Gradient support control system and method for gearbox HIL rack

Abstract

The invention belongs to the field of vehicle testing, and particularly discloses a gradient support control system and method for a gearbox HIL rack, and the system is characterized in that a gearbox controller obtains a real-time gradient value of a gradient support through the detection of an acceleration sensor, and transmits the real-time gradient value to the gearbox HIL rack; the gearbox HIL rack receives the real-time gradient value of the gradient support sent by the gearbox controller, the difference between the real-time gradient value of the gradient support and the gradient set value at the moment is obtained, and the difference is input into a PID module after positive and negative negation; the PID module processes the received deviation data and outputs and transmits the deviation data to a gearbox HIL rack; and the gearbox HIL rack controls a stepping motor of the gradient support to operate according to the compensated gradient set value. The gradient support is controlled to move when the vehicle is simulated to move, acceleration generated by vehicle movement is counteracted in a negative slope giving mode, so that a gradient signal sent by the controller can be always equal to a gradient value set by a model, and the test accuracy is improved.

Description

Technical Field

[0001] The invention belongs to the field of vehicle testing, and in particular relates to a control system and method for a slope bracket used in a gearbox HIL test bench. Background Art

[0002] HIL testing (hardware-in-the-loop testing) is an important verification method for system integration testing in the development of vehicle control strategy systems. It can shorten the development cycle of the controller and reduce development costs. In order to detect the specific functions of the transmission controller, a transmission HIL test bench was built to test the functions of the transmission controller. Because the laboratory environment is different from that of the vehicle, the transmission controller cannot move with the vehicle as it does in the vehicle, which will cause the transmission controller to be unable to receive the key signal of slope changes, thus having a certain impact on the test results. In order for the transmission controller to receive changes in the slope, an external slope bracket is used to change the inclination angle of the transmission controller so that the transmission controller can receive changes in the slope.

[0003] As for the control of the slope bracket, it is a more important link, because the source of the slope value is obtained by the acceleration sensor in the transmission controller through Karman filtering. Therefore, when the test bench simulates that the vehicle is stationary, the acceleration sensor signal in the transmission controller only comes from the component of gravity acceleration caused by the slope, so the slope is easier to calculate at this time. However, when the vehicle is moving, the value of the acceleration sensor has more acceleration during the vehicle's movement. At this time, if the slope bracket is not controlled to make corresponding movements, the slope value will fluctuate over a large range during the movement, which is obviously inconsistent with the actual situation. Therefore, it is necessary to control the slope bracket to give the transmission controller a "slope" in the opposite direction to offset the slope caused by the vehicle's movement, so that the slope issued by the transmission controller is the slope set at this time.

[0004] Therefore, it is very important to control the correct movement of the slope bracket at the right time. The general control scheme has certain shortcomings, such as directly inverting the acceleration in the model, summing this value with the set slope value, and outputting this to the transmission controller; or looking up the table through factors such as vehicle speed and acceleration to get the output value at this time, and output it to the transmission controller. The above schemes are either too large in workload and will consume a lot of time and energy, or the accuracy is not enough and the slope bracket compensation effect is not good, or the change frequency is too fast and the slope bracket reaction cannot be synchronized. Summary of the invention

[0005] To solve the above problems, the present invention provides a slope bracket control system and method for a gearbox HIL test bench, which controls the movement of the slope bracket when simulating vehicle movement, and offsets the acceleration caused by the vehicle movement by giving a "negative slope", so that the slope signal issued by the controller can always be equal to the slope value set by the model, thereby improving the accuracy of the test.

[0006] In a first aspect, the technical solution of the present invention provides a slope support control system for a gearbox HIL test bench, comprising: The slope bracket is used to place the gearbox controller and the tilt angle is controlled by the stepper motor; A gearbox controller, used for outputting a real-time slope value of a slope bracket to a gearbox HIL test bench through detection by an acceleration sensor; The gearbox HIL test bench is used to make a difference between the real-time slope value of the slope bracket and the slope setting value at this time, and then input the difference into the PID module after inverting the positive and negative, and compensate the slope setting value according to the output of the PID module, and control the operation of the stepper motor according to the compensated slope setting value; The PID module is used to process the received deviation data and transmit the output to the gearbox HIL test bench.

[0007] In an optional embodiment, the gearbox HIL test bench compensates the slope setting value according to the output of the PID module, specifically including: The output of the PID module is summed with the current slope setting value to obtain the current slope setting value after compensation.

[0008] In an optional implementation, the PID module performs integration processing on the received input deviation data, and the calculation formula of the PID module is:

[0009] In the formula, is the output of the PID module, is the deviation data, is the integration time.

[0010] In an optional embodiment, the acceleration sensor is used to detect and output the real-time slope value of the slope bracket to the gearbox HIL test bench, which specifically includes: Detect the real-time acceleration value through the acceleration sensor; Calculate the real-time slope value of the slope bracket through the real-time acceleration value; Send the real-time slope value of the slope bracket to the gearbox HIL test bench.

[0011] In a second aspect, the technical solution of the present invention provides a method for controlling a slope support for a gearbox HIL test bench, comprising the following steps: The gearbox controller obtains the real-time slope value of the slope bracket through the detection of the acceleration sensor and sends it to the gearbox HIL test bench; The gearbox HIL test bench receives the real-time slope value of the slope bracket sent by the gearbox controller, subtracts the real-time slope value of the slope bracket from the slope setting value at that time, reverses the positive and negative values, and then inputs it into the PID module; The PID module processes the received deviation data and transmits the output to the gearbox HIL test bench; The gearbox HIL test bench controls the stepper motor operation of the slope bracket according to the compensated slope setting value.

[0012] In an optional embodiment, the gearbox HIL test bench controls the operation of the stepper motor of the slope bracket according to the compensated slope setting value, specifically including: The gearbox HIL test bench sums the output of the PID module and the slope setting value at this time as the slope setting value at this time after compensation; The operation of the stepper motor of the slope bracket is controlled by the slope setting value after compensation.

[0013] In an optional implementation, the PID module processes the received deviation data, specifically including: The PID module performs integration processing on the received input deviation data. The calculation formula of the PID module is:

[0014] In the formula, is the output of the PID module, is the deviation data, is the integration time.

[0015] In an optional implementation, the gearbox controller obtains the real-time slope value of the slope bracket through detection by the acceleration sensor and sends it to the gearbox HIL test bench, specifically including: The gearbox controller detects the real-time acceleration value through the acceleration sensor; Calculate the real-time slope value of the slope bracket through the real-time acceleration value; Send the real-time slope value of the slope bracket to the gearbox HIL test bench.

[0016] In an optional embodiment, the real-time slope value of the slope support is sent to the gearbox HIL test bench, specifically including: Construct a feedback message, which includes the real-time slope value of the slope bracket; Send feedback message to the gearbox HIL test bench.

[0017] In an optional embodiment, after the gearbox HIL test bench receives the real-time slope value of the slope bracket sent by the gearbox controller, the following steps are further included: The gearbox HIL test bench obtains the slope configuration parameters, including the initial slope value, the target slope value and the slope change rate; The slope setting value at this time is calculated according to the slope configuration parameters.

[0018] The present invention provides a control system and method for a slope bracket for a gearbox HIL test bench, which has the following beneficial effects compared to the prior art: the gearbox HIL test bench makes a difference between the real-time slope value of the slope bracket and the slope setting value at this time, and then inputs the difference into a PID module after inverting the positive and negative values, and the PID module processes the deviation data, and the gearbox HIL test bench compensates the slope setting value according to the output of the PID module, and further controls the operation of the stepper motor according to the compensated slope setting value. The present invention controls the slope bracket to move when simulating vehicle movement, and offsets the acceleration generated by vehicle movement by giving a "negative slope", so that the slope signal issued by the controller can always be equal to the slope value set by the model, thereby improving the accuracy of the test, and the closed-loop PID negative feedback control has a significantly better control effect, higher accuracy and a certain anti-interference ability. BRIEF DESCRIPTION OF THE DRAWINGS In order to more clearly illustrate the technical solution of the present invention, the accompanying drawings required for use in the description will be briefly introduced below. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0019] Figure 1 A schematic structural diagram of a slope support control system for a gearbox HIL test bench provided in an embodiment of the present invention.

[0020] Figure 2 A schematic flow chart of a method for controlling a slope support for a gearbox HIL test bench provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0021] In order to make the purpose, features and advantages of the present invention more obvious and easy to understand, the technical scheme of the present invention will be clearly and completely described below in conjunction with the drawings in this specific embodiment. Obviously, the embodiments described below are only part of the embodiments of the present invention, not all of them. Based on the embodiments in this patent, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this patent.

[0022] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used in the specification of the present invention herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0023] Figure 1 FIG. 1 is a schematic diagram of a control system structure of a slope support for a gearbox HIL test bench provided by an embodiment of the present invention. Figure 1 The system includes a slope support, a gearbox controller, a gearbox HIL bench and a PID module.

[0024] Slope bracket, used to place the gearbox controller, and the inclination angle is controlled by the stepper motor.

[0025] The gearbox controller is used to detect through an acceleration sensor to output the real-time slope value of the slope bracket to the gearbox HIL test bench.

[0026] The gearbox HIL test bench is used to make the difference between the real-time slope value of the slope bracket and the slope setting value at this time, and then input the difference into the PID module after reversing the positive and negative, and compensate the slope setting value according to the output of the PID module, and control the operation of the stepper motor according to the compensated slope setting value.

[0027] The PID module is used to process the received deviation data and transmit the output to the gearbox HIL test bench.

[0028] This embodiment uses a PID module to control a negative feedback system, in which the slope bracket serves as the actuator of the control system and the transmission controller serves as the controlled object of the control system. The slope signal transmitted by the transmission controller is received by the transmission HIL test bench, which serves as a measuring mechanism in this process. At the same time, the transmission HIL test bench also serves as an actuator of the control system, thereby forming a complete control system.

[0029] It should be noted that in order to allow the gearbox to sense the change in slope, an external slope bracket is installed. The main working principle of the slope bracket is to set a stepper motor inside the slope bracket, and to control whether the stepper motor moves and the corresponding direction of movement by changing the input frequency of the stepper motor. In this embodiment, the gearbox HIL bench controls the operation of the stepper motor according to the compensated slope setting value. Specifically, the gearbox HIL bench sends two signals to the stepper motor, one is a Boolean signal that controls the direction of movement of the stepper motor, and the other is a pwm signal that controls whether the stepper motor moves. When the Boolean signal is 1, it means that the stepper motor moves in the far direction, indicating that the slope value given to the controller by the slope bracket increases at this time; when the Boolean signal is 0, it means that the stepper motor moves in the near direction, indicating that the slope value given to the controller by the slope bracket decreases at this time. As for the pwm signal that controls the stepper motor, frequency control is used, and the duty cycle is fixed at 50%. By changing the frequency of the pwm signal, the movement speed of the stepper motor is controlled, and the stepper motor stops moving when the frequency is 0.

[0030] The process of controlling the slope bracket to generate the slope is to first input a target slope value and convert it into the position value of the stepper motor track through the method of gain and offset. Then, according to the current position value of the stepper motor, calculate the "number of steps" and the direction of movement of the stepper motor. Then, according to the calculated direction of movement and number of steps, send the corresponding Boolean signal and PWM signal to the stepper motor.

[0031] In this embodiment, the movement of the stepper motor will change the tilt angle of the gearbox controller, thereby changing the acceleration value read by the acceleration sensor in the gearbox controller, and further affecting the slope value output by the gearbox controller. Therefore, it is very important to control the input signal of the stepper motor so that it can move correctly.

[0032] In order to accurately control the input signal of the stepper motor, the gearbox HIL test bench of this embodiment subtracts the real-time slope value of the slope bracket from the slope setting value at this time, reverses the positive and negative values, and inputs the result into the PID module. The PID module processes the received deviation data and compensates the slope setting value according to the output of the PID module. Then, the stepper motor is controlled according to the compensated slope setting value.

[0033] Specifically, this embodiment uses the slope value message sent by the gearbox controller for feedback, and the value of the message feedback is subtracted from the set slope value and then the sign is reversed, so that the deviation between the measured slope and the actual set slope is obtained, and then this deviation is used as the input of the PID module, and the output of the deviation at this time is calculated by the PID module, and then this output is summed with the slope value set at this time as the slope value input to the slope bracket, and then after a series of calculations, this slope value is converted into a PWM signal directly input to the stepper motor. Because the deviation changes all the time, the output value will also change at any time, so that the slope value sent by the controller can be compensated at any time.

[0034] Considering that if the deviation between the value of the message feedback and the set slope value is directly used as the output, residuals will appear, resulting in unsatisfactory accuracy and failure to meet the control requirements, this embodiment uses a PID module to control the negative feedback system, specifically through the PI control of the PID module, because integral control must be used to eliminate residuals, while differential control is not necessary in this control system and may reduce accuracy due to parameter setting, so it is not used. The above PID control can complete the control of the slope bracket, thereby solving the problem of being unable to change the slope of the controller in the HIL laboratory.

[0035] Specifically, the PID module takes the difference between the slope value fed back by the SSI message and the slope value set at this time as the deviation of the system, and the deviation is used as the input e(t) of the PID control system. The calculation formula of the PID module is:

[0036] In the formula, is the output of the PID module, is the deviation data, is the integration time.

[0037] After the above calculation, the output of the PID control system can be obtained, and the output and the set slope value are summed as the output of the slope value of the slope bracket, and then after a series of calculations, the slope value is converted into a PWM signal that is directly input to the stepper motor. The output signal is converted to a PWM signal through the conversion, and the slope value is sent to the stepper motor in the slope bracket through the test bench to control the movement of the stepper motor. Feedback is performed by the test bench receiving the slope value in the SSI message sent by the TCU, thereby forming a negative feedback control system.

[0038] This embodiment uses PID control, which can achieve good control effect, high precision, strong robustness and simple structure. In this control system, only the setting The value of the calculation is small. Because this control system uses PI control and The value of is 1. According to the Ziegler-Nichols law, the value of the critical proportional gain Ku can be obtained. According to the value of the critical oscillation period, we can get The value of , so we can get the required adjustment Because in this system, compared with the open-loop methods such as table lookup or model acceleration calculation, the closed-loop PID negative feedback control has a better control effect, higher accuracy and certain anti-interference ability. Table 1 is the Ziegler-Nichols law table for PID parameter tuning, where Ku is the critical proportional gain and Pu is the critical oscillation period.

[0039] Table 1: Ziegler-Nichols law table for PID parameter tuning

[0040] An embodiment of a gearbox HIL test bench slope support control system is described in detail above. Based on the gearbox HIL test bench slope support control system described in the above embodiment, an embodiment of the present invention also provides a gearbox HIL test bench slope support control method corresponding to the system.

[0041] Figure 2 A schematic flow chart of a method for controlling a slope support for a gearbox HIL test bench provided by an embodiment of the present invention is shown in FIG. Figure 2 As shown, the method includes the following steps.

[0042] S1, the gearbox controller obtains the real-time slope value of the slope bracket through the detection of the acceleration sensor and sends it to the gearbox HIL test bench.

[0043] S1.1, the gearbox controller detects the real-time acceleration value through the acceleration sensor.

[0044] S1.2, calculate the real-time slope value of the slope bracket through the real-time acceleration value.

[0045] In this embodiment, the slope value is calculated by the acceleration value detected by the acceleration sensor. The acceleration sensor can provide positive and negative acceleration values, which represent acceleration and deceleration respectively. In the slope measurement, it is necessary to pay attention to the direction of the acceleration. For example, when the front of the car is facing downward, negative acceleration is displayed, and when the front of the car is facing upward, positive acceleration is displayed.

[0046] The relationship between the slope θ and the gravitational acceleration g and the measured acceleration value a can be expressed by the following formula: θ = arctan(a / g) Where a is the acceleration measured by the sensor (note the direction), and g is the acceleration due to gravity (approximately 9.81 m / s²).

[0047] By calculating the inverse tangent value arctan, the value of the slope θ can be obtained, which represents the angle of inclination of the gearbox controller during the movement of the stepper motor.

[0048] S1.3, sends the real-time slope value of the slope bracket to the gearbox HIL test bench.

[0049] This embodiment is sent in the form of a message. First, a feedback message is constructed, the feedback message includes a real-time slope value of the slope bracket, and then the feedback message is sent to the gearbox HIL test bench.

[0050] S2, the gearbox HIL test bench receives the real-time slope value of the slope bracket sent by the gearbox controller, subtracts the real-time slope value of the slope bracket from the slope setting value at this time, reverses the positive and negative values, and then inputs it into the PID module.

[0051] To calculate the deviation data, the gearbox HIL test bench receives the real-time slope value of the slope bracket sent by the gearbox controller, obtains the slope configuration parameters, including the initial slope value, the target slope value and the slope change rate, and then calculates the slope setting value at this time according to the slope configuration parameters.

[0052] S3, the PID module processes the received deviation data and transmits the output to the gearbox HIL test bench.

[0053] In this embodiment, the PID module performs integration processing on the received input deviation data. The calculation formula of the PID module is:

[0054] In the formula, is the output of the PID module, is the deviation data, is the integration time.

[0055] S4, the gearbox HIL test bench controls the stepper motor operation of the slope bracket according to the compensated slope setting value.

[0056] In this embodiment, the gearbox HIL test bench sums the output of the PID module and the slope setting value at this time as the compensated slope setting value at this time, and controls the operation of the stepper motor of the slope bracket through the compensated slope setting value at this time.

[0057] The slope bracket control method for the gearbox HIL test bench of this embodiment is implemented based on the aforementioned gearbox HIL test bench slope bracket control system. Therefore, the specific implementation method of this method can be seen in the implementation example part of the gearbox HIL test bench slope bracket control system in the previous text. Therefore, its specific implementation method can refer to the description of the corresponding embodiments of each part and will not be elaborated here.

[0058] In addition, since the transmission HIL test bench slope support control method of the present embodiment is implemented based on the aforementioned transmission HIL test bench slope support control system, its function corresponds to that of the aforementioned system and will not be described in detail here.

[0059] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A slope support control system for a gearbox HIL test bench, characterized in that: include: The slope bracket is used to place the gearbox controller and the tilt angle is controlled by the stepper motor; A gearbox controller, used for outputting a real-time slope value of a slope bracket to a gearbox HIL test bench through detection by an acceleration sensor; The gearbox HIL test bench is used to make a difference between the real-time slope value of the slope bracket and the slope setting value at this time, and then input the difference into the PID module after inverting the positive and negative, and compensate the slope setting value according to the output of the PID module, and control the operation of the stepper motor according to the compensated slope setting value; The PID module is used to process the received deviation data and transmit the output to the gearbox HIL test bench.

2. The gearbox HIL test bench slope support control system according to claim 1, characterized in that: The gearbox HIL test bench compensates the slope setting value according to the output of the PID module, including: The output of the PID module is summed with the current slope setting value to obtain the current slope setting value after compensation.

3. The gearbox HIL test bench slope support control system according to claim 1, characterized in that: The PID module performs integration processing on the received input deviation data. The calculation formula of the PID module is: In the formula, is the output of the PID module, is the deviation data, is the integration time.

4. The gearbox HIL test bench slope support control system according to claim 1, characterized in that: The acceleration sensor is used to detect and output the real-time slope value of the slope bracket to the gearbox HIL test bench, including: Detect the real-time acceleration value through the acceleration sensor; Calculate the real-time slope value of the slope bracket through the real-time acceleration value; Send the real-time slope value of the slope bracket to the gearbox HIL test bench.

5. A method for controlling a slope support for a gearbox HIL test bench, characterized in that: The following steps are involved: The gearbox controller obtains the real-time slope value of the slope bracket through the detection of the acceleration sensor and sends it to the gearbox HIL test bench; The gearbox HIL test bench receives the real-time slope value of the slope bracket sent by the gearbox controller, subtracts the real-time slope value of the slope bracket from the slope setting value at that time, reverses the positive and negative values, and then inputs it into the PID module; The PID module processes the received deviation data and transmits the output to the gearbox HIL test bench; The gearbox HIL test bench controls the stepper motor operation of the slope bracket according to the compensated slope setting value.

6. The method for controlling the slope support for a gearbox HIL test bench according to claim 5, characterized in that: The gearbox HIL test bench controls the stepper motor operation of the slope bracket according to the compensated slope setting value, including: The gearbox HIL test bench sums the output of the PID module and the slope setting value at this time as the slope setting value at this time after compensation; The operation of the stepper motor of the slope bracket is controlled by the slope setting value after compensation.

7. The method for controlling a slope support for a gearbox HIL test bench according to claim 6, characterized in that: The PID module processes the received deviation data, including: The PID module performs integration processing on the received input deviation data. The calculation formula of the PID module is: In the formula, is the output of the PID module, is the deviation data, is the integration time.

8. The method for controlling a slope support for a gearbox HIL test bench according to any one of claims 5 to 7, characterized in that: The gearbox controller obtains the real-time slope value of the slope bracket through the detection of the acceleration sensor and sends it to the gearbox HIL test bench, including: The gearbox controller detects the real-time acceleration value through the acceleration sensor; Calculate the real-time slope value of the slope bracket through the real-time acceleration value; Send the real-time slope value of the slope bracket to the gearbox HIL test bench.

9. The method for controlling a slope support for a gearbox HIL test bench according to claim 8, characterized in that: Send the real-time slope value of the slope bracket to the gearbox HIL test bench, including: Construct a feedback message, which includes the real-time slope value of the slope bracket; Send feedback message to the gearbox HIL test bench.

10. The method for controlling a slope support for a gearbox HIL test bench according to any one of claims 5 to 7, characterized in that: After the gearbox HIL test bench receives the real-time slope value of the slope bracket sent by the gearbox controller, the following steps are also included: The gearbox HIL test bench obtains the slope configuration parameters, including the initial slope value, the target slope value and the slope change rate; The slope setting value at this time is calculated according to the slope configuration parameters.

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