A method for suppressing overshoot of a plug-type fast-response gas valve movement

Abstract

The application provides a kind of plug type fast response gas valve movement overshoot suppression control method, and adopts the three-ring nested control mode of valve core position-motor speed-motor phase current, improves the response speed and anti-disturbance ability of motor acceleration and deceleration process by controlling phase current, improves the speed regulation performance by speed loop, and finally realizes the accurate following of valve core target position by position control loop, which can realize zero static error control.The application provides a kind of plug type fast response gas valve movement overshoot suppression control method, effectively suppresses valve core movement overshoot, resists the disturbance of aerodynamic load change, and the control overshoot of valve core under load is less than 2% verified.

Description

Technical Field

[0001] This invention relates to a method for suppressing motion overshoot control of a throat-plug type fast-response gas valve, belonging to the field of solid rocket motor attitude control technology. Background Technology

[0002] Throat-plug type solid rocket motors possess numerous advantages over solid rocket motors, such as simple structure and ease of storage. They also enable continuous thrust adjustment, allowing for attitude stabilization control and trajectory adjustment based on missile flight conditions, making them a crucial direct force control device in weapon systems. During missile flight, thrust adjustment response is critically fast. However, the motor servo mechanism is constrained by mass limitations, resulting in relatively small drive power margins. Furthermore, the valve core is affected by high-speed airflow and aerodynamic loads, causing load variations at different opening positions. Therefore, rapid step movements of the valve core can easily lead to significant overshoot, affecting the thrust stability and adjustment accuracy of the attitude control motor. This paper addresses this issue by implementing a three-loop nested control system based on valve core position, motor speed, and motor current. Position deviation rate is introduced for target value discrimination. When the target position changes rapidly, the velocity loop's trajectory is planned and designed, while the position deviation is directly incorporated into the current control loop to accelerate current response and overcome disturbances caused by load changes. This ensures response speed while enhancing anti-disturbance capabilities and reducing position overshoot.

[0003] Currently, the main problems in the motion control of throat-plug type fast-response gas regulating valves are as follows:

[0004] 1. The power margin of the motor servo drive is small. Due to the structural weight limitations of the attitude control motor, the margin is small when selecting and designing the servo drive. It is usually used for short-term overload operation, and the control stability during valve core movement is poor.

[0005] 2. The load on the valve core changes significantly. When the valve core moves backward and the valve opens, the pneumatic pressure at the valve core head is high, which helps the valve core move. When the valve core moves forward and the valve closes, the pressure at the valve core head decreases while the pressure at the tail is high. The direction of the pneumatic force changes, but it is still in the same direction as the movement and still helps the valve core move. This has positive feedback disturbance characteristics, which makes the control system tend to diverge.

[0006] 3. Servo mechanisms have low inertia and high dynamic response requirements. To meet the rapid response of thrust adjustment, the valve core movement requires high dynamics. However, the reduction ratio of the servo motor is relatively small, resulting in low system inertia. Load changes have a significant impact on motor stability, making it difficult to balance speed and stability. Under load disturbances, overshoot and control instability are likely to occur. Summary of the Invention

[0007] The problem solved by this invention is: in the process of rapid thrust adjustment of a throat-plug type solid rocket motor, the valve core position control has large overshoot and poor control stability. The invention proposes a motion overshoot suppression control method for the throat-plug type gas valve. The method can perform motion planning of the motor speed loop according to the change of valve core position deviation rate, accelerate the current response to resist load disturbances, realize valve core position overshoot suppression, enhance the anti-disturbance capability of the control system, and suppress position overshoot while ensuring the requirements of rapid motion.

[0008] The technical solution provided by this invention is: a method for suppressing and controlling motion overshoot of a throat-plug type fast-response gas valve, characterized by comprising the following steps:

[0009] (1) Design the motor phase current control circuit:

[0010] Based on the motor's rated operating current, overload capacity, and torque coefficient, and considering the workload and start-up response time requirements, the maximum allowable instantaneous drive current during motor operation is set, a corresponding current sensor is selected, and the deviation between the target current and the current sensor's measured value is used as the input to the current feedback controller.

[0011] (2) Design of motor speed control circuit:

[0012] Based on the motor's rated speed, reduction ratio, and response time requirements, the maximum operating speed of the motor is set, and the corresponding speed sensor is selected. The deviation between the target speed and the feedback from the speed sensor is used as the input of the speed controller, and the output of the speed controller is the target current, thus completing the nesting of the speed loop and the current loop.

[0013] (3) Design of valve core position control loop:

[0014] 31) Given the target position of the valve core adjustment, acquire the current valve core position fed back by the position sensor, calculate the position deviation Δx, perform a differential operation on the position deviation, and obtain the position deviation rate.

[0015] 32) Based on the position adjustment frequency response requirements, design the position deviation rate threshold value.

[0016] 33) Compare position deviation rates With threshold value like The position deviation Δx is then used as the input to the position controller. After calculation by the controller, the target value of the velocity loop is directly output, such as... Then, motion planning design is performed on the target value of the speed loop to avoid excessive speed commands, which would cause the motor to have difficulty decelerating in a short time after the valve core is in place, resulting in overshoot.

[0017] 34) When When the position deviation Δx is proportionally calculated, it is directly used as part of the target value of the current loop to quickly start current control to overcome load disturbances, while achieving fast response and overshoot-free control.

[0018] Preferably, the motion control structure is based on a three-loop nested structure of valve core position, motor speed, and motor phase current;

[0019] Preferably, the target value of the velocity loop is planned and designed based on the rate of change of the position loop deviation;

[0020] Preferably, for rapidly changing target values ​​of the position loop, the position deviation is directly used as part of the target value of the current loop after proportional calculation;

[0021] Preferably, a position change rate threshold is designed based on the frequency response requirements of the valve core adjustment movement to determine whether the valve core position is a smooth and continuous movement.

[0022] Preferably, based on the valve drive load, motor rated power and overload capacity, the maximum allowable instantaneous drive current during motor operation is set as the command peak value of the current control loop. The current loop control bandwidth is designed, usually 20kHz. Two current sensors with high frequency response characteristics are selected to measure the current of motor A phase and B phase respectively.

[0023] Preferably, the maximum position deviation rate of the valve is designed based on the command cycle requirements for valve position adjustment and the maximum rate of change of the target position value. When the position deviation rate is greater than Then, motion planning is performed on the speed loop. Based on the motor speed regulation capability and position deviation rate, the target quantity of the speed loop is planned using a triangular or trapezoidal method. The purpose is to ensure that when the valve core is in place, the motor deceleration process can follow the change of the target speed quantity well, thereby achieving motion overshoot suppression.

[0024] Preferably, the valve core mechanism position control loop and the motor speed control loop use the same control cycle. Within each control cycle, the position deviation rate comparison, speed loop target value planning judgment, speed planning design, etc. are completed. When the motor rotates at a constant speed, the valve core mechanism moves at a constant speed. The position loop sensor feeds back the valve core position signal, and the encoder feeds back the angular displacement increment of the motor rotation. The motor speed is obtained by dividing by the speed loop control cycle.

[0025] Preferably, considering the influence of the reducer and transmission mechanism, the relationship between the motor speed and the valve core movement rate is established. Based on the rated motor speed and the valve core adjustment response time requirements, the maximum operating speed v of the motor is designed. max During the movement of the valve core mechanism, when the target value of the motor speed calculated by the position loop controller exceeds the maximum working speed, the speed loop target value is planned using a trapezoidal instruction; when the target value of the motor speed is less than the maximum working speed, the speed loop target value is planned using a triangular instruction.

[0026] Preferably, the speed loop target value planning aims to: artificially slow down the rate of change of the speed target value during the high-dynamic acceleration and deceleration process of the motor, so as to ensure that when the valve core is in place, the motor deceleration process can better follow the change of the speed target value, avoid the motor speed deviation caused by load changes during rapid movement of the mechanism, and thus suppress the position overshoot.

[0027] Preferably, a current saturation output is set so that when the motor speed continuously deviates from the target value or the current compensation given by the position loop is too large, the current loop controller has a saturation current limiting capability to prevent damage to the motor and the current sensor.

[0028] The advantages of this invention compared to the prior art are:

[0029] (1) The method for suppressing motion overshoot of a fast-response gas valve with a throat plug in this invention can realize the design and planning of the motor speed control loop, limit the rate of change of the speed target value during the dynamic acceleration and deceleration of the motor, ensure the following performance of the motor speed, and reduce the speed loop target value to zero when the valve core moves to the position, and the actual speed of the motor is also zero, and the mechanism stops moving to achieve overshoot control.

[0030] (2) In this invention, when the motor resists the load of the valve core to dynamically accelerate or decelerate, the position deviation rate is compensated into the target value of the current loop, bypassing the speed loop to speed up the output of the target value of the current, improving the current response before the valve core accelerates, ensuring the mechanical characteristic stiffness of the motion control system, improving the valve core adjustment response speed and taking into account the anti-disturbance capability. Attached Figure Description

[0031] Figure 1 (a) is a schematic diagram of the triangular velocity target value planning in this invention. Figure 1 (b) Actual results of triangle planning Figure 2 (a) is a schematic diagram of the trapezoidal velocity target value planning in this invention. Figure 2 (b) Actual measured results of trapezoidal programming Figure 3 This is a schematic diagram of the control method flow in this invention. Detailed Implementation

[0032] The following will provide a more detailed description of a throat-plug type fast-response gas valve motion overshoot suppression control method according to the present invention, with reference to the accompanying drawings.

[0033] This invention provides a method for suppressing motion overshoot control of a throat-plug type fast-response gas valve, the method comprising the following implementation steps:

[0034] Step 1: Current control loop design;

[0035] Its features include: setting the maximum allowable instantaneous drive current during motor operation; when the current loop output is saturated, the motor starts at maximum power; designing the current loop control bandwidth, with an empirical value of 20kHz; selecting two current sensors with high-frequency response characteristics to measure the current of motor phase A and phase B respectively; and using proportional-integral control for current control.

[0036] Step 2: Speed ​​control loop design:

[0037] 21) Speed ​​calculation and fluctuation deviation design

[0038] According to one embodiment of the present invention, the motor speed is calculated by dividing the angular displacement increment sampled by the encoder over two control cycles by the control cycle. An allowable speed fluctuation is designed to prevent fluctuations in angular displacement sampling from affecting speed control. When the deviation between the measured speed and the target speed exceeds the allowable fluctuation, speed control is performed using the measured speed as feedback. The speed loop control bandwidth is designed, with an empirical value of 4kHz, and proportional-integral control can be employed.

[0039] 22) Maximum operating speed and maximum acceleration process planning

[0040] When the position deviation rate is greater than the critical value At the same time, motion planning is performed on the motor speed and acceleration process.

[0041] According to one embodiment of the present invention, the maximum operating speed v of the motor is designed. max For small servo motors with high speed and good starting performance, the reference value is 0.5 to 0.7 times the rated no-load speed. For slow motors with low rated speed, the reference value is 0.7 to 0.9 times the rated no-load speed.

[0042] Its features include: planning the target value of the velocity loop according to the uniform acceleration process, with the acceleration time t taken as 0.15 to 0.2 times the step response time, and determined by the maximum operating speed v. max The maximum acceleration a is obtained by considering the acceleration time t. max The motor is in a max During uniform acceleration, the position loop deviation is directly compensated for in the current loop, and the current loop outputs positively to saturation, providing sufficient acceleration current so that the motor accelerates at its maximum capacity under the current load conditions. When the target motor speed calculated by the position loop controller exceeds the maximum operating speed v... max At that time, the target value of the motor speed is maintained at its maximum value v. max Until the target speed calculated by the position loop controller is less than the maximum operating speed v max When the speed loop desaturates, the current loop reverses its output to provide braking current, and the motor begins to decelerate, which is achieved by using the trapezoidal programming method.

[0043] According to one embodiment of the present invention, when the target value of the motor speed calculated by the position loop controller consistently fails to reach the maximum operating speed v max At that time, the motor moves at a max The motor undergoes uniform acceleration, and after the measured speed reaches the calculated speed, it enters a deceleration state, which is achieved using the triangle programming method. By planning the speed target value, the maximum speed of the motor is limited and there is sufficient deceleration time. This ensures that when the valve core position approaches the target position, the actual speed of the motor gradually decreases to zero following the change of the target value. In other words, when the valve core moves to the correct position, the speed control is zero, thus achieving position control without overshoot.

[0044] Step 3: Position control loop design:

[0045] 31) Given the target position of the valve core adjustment, acquire the current valve core position fed back by the position sensor, calculate the position deviation Δx, perform a differential operation on the position deviation, and obtain the position deviation rate.

[0046] 32) Based on the requirements for position adjustment response time and maximum stroke, design the position deviation rate limit value.

[0047] 33) Compare position deviation rates With threshold value when It is assumed that the valve core moves smoothly and continuously, and the target speed value is not designed or planned. The position deviation Δx is used as the input of the position controller. After the controller calculates, the target speed value is output, and the process is carried out as described in step (21). If the valve core is considered to be in a rapid step motion, then the motion planning design described in step (22) is performed on the target value of the speed loop to avoid excessive deviation between the target value of the speed and the actual speed, which would lead to difficulty in deceleration and overshoot.

[0048] 34) When When the position deviation Δx is proportionally calculated, it is directly used as part of the target value of the current loop to quickly start current control to overcome load disturbances, while achieving fast response and overshoot-free control.

[0049] The invention proposes a method for suppressing motion overshoot in a throat-plug type fast-response gas valve. The method compares the response process of the valve core during full-stroke and half-stroke rapid step motion. It can achieve overshoot-free control when the valve core is subjected to load disturbance, ensuring the valve motion response speed while effectively suppressing the step response overshoot phenomenon caused by load changes.

Claims

1. A method for suppressing motion overshoot control of a throat-plug type fast-response gas valve, characterized in that, Includes the following steps: Step 1: Design motor phase current control; Step 2: Design motor speed control; Step 3: Design valve core position control; Step 1 includes: based on the motor's rated operating current, overload capacity, and torque coefficient, considering the workload and start-up response time requirements, setting the maximum allowable instantaneous drive current during motor operation, selecting the corresponding current sensor, and using the deviation between the target current and the current sensor's measured value as the input to the current feedback controller. Step 2 includes: setting the maximum operating speed of the motor based on the rated speed, reduction ratio, and response time requirements; selecting the corresponding speed sensor; using the deviation between the target speed and the feedback from the speed sensor as the input to the speed controller; and outputting the target current, thus completing the nesting of the speed loop and the current loop. Specifically, Step 2 includes: 21) Speed ​​calculation and fluctuation deviation design; The motor speed is calculated by dividing the angular displacement increment sampled by the encoder in two control cycles by the control cycle; The allowable speed fluctuation is designed to prevent the fluctuation of angular displacement sampling from affecting the speed control. When the deviation between the measured speed and the target speed is greater than the allowable fluctuation, the measured speed is used as the feedback quantity for speed control. The speed loop control bandwidth is designed. 22) Maximum operating speed and maximum acceleration process planning; when the position loop deviation rate is greater than the critical value At the same time, motion planning is performed on the motor speed and acceleration process to design the maximum operating speed v of the motor. max ; Based on the target value of the speed loop planned for the uniform acceleration process, the acceleration time t is taken as 0.15 to 0.2 times the step response time, derived from the maximum operating speed v. max The maximum acceleration a is obtained by considering the acceleration time t. max The motor is in a max During uniform acceleration, the position loop deviation is directly compensated to the current loop, and the current loop output is saturated in the positive direction, providing sufficient acceleration current. The motor accelerates at its maximum capacity under the current load conditions. When the target motor speed calculated by the position loop controller exceeds the maximum operating speed v... max At that time, the target value of the motor speed is maintained at its maximum value v. max Until the target speed calculated by the position loop controller is less than the maximum operating speed v max When the speed loop desaturates, the current loop outputs in reverse to provide braking current, and the motor begins to decelerate, which is the use of the trapezoidal programming method. When the target motor speed calculated by the position loop controller consistently fails to reach the maximum operating speed v max At that time, the motor moves at a max The motion undergoes uniform acceleration. Once the measured rotational speed reaches the calculated rotational speed, it enters a deceleration state, which is achieved by using the triangle programming method. Step 3 includes: Step 31) Given the target position of the valve core adjustment, acquire the current valve core position fed back by the position sensor, calculate the position loop deviation Δx, perform a differential operation on the position loop deviation, and obtain the position loop deviation rate. Step 32) Based on the position loop adjustment response time and maximum stroke requirements, design the position loop deviation rate limit value. Step 33) Compare the position loop deviation rate With threshold value when It is assumed that the valve core moves smoothly and continuously, and the target speed value is not designed or planned. The position loop deviation Δx is used as the input of the position loop controller. After the controller calculates, the target speed value is output, and the process is carried out as described in step (21). If the valve core is considered to be in a rapid step motion, then the motion planning design described in step (22) is performed on the target value of the velocity loop; Step 34) When When the position loop deviation Δx is proportionally calculated, it is directly used as part of the current loop target value to quickly start current control to overcome load disturbances, while achieving fast response and overshoot-free control.

2. The method for suppressing motion overshoot control of a throat-plug type fast-response gas valve according to claim 1, characterized in that: The control method described above is for the movement control of the valve core of an electrically adjustable gas valve, and adopts a three-loop nested control mode of valve core position, motor speed and motor phase current.

3. The method for suppressing motion overshoot control of a throat-plug type fast-response gas valve according to claim 2, characterized in that: The target value of the velocity loop is planned and designed based on the rate of change of the position loop deviation.

4. The method for suppressing motion overshoot control of a throat-plug type fast-response gas valve according to claim 3, characterized in that: For rapidly changing target values ​​of the position loop, the position loop deviation is directly used as part of the target value of the current loop after proportional calculation.

5. The method for suppressing motion overshoot control of a throat-plug type fast-response gas valve according to claim 4, characterized in that: Based on the frequency response requirements of the valve core adjustment motion, a position change rate threshold is designed to determine whether the valve core position is a smooth and continuous motion.

Images