the vehicle facing down, and parking on flat ground. When the disturbance observation value is greater than or equal to zero, it indicates that the parking posture is parking with the front of the vehicle facing down or parking on flat ground; when the disturbance observation value is less than zero, it indicates that the parking posture is parking with the front of the vehicle facing up or parking on flat ground.

[0030] According to an embodiment of the present disclosure, the parking posture recognition module sets the direction value of the target speed of the traction motor according to the disturbance observation value, including: when the disturbance observation value is greater than or equal to zero, setting the direction value of the target speed of the traction motor to a positive direction value; when the disturbance observation value is less than zero, setting the direction value of the target speed of the traction motor to a negative direction value.

[0031] According to an embodiment of the present disclosure, the adjustment module adjusts the control quantity according to the direction value of the target speed to generate a control output quantity for controlling the traction motor, including: using the direction value of the target speed to limit the polarity of the control quantity so that the direction value of the target speed is different from the polarity of the control quantity.

[0032] According to an embodiment of the present disclosure, the adjustment module adjusts the control quantity according to the direction value of the target speed to generate a control output quantity for controlling the traction motor, including: when the direction value of the target speed is a positive direction value, if the control quantity is greater than zero, the control output quantity is set to zero; when the direction value of the target speed is a negative direction value, if the control quantity is less than zero, the control output quantity is set to zero.

[0033] An embodiment of the present disclosure provides a computer-readable storage medium having computer-executable instructions stored thereon. When the instructions are executed by a processor, the instructions are used to implement the method as described in one of the embodiments of the present disclosure.

[0034] The parking control method and control system disclosed herein eliminate reliance on mechanical components and achieve stable parking directly through closed-loop control of the traction motor, making frequent starts and stops smoother and effectively reducing wear and fatigue of mechanical components. The fixed speed for constant-speed ramping can be set according to actual application requirements, thereby ensuring flexibility when parking on slopes while ensuring driving safety. Furthermore, the parking control method and control system disclosed herein are based on disturbance observation and can sense parking posture without the need for additional slope and load sensors, resulting in strong cost-effectiveness.

[0035] Furthermore, the parking control method and control system disclosed herein utilize and implement a method for rolling down a steep slope at a constant speed and for stopping the vehicle without energy consumption on a gentle slope or on flat ground. This method offers energy advantages over the "parking in any parking position" method. Rolling down a slope at a constant speed at a low speed has minimal impact on parking stability. Furthermore, it effectively alerts the driver to the parking position, improving the safety of electric vehicles on slopes.

[0036] According to the parking control method and parking control system disclosed herein, there is no conflict between parking control under different parking postures, and there is no conflict between parking control and normal driving control. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] To more clearly illustrate the technical solutions of the embodiments of the present disclosure, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some exemplary embodiments of the present disclosure, and those skilled in the art can derive other drawings based on these drawings without inventive effort.

[0038] FIG1 shows a schematic flow chart of a parking control method according to an embodiment of the present disclosure;

[0039] FIG2 shows a logic diagram of a parking control method according to an embodiment of the present disclosure;

[0040] FIG3 shows a schematic diagram of a parking control system according to an embodiment of the present disclosure;

[0041] FIG4 shows a schematic diagram of a parking control system according to another embodiment of the present disclosure;

[0042] 5a, 5b, 5c and 5d are schematic diagrams showing simulation results of a parking control method according to an embodiment of the present disclosure;

[0043] FIG6 is a schematic diagram showing simulation results of a parking control method according to another embodiment of the present disclosure. DETAILED DESCRIPTION

[0044] In order to make the purpose, technical solutions and advantages of the present disclosure more apparent, the exemplary embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present disclosure, rather than all the embodiments of the present disclosure, and it should be understood that the present disclosure is not limited to the exemplary embodiments described herein.

[0045] In this specification and the accompanying drawings, substantially the same or similar steps and elements are denoted by the same or similar reference numerals, and repeated descriptions of these steps and elements will be omitted. At the same time, in the description of the present disclosure, the terms "first", "second", etc. are only used to distinguish the description and are not to be understood as indicating or implying relative importance or ranking.

[0046] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which the present disclosure pertains. The terms used herein are for the purpose of describing embodiments of the present invention only and are not intended to limit the present invention.

[0047] To facilitate description of the present disclosure, concepts related to the present disclosure are introduced below.

[0048] Electric vehicle: A vehicle or device powered by an electric power source and having an electric motor capable of providing traction. In this disclosure, "vehicle" also includes other forms of vehicles or devices capable of executing the parking control method according to the embodiments of this disclosure.

[0049] Parking control: Used to stabilize the vehicle after braking, but not necessarily to bring the vehicle to a stop.

[0050] Disturbance observation: The basic idea of ​​disturbance observation is to treat the differences between the actual model and the ideal model output caused by external disturbances and changes in model parameters as equivalent control inputs. That is, equivalent disturbances are observed and equal compensation is introduced into the control to achieve complete suppression or compensation of disturbances.

[0051] FIG1 shows a schematic flow chart of a parking control method according to an embodiment of the present disclosure.

[0052] As shown in FIG. 1 , the parking control method according to an embodiment of the present disclosure may include steps S1 - S6 , for example.

[0053] In step S1 , for example, the actual rotational speed of a traction motor in an electric vehicle may be acquired.

[0054] In step S2 , for example, a parking command may be detected.

[0055] According to an embodiment of the present disclosure, a parking command may be generated, for example, by at least one of the following conditions: the accelerator pedal opening is 0; the brake pedal opening is greater than 0; the handbrake is pulled; the speed gear is in neutral; the steering gear is in neutral.

[0056] By collecting the actual speed and parking instruction, in step S3, for example, when there is a parking instruction and the speed value of the actual speed of the traction motor is less than or equal to the first set speed value, a disturbance observation can be performed on the operating condition of the electric vehicle to obtain a disturbance observation value related to the operating condition of the electric vehicle.

[0057] The first set speed value may be, for example, 0. That is, when a parking command is present and the actual speed value is 0, a disturbance observation is performed on the operating condition of the electric vehicle. Alternatively, the first set speed value may be, for example, a value close to 0, such as a low speed of 2 rpm or 5 rpm.

[0058] Control based on disturbance observation classifies all uncertain factors acting on the controlled object as "total disturbance", uses the input and output of the controlled object to estimate and compensate for the "total disturbance", and controls by reducing the impact of the estimated disturbance on the control model's approximation to the known part, that is, actively resisting disturbance. In this way, there is no need (and it is difficult in actual situations) to directly measure the effects of internal and external disturbances, nor is there any need to know the laws of disturbance.

[0059] Based on the principle of disturbance observation, the disturbance observation value associated with the operating condition of the electric vehicle represents the equivalent disturbance caused by external and internal disturbances, which leads to the difference between the actual model output and the ideal model output. Disturbances include gravity, friction, wind resistance, and transmission mechanism aging. Depending on their impact on the movement of the electric vehicle, disturbances can be divided into disturbances that promote movement and disturbances that hinder movement. For example, gravity is a disturbance that promotes movement, while friction, which is opposite to the direction of movement, is a disturbance that hinders movement.

[0060] The disturbance observation value of the disturbance observation can be used to indicate the parking posture of the electric vehicle. The parking posture may include, for example, parking with the front of the vehicle facing up, parking with the front of the vehicle facing down, and parking on flat ground. For example, when the disturbance observation value is greater than or equal to zero, the parking posture is indicated as parking with the front of the vehicle facing down or parking on flat ground; when the disturbance observation value is less than zero, the parking posture is indicated as parking with the front of the vehicle facing up or parking on flat ground. This is because, when the speed value of the actual speed is 0 or close to 0, the disturbance observation value can basically reflect the disturbance other than the motor-related disturbance. Therefore, the parking posture of the electric vehicle can be determined by the disturbance observation value observed when the speed value of the actual speed is 0 or close to 0, and the target speed of the traction motor can be set.

[0061] The direction value of the target speed of the traction motor can, for example, be associated with the parking posture. According to an embodiment of the present disclosure, for example, the direction of the vehicle's head can be considered the positive direction of motion. Therefore, when the vehicle is parked with its head facing up, the positive direction of motion is upward along the vehicle body, while the direction of the target speed for constant-speed hill gliding is downward along the vehicle body, and its direction value is a negative direction value. When the vehicle is parked with its head facing down, the positive direction of motion is downward along the vehicle body, while the direction of the target speed for constant-speed hill gliding is also downward along the vehicle body, and its direction value is a positive direction value.

[0062] However, the disturbance observation value cannot distinguish between parking with the front of the vehicle facing up and parking on flat ground, nor can it distinguish between parking with the front of the vehicle facing down and parking on flat ground. This is because, in flat ground parking, the direction of the disturbance may be the same as or opposite to the direction of the front of the vehicle, instead of the gravity component that occupies the main component of the disturbance always being downward along the vehicle body, and the friction force when sliding down the slope always being upward along the vehicle body.

[0063] In step S4 , a direction value of the target speed of the traction motor is set according to the disturbance observation value, and the speed value of the target speed of the traction motor is set as a second set speed value.

[0064] The step of setting the direction value of the target speed of the traction motor according to the disturbance observation value may include, for example: when the disturbance observation value is greater than or equal to zero, setting the direction value of the target speed of the traction motor to a positive direction value; when the disturbance observation value is less than zero, setting the direction value of the target speed of the traction motor to a negative direction value.

[0065] That is, during disturbance observation, the target speed of the traction motor is set to the second set speed, but the direction of the target speed is divided into positive and negative directions according to the polarity of the disturbance observation value.

[0066] The second set speed value may be, for example, a preset rolling speed value, with the first set speed value being less than or equal to the second set speed value. The preset rolling speed value, for example, enables the electric vehicle to roll down a slope at a low speed of 0.1 km / h or 0.2 km / h, thereby achieving safe parking control. When the electric vehicle rolls down a slope at a low speed of 0.2 km / h, the motor-side speed value is, for example, 50 r / min.

[0067] In step S5, if a parking command is issued and the target speed of the traction motor is set to a second set speed value, a control variable is generated based on the actual speed of the traction motor and the target speed. The actual speed is brought closer to the target speed by performing control based on disturbance observation.

[0068] In step S6 , the control amount is adjusted according to the direction value of the target speed to generate a control output amount for controlling the traction motor.

[0069] Adjusting the control amount according to the direction value of the target speed may, for example, include: using the direction value of the target speed to restrict the polarity of the control amount, such that the direction value of the target speed and the polarity of the control amount are different. Preferably, when the direction value of the target speed is a positive direction value (i.e., consistent with the direction of the vehicle head), if the control amount is greater than zero, the control output amount is set to zero; and when the direction value of the target speed is a negative direction value (i.e., opposite to the direction of the vehicle head), if the output amount is less than zero, the control output amount is set to zero.

[0070] As mentioned above, disturbances can include those that promote motion and those that hinder motion, depending on their impact on the motion of the electric vehicle. When an electric vehicle is on a steep slope, the component of gravity along the vehicle body and other disturbances that promote motion are always greater than friction and other disturbances that hinder motion. To achieve the electric vehicle's steady-speed slope gliding, i.e., stable motion without acceleration, the motor needs to provide electromagnetic torque to balance the disturbances that promote motion and those that hinder motion, keeping the electric vehicle in a balanced state. In this case, the direction value of the target speed directly achieves a different polarity from the control variable, and the control variable does not need to be adjusted and can be directly used as the control output. However, when the electric vehicle is on a slope with a smaller slope or on flat ground, the component of gravity along the vehicle body and other disturbances that promote motion are equal to or even smaller than the friction and other disturbances that hinder motion. The motor does not need to provide electromagnetic torque to balance the disturbances that promote motion and the disturbances that hinder motion. It only needs to let the electric vehicle balance naturally, that is, be stationary (instead of providing torque that promotes motion to force the disturbances that promote motion and the disturbances that hinder motion to be equal). In this case, if the direction value of the target speed is the same as the polarity of the control quantity, the control output is set to zero and the traction motor is further controlled so that the traction motor actually does not consume energy.

[0071] More specifically, for example, when an electric vehicle is parked on a slope with a small slope, the component of gravity along the vehicle body and other disturbances that promote motion may be equal to or even smaller than friction and other disturbances that hinder motion, allowing the electric vehicle to remain stationary without the need for additional electromagnetic torque. However, according to the above calculation method, the control amount calculated based on constant-speed slope sliding (opposite to the direction of the vehicle's nose pointing upward, its polarity is negative) will generate an electromagnetic torque in the downhill direction, which is actually useless. Therefore, in this state, the calculated control amount can be set to 0, eliminating the need to provide additional electromagnetic torque, thereby achieving energy-free parking on a slope with a small slope.

[0072] For another example, when an electric vehicle is on a slope with a small slope, when the electric vehicle is parked with the front of the vehicle facing down, the gravity component along the vehicle body and other disturbances that promote movement may be equal to or even smaller than the friction and other disturbances that hinder movement, allowing the electric vehicle to remain stationary without the need for additional electromagnetic torque. However, according to the above calculation method, the control amount calculated based on the constant speed slope (the same as the direction of the vehicle facing down, its polarity is positive) will generate an electromagnetic torque in the downhill direction, which is actually useless. Therefore, in this state, the calculated control amount can also be set to 0 so that no additional electromagnetic torque is provided, thereby achieving energy-free parking on a slope with a small slope.

[0073] By limiting the polarity of the control variable, the parking control method according to the embodiment of the present disclosure achieves constant-speed rolling on steep slopes and energy-free parking on shallow slopes and flat ground. During this process, there is no need to explicitly know the specific size of the slope or whether the flat ground is actually flat with a zero inclination angle. This parking control method can ensure stable parking control of the electric vehicle, that is, either rolling at a low, preset speed or coming to a standstill. The parking control method according to the embodiment of the present disclosure does not require the use of mechanical components, but achieves stable and energy-saving parking control solely through the control of the motor.

[0074] According to an embodiment of the present disclosure, when a parking command is present but the actual speed of the traction motor is still greater than or equal to the first set speed value, the target speed of the traction motor is set to zero or a speed value approximately equal to zero, and a control variable is generated based on the actual speed of the traction motor and the target speed, and the control variable is used as a control output for controlling the traction motor. In this case, the target speed is not set to the second set speed, and the control variable is not adjusted. It should be understood that setting the target speed of the traction motor to zero or a speed value approximately equal to zero is essentially a value set for ease of control, and the specific speed value can be set according to actual needs.

[0075] The parking control method according to the embodiment of the present disclosure is a closed-loop control method, and steps S1 to S6 do not represent a strict execution order, but may be executed in parallel or in reverse.

[0076] According to an embodiment of the present disclosure, the traction motor may be, for example, a brushed DC motor, a switched reluctance motor, a permanent magnet synchronous motor, an asynchronous motor, or the like.

[0077] FIG2 shows a logic diagram of a parking control method according to an embodiment of the present disclosure.

[0078] According to an embodiment of the present disclosure, a first flag bit, flag, and a second flag bit, lp, are set, and their initial values ​​are respectively 0. The first flag bit, flag, indicates whether the traction motor has started to perform rolling control, and the second flag bit, lp, indicates the parking posture of the electric vehicle or the direction value of the target speed of the traction motor.

[0079] As shown in FIG2 , the parking control method according to the embodiment of the present disclosure is a closed-loop control method, and parameter acquisition and judgment are performed cyclically, thereby assigning values ​​to the first flag flag and the second flag lp, and outputting the control output i accordingly. f '.

[0080] According to the parking control method of the embodiment of the present disclosure, the actual speed n of the traction motor in the electric vehicle and the control quantity i of the disturbance observation are collected. f , the disturbance observation value z2 of the disturbance observation, and the parking instruction. If there is no parking instruction, the first flag bit flag and the second flag bit lp maintain the initial value, that is, 0. If there is a parking instruction, it is further determined whether the first flag bit flag is 1.

[0081] If a parking instruction is present, and the first flag is 0, a further determination is made as to whether the speed value (or absolute value) of the actual speed n is less than or equal to the first set speed value. In this embodiment, the first set speed value is, for example, 0, and therefore, a determination is made as to whether the speed value of the actual speed n is less than or equal to 0. If the speed value of the actual speed n is greater than 0, the first flag, flag, and the second flag, lp, remain at their initial values, i.e., 0. However, due to the presence of a parking instruction, the speed value of the actual speed n decreases with each cycle. While the speed value of the actual speed n decreases, a logical determination is still performed cyclically, for example, every 0.5 ms. When a parking instruction is present and the actual speed value of the traction motor decreases to the first set speed value (0 in this embodiment), the first flag, flag, is assigned a value of 1 (flag=1) to indicate the start of coasting control. In this case, the speed value of the target speed of the traction motor is set to the second set speed value, and lp is assigned a value based on the polarity of the disturbance observation value z2 in this cycle. If z2<0, set lp=-1, indicating that the electric vehicle is in the parking posture with the front of the vehicle facing up or on flat ground, the speed value of the target speed is the second set speed value, and the direction value is a negative direction value, that is, the target speed n0=-|ns|r / min (that is, used to control the speed of the vehicle sliding down when the front of the vehicle is parked); if z2≥0, set lp=1, indicating that the electric vehicle is in the parking posture with the front of the vehicle facing down or on flat ground, the speed value of the target speed is the second set speed value, and the direction value is a positive direction value, that is, the target speed n0=+|ns|r / min (that is, used to control the speed of the vehicle sliding down when the front of the vehicle is parked), where ns is the preset slope speed value.

[0082] After the first flag flag and the second flag lp are assigned values ​​other than the initial values, parameter acquisition and judgment are continued in a new logic loop. If there is a parking instruction and flag = 1, the second flag lp is further judged and the control amount i is adjusted according to the second flag lp. f If lp = 1, it means that the electric vehicle is in the parking posture with the front of the vehicle facing down or on flat ground, and the target speed is n0 = +|ns|r / min. When the control quantity i f When ≤0 (i.e., the electromagnetic torque to be generated is the hindering torque that hinders the electric vehicle from moving in the direction of the vehicle head, in order to compensate for the influence of the gravity force along the vehicle body), the control output i for controlling the traction motor is set. f '=i f , thereby controlling the electric vehicle to achieve constant speed sliding; and when the control quantity i f >0 (i.e., the electromagnetic torque to be generated is the driving torque that prompts the electric vehicle to move in the direction of the vehicle head), then the control output i is set f'=0, so that the electric vehicle is naturally stationary. Similarly, if lp=-1, it means that the electric vehicle is in the parking posture with the front of the vehicle facing up or on flat ground, and the target speed is n0=-|ns|r / min. When the control quantity i f When ≥0 (i.e., the electromagnetic torque to be generated is the driving torque to drive the electric vehicle in the direction of the vehicle head), the control output i for controlling the traction motor is set. f '=i f , thereby controlling the electric vehicle to achieve constant speed sliding; and when the control quantity i f <0 (i.e., the electromagnetic torque to be generated is the hindering torque that hinders the electric vehicle from moving in the direction of the vehicle head), set the control output i f '=0. According to an embodiment of the present disclosure, it is necessary to satisfy the requirement that the polarity of the vehicle head direction (or the direction value of the target speed) is different from the polarity of the control amount. The control amount is adjusted in this way so that when the polarity of the control amount calculated during parking control is the same as the polarity of the vehicle head direction (or the direction value of the target speed), the control output amount used to control the traction electrode is set to 0 to save power.

[0083] In summary, when there is a parking command and flag=1:

[0084] If z2<0, set lp=-1, n0=-|ns|r / min;

[0085] If z2 ≥ 0, set lp = 1, n0 = +|ns|r / min;

[0086] If lp=-1 and i f ≥0, set i f '=i f ;

[0087] If lp=-1 and i f <0, set i f '=0;

[0088] If lp=1 and i f ≤0, set i f '=i f ;

[0089] If lp=1 and i f >0, set i f '=0.

[0090] In parking control, if there is no longer a parking instruction, the first flag bit flag and the second flag bit lp are reset to 0.

[0091] FIG3 shows a schematic diagram of a parking control system according to an embodiment of the present disclosure.

[0092] As shown in FIG3 , the parking control system according to an embodiment of the present disclosure includes a speed sensor 100 , a parking command acquisition module 200 , a parking posture recognition module 300 , a disturbance observation module 400 , an adjustment module 500 , a current control module 600 and a power circuit 700 .

[0093] The rotation speed sensor 100 may be configured, for example, to collect an actual rotation speed n of a traction motor in an electric vehicle.

[0094] The parking command collecting module 200 may be configured to collect a parking command p, for example.

[0095] For example, the parking posture recognition module 300 can be configured to perform a disturbance observation on the operating condition of the electric vehicle when a parking command p is present and the actual speed n of the traction motor is less than or equal to a first set speed value. The parking posture recognition module 300 obtains a disturbance observation value z2 related to the operating condition of the electric vehicle, sets a direction value for the target speed n0 of the traction motor based on the disturbance observation value z2, and sets the speed value of the target speed n0 of the traction motor to a second set speed value. The disturbance observation value z2 indicates the parking posture of the electric vehicle, and the direction value of the target speed n0 of the traction motor is associated with the parking posture. Parking postures can include, for example, head-up parking, head-down parking, and level parking. When the disturbance observation value z2 is greater than or equal to zero, the parking posture is indicated as head-down parking or level parking; when the disturbance observation value z2 is less than zero, the parking posture is indicated as head-up parking or level parking.

[0096] The parking posture recognition module 300 can, for example, set a direction value for the target speed n0 of the traction motor M based on the disturbance observation value z2. For example, when the disturbance observation value z2 is greater than or equal to zero, the direction value of the target speed n0 of the traction motor M is set to a positive direction value; when the disturbance observation value z2 is less than zero, the direction value of the target speed n0 of the traction motor M is set to a negative direction value. The second set speed value is, for example, a preset hill-climbing speed value ns. Therefore, with the help of the parking posture recognition module 300, when a parking command p is present and the actual speed n of the traction motor is less than or equal to the first set speed value, if z2 < 0, the target speed n0 is set to -|ns|r / min; if z2 ≥ 0, the target speed n0 is set to +|ns|r / min.

[0097] The disturbance observation module 400 can be configured to perform disturbance observation, for example, and generate a control variable i based on the actual speed n of the traction motor and the target speed n when there is a parking instruction p and the speed value of the target speed n0 of the traction motor is set to the second set speed value. f .

[0098] When there is a parking instruction p and the actual speed n of the traction motor M is greater than or equal to the first set speed value, the parking posture recognition module 300 is configured to set the target speed n0 of the traction motor M to zero, and the disturbance observation module 400 is configured to generate a control variable i based on the actual speed n and the target speed n0 of the traction motor M. f , and the control quantity i f As the control output i for controlling the traction motor M f '.

[0099] After setting the target speed n0 of the traction motor to the second set speed value, the adjustment module 500 can be configured to adjust the control amount i according to the direction value of the target speed n0. f Adjustment is performed to generate a control output i for controlling the traction motor M f '. As shown in Figure 3, the control output i f For example, it can be used as an input of the disturbance observation module 400 for closed-loop control.

[0100] The adjustment module 500 can be configured to adjust the control variable i using the direction value of the target speed n0. f Polarity restriction is performed so that the direction value of the target speed n0 is consistent with the control quantity i f The polarity is different.

[0101] The adjustment module 500 can be configured to adjust the control variable i by using the direction value of the target speed n0 in the following manner: f Polarity limitation: When the direction value of the target speed n0 is positive, if the control quantity i f If it is greater than zero, the output i will be controlled f 'Set to zero; if the control quantity i f Less than or equal to zero, the output i will be controlled f 'Set to be equal to the control quantity i f When the direction value of the target speed n0 is negative, if the control quantity i f If it is less than zero, the output i will be controlled f 'Set to zero; if the control quantity i f If it is greater than or equal to zero, the output i will be controlled f 'Set to be equal to the control quantity i f Therefore, with the help of the adjustment module 500, when the target speed n0 = +|ns|r / min, if the control variable i f ≤0, set the control output i f '=i f , if the control quantity i f >0, set the control output i f'=0; When the target speed n0=-|ns|r / min, if the control quantity i f <0, set the control output i f '=0, if the control quantity i f ≥0, set the control output i f '=i f .

[0102] The control variable i is adjusted by the adjustment module 500 f Polarity limitation is performed to enable electric vehicles to roll down a slope at a constant speed on a steep slope and to stop on flat ground or on a slope with a small slope without energy consumption.

[0103] The current control module 600 can be configured to control the output i f 'Generate a power circuit control current for controlling the power circuit.

[0104] The power circuit 700 can be configured to control the traction motor M, for example, to control the speed, etc., according to the power circuit control current. As shown in FIG3 , the power current of the power circuit 700 can be used as an input of the current control module 600 for closed-loop control, so that the power current approaches the control output i f '.

[0105] FIG4 shows a schematic diagram of a parking control system according to another embodiment of the present disclosure. Only the differences from the parking control system shown in FIG3 are described below.

[0106] As shown in FIG4 , the disturbance observation module 400 may be, for example, an active disturbance rejection control module 401 .

[0107] Active disturbance rejection control (ADRC) is a model-free control method suitable for controlled systems with unknown dynamic characteristics and internal and external disturbances. This algorithm only requires approximating the dynamic characteristics of the controlled system to design a controller with robust disturbance rejection and no overshoot. According to an embodiment of the present disclosure, the ADRC module 401 includes a tracking differentiator (TD), a state observer (ESO), and an error feedback controller (SEF).

[0108] The tracking differentiator TD is used to introduce a transition process so that the input signal, ie, the target rotation speed n0, changes from the initial value to the target value in a smooth transition rather than a step, thereby resolving the contradiction between rapidity and overshoot.

[0109] The state observer ESO is used to obtain estimates of various state variables (such as speed, disturbance). In this embodiment, the state observer ESO outputs a speed observation value z1 and a disturbance observation value z2.

[0110] The error feedback controller SEF is similar to the feedback controller in the classical feedback control structure and is configured to make the error equal to zero.

[0111] The input variable of the tracking differentiator TD is the target speed n0, which can be, for example, the first set speed or the second set speed. The output variable of the tracking differentiator TD is the transition speed n1. The tracking differentiator TD is used to arrange the transition process so that the transition speed n1 approaches the target speed n0 without overshoot. The time span of the transition process can be set.

[0112] The input of the state observer ESO is the control output i f ' and the first speed difference. The first speed difference is the actual speed n minus the speed observation value z1. The output of the state observer ESO is the speed observation value z1 and the disturbance observation value z2.

[0113] The inputs of the error feedback controller SEF are the second speed difference and the disturbance observation z2, where the operator of the disturbance observation z2 in the input (not z2 itself) is negative. The second speed difference is the transition speed minus the speed observation z1. The output of the error feedback controller SEF is the control variable i f .

[0114] The parking process is influenced by numerous factors, and the entire control system exhibits severe nonlinearity. Control methods, such as traditional PI control, struggle to meet the dynamic and static characteristics required by complex operating conditions. The parking control method and parking control system according to embodiments of the present disclosure can, for example, perform active disturbance rejection control using the control output of the traction motor as the controlled object, thereby achieving speed regulation performance over a wide speed range. By arranging a transition process and performing feedback adjustment on errors, the system achieves improved dynamic and steady-state performance. Furthermore, a state observer is added to estimate and compensate for internal and external disturbances in real time, improving the system's disturbance rejection performance. This makes the system more suitable for scenarios with severe nonlinearity and variable loads, such as parking control.

[0115] 5a, 5b, 5c and 5d are schematic diagrams showing simulation results of the parking control method according to an embodiment of the present disclosure.

[0116] In this embodiment, a four-phase switched reluctance motor is used as an example of a traction motor, and the four-phase conduction current i is shown when the electric vehicle adopts a head-up parking posture and performs parking control according to the parking control method according to the embodiment of the present disclosure. a 、i b 、i c 、i d Changes over time. Four-phase conduction current i a 、i b 、i c 、id The size of is controlled so as to approach the control output i of the parking control method according to the embodiment of the present disclosure. f 'Or control output i f 'Related quantities, such as the chopped control output i f '. Four-phase conduction current i a 、i b 、i c 、i d The conduction sequence determines the speed direction of the traction motor.

[0117] Figure 5a illustrates a situation where a parking command is in effect but the actual speed of the traction motor remains greater than or equal to a first set speed value (e.g., 0). Referring to the logic diagram shown in Figure 2 , in this situation, the first flag bit, flag, = 0, the second flag bit, lp, = 0, the target speed of the traction motor is set to zero, the actual speed gradually decreases, the current conduction phase sequence is phase a - phase b - phase c - phase d, and the direction of the traction motor's speed remains unchanged.

[0118] Figure 5b illustrates a situation where a parking command is present and the actual speed of the traction motor is less than or equal to the first set speed value over time. As shown in Figure 5b, according to the parking control method according to an embodiment of the present disclosure, when the actual speed of the traction motor is less than or equal to the first set speed value, the values ​​of the first flag, flag, and the second flag, lp, change. That is, flag = 1, indicating that the target speed of the traction motor is set to the second set speed value, and lp = -1, indicating that the observed disturbance observation value z2 is less than 0. The electric vehicle is in a nose-up parking posture or a flat-ground parking posture, and the target speed is n0 = -|ns|r / min. The electric vehicle begins control at the target speed n0 = -|ns|r / min. Since the simulation setting shows the electric vehicle in a nose-up parking posture, the parking control method according to an embodiment of the present disclosure accurately determines the parking posture. The conduction phase sequence of the current changes to phase c-phase b-phase a-phase d, and the direction of the traction motor speed changes, which confirms that the direction value of the target speed of the traction motor set according to the disturbance observation value is a negative direction value.

[0119] FIG5c shows a situation in which an electric vehicle is stably parked according to the parking control method according to an embodiment of the present disclosure. The values ​​of the first flag bit flag and the second flag bit lp are kept flag=1 and lp=-1, and the four-phase conduction current i a 、i b 、i c 、i d The size and conduction phase sequence reach a stable state, and the electric vehicle has a stable actual speed in the negative direction, realizing constant speed hill sliding.

[0120] Figure 5d shows the situation where the parking control is canceled and the vehicle starts to move. As shown in Figure 5d, after the parking command is canceled, the first flag bit flag and the second flag bit lp are reset to 0, the traction motor receives the new target speed command (for example, determined by the degree of accelerator pedal opening), and the current i a 、i b 、i c 、i d The size of the conduction phase changes accordingly, and the conduction phase sequence changes back to phase a-phase b-phase c-phase d, and the electric vehicle successfully starts the starting process.

[0121] FIG6 is a schematic diagram showing simulation results of a parking control method according to another embodiment of the present disclosure.

[0122] In this embodiment, the four-phase conduction current i is shown when the electric vehicle takes a parking posture of flat ground parking and the parking control method according to the embodiment of the present disclosure is executed. a 、i b 、i c 、i d Changes over time. FIG6 shows only the parking control phase similar to FIG5b.

[0123] Figure 6 illustrates a situation where a parking command is in effect and the actual speed of the traction motor is less than or equal to a first set speed value over time. As shown in Figure 6, according to the parking control method according to an embodiment of the present disclosure, when the actual speed of the traction motor is less than or equal to the first set speed value, the values ​​of the first flag bit, flag, and the second flag bit, lp, change. For example, flag = 1, indicating that the target speed of the traction motor is set to the second set speed value, and lp = 1, indicating that the observed disturbance observation value, z2, is ≥ 0, the electric vehicle is in a head-down parking position or a flat-ground parking position, and the target speed is n0 = +|ns|r / min.

[0124] With the influence of the accumulated disturbance observation value z2 greater than or equal to zero and the speed error, the control quantity i f It gradually approaches zero and may break through zero, which means that the disturbance that hinders the movement is greater than the disturbance that promotes the movement. f Polarity limitation is performed, then the control quantity i f The changing trend of is to break through zero and control the traction motor to generate electromagnetic torque as a disturbance to compensate for the movement. According to the embodiment of the present disclosure, the control quantity i is adjusted according to the direction value of the target speed. f Adjustment is performed to generate a control output i for controlling the traction motor f ', when lp=1, if i f ≤0, set i f '=i f ; if if >0, set i f '=0. As the control quantity i f Gradually approaches 0, the conduction current i a 、i b 、i c 、i d Also gradually approaches 0. By limiting the polarity of the control quantity, the electric vehicle can be parked on flat ground or on a slope with a small slope without energy consumption (no current in the motor winding). It should be understood that the conduction current i a 、i b 、i c 、i d It is displayed as a scalar in the attached figure, and its value only reflects the magnitude of the on-state current, not the control quantity i f positive and negative relationship.

[0125] The embodiments of the present disclosure are listed in the parking scenario. It should be understood that the concept of controlling the motor with low energy consumption or no energy consumption through disturbance observation and polarity restriction of the control quantity can also be extended to other fields of motor control, and is particularly suitable for electric vehicle drive systems, household appliances, general industry, servo drives, engineering machinery, etc.

[0126] It should be noted that the flowcharts and block diagrams in the accompanying drawings illustrate the possible implementation architecture, functions and operations of the systems, methods and computer program products according to various embodiments of the present disclosure. In this regard, each box in the flowchart or block diagram can represent a module, program segment, or a part of the code, and the module, program segment, or a part of the code contains at least one executable instruction for implementing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the box can also occur in an order different from that marked in the accompanying drawings. For example, two boxes represented in succession can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each box in the block diagram and / or flowchart, and the combination of boxes in the block diagram and / or flowchart, can be implemented using a dedicated hardware-based system that performs the specified function or operation, or can be implemented using a combination of dedicated hardware and computer instructions.

[0127] In general, various example embodiments of the present disclosure may be implemented in hardware or dedicated circuitry, software, firmware, logic, or any combination thereof. Certain aspects may be implemented in hardware, while other aspects may be implemented in firmware or software that may be executed by a controller, microprocessor, or other computing device. When various aspects of the embodiments of the present disclosure are illustrated or described as block diagrams, flow charts, or using some other graphical representation, it will be understood that the blocks, devices, systems, techniques, or methods described herein may be implemented, as non-limiting examples, in hardware, software, firmware, dedicated circuitry or logic, general-purpose hardware or a controller or other computing device, or some combination thereof.

[0128] The exemplary embodiments of the present disclosure described in detail above are merely illustrative and not restrictive. Those skilled in the art will appreciate that various modifications and combinations may be made to these embodiments or their features without departing from the principles and spirit of the present disclosure, and such modifications should fall within the scope of the present disclosure.

Claims

1. A parking control method for an electric vehicle, comprising: Collecting the actual speed of a traction motor in the electric vehicle; Collecting a parking instruction; When there is the parking instruction and the speed value of the actual speed of the traction motor is less than or equal to a first set speed value, observing the operating condition of the electric vehicle to obtain a disturbance observation value related to the operating condition of the electric vehicle, setting a direction value of a target speed of the traction motor according to the disturbance observation value, and setting the speed value of the target speed of the traction motor to a second set speed value, wherein the disturbance observation value is used to indicate a parking posture of the electric vehicle, and the direction value of the target speed of the traction motor is associated with the parking posture; And When there is the parking instruction and the speed value of the target speed of the traction motor is set to the second set speed value, generating a control quantity based on the actual speed and the target speed of the traction motor, and adjusting the control quantity according to the direction value of the target speed to generate a control output quantity for controlling the traction motor.

2. The parking control method according to claim 1, further comprising: When there is the parking instruction and the speed value of the actual speed of the traction motor is greater than or equal to the first set speed value, setting the target speed of the traction motor to zero, generating a control quantity based on the actual speed and the target speed of the traction motor, and using the control quantity as a control output quantity for controlling the traction motor.

3. The parking control method according to claim 1, wherein, The parking posture includes parking with the front of the vehicle facing up, parking with the front of the vehicle facing down, and parking on a flat ground, wherein When the disturbance observation value is greater than or equal to zero, it indicates that the parking posture is parking with the front of the vehicle facing down or parking on a flat ground; When the disturbance observation value is less than zero, it indicates that the parking posture is parking with the front of the vehicle facing up or parking on a flat ground.

4. The parking control method according to claim 1, wherein, The setting of the direction value of the target speed of the traction motor according to the disturbance observation value includes: When the disturbance observation value is greater than or equal to zero, setting the direction value of the target speed of the traction motor to a positive direction value; When the disturbance observation value is less than zero, setting the direction value of the target speed of the traction motor to a negative direction value.

5. The parking control method according to claim 1, wherein The second set speed value is a preset speed value for preventing the vehicle from rolling backward, and the first set speed value is less than or equal to the second set speed value.

6. The parking control method according to claim 1, wherein, Adjusting the control quantity according to the direction value of the target speed to generate a control output quantity for controlling the traction motor includes: Using the direction value of the target speed to perform polarity limitation on the control quantity, so that the direction value of the target speed is different from the polarity of the control quantity.

7. The parking control method according to claim 6, wherein, Adjusting the control quantity according to the direction value of the target speed to generate a control output quantity for controlling the traction motor includes: When the direction value of the target speed is a positive direction value, if the control quantity is greater than zero, the control output quantity is set to zero; When the direction value of the target speed is a negative direction value, if the control quantity is less than zero, the control output quantity is set to zero.

8. The parking control method according to claim 1, wherein, Generate the parking instruction by at least one of the following conditions: The opening degree of the accelerator pedal is 0; The opening degree of the brake pedal is greater than 0; The handbrake is pulled; The speed gear is placed in neutral; The direction gear is placed in neutral.

9. A parking control system for an electric vehicle, comprising: A rotational speed sensor configured to collect the actual rotational speed of a traction motor in the electric vehicle; A parking instruction acquisition module configured to acquire a parking instruction; A parking attitude recognition module configured to, when there is the parking instruction and the rotational speed value of the actual rotational speed of the traction motor is less than or equal to a first set rotational speed value, perform disturbance observation on the operating condition of the electric vehicle, wherein the parking attitude recognition module obtains a disturbance observation value related to the operating condition of the electric vehicle, sets a direction value of the target rotational speed of the traction motor according to the disturbance observation value, and sets the rotational speed value of the target rotational speed of the traction motor as a second set rotational speed value, wherein the disturbance observation value is used to indicate the parking attitude of the electric vehicle, and the direction value of the target rotational speed of the traction motor is associated with the parking attitude; A disturbance observation module configured to perform the disturbance observation and, when there is the parking instruction and the rotational speed value of the target rotational speed of the traction motor is set as the second set rotational speed value, generate a control quantity based on the actual rotational speed and the target rotational speed of the traction motor; An adjustment module configured to adjust the control quantity according to the direction value of the target rotational speed to generate a control output quantity for controlling the traction motor; A current control module configured to generate a power circuit control current for controlling a power circuit according to the control output quantity; A power circuit configured to control the traction motor according to the power circuit control current. The disturbance observation module is an active disturbance rejection control module, and the active disturbance rejection control module includes a tracking differentiator, a state observer, and an error feedback controller:

10. The parking control system according to claim 9, wherein, The input quantity of the tracking differentiator is the target rotational speed, and the output quantity of the tracking differentiator is a transition rotational speed; The input quantity of the state observer is the control output quantity and a first rotational speed difference, the first rotational speed difference is the actual rotational speed minus the rotational speed observation value, and the output quantities of the state observer are the rotational speed observation value and the disturbance observation value; The input quantity of the error feedback controller is a second rotational speed difference and the disturbance observation value, the second rotational speed difference is the transition rotational speed minus the rotational speed observation value, and the output quantity of the error feedback controller is the control quantity.

11. According to the parking control system of claim 9, when there is the parking instruction and the rotational speed value of the actual rotational speed of the traction motor is greater than or equal to the first set rotational speed value, the parking attitude recognition module is configured to set the target rotational speed of the traction motor to zero, and the disturbance observation module is configured to generate a control quantity based on the actual rotational speed and the target rotational speed of the traction motor, and use the control quantity as a control output quantity for controlling the traction motor. The parking attitude includes parking with the front of the vehicle facing upward, parking with the front of the vehicle facing downward, and parking on flat ground, wherein, 12. The parking control system according to claim 9, wherein, ​ When the disturbance observation value is greater than or equal to zero, it indicates that the parking attitude is nose - down parking or flat - ground parking; When the disturbance observation value is less than zero, it indicates that the parking attitude is nose - up parking or flat - ground parking.

13. The parking control system according to claim 9, wherein, The parking attitude recognition module sets the direction value of the target speed of the traction motor according to the disturbance observation value, including: When the disturbance observation value is greater than or equal to zero, set the direction value of the target speed of the traction motor as the positive direction value; When the disturbance observation value is less than zero, set the direction value of the target speed of the traction motor as the negative direction value.

14. The parking control system according to claim 9, wherein, The adjustment module adjusts the control quantity according to the direction value of the target speed to generate a control output quantity for controlling the traction motor, including: Using the direction value of the target speed, perform polarity limitation on the control quantity, so that the direction value of the target speed is different from the polarity of the control quantity.

15. The parking control system according to claim 14, wherein, The adjustment module adjusts the control quantity according to the direction value of the target speed to generate a control output quantity for controlling the traction motor, including: When the direction value of the target speed is the positive direction value, if the control quantity is greater than zero, then the control output quantity is set to zero; When the direction value of the target speed is the negative direction value, if the control quantity is less than zero, then the control output quantity is set to zero.

16. A computer - readable storage medium, on which computer - executable instructions are stored, and the instructions are used to implement the method according to any one of claims 1 - 8 when executed by a processor.

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