Vehicle analog simulation control method, system and device and storage medium

Abstract

The invention discloses a vehicle analog simulation control method, system and device and a storage medium, belongs to the technical field of vehicle control, and solves the technical problem that an existing PID controller cannot achieve an ideal control effect. The method comprises the following steps: acquiring a feedback actual vehicle speed signal, and converting to obtain an actual vehicle speed; calculating the vehicle speed deviation between the target vehicle speed and the actual vehicle speed; calculating a proportional term, an integral term and a differential term of the PID according to the vehicle speed deviation so as to obtain an original required torque percentage of the whole vehicle; carrying out maximum value limitation and minimum value limitation on the original demand torque percentage of the whole vehicle to obtain a limited torque percentage; checking the torque external characteristic Map of the whole vehicle according to the actual vehicle speed, and obtaining the maximum torque capable of being output by the whole vehicle at the current vehicle speed; the whole vehicle demand torque is obtained by multiplying the limited torque percentage by the maximum torque; and controlling the engine to work according to the vehicle demand torque. The calculation amount can be reduced, and the effectiveness and stability of control can be effectively ensured.

Description

Technical Field

[0001] The present invention relates to the field of vehicle control technology, and more specifically, to a vehicle simulation control method, system, device and storage medium. Background Art

[0002] The longitudinal control of the vehicle is mainly speed control and longitudinal position adjustment. The vehicle speed is controlled by controlling the brake, accelerator, gear, etc. For automatic transmission vehicles, the control objects are actually the brake and accelerator. The longitudinal control algorithm usually adopts the PID (Proportion Integration Differentiation) control algorithm.

[0003] However, there are nonlinearities and time-varying uncertainties in the vehicle operation process, and it is impossible to establish an accurate mathematical model, so the PID controller cannot achieve the ideal control effect. Summary of the invention

[0004] The technical problem to be solved by the present invention is to address the above-mentioned deficiencies in the prior art. One purpose of the present invention is to provide a vehicle simulation control method that can reduce the amount of calculation and efficiently ensure the effectiveness and stability of control.

[0005] A second object of the present invention is to provide a vehicle control system.

[0006] A third object of the present invention is to provide a computer device.

[0007] A fourth objective of the present invention is to provide a computer storage medium.

[0008] In order to achieve the above-mentioned objective 1, the present invention provides a vehicle simulation control method, comprising the following steps:

[0009] Step 1. Obtain the actual vehicle speed signal fed back and convert it to obtain the actual vehicle speed;

[0010] Step 2. Calculate the speed deviation between the target speed and the actual speed;

[0011] Step 3. Calculate the proportional term, integral term and differential term of PID according to the vehicle speed deviation, and calculate the original required torque percentage of the whole vehicle according to the proportional term, integral term and differential term of PID in one step;

[0012] Step 4. Performing maximum and minimum limits on the original required torque percentage of the vehicle to obtain a limited torque percentage;

[0013] Step 5. Look up the vehicle torque external characteristic Map according to the actual vehicle speed to obtain the maximum torque that the vehicle can output at the current vehicle speed;

[0014] Step 6. Obtain the vehicle required torque by multiplying the limit torque percentage by the maximum torque;

[0015] Step 7: Control the engine operation according to the required torque of the whole vehicle.

[0016] As a further improvement, in step 1, a first-order low-pass filter is used to perform low-pass filtering on the fed-back actual vehicle speed signal.

[0017] Furthermore, PI robust control is adopted.

[0018] Further, the vehicle system can be described as:

[0019]

[0020] Where x = [x1 x2] is the position and velocity; J is the moment of inertia of the system; C is the viscosity coefficient; d is the disturbance added to the control input;

[0021] Assume xd is the position command, e = xl – xd is the position tracking error, that is

[0022]

[0023] The error function is defined as:

[0024]

[0025] Where c>0

[0026] definition

[0027] but

[0028]

[0029] The following relationship is obtained

[0030]

[0031] The control law is designed as

[0032]

[0033] In the formula, k p >0;k i >0;u m is the model-based control term; u r is the robust term;

[0034] Pick

[0035]

[0036] ur =k r sgn(s);

[0037] In the formula, k r ≥|d max |, then

[0038]

[0039] Thus we get

[0040]

[0041] In order to achieve the above-mentioned second objective, the present invention provides a vehicle simulation control system, comprising:

[0042] An acquisition module is used to acquire the feedback actual vehicle speed signal and convert it into the actual vehicle speed;

[0043] A deviation calculation module, used for calculating a speed deviation between a target speed and the actual speed;

[0044] A torque percentage calculation module, used for calculating the proportional term, integral term and differential term of PID according to the vehicle speed deviation, and performing a one-step calculation according to the proportional term, integral term and differential term of PID to obtain the original required torque percentage of the whole vehicle;

[0045] A torque limiting calculation module is used to perform a maximum value limit and a minimum value limit on the original required torque percentage of the whole vehicle to obtain a torque limiting percentage;

[0046] A maximum torque calculation module is used to check the vehicle torque external characteristic Map according to the actual vehicle speed to obtain the maximum torque that the vehicle can output at the current vehicle speed;

[0047] A required torque calculation module, used for obtaining the required torque of the whole vehicle by multiplying the limit torque percentage by the maximum torque;

[0048] The control module is used to control the operation of the engine according to the required torque of the whole vehicle.

[0049] In order to achieve the third objective above, the present invention provides a computer device, including a memory and a processor, wherein the memory stores a computer program, and the processor implements the above-mentioned vehicle simulation control method when executing the computer program.

[0050] In order to achieve the fourth objective above, the present invention provides a computer-readable storage medium having a computer program stored thereon, and when the computer program is executed by a processor, the vehicle simulation control method mentioned above is implemented.

[0051] Beneficial Effects

[0052] Compared with the prior art, the present invention has the following advantages:

[0053] The present invention calculates the error between the target speed and the measured speed and considers the appropriate selection of Kd, Ki and Kp to perform reasonable closed-loop PID control. In addition, PI robustness control is adopted to reduce the amount of calculation, and the stability and durability of control can be effectively and quickly achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] Figure 1 It is a control flow chart of the present invention. DETAILED DESCRIPTION

[0055] The present invention will be further described below with reference to the specific embodiments in the accompanying drawings.

[0056] See also Figure 1 , a vehicle simulation control method, comprising the following steps:

[0057] Step 1. Obtain the actual vehicle speed signal fed back and convert it to obtain the actual vehicle speed; specifically, use a first-order low-pass filter to low-pass filter the actual vehicle speed signal fed back to remove high-frequency interference, and then convert it to obtain the actual vehicle speed after low-pass filtering.

[0058] Step 2. Calculate the speed deviation between the target speed and the actual speed, where the target speed is the target speed input by the simulation;

[0059] Step 3. Calculate the proportional term Kp, integral term Ki and differential term Kd of PID according to the vehicle speed deviation, and calculate the original required torque percentage of the whole vehicle according to the proportional term Kp, integral term Ki and differential term Kd of PID in one step;

[0060] Step 4. Perform maximum and minimum limits on the original required torque percentage of the vehicle to obtain a limited torque percentage; the maximum and minimum limits are performed to limit the engine torque from being too large or too small to prevent engine damage and abnormal operation;

[0061] Step 5. Check the vehicle torque external characteristic map according to the actual vehicle speed to obtain the maximum torque that the vehicle can output at the current speed;

[0062] Step 6. Obtain the vehicle required torque by multiplying the limit torque percentage by the maximum torque;

[0063] Step 7: Control the engine operation according to the torque required by the vehicle.

[0064] Furthermore, PI robust control is adopted, that is, model-based PI robust control. Specifically:

[0065] The vehicle system can be interpreted as an uncertain mechanical system. The vehicle system can be described as:

[0066]

[0067] Where x = [x1 x2] is the position and velocity; J is the moment of inertia of the system; C is the viscosity coefficient; d is the disturbance added to the control input;

[0068] Assume xd is the position command, e = xl – xd is the position tracking error, that is

[0069]

[0070]

[0071] The error function is defined as:

[0072]

[0073] Where c>0

[0074] definition

[0075] but

[0076]

[0077] The following relationship is obtained

[0078]

[0079] The control law is designed as

[0080]

[0081] In the formula, k p >0;k i >0;u m is the model-based control term; u r is the robust term;

[0082] Pick

[0083]

[0084] u r =k r sgn(s);

[0085] In the formula, k r ≥|d max |, then

[0086]

[0087] Thus we get

[0088]

[0089] With the above methods, PI robust control can reduce the amount of calculation and very efficiently ensure the effectiveness and stability of control.

[0090] It is also possible to establish a working condition map according to the working condition of a specific vehicle model. The working condition map includes the throttle opening, the current vehicle speed, and the working condition coefficient, that is, the working condition coefficients of different working conditions are calibrated according to the throttle opening and the current vehicle speed. Different working conditions include normal driving conditions and escape conditions. The working condition coefficient of the normal driving condition is 1, and the working condition coefficient of the escape condition is greater than 1. The working condition coefficient of the escape condition needs to ensure that the engine is not damaged, or that the engine is not damaged within the set time. It is specifically calibrated according to different vehicle models. In step 6, the current working condition coefficient is obtained according to the current throttle opening and the current vehicle speed. The limiting torque percentage is multiplied by the maximum torque and the working condition coefficient in turn to obtain the required torque of the whole vehicle. The purpose is to improve the vehicle's escape ability, such as the escape ability of agricultural machinery and engineering machinery.

[0091] A vehicle simulation control system, comprising:

[0092] An acquisition module is used to acquire the feedback actual vehicle speed signal and convert it into the actual vehicle speed;

[0093] A deviation calculation module, used for calculating the speed deviation between the target speed and the actual speed;

[0094] The torque percentage calculation module is used to calculate the proportional term, integral term and differential term of PID according to the vehicle speed deviation, and to calculate the original required torque percentage of the whole vehicle in one step according to the proportional term, integral term and differential term of PID;

[0095] A torque limit calculation module is used to set a maximum value and a minimum value for the original required torque percentage of the vehicle to obtain a torque limit percentage;

[0096] The maximum torque calculation module is used to check the vehicle torque external characteristic map according to the actual vehicle speed and obtain the maximum torque that the vehicle can output at the current speed;

[0097] A required torque calculation module is used to obtain the required torque of the vehicle by multiplying the maximum torque by the limited torque percentage;

[0098] The control module is used to control the engine operation according to the torque required by the vehicle.

[0099] A computer device includes a memory and a processor. The memory stores a computer program. When the processor executes the computer program, the above-mentioned vehicle simulation control method is implemented.

[0100] A computer-readable storage medium stores a computer program, which implements the above-mentioned vehicle simulation control method when executed by a processor.

[0101] The above are only preferred embodiments of the present invention. It should be pointed out that for those skilled in the art, several modifications and improvements can be made without departing from the structure of the present invention, which will not affect the effect of the implementation of the present invention and the practicality of the patent.

Claims

1. A vehicle simulation control method, characterized in that: The following steps are involved: Step 1. Obtain the actual vehicle speed signal fed back and convert it to obtain the actual vehicle speed; Step 2. Calculate the speed deviation between the target speed and the actual speed; Step 3. Calculate the proportional term, integral term and differential term of PID according to the vehicle speed deviation, and calculate the original required torque percentage of the whole vehicle according to the proportional term, integral term and differential term of PID in one step; Step 4. Performing maximum and minimum limits on the original required torque percentage of the vehicle to obtain a limited torque percentage; Step 5. Look up the vehicle torque external characteristic Map according to the actual vehicle speed to obtain the maximum torque that the vehicle can output at the current vehicle speed; Step 6. Obtain the vehicle required torque by multiplying the limit torque percentage by the maximum torque; Step 7: Control the engine operation according to the required torque of the whole vehicle.

2. A vehicle simulation control method according to claim 1, characterized in that: In step 1, a first-order low-pass filter is used to perform low-pass filtering on the feedback actual vehicle speed signal.

3. A vehicle simulation control method according to claim 1, characterized in that: PI robust control is adopted.

4. A vehicle simulation control method according to claim 3, characterized in that: The vehicle system can be described as: Where x = [x1 x2] is the position and velocity; J is the moment of inertia of the system; C is the viscosity coefficient; d is the disturbance added to the control input; Assume xd is the position command, e = xl – xd is the position tracking error, that is The error function is defined as: Where c>0 definition but The following relationship is obtained The control law is designed as In the formula, k p >0;k i >0;u m is the model-based control term; u r is a robust term; u r =k r sgn(s); In the formula, k r ≥|d max |, then Thus we get 5. A vehicle simulation control system, characterized in that: include: An acquisition module is used to acquire the feedback actual vehicle speed signal and convert it into the actual vehicle speed; A deviation calculation module, used for calculating a speed deviation between a target speed and the actual speed; A torque percentage calculation module, used for calculating the proportional term, integral term and differential term of PID according to the vehicle speed deviation, and performing a one-step calculation according to the proportional term, integral term and differential term of PID to obtain the original required torque percentage of the whole vehicle; A torque limiting calculation module is used to perform a maximum value limit and a minimum value limit on the original required torque percentage of the whole vehicle to obtain a torque limiting percentage; A maximum torque calculation module is used to check the vehicle torque external characteristic Map according to the actual vehicle speed to obtain the maximum torque that the vehicle can output at the current vehicle speed; A required torque calculation module, used for obtaining the required torque of the whole vehicle by multiplying the limit torque percentage by the maximum torque; The control module is used to control the operation of the engine according to the required torque of the whole vehicle.

6. A computer device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that: When the processor executes the computer program, the vehicle simulation control method described in any one of claims 1-4 is implemented.

7. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, a vehicle simulation control method as described in any one of claims 1 to 4 is implemented.

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