A collaborative control system and method for a steering test bench

Abstract

The present invention belongs to the technical field of steering test bench control, and particularly relates to a collaborative control system and method for a steering test bench; it includes a left linear actuator cylinder, a right linear actuator cylinder, a rotary motor, an EPS, a left linear actuator cylinder fixing member, a right linear actuator cylinder fixing member, a left linear actuator cylinder connector, a right linear actuator cylinder connector, a rotary motor fixing frame, a rotary motor connector, a steering column, a steering wheel, an EPS fixing member, a base and a real-time control system; bilateral linear actuator cylinders are adopted, the signal of SAS is used as the input of the vehicle dynamics simulation software, and the two linear actuator cylinders are decoupled from the rotary motor; and by fixing one of the linear actuator cylinders, the two linear actuator cylinders are decoupled again; the adjustment process of the entire test bench is simplified.

Description

Technical Field

[0001] The invention belongs to the technical field of steering test bench control, and particularly relates to a steering test bench collaborative control system and method. Background Art

[0002] With the development of automotive electronic control systems, more and more vehicles are equipped with electric power steering devices (referred to as EPS). EPS needs to conduct hardware-in-the-loop bench tests. At the steering tie rod end, a linear actuator needs to be connected to simulate the actual vehicle load. At the steering wheel end, a rotary motor needs to be connected. While the rotary motor is rotating, a changing load force needs to be applied at the steering tie rod end simultaneously. Therefore, during hardware-in-the-loop tests, two linear actuators and the rotary motor need to act cooperatively. The currently adopted test method is to use a single-side linear actuator instead of a double-side linear actuator to simulate the actual vehicle load. However, in the actual vehicle, load forces are applied to both steering tie rod ends. Therefore, this method cannot fully simulate the actual vehicle state. Summary of the Invention

[0003] To overcome the above problems, the invention provides a steering test bench collaborative control system and method, which adopts double-side linear actuators and a collaborative control method for a total of three systems, namely two linear actuators and a rotary motor, and is suitable for hardware-in-the-loop bench tests in joint simulation with a vehicle dynamics model.

[0004] A steering test bench collaborative control system includes a left linear actuator 1, a right linear actuator 2, a rotary motor 3, an EPS 4, a left linear actuator fixing member 5, a right linear actuator fixing member 6, a left linear actuator connector 7, a right linear actuator connector 8, a rotary motor fixing frame 9, a rotary motor connector 10, a steering column 11, a steering wheel 12, an EPS fixing member 13, a base 14, and a real-time control system. Among them, the left linear actuator fixing member 5, the EPS fixing member 13, and the right linear actuator fixing member 6 are sequentially fixed on the base 14 from left to right. The rotary motor fixing frame 9 is fixed on the base 14 at the front end of the EPS fixing member 13. The left linear actuator 1 is fixed on the left linear actuator fixing member 5 and is connected to one end of the EPS 4 through the left linear actuator connector 7. The right linear actuator 2 is fixed on the right linear actuator fixing member 6 and is connected to the other end of the EPS 4 through the right linear actuator connector 8. The steering column 11 is connected to the transmission shaft of the rotary motor 3, and the steering column 11 and the rotary motor 3 are jointly fixed on the rotary motor fixing frame 9 through the rotary motor connector 10. The EPS 4 is fixed on the EPS fixing member 13. The steering column 11, the EPS 4, and the steering wheel 12 are connected together according to the actual vehicle connection method and spatial position, and a steering wheel angle sensor is installed on the steering column 11. Force sensors are respectively provided at the front ends of the left linear actuator 1 and the right linear actuator 2.

[0005] The real-time control system includes vehicle dynamics simulation software and a test bench controller. The test bench controller is respectively connected to the rotary motor 3, EPS 4, vehicle dynamics simulation software, left linear actuator 1, and right linear actuator 2 for control. The vehicle dynamics simulation software is also connected to the steering wheel angle sensor on the steering column 11 for control.

[0006] The test bench controller sends the preset steering wheel angle to the rotary motor 3 and drives it to rotate. The rotary motor 3 drives the steering wheel 12 to rotate through the steering column 11. The steering wheel angle sensor on the steering column 11 sends the detected angle of the steering wheel 12 to the vehicle dynamics simulation software. The vehicle dynamics simulation software calculates the load forces at the ends of the left and right tie rods and sends them to the test bench controller. The test bench controller calculates the target load force values of the left linear actuator 1 and the right linear actuator 2 and sends them to the left linear actuator 1 and the right linear actuator 2 to drive their linear motion. At the same time, the force sensors at the front ends of the left linear actuator 1 and the right linear actuator 2 feedback the actual load force values of the left linear actuator 1 and the right linear actuator 2 to the test bench controller.

[0007] A collaborative control method for a steering test bench is implemented by the test bench controller. The test bench controller is provided with actuator control systems for respectively controlling the left linear actuator 1 and the right linear actuator 2. The actuator control system includes a linear actuator signal conditioning and direction conversion module, a linear actuator delay adjustment module, a linear actuator PID adjustment module, a linear actuator force control calibration value MAP, and a differential link, where:

[0008] The linear actuator signal conditioning and direction conversion module is used to receive the load force value at the end of the tie rod sent by the vehicle dynamics simulation software. After a calculation process of filtering and conditioning, and converting the load force at the end of the tie rod to the actuator force direction, it outputs the adjusted load force value of the linear actuator.

[0009] The adjusted load force value of the linear actuator calculates the differential value of the adjusted load force of the linear actuator through the differential link, and inputs it into the linear actuator delay adjustment module and the linear actuator PID adjustment module respectively.

[0010] The linear actuator delay adjustment module calculates the delayed load force value of the linear actuator through signal delay processing according to the delay time MAP and the differential value of the adjusted load force in the linear actuator force control calibration value MAP, and sends it to the linear actuator PID adjustment module.

[0011] The linear actuator PID adjustment module is used to receive the actual load force value input by the force sensor at the front end of the linear actuator, and calculate the target load force value of the linear actuator according to the actual load force value of the linear actuator, the PID MAP in the linear actuator force control calibration value MAP module of the linear actuator, the differential value of the load force conditioning of the linear actuator, and the delay value of the load force of the linear actuator, and drive the linear actuator according to the target load force value of the linear actuator.

[0012] The calculation process of the force control calibration value MAP of the right linear actuator 2 includes the following contents:

[0013] I. Disengage the clutch of the slewing motor 3 to disconnect the slewing motor 3 from the steering wheel 12;

[0014] II. Set the control mode of the left linear actuator 1 to displacement control, and the displacement target value is 0;

[0015] III. The force control target value curve of the right linear actuator 2 is:

[0016] F ref = Asin(2πft) (t≥0)

[0017] where A is the amplitude of the force control target value, f is the frequency of the sine curve, and t is the time;

[0018] IV. Divide A and f into several segments A i and f j . The number of segments of A is M, and the number of segments of f is N. Then:

[0019]

[0020]

[0021] V. With the input of the two variables A i and f j , by adjusting the PID value in the actuator control system and comparing it with the target load force value of the right linear actuator 2, calculate the overshoot σ and delay time ρ of the actual load force value of the right linear actuator 2 until σ and ρ meet the requirements: σ≤10%, ρ≤5ms. When the PID adjustment is completed, record the P, I, D, and ρ values at this time to form the force control calibration value of the right linear actuator 2; combine all the segments one by one to obtain the force control calibration value MAP of the right linear actuator 2, that is:

[0022] [P k I k D k ρ k →A i , f j(i=1, 2,..., M, j=1, 2,..., N, k=1, 2,..., M×N).

[0023] The calculation process of the force control calibration value MAP of the left linear actuator cylinder 1 by the linear actuator force control calibration value MAP module is the same as the calculation process of the force control calibration value MAP of the right linear actuator cylinder 2. The difference is that the right linear actuator cylinder 2 is replaced by the left linear actuator cylinder 1 to obtain the force control calibration value MAP of the left linear actuator cylinder 1.

[0024] To eliminate the influence of the rotation direction of the rotary motor 3 on the coordinated motion of the left linear actuator 1 and the right linear actuator 2, the linear actuator PID adjustment module first performs adjustments when the rotary motor 3 is turned off, so that the left linear actuator 1 and the right linear actuator 2 move in coordination. The specific process is as follows:

[0025] Input the force control calibration value MAP of the left linear actuator 1 and the right linear actuator 2 into the actuator controller; then send the delay time MAP of the left linear actuator 1 to the linear actuator delay adjustment module of the right linear actuator 2, and the delay time MAP of the right linear actuator 2 to the linear actuator delay adjustment module of the left linear actuator 1. For different linear actuator load force delay values and linear actuator load force adjustment differential values, the corresponding segment A i With f j According to the principle of proximity, the corresponding delay time ρ is obtained for delay processing; the left linear actuator PID MAP is sent to the linear actuator PID adjustment module of the left linear actuator 1, and the right linear actuator PID MAP is sent to the linear actuator PID adjustment module of the right linear actuator 2. For different linear actuator load force delay values and linear actuator load force adjustment differential values, the corresponding segment A i With f j , according to the principle of proximity, the corresponding P, I, and D are obtained, and real-time PID adjustment is performed.

[0026] After eliminating the influence of the rotation direction of the rotary motor 3 on the coordinated motion of the left linear actuator 1 and the right linear actuator 2, the linear actuator PID adjustment module performs adjustments when the rotary motor 3 is turned on, so that the left linear actuator 1, the right linear actuator 2, and the rotary motor 3 move in coordination. The specific process is as follows:

[0027] The clutch of the rotary motor 3 is opened to connect the rotary motor 3 to the steering wheel 12, so that the two linear actuators and the rotary motor 3 are actuated in coordination. The target value curve of the steering wheel 12 angle is set as follows:

[0028] δ ref =Bsin(2πft) (t≥0)

[0029] B is the amplitude of the target value of the steering wheel 12 rotation angle. Adjust the value of B to make the target value of the force control of the linear actuator close to A. i , at different A i and f j , perform fine-tuning of the P, I, D of the two linear actuators to ensure that the overshoot σ and delay time ρ of the actual load force value meet the requirements: σ ≤ 10%, ρ ≤ 5 ms.

[0030] Advantages of the present invention:

[0031] The present invention uses the signal of SAS as the input of the vehicle dynamics simulation software to decouple the two linear actuators and the rotary motor; and by fixing one of the linear actuators, the two linear actuators are decoupled again; the adjustment process of the entire test bench is simplified.

[0032] The present invention extracts two influencing factors, enabling the PID of the force control to be adjusted online, improving the followability of the actual value of the force control to the target value. Description of the drawings

[0033] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings to be used in the description of the embodiments of the present invention. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained according to the content of the embodiments of the present invention and these drawings.

[0034] Figure 1 is a schematic diagram of the control system structure of the present invention.

[0035] Figure 2 is a working flowchart of the real-time control system of the present invention.

[0036] Figure 3 is a method flowchart of the present invention.

[0037] Among them: left linear actuator 1, right linear actuator 2, rotary motor 3, EPS 4, left linear actuator fixing part 5, right linear actuator fixing part 6, left linear actuator connector 7, right linear actuator connector 8, rotary motor fixing frame 9, rotary motor connector 10, steering column 11, steering wheel 12, EPS fixing part 13, base 14. Detailed implementation manners

[0038] The following will further elaborate on the present invention in conjunction with the drawings and embodiments. It can be understood that the specific embodiments described herein are only used to explain the present invention, rather than limiting the present invention. Additionally, it should be noted that for the sake of description, only parts related to the present invention are shown in the drawings, rather than all the structures.

[0039] In the description of the present invention, unless otherwise clearly defined and limited, the terms "connected", "connected to", and "fixed" shall be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two components or the interaction relationship between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0040] In the present invention, unless otherwise clearly defined and limited, the first feature being "above" or "below" the second feature may include the direct contact between the first and second features, or may include the situation where the first and second features are not in direct contact but in contact through other features therebetween. Moreover, the first feature being "above", "over", and "on" the second feature includes that the first feature is directly above and obliquely above the second feature, or merely means that the horizontal height of the first feature is higher than that of the second feature. The first feature being "below", "under", and "beneath" the second feature includes that the first feature is directly below and obliquely below the second feature, or merely means that the horizontal height of the first feature is lower than that of the second feature.

[0041] In the description of this embodiment, the orientation or positional relationship such as "above", "below", "left", and "right" is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of description and simplifying the operation, rather than indicating or implying that the device or component referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present invention. In addition, the terms "first" and "second" are only used for distinction in description and have no special meaning.

[0042] Embodiment 1

[0043] A collaborative control system for a steering test bench, comprising a left linear actuator 1, a right linear actuator 2, a rotary motor 3, an EPS 4, a left linear actuator fixing member 5, a right linear actuator fixing member 6, a left linear actuator connector 7, a right linear actuator connector 8, a rotary motor fixing frame 9, a rotary motor connector 10, a steering column 11, a steering wheel 12, an EPS fixing member 13, a base 14 and a real-time control system. The left linear actuator fixing member 5, the EPS fixing member 13 and the right linear actuator fixing member 6 are sequentially fixed on the base 14 from left to right. The rotary motor fixing frame 9 is fixed on the base 14 at the front end of the EPS fixing member 13. The left linear actuator 1 is fixed on the left linear actuator fixing member 5 and is connected to one end of the EPS 4 through the left linear actuator connector 7. The right linear actuator 2 is fixed on the right linear actuator fixing member 6 and is connected to the other end of the EPS 4 through the right linear actuator connector 8. The steering column 11 is connected to the transmission shaft of the rotary motor 3, and the steering column 11 and the rotary motor 3 are jointly fixed on the rotary motor fixing frame 9 through the rotary motor connector 10. The EPS 4 is fixed on the EPS fixing member 13. The steering column 11, the EPS 4 and the steering wheel 12 are connected together according to the actual vehicle connection method and spatial position, and a steering wheel angle sensor (SAS) is installed on the steering column 11. Force sensors are respectively provided at the front ends of the left linear actuator 1 and the right linear actuator 2.

[0044] The real-time control system includes vehicle dynamics simulation software (CarsimRT) and a test bench controller. The test bench controller is respectively connected to the rotary motor 3, the EPS 4, the vehicle dynamics simulation software, the left linear actuator 1 and the right linear actuator 2 for control. The vehicle dynamics simulation software is also connected to the steering wheel angle sensor (SAS) on the steering column 11 for control.

[0045] As described above Figure 2 As shown, the test bench controller sends a preset steering wheel angle to the rotary motor 3 and drives it to rotate. The rotary motor 3 drives the steering wheel 12 to rotate through the steering column 11. The steering wheel angle sensor on the steering column 11 sends the detected steering wheel 12 angle to the vehicle dynamics simulation software. The vehicle dynamics simulation software calculates the left and right steering tie rod end load forces and sends them to the test bench controller. The test bench controller calculates the load force target values of the left linear actuator 1 and the right linear actuator 2 and sends them to the left linear actuator 1 and the right linear actuator 2 to drive their linear motion. At the same time, the force sensors at the front ends of the left linear actuator 1 and the right linear actuator 2 feedback the actual load force values of the left linear actuator 1 and the right linear actuator 2 to the test bench controller.

[0046] A collaborative control method for a steering test bench, implemented by the test bench controller, as Figure 3As shown, the test bench controller is equipped with an actuator control system for controlling the left linear actuator 1 and the right linear actuator 2 respectively. The actuator control system includes a linear actuator signal conditioning and direction conversion module, a linear actuator delay adjustment module, a linear actuator PID adjustment module, a linear actuator force control calibration value MAP, and a differential link, where:

[0047] The linear actuator signal conditioning and direction conversion module is used to receive the left and right steering tie rod end load force values sent by the vehicle dynamics simulation software. After signal conditioning such as filtering and the calculation process of converting the steering tie rod end load force to the actuator force direction (this module first filters the left and right steering tie rod end load forces to eliminate data with large deviations, and then converts the directions of the left and right steering tie rod end load forces to unify the load force directions, obtaining the load force conditioning values of the left linear actuator 1 and the right linear actuator 2), and outputs the load force conditioning values of the left linear actuator 1 and the right linear actuator 2;

[0048] The load force conditioning values of the left linear actuator 1 and the right linear actuator 2 are used to calculate the load force conditioning differential values of the left linear actuator 1 and the right linear actuator 2 through the differential link, and input them into the linear actuator delay adjustment module and the linear actuator PID adjustment module respectively;

[0049] The linear actuator delay adjustment module calculates the load force delay values of the left linear actuator 1 and the right linear actuator 2 through signal delay processing according to the delay time MAP and the load force conditioning differential values in the linear actuator force control calibration value MAP, and sends them to the linear actuator PID adjustment module;

[0050] The linear actuator PID adjustment module is used to receive the actual load force values input by the force sensors at the front ends of the left linear actuator 1 and the right linear actuator 2, and calculate the load force target values of the left linear actuator 1 and the right linear actuator 2 according to the actual load force values of the left linear actuator 1 and the right linear actuator 2, the PID MAP in the linear actuator force control calibration value MAP module of the left linear actuator 1 and the right linear actuator 2, the load force conditioning differential values of the left linear actuator 1 and the right linear actuator 2, and the load force delay values of the left linear actuator 1 and the right linear actuator 2, and drive the left linear actuator 1 and the right linear actuator 2 according to the load force target values of the linear actuators.

[0051] The calculation process of the force control calibration value MAP of the right linear actuator 2 includes the following contents:

[0052] I. Disengage the clutch of the slewing motor 3 to disconnect the slewing motor 3 from the steering wheel 12;

[0053] II. Set the control mode of the left linear actuator 1 as displacement control, and the displacement target value is 0;

[0054] III. The force control target value curve of the right linear actuator 2 is:

[0055] F ref = Asin(2πft) (t≥0)

[0056] where A is the amplitude of the force control target value, with the unit of N, f is the frequency of the sine curve, with the unit of Hz, and t is the time;

[0057] IV. Divide A and f into several segments A i and f j . Set the number of segments of A as M = 5, and the number of segments of f as N = 4. Then:

[0058]

[0059]

[0060] V. Under the input of the two variables A i and f j , by adjusting the PID values in the actuator control system (integrated in the test bench control program) and comparing with the load force target value of the right linear actuator 2, calculate the overshoot σ and delay time ρ of the actual load force value of the right linear actuator 2 until σ and ρ meet the requirements: σ ≤ 10%, ρ ≤ 5ms. Consider the PID adjustment completed. The adjustment method can use manual adjustment or apply automated test algorithms for optimizing to find extreme values (such as particle swarm algorithm, simulated annealing algorithm, etc.). Record the P, I, D, ρ values at this time to form the force control calibration value of the right linear actuator 2; Combine all segments one by one to obtain the force control calibration value MAP of the right linear actuator 2, that is:

[0061] [P k I k D k ρ k → A i , f j (i = 1, 2,..., M, j = 1, 2,..., N, k = 1, 2,..., M×N).

[0062] The calculation process of the force control calibration value MAP of the left linear actuator by the linear actuator force control calibration value MAP module is the same as that of the force control calibration value MAP of the right linear actuator 2, except that the right linear actuator 2 is replaced by the left linear actuator 1 to obtain the force control calibration value MAP of the left linear actuator 1.

[0063] To eliminate the influence of the rotation direction of the rotary motor 3 itself on the coordinated movement of the left linear actuator 1 and the right linear actuator 2, the linear actuator PID adjustment module first makes adjustments when the rotary motor 3 is turned off, so that the left linear actuator 1 and the right linear actuator 2 move in coordination. The specific process is as follows:

[0064] Input the force control calibration value MAP of the left linear actuator 1 and the right linear actuator 2 into the actuator controller; then send the delay time MAP of the left linear actuator 1 to the linear actuator delay adjustment module of the right linear actuator 2, and send the delay time MAP of the right linear actuator 2 to the linear actuator delay adjustment module of the left linear actuator 1. For different linear actuator load force delay values and the load force conditioning differential values of the linear actuator, the corresponding segment A i and f j , according to the principle of proximity, obtain the corresponding delay time ρ for delay processing; send the left linear actuator PID MAP to the linear actuator PID adjustment module of the left linear actuator 1, and send the right linear actuator PID MAP to the linear actuator PID adjustment module of the right linear actuator 2. For different linear actuator load force delay values and the load force conditioning differential values of the linear actuator, the corresponding segment A i and f j , according to the principle of proximity, obtain the corresponding P, I, D for real-time variable PID adjustment.

[0065] After eliminating the influence of the rotation direction of the rotary motor 3 itself on the coordinated movement of the left linear actuator 1 and the right linear actuator 2, the linear actuator PID adjustment module then makes adjustments when the rotary motor 3 is turned on, so that the left linear actuator 1, the right linear actuator 2 and the rotary motor 3 move in coordination. The specific process is as follows:

[0066] Turn on the clutch of the rotary motor 3 to connect the rotary motor 3 to the steering wheel 12, so that the two linear actuators and the rotary motor 3 act in coordination. Set the corner target value curve of the steering wheel 12 as:

[0067] δ ref = Bsin(2πft) (t≥0)

[0068] B is the amplitude of the corner target value of the steering wheel 12 (degrees), f is the frequency of the sine curve (Hz), which is the same as in step 3. Adjust the value of B so that the force control target value of the obtained linear actuator is close to A i , at different A i and f j , make fine adjustments to the P, I, D of the two linear actuators to ensure that the overshoot σ of the actual load force value and the delay time ρ meet the requirements: σ≤10%, ρ≤5ms.

[0069] Embodiment 2

[0070] As shown in Figure 1 , the left linear actuator fixing part 5, the right linear actuator fixing part 6, the EPS fixing part 13, and the rotary motor fixing frame 9 are fixed on the base 14; the left linear actuator 1 is fixed on the left linear actuator fixing part 5 and is connected to the EPS 4 through the left linear actuator connector 7; the right linear actuator 2 is fixed on the right linear actuator fixing part 6 and is connected to the EPS 4 through the right linear actuator connector 8; the steering column 11 and the rotary motor 3 are fixed on the rotary motor connector 10, and the rotary motor connector 10 is fixed on the rotary motor fixing frame 9; the steering column 11, the EPS 4, and the steering wheel 12 are connected together according to the actual vehicle connection method and spatial position; the EPS 4 is fixed on the EPS fixing part 13; the piston rods of the left linear actuator 1 and the right linear actuator 2 can only perform telescopic sliding along their respective axes; the rotary motor 3 can only rotate along the axis of the steering column 11; the steering wheel angle sensor (SAS) is installed on the steering column 11 and rotates at the same speed as the steering column 11.

[0071] As shown in Figure 2 , the real-time control system includes vehicle dynamics simulation software (CarsimRT) and test bench control program. The test bench control program sends the steering wheel angle to the rotary motor 3 to drive its rotation, which drives the steering column 11 to rotate. The SAS on it sends the detected steering wheel angle to the vehicle dynamics simulation software. The vehicle dynamics simulation software calculates the load forces at the ends of the left and right tie rods and sends them to the test bench control program. The test bench control program calculates the target load force values of the left linear actuator 1 and the right linear actuator 2 and sends them to the left linear actuator 1 and the right linear actuator 2 to drive their linear motion, and feeds back the actual load force values of the left linear actuator 1 and the right linear actuator 2 to the test bench control program through the force sensors at the front ends of the two actuators.

[0072] The present invention aims to provide a cooperative control method for a steering test bench.

[0073] I. Design of the actuator control program:

[0074] The actuator cylinder control program is an integral part of the test bench control program. The actuator cylinder control program includes signal conditioning and direction conversion modules for the left linear actuator cylinder 1 and the right linear actuator cylinder 2, a linear actuator cylinder delay adjustment module, a linear actuator cylinder PID adjustment module, a force control calibration value MAP, and a differential link. The signal conditioning and direction conversion module receives the load force values at the left and right steering tie rod ends sent by the vehicle dynamics simulation software. After signal conditioning such as filtering and the calculation process of converting the load force at the steering tie rod end to the force direction of the actuator cylinder, it outputs the load force conditioning values of the left linear actuator cylinder 1 and the right linear actuator cylinder 2 to the linear actuator cylinder delay adjustment module; the load force conditioning values of the left linear actuator cylinder 1 and the right linear actuator cylinder 2 are used to calculate the differential values of the load force conditioning of the left linear actuator cylinder 1 and the right linear actuator cylinder 2 through the differential link; the linear actuator cylinder delay adjustment module calculates the load force delay values of the left linear actuator cylinder 1 and the right linear actuator cylinder 2 based on the delay time MAP and the differential values of the load force conditioning through signal delay processing and sends them to the linear actuator cylinder PID adjustment module; the linear actuator cylinder PID adjustment module calculates the target load force values of the left linear actuator cylinder 1 and the right linear actuator cylinder 2 based on the actual load force values of the left linear actuator cylinder 1 and the right linear actuator cylinder 2, the PID MAP in the force control calibration value MAP of the left linear actuator cylinder 1 and the right linear actuator cylinder 2, and the differential values of the load force conditioning and drives the left linear actuator cylinder 1 and the right linear actuator cylinder 2; the specific steps are shown in Figure 3 。

[0075] II. Calculation of the force control calibration value MAP for the left and right linear actuator cylinders:

[0076] 1. Disengage the clutch of the slewing motor 3 to disconnect the slewing motor 3 from the steering wheel;

[0077] 2. Set the control mode of the left linear actuator cylinder 1 to displacement control with a displacement target value of 0;

[0078] 3. The force control target value curve of the right linear actuator cylinder 2 is:

[0079] F ref =Asin(2πft) (t≥0)

[0080] where A is the amplitude of the force control target value (N) and f is the frequency of the sine curve (Hz)

[0081] 4. Divide A and f into several segments A i and f j , generally, M = 5 and N = 4 can be set

[0082]

[0083]

[0084] 5. At A i and fj With the input of two variables, by adjusting the PID values in the actuator cylinder control program (integrated in the test bench control program), compared with the force target value of the right linear actuator cylinder 2, the overshoot σ and delay time ρ of the actual force value are calculated. Generally, it is required that σ ≤ 10% and ρ ≤ 5 ms. When this is regarded as the completion of PID adjustment, the adjustment method can use manual adjustment or apply automated test algorithms for optimizing extreme values (such as particle swarm algorithm, simulated annealing algorithm, etc.). Record the P, I, D, and ρ values at this time to form the force control calibration value of the right linear actuator cylinder 2. Combine all segments one by one to obtain the force control calibration value MAP of the right linear actuator cylinder 2.

[0085] That is:

[0086] [P k I k D k ρ k → A i , f j (i = 1, 2,..., M, j = 1, 2,..., N, k = 1, 2,..., M×N)

[0087] 6. Set the control mode of the right linear actuator cylinder 2 to displacement control, and the displacement target value is 0. According to the order of steps 3 - 5, obtain the force control calibration value MAP of the left linear actuator cylinder 1;

[0088] 7. Incorporate the force control calibration value MAP of the left and right linear actuator cylinders obtained in step 5 and step 6 into the actuator cylinder control program. Among them, send the delay time MAP of the left linear actuator cylinder 1 to the linear actuator cylinder delay adjustment module of the right linear actuator cylinder 2, and send the delay time MAP of the right linear actuator cylinder 2 to the linear actuator cylinder delay adjustment module of the left linear actuator cylinder 1; for different linear actuator cylinder load force delay values and linear actuator cylinder load force conditioning differential values, for the corresponding segments Ai and fj, according to the principle of proximity, obtain the corresponding delay time ρ and perform delay processing; send the left linear actuator cylinder PID MAP to the linear actuator cylinder PID adjustment module of the left linear actuator cylinder 1, and send the right linear actuator cylinder PID MAP to the linear actuator cylinder PID adjustment module of the right linear actuator cylinder 2; for different linear actuator cylinder load force delay values and linear actuator cylinder load force conditioning differential values, for the corresponding segment A i and f j , according to the principle of proximity, obtain the corresponding P, I, D, and perform real-time variable PID adjustment.

[0089] 8. Turn on the clutch of the rotary motor 3 to connect the rotary motor 3 with the steering wheel, so that the two linear actuator cylinders and the rotary motor 3 act in coordination. Set the steering wheel angle target value curve as:

[0090] δ ref= Bsin(2πft) (t≥0)

[0091] B is the amplitude of the steering wheel angle target value (degrees), f is the frequency of the sine curve (Hz), which is the same as that in step 3. Adjust the value of B to make the force control target value of the obtained linear actuator close to A i , at different A i and f j , fine-tune the P, I, D of the two actuators to ensure that the overshoot σ and delay time ρ of the actual force value satisfy σ≤10%, ρ≤5ms.

[0092] The preferred embodiments of the present invention have been described in detail above in conjunction with the accompanying drawings. However, the protection scope of the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, any person skilled in the art within the technical scope disclosed by the present invention can make equivalent substitutions or changes according to the technical solution and inventive concept of the present invention. These simple modifications all fall within the protection scope of the present invention.

[0093] In addition, it should be noted that, in the above specific embodiments, the various specific technical features described can be combined in any suitable way without conflict. To avoid unnecessary repetition, the present invention will not separately describe various possible combination methods.

[0094] Furthermore, any arbitrary combination can be made between different embodiments of the present invention as long as it does not violate the idea of the present invention, and it should also be regarded as the content disclosed by the present invention.

Claims

1. A collaborative control method for a steering test bench, characterized in that It is implemented by the test bench controller. The test bench controller is equipped with actuator control systems for controlling the left linear actuator (1) and the right linear actuator (2) respectively. The actuator control system includes a linear actuator signal conditioning and direction conversion module, a linear actuator delay adjustment module, a linear actuator PID adjustment module, a linear actuator force control calibration value MAP, and a differential link, where: The linear actuator signal conditioning and direction conversion module is used to receive the load force value at the steering tie rod end sent by the vehicle dynamics simulation software, and through the calculation process of filtering and conditioning, and converting the load force at the steering tie rod end to the actuator force direction, it outputs the load force conditioning value of the linear actuator; The load force conditioning value of the linear actuator calculates the load force conditioning differential value of the linear actuator through the differential link, and inputs it into the linear actuator delay adjustment module and the linear actuator PID adjustment module respectively; The linear actuator delay adjustment module calculates the load force delay value of the linear actuator through the delay processing of the signal according to the delay time MAP and the load force conditioning differential value in the linear actuator force control calibration value MAP, and sends it to the linear actuator PID adjustment module; The linear actuator PID adjustment module is used to receive the actual load force value input by the force sensor at the front end of the linear actuator, and calculate the target load force value of the linear actuator according to the actual load force value of the linear actuator, the PID MAP in the linear actuator force control calibration value MAP module of the linear actuator, the load force conditioning differential value of the linear actuator, and the load force delay value of the linear actuator, and drive the linear actuator according to the target load force value of the linear actuator.

2. The collaborative control method of a steering test bench according to claim 1, wherein The calculation process of the force control calibration value MAP of the right linear actuator (2) includes the following content: I. Disengage the clutch of the slewing motor (3) to disconnect the slewing motor (3) from the steering wheel (12); II. Set the control mode of the left linear actuator (1) to displacement control, and the displacement target value is 0; III. The force control target value curve of the right linear actuator (2) is: F ref = Asin(2πft) (t ≥ 0) where A is the amplitude of the force control target value, f is the frequency of the sine curve, and t is the time; IV. Divide A and f into several segments A i and f j , the number of segments of A is M, and the number of segments of f is N, then: V. At A i With f j Under the input of two variables, by adjusting the PID value in the actuator control system and comparing it with the target load force of the right linear actuator (2), calculate the overshoot σ and delay time ρ of the actual load force of the right linear actuator (2). Until σ and ρ meet the requirements: σ ≤ 10%, ρ ≤ 5 ms, it is considered that the PID adjustment is completed. Record the P, I, D, and ρ values at this time to form the force control calibration value of the right linear actuator (2); Combine all the segments one by one to obtain the force control calibration value MAP of the right linear actuator (2), that is: [P k I k D k ρ k →A i ,f j (i = 1, 2,..., M, j = 1, 2,..., N, k = 1, 2,..., M×N).

3. A collaborative control method for a steering test bench according to claim 2, characterized in that The calculation process of the force control calibration value MAP module for the left linear actuator (1) is the same as that of the force control calibration value MAP of the right linear actuator (2), except that the right linear actuator (2) is replaced by the left linear actuator (1) to obtain the force control calibration value MAP of the left linear actuator (1).

4. The collaborative control method of a steering test bench according to claim 3, characterized in that To eliminate the influence of the self-rotation direction of the slewing motor (3) on the coordinated movement of the left linear actuator (1) and the right linear actuator (2), the linear actuator PID adjustment module first adjusts when the slewing motor (3) is turned off to make the left linear actuator (1) and the right linear actuator (2) move coordinately. The specific process is as follows: Input the force control calibration value MAP of the left linear actuator (1) and the right linear actuator (2) into the actuator controller; then send the delay time MAP of the left linear actuator (1) to the linear actuator delay adjustment module of the right linear actuator (2), and send the delay time MAP of the right linear actuator (2) to the linear actuator delay adjustment module of the left linear actuator (1). For different linear actuator load force delay values and the differential value of the load force conditioning of the linear actuator, corresponding to segment A i and f j , according to the principle of proximity, obtain the corresponding delay time ρ for delay processing; send the left linear actuator PID MAP to the linear actuator PID adjustment module of the left linear actuator (1), and send the right linear actuator PID MAP to the linear actuator PID adjustment module of the right linear actuator (2). For different linear actuator load force delay values and the differential value of the load force conditioning of the linear actuator, corresponding to segment A i and f j , according to the principle of proximity, obtain the corresponding P, I, D for real-time variable PID adjustment.

5. A collaborative control method for a steering test bench according to claim 4, characterized in that After excluding the influence of the rotation direction of the rotary motor (3) itself on the coordinated movement of the left linear actuator (1) and the right linear actuator (2), the linear actuator PID adjustment module adjusts when the rotary motor (3) is turned on, so that the left linear actuator (1), the right linear actuator (2) and the rotary motor (3) move in coordination. The specific process is as follows: Turn on the clutch of the rotary motor (3) to connect the rotary motor (3) to the steering wheel (12), and make the two linear actuators act in coordination with the rotary motor (3). Set the steering angle target value curve of the steering wheel (12) as: δ ref = Bsin(2πft) (t ≥ 0) B is the amplitude of the target value of the steering wheel (12) angle. Adjust the value of B so that the obtained force control target value of the linear actuator is close to A i , at different A i and f j , fine-tune the P, I, D of the two linear actuators to ensure that the overshoot σ and delay time ρ of the actual load force value meet the requirements: σ ≤ 10%, ρ ≤ 5 ms.

6. A collaborative control method for a steering test bench according to claim 1, characterized in that The applied steering test bench coordinated control system includes a left linear actuator (1), a right linear actuator (2), a rotary motor (3), an EPS (4), a left linear actuator fixing member (5), a right linear actuator fixing member (6), a left linear actuator connector (7), a right linear actuator connector (8), a rotary motor fixing frame (9), a rotary motor connector (10), a steering column (11), a steering wheel (12), an EPS fixing member (13), a base (14) and a real-time control system. Among them, the left linear actuator fixing member (5), the EPS fixing member (13) and the right linear actuator fixing member (6) are fixed on the base (14) from left to right in sequence. The rotary motor fixing frame (9) is fixed on the base (14) at the front end of the EPS fixing member (13). The left linear actuator (1) is fixed on the left linear actuator fixing member (5) and is connected to one end of the EPS (4) through the left linear actuator connector (7); the right linear actuator (2) is fixed on the right linear actuator fixing member (6) and is connected to the other end of the EPS (4) through the right linear actuator connector (8); the steering column (11) is connected to the transmission shaft of the rotary motor (3), and the steering column (11) and the rotary motor (3) are jointly fixed on the rotary motor fixing frame (9) through the rotary motor connector (10). The EPS (4) is fixed on the EPS fixing member (13); the steering column (11), the EPS (4) and the steering wheel (12) are connected together according to the actual vehicle connection method and spatial position, and a steering wheel angle sensor is installed on the steering column (11). Force sensors are respectively arranged at the front ends of the left linear actuator (1) and the right linear actuator (2); The real-time control system includes vehicle dynamics simulation software and a test bench controller. Among them, the test bench controller is respectively connected to the rotary motor (3), the EPS (4), the vehicle dynamics simulation software, the left linear actuator (1) and the right linear actuator (2) for control connection. The vehicle dynamics simulation software is also connected to the steering wheel angle sensor on the steering column (11) for control connection.

7. A collaborative control method for a steering test bench according to claim 6, characterized in that The test bench controller sends the preset steering wheel angle to the slewing motor (3) and drives it to rotate. The slewing motor (3) drives the steering wheel (12) to rotate through the steering column (11). The steering wheel angle sensor on the steering column (11) sends the detected steering wheel (12) angle to the vehicle dynamics simulation software. The vehicle dynamics simulation software calculates the load forces at the ends of the left and right steering tie rods and sends them to the test bench controller. The test bench controller calculates the target load force values of the left linear actuator (1) and the right linear actuator (2) and sends them to the left linear actuator (1) and the right linear actuator (2), driving them to move linearly. At the same time, the force sensors at the front ends of the left linear actuator (1) and the right linear actuator (2) feedback the actual load force values of the left linear actuator (1) and the right linear actuator (2) to the test bench controller.

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