Electric vehicle speed control system and control method based on PID (Proportion Integration Differentiation) control

Abstract

The invention relates to an electric vehicle speed control system and control method based on PID control, and solves the problems of slow vehicle speed adjustment, overshoot and the like of a current vehicle control system. Comprising a speed error input module, a PID controller and a torque output module. Comprising the following steps that 1, the current vehicle speed V1, the maximum vehicle speed V, the current motor rotating speed Spd1 and the motor torque T1 are obtained; 2, according to the current rotating speed Spd1 of the motor, the required torque T2 of the motor at the next moment is obtained; 3, a step-by-step PID regulator is set, the first-stage regulation limit value is M1, and the second-stage regulation limit value is M2; when V-V1gt; when M1 is greater than M1, the P value is increased to enable the vehicle speed V to approach the maximum vehicle speed V; when M2lt; v-V1lt, V-V1lt; when M1 is greater than M1, the P value is reduced, and the I value is increased to prevent system overshoot; 4, when the vehicle speed error is smaller than the second-level limit value M2, control is stopped so that the vehicle speed can be stabilized at the target speed; and 5, limiting the upper and lower limits of integration to avoid the problem of integration saturation. According to the invention, the vehicle speed can be controlled more accurately and stably.

Description

Technical Field

[0001] The present invention relates to a speed control system, and particularly to an electric vehicle speed control system and control method based on PID control. Background Art

[0002] In modern transportation, electric vehicles have become one of the main means of transportation. However, the speed control of electric vehicles remains a challenging problem. Traditional speed control algorithms often fail to balance the requirements of system stability, control accuracy, and adjustment speed, making it difficult to meet the actual needs of speed control. Among them, the vehicle control system is one of the key technologies to improve the driving comfort and safety of drivers. At present, there are problems such as slow vehicle speed adjustment and excessive overshoot in the vehicle control system. Summary of the Invention

[0003] The electric vehicle speed control system based on PID control of the present invention aims to achieve stable and efficient operation of the electric vehicle, improve vehicle safety and energy conservation. By precisely controlling the motor speed of the electric vehicle, the system can keep the vehicle at a stable speed under different road conditions, quickly respond when braking is required, and avoid energy waste caused by excessive acceleration or deceleration, thereby improving the battery life and overall efficiency of the electric vehicle.

[0004] The present invention is realized by the following technical solutions:

[0005] An electric vehicle speed control system based on PID control includes a speed error input module, a PID controller, and a torque output module. Among them, the speed error input module is used to measure the error between the current vehicle speed and the set target speed; the PID controller processes the speed error and outputs a corresponding torque value; the torque output module transmits the torque value output by the PID controller to the motor controller to adjust the motor torque.

[0006] An electric vehicle speed control method based on PID control includes the following steps:

[0007] Step 1: Obtain the current vehicle speed V1, the maximum vehicle speed V, the current motor speed Spd1, and the motor torque T1;

[0008] Step 2: Calculate the required torque T2 of the motor at the next moment according to the current motor speed Spd1;

[0009] Step 3: Set a step-by-step PID regulator with a first-level adjustment limit value of M1 and a second-level adjustment limit value of M2; when V - V1 > M1, appropriately increase the P value to make the vehicle speed V approach the maximum vehicle speed V as soon as possible; when M2 < V - V1 < M1, appropriately decrease the P value and gradually increase the I value to prevent system overshoot, ensure stability and improve the response speed;

[0010] Step 4: When the vehicle speed error is less than the secondary limit M2, stop the control to stabilize the vehicle speed at the target speed;

[0011] Step 5: Limit the upper and lower limits of the integral to avoid the integral saturation problem.

[0012] The electric vehicle speed control system and control method based on step-by-step, anti-integral saturation PID regulation provided by the present invention can control the vehicle speed more accurately and stably, and can adapt to different road conditions and user needs, thereby achieving efficient, stable and safe operation of the electric vehicle, and bringing more convenience and comfort to people's travel. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is the control principle diagram of the present invention;

[0014] Figure 2 It is a general control principle diagram of the present invention. DETAILED DESCRIPTION

[0015] like Figure 1 , 2 As shown, the present invention is an electric vehicle speed control system based on PID control, including a speed error input module, a PID controller, and a torque output module, wherein the speed error input module is used to measure the error between the current vehicle speed and the set target speed; the PID controller processes the speed error and outputs a corresponding torque value; the torque output module transmits the torque value output by the PID controller to the motor controller to adjust the motor torque.

[0016] Specifically, the PID controller is a classic control algorithm that can dynamically adjust the motor speed or torque according to the difference between the actual feedback signal and the set target value to achieve precise control of the vehicle speed. In addition, the PID controller can also adaptively adjust the control parameters according to real-time environmental signals to ensure the best control effect under different road conditions.

[0017] The speed error input module is used to measure the error between the current vehicle speed and the set target speed; the PID controller processes the speed error and outputs the corresponding torque value; the torque output module transmits the torque value output by the PID controller to the motor controller to adjust the motor torque. The specific control method is as follows:

[0018] Step 1: Obtain the current vehicle speed V1, the maximum vehicle speed V, the current motor speed Spd1 and the motor torque T1; Step 2: According to the current motor speed Spd1, obtain the required torque T2 of the motor at the next moment;

[0019] Step 3: Set a step-by-step PID regulator with the first-level adjustment limit being M1 and the second-level adjustment limit being M2. When V - V1 > M1, appropriately increase the P value to make the vehicle speed V approach the maximum speed V as soon as possible. When M2 < V - V1 < M1, appropriately decrease the P value and gradually increase the I value to prevent system overshoot, ensure stability, and improve the response speed.

[0020] Step 4: When the vehicle speed error is less than the second-level limit M2, stop the control to keep the vehicle speed stable at the target speed.

[0021] Step 5: At the same time, we limit the upper and lower limits of integration to avoid the occurrence of integral saturation problems.

[0022] The present invention adopts an electric vehicle speed system based on a step-by-step PID algorithm. Compared with traditional speed control methods, its control method has the following advantages:

[0023] 1. This method adopts a step-by-step regulator, which can dynamically adjust the adjustment coefficient, thus better ensuring the stability of speed control.

[0024] 2. This method adopts the upper and lower limits of integration to prevent integral saturation, thus avoiding unpredictable fluctuations during the speed control process, and improving the anti-interference ability and dynamic responsiveness of the system.

[0025] 3. Appropriate P and I values can be selected according to different driving conditions to expand the application range; 4. It is applicable to various types of electric vehicles and has universality.

Claims

1. An electric vehicle speed control system based on PID control, characterized by: It includes a speed error input module, a PID controller, and a torque output module. Among them, the speed error input module is used to measure the error between the current vehicle speed and the set target speed; the PID controller processes the speed error and outputs a corresponding torque value; the torque output module transmits the torque value output by the PID controller to the motor controller to adjust the motor torque.

2. A method for controlling the speed of an electric vehicle based on PID control, characterized in that: It includes the following steps: Step 1: Obtain the current vehicle speed V1, the maximum vehicle speed V, the current motor speed Spd1, and the motor torque T1; Step 2: Calculate the required torque T2 of the motor at the next moment according to the current motor speed Spd1; Step 3: Set a step-by-step PID regulator with the first-level adjustment limit value M1 and the second-level adjustment limit value M2; when V - V1 > M1, appropriately increase the P value to make the vehicle speed V approach the maximum vehicle speed V as soon as possible; when M2 < V - V1 < M1, appropriately decrease the P value and gradually increase the I value to prevent system overshoot, ensure stability and improve the response speed; Step 4: When the vehicle speed error is less than the second-level limit value M2, stop the control to make the vehicle speed stable at the target speed; Step 5: Limit the upper and lower limits of integration to avoid the occurrence of integral saturation problems.

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