Rocket engine valve servo controller speed without feedback robust control method

Abstract

The application discloses a kind of rocket engine valve servo controller rotation speed no feedback robust control method, this method includes the following steps: obtaining target position instruction and measured position information, generate speed reference value;Obtain measured speed value and speed estimate value, and carry out data fusion, send into speed synthesizer and obtain high reliable speed synthesis value;According to the difference of speed reference value and high reliable speed synthesis value, generate current reference value;Real-time measurement motor three-phase current, and carry out coordinate transformation, to obtain the current error in the rotating coordinate system with current reference value;According to current error by current loop PI control device generates the voltage instruction in the rotating coordinate system, the voltage instruction is carried out inverse PARK transformation, obtains the voltage instruction in the stationary coordinate system, and utilizes space vector pulse width modulation to generate the switching signal of inverter, to drive motor operation.The application can provide higher safety guarantee for various abnormalities of engine valve in rocket recovery.

Description

Technical Field

[0001] This invention relates to the field of rocket engine technology, and in particular to a robust, feedback-free control method for the rotational speed of a rocket engine valve servo controller. Background Technology

[0002] The engine fuel main valve servo motor controller is a single unit product of the launch vehicle control subsystem. The first stage of the launch vehicle uses multiple engines, and each engine has a servo motor to adjust the opening of the first stage engine fuel main valve to meet the operating condition control requirements of the engine.

[0003] The first-level engine servo controller sends servo system position commands via the internal bus through the internally bound timing sequence. It compares the command with the current position feedback value to obtain an error signal. The control algorithm processes the error signal to obtain the control quantity, which is then used by the power motor drive circuit to generate the drive current for the servo motor. This causes the servo motor to rotate according to the magnitude and polarity of the control quantity. Through the reducer, the servo system outputs the corresponding torque and speed to reach the commanded position, thereby changing the opening of the flow regulator and realizing engine operating condition control.

[0004] Under various complex operating conditions of rocket engines, the sensors of the rocket engine valve servo controller may encounter problems with abnormal operation. For example, the space electromagnetic interference speed sensor may experience increased noise and be unable to provide accurate speed feedback. In this case, the speed loop of the servo motor will fail to function. Especially during rocket recovery, the rocket's electromagnetic and mechanical environments will face unprecedented challenges, making it more likely that the speed controller feedback loop will malfunction. Summary of the Invention

[0005] The purpose of this invention is to provide a robust control method for the rotational speed of a rocket engine valve servo controller without feedback, so as to solve the control failure problem caused by the transient abnormality of the rotational speed sensor in the rocket engine valve servo controller.

[0006] This invention is achieved using the following technical solution: a robust control method for the rotational speed of a rocket engine valve servo controller without feedback. The control method is based on a servo motor system and includes the following steps: The target position command and measured position information are acquired, and the velocity reference value is generated by the position loop PI control device. Based on the measured location information, the speed estimator estimates the speed, and the speed synthesizer fuses the estimated speed value with the measured speed value to obtain a highly reliable synthesized speed value. Based on the speed reference value and the high-reliability speed composite value, the current reference value in the rotating coordinate system is generated by the speed loop PI control device. The three-phase current of the motor is measured in real time, and coordinate transformation is performed to obtain the current value in the rotating coordinate system. The current value is then compared with the current reference in the rotating coordinate system to obtain the current error in the rotating coordinate system. Based on the current error in the rotating coordinate system, the current loop PI control device generates a voltage command in the rotating coordinate system. This voltage command undergoes an inverse PARK transformation to obtain a voltage command in the stationary coordinate system. The space vector pulse width modulation is then used to generate the inverter's switching signal, thereby driving the motor to run.

[0007] Furthermore, the servo motor system adopts a cascaded control structure consisting of a position loop, a speed loop, and a current loop. The motor's motion state is controlled step by step through multiple closed loops. The cascaded control structure follows the design principle of slow outer loops and fast inner loops. The position loop is located in the outermost layer, the speed loop in the middle layer, and the current loop in the innermost layer. The position loop, speed loop, and current loop achieve coordinated control of the motor's mechanical motion and electromagnetic process by generating reference quantities step by step.

[0008] Furthermore, the servo motor system includes a permanent magnet synchronous motor, a speed estimator, and a speed synthesizer. The speed estimator is connected to the permanent magnet synchronous motor via a position sensor, and the speed synthesizer is connected to the permanent magnet synchronous motor via a speed sensor. The speed estimator and the speed synthesizer are also connected.

[0009] Furthermore, the servo motor system also includes a position loop PI control device, a speed loop PI control device, and a current loop PI control device connected in sequence. The input end of the position loop PI control device is connected to the position sensor, and the output end is connected to the speed loop PI control device together with the output end of the speed synthesizer. The output end of the current loop PI control device is connected to the permanent magnet synchronous motor through a modulation unit.

[0010] Furthermore, the modulation unit includes an IPARK coordinate transformation device, a space vector pulse width modulation device, and an inverter connected in sequence, and the output terminal of the inverter is connected to the permanent magnet synchronous motor and the coordinate transformation unit respectively.

[0011] Furthermore, the coordinate transformation unit includes a CLARK coordinate transformation device and a PARK coordinate transformation device connected in sequence. The input end of the CLARK coordinate transformation device is connected to the output end of the inverter. The input end of the PARK coordinate transformation device is also connected to the permanent magnet synchronous motor through an angle sensor. The angle sensor is also connected to the PARK coordinate transformation device. The output end of the PARK coordinate transformation device is connected to the current loop PI control device.

[0012] Furthermore, the calculation method for the speed estimate is as follows: ; in, This is the position differential velocity estimate; This represents the position at the current sampling time. This is the position at the previous sampling time. The system sampling period; This is the measurement scale conversion factor.

[0013] Furthermore, the data fusion specifically includes the following steps: A consistency detection method is used for fault detection; A locking and unlocking mechanism based on continuous counting is adopted to automatically switch states; A weighted fusion algorithm is used for speed fusion; The fused velocity is subjected to a first-order low-pass filter to obtain the composite velocity value.

[0014] Furthermore, the locking and unlocking mechanism based on continuous counting is specifically as follows: when When this happens, the sensor is determined to be faulty and enters a fault lockout state; when When the sensor is unlocked and resumed to normal operation, the status switches to normal. in, The number of consecutive anomalies; For consecutive normal counts; To lock the threshold; The threshold for unlocking.

[0015] Furthermore, the speed fusion specifically refers to: ; in, For fusion speed; For fusion weighting coefficients; This is the position differential velocity estimate; This is the measurement value from the speed sensor.

[0016] The beneficial effects of this invention are as follows: This invention ensures the reliability of the speed loop feedback speed through the design of a speed synthesizer and a speed estimator. Under normal circumstances, the output of the speed synthesizer is a filtered output from the speed estimator and the speed sensor, calculated in a certain ratio. When the speed sensor fails, the speed synthesizer only uses the filtered output of the speed estimator to generate the detected speed. This approach ensures the accuracy of speed detection under abnormal conditions, thereby guaranteeing the robustness of the entire control system and providing higher safety assurance for various anomalies of engine valves during rocket recovery. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0018] Figure 1 This is a block diagram of a servo motor system. Figure 2 Here is a flowchart of the speed synthesizer process; Figure 3 Inject simulation diagrams for speed feedback faults; Figure 4 The simulation results are shown in the figure. In the diagram, 1-position loop PI control device, 2-speed loop PI control device, 3-first current loop PI control device, 4-second current loop PI control device, 5-IPARK coordinate transformation device, 6-space vector pulse width modulation device, 7-inverter, 8-permanent magnet synchronous motor, 9-PARK coordinate transformation device, 10-CLARK coordinate transformation device, 11-angle sensor, 12-speed sensor, 13-position sensor, 14-speed estimator, 15-speed synthesizer. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0020] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0021] The following detailed description of some embodiments of the present invention is provided in conjunction with the accompanying drawings. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0022] See Figure 1 A robust control method for the rotational speed of a rocket engine valve servo controller without feedback, the control method being implemented based on a servo motor system, includes the following steps: The system acquires the target position command and the measured position information, calculates the error between the two, and generates a speed reference value by the position loop PI control device. The measured speed value is obtained, and the speed is estimated using a speed estimator based on the measured location information. The estimated speed value and the measured speed value are then fed into a speed synthesizer for data fusion to obtain a highly reliable speed synthesized value. Based on the speed reference value and the high-reliability combined speed value, the error between the two is calculated, and the current reference value in the rotating coordinate system is generated by the speed loop PI control device. The three-phase current of the motor is measured in real time, and coordinate transformation is performed. The current error in the rotating coordinate system is obtained by comparing it with the current reference value. Based on the current error in the rotating coordinate system, the current loop PI control device generates a voltage command in the rotating coordinate system. This voltage command undergoes an inverse PARK transformation to obtain a voltage command in the stationary coordinate system. The space vector pulse width modulation is then used to generate the inverter's switching signal, thereby driving the motor to run.

[0023] In this embodiment, the servo motor system adopts a cascaded control structure consisting of a position loop, a speed loop, and a current loop. The motor's motion state is controlled step by step through multiple closed loops. The cascaded control structure follows the design principle of slow outer loops and fast inner loops. The position loop is located in the outermost layer, the speed loop in the middle layer, and the current loop in the innermost layer. The position loop, speed loop, and current loop achieve coordinated control of the motor's mechanical motion and electromagnetic process by generating reference quantities step by step. Specifically, this includes: U-current control, V-speed control, and W-position control.

[0024] In this embodiment, the servo motor system includes a permanent magnet synchronous motor 8, a speed estimator 14, and a speed synthesizer 15. The speed estimator 14 is connected to the permanent magnet synchronous motor 8 through a position sensor 13, and the speed synthesizer 15 is connected to the permanent magnet synchronous motor 8 through a speed sensor 12. The speed estimator 14 and the speed synthesizer 15 are connected together.

[0025] In this embodiment, the servo motor system further includes a position loop PI control device 1, a speed loop PI control device 2, and a current loop PI control device connected in sequence. The input terminal of the position loop PI control device 1 is connected to the position sensor 13, and its output terminal is connected to the speed loop PI control device 2 along with the output terminal of the speed synthesizer 15. The output terminal of the current loop PI control device is connected to the permanent magnet synchronous motor 8 through a modulation unit. Further, the modulation unit includes an IPARK coordinate transformation device 5, a space vector pulse width modulation device 6, and an inverter 7 connected in sequence. The output terminal of the inverter 7 is connected to the permanent magnet synchronous motor 8 and the coordinate transformation unit, respectively. Furthermore, the coordinate transformation unit includes a CLARK coordinate transformation device 10 and a PARK coordinate transformation device 9 connected in sequence. The input terminal of the CLARK coordinate transformation device 10 is connected to the output terminal of the inverter 7. The input terminal of the PARK coordinate transformation device 9 is also connected to the permanent magnet synchronous motor 8 through an angle sensor 11. The angle sensor 11 is also connected to the PARK coordinate transformation device 5. The output terminal of the PARK coordinate transformation device 9 is connected to the current loop PI control device.

[0026] In this embodiment, the current loop PI control device includes a first current loop PI control device 3 and a second current loop PI control device 4. The input terminal of the first current loop PI control device 3 is connected to the speed loop PI control device 2 and the PARK coordinate transformation device 9, respectively, and the input terminal of the second current loop PI control device 4 is connected to the PARK coordinate transformation device 9.

[0027] Based on a servo motor system, the feedback-free robust control method specifically includes: First, the upper-level control system or trajectory planning module issues the target position command. The actual position of the motor is measured in real time using position sensor 13. The position error is obtained by comparing it with the reference position: ; The position loop uses a proportional-integral (PI) control device (i.e., position loop PI control device 1), which generates a speed reference value based on the position error. ; The speed value is detected by the speed sensor 12 and the speed estimate is generated by the speed estimator 14. The speed estimate of the speed estimator is obtained by performing differential operation on the position value of the position sensor. Finally, the speed synthesizer 15 outputs the synthesized speed based on the speed estimate generated by the speed estimator and the speed value detected by the speed sensor.

[0028] Specifically, the velocity estimator obtains position detection information through differential and proportional operations on the position detection values. The position difference velocity estimation is as follows: ; in, This is the position differential velocity estimate; This represents the position at the current sampling time. This is the position at the previous sampling time. The system sampling period; This is the measurement scale conversion factor.

[0029] Differential speed measurement can provide basic speed feedback in the event of sensor failure, but since differential operations amplify measurement noise, it needs to be smoothed using filtering methods. The filtering function is performed in the speed synthesizer.

[0030] See Figure 2 The speed synthesizer 15 synthesizes reliable speed information based on the current speed feedback and position feedback information. The speed synthesizer includes processing steps such as speed loop feedback value fault detection, automatic fault switching, speed fusion, and speed filtering.

[0031] Speed ​​loop feedback value fault detection To determine if the speed sensor is malfunctioning, the algorithm employs a consistency detection method. The reliability of the measurement is determined by comparing the measured speed with a reference speed. Let... The value is measured by the speed sensor. For reference speed, As a detection threshold, the reliability determination condition is: ; The threshold function is defined as: ; in, This is the relative threshold coefficient. For absolute thresholds, if the following conditions are met: ; If the speed sensor reading is unreliable, then the measurement is considered to be faulty. This detection method can effectively identify abnormal conditions such as sensor abrupt changes, jamming, zero-dropping, and drift.

[0032] Automatic fault switching To avoid frequent switching due to transient noise, this invention introduces a locking and unlocking mechanism based on continuous counting. Let... The number of consecutive anomalies. For consecutive normal counts, To lock the threshold, To unlock the threshold, when When the sensor malfunctions, the system determines it is faulty and enters a fault-locked state. In this state, the system uses only the position differential velocity as the feedback signal. When the system achieves a certain number of consecutive normal operation cycles... When this happens, the system unlocks and resumes using the speed sensor. The status then switches to normal.

[0033] Speed ​​Fusion Under normal sensor conditions, to improve velocity estimation accuracy, this invention employs a weighted fusion method to combine the sensor-measured velocity with the position differential velocity: ; in To integrate the weighting coefficients, when the system is in a sensor fault-locked state: ; This strategy can improve speed accuracy when measurements are reliable, while ensuring that the system still has stable speed feedback when the sensor fails.

[0034] Velocity filtering To further reduce noise and improve output stability, a first-order low-pass filter is applied to the fused speed: ; in For the final output speed, For the filter coefficients, the discrete transfer function of the filter is: ; Low-pass filtering can effectively suppress high-frequency noise caused by position difference and make the switching process of speed sensor smoother.

[0035] The speed loop is based on the speed reference value. The difference between the synthesis rate and the value of the synthesis rate is adjusted.

[0036] The speed loop PI control device 2 outputs the motor torque command or equivalent current reference value. For the permanent magnet synchronous motor 8, the electromagnetic torque and Since the shaft current is approximately proportional, the output of the speed controller is usually expressed as... Shaft current reference value The main function of the speed loop is to regulate the motor speed and suppress load disturbances, thereby improving the dynamic response capability of the system.

[0037] Angle sensor 11 measures the actual angle of the motor in real time to support coordinate transformation of IPARK and PARK devices. Specifically, this includes: transforming the three-phase current to quiescent current using CLARK coordinate transformation device 10, and obtaining the PARK coordinate transformation device 9. shaft and shaft current and respectively compared with the reference value The current error is obtained through comparison. Then, the output is obtained through the current loop PI control device (including the first current loop PI control device 3 and the second current loop PI control device 4). shaft and Shaft voltage command Finally, the IPARK coordinate transformation device 5 will... The voltage command in the rotating coordinate system is converted into the voltage command in the stationary coordinate system, and the switching signal of the inverter 7 is generated by space vector pulse width modulation 6, thereby driving the permanent magnet synchronous motor 8 to run.

[0038] See Figure 3 , Figure 4 To verify the reliability of the method of the present invention, the control system was simulated. A simulated abnormality was generated by setting the speed detection value in the 10s-11s interval to 0. The simulation results show that before using the method of the present invention, the position detection value fluctuated significantly between 10s and 11s, and the position control result differed greatly from the expected position command. After using the method of the present invention, the position command value was completely consistent with the position detection value, demonstrating very strong robustness.

[0039] The electromagnetic and mechanical environments change drastically during rocket recovery, which can easily lead to problems such as circuit failures, electromagnetic noise interference, and poor wiring connections. The method of this invention can improve the reliability of the engine valve controller, providing a higher level of safety for the system.

[0040] It should be noted that, for the sake of simplicity, the foregoing embodiments are all described as a series of actions. However, those skilled in the art should understand that this application is not limited to the described order of actions, because according to this application, some steps can be performed in other orders or simultaneously. Furthermore, those skilled in the art should also understand that the embodiments described in the specification are preferred embodiments, and the actions involved are not necessarily essential to this application.

[0041] The above embodiments describe the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Modifications and variations made by those skilled in the art without departing from the spirit and scope of the invention should be within the protection scope of the appended claims.

Claims

1. A robust control method for the speed of a valve servo controller of a rocket engine, said control method being based on a servo motor system, characterized in that, Includes the following steps: The target position command and measured position information are acquired, and a speed reference value is generated by the position loop PI control device based on the difference between the two. The measured velocity value is obtained, and the velocity is estimated based on the measured location information. The estimated velocity value is then fused with the measured velocity value to obtain a highly reliable composite velocity value. Based on the speed reference value and the high-reliability combined speed value, the speed error is calculated, and the current reference value is generated by the speed loop PI control device. The three-phase current of the motor is measured in real time, and coordinate transformation is performed. The current error in the rotating coordinate system is obtained by comparing it with the current reference value. Based on the current error, the current loop PI control device generates a voltage command in the rotating coordinate system. The voltage command is then subjected to inverse PARK transformation to obtain a voltage command in the stationary coordinate system. The inverter's switching signal is generated using space vector pulse width modulation, thereby driving the motor to run.

2. The robust control method for the rocket engine valve servo controller speed without feedback of claim 1, wherein, The servo motor system adopts a cascaded control structure consisting of a position loop, a speed loop, and a current loop. The motor's motion state is controlled step by step through multiple closed loops. The cascaded control structure follows the design principle of slow outer loops and fast inner loops. The position loop is located in the outermost layer, the speed loop in the middle layer, and the current loop in the innermost layer. The position loop, speed loop, and current loop achieve coordinated control of the motor's mechanical motion and electromagnetic process by generating reference quantities step by step.

3. The robust control method of claim 2, wherein The servo motor system includes a permanent magnet synchronous motor (8), a speed estimator (14), and a speed synthesizer (15). The speed estimator (14) is connected to the permanent magnet synchronous motor (8) through a position sensor (13), and the speed synthesizer (15) is connected to the permanent magnet synchronous motor (8) through a speed sensor (12). The speed estimator (14) and the speed synthesizer (15) are connected together.

4. The rocket engine valve servo controller speed feedback-free robust control method as described in claim 3, characterized in that, The servo motor system also includes a position loop PI control device (1), a speed loop PI control device (2) and a current loop PI control device connected in sequence. The input end of the position loop PI control device (1) is connected to the position sensor (13), and the output end is connected to the speed loop PI control device (2) together with the output end of the speed synthesizer (15). The output end of the current loop PI control device is connected to the permanent magnet synchronous motor (8) through the modulation unit.

5. The rocket engine valve servo controller speed feedback-free robust control method as described in claim 4, characterized in that, The modulation unit includes an IPARK coordinate transformation device (5), a space vector pulse width modulation device (6), and an inverter (7) connected in sequence. The output of the inverter (7) is connected to the permanent magnet synchronous motor (8) and the coordinate transformation unit, respectively.

6. The rocket engine valve servo controller speed feedback-free robust control method as described in claim 5, characterized in that, The coordinate transformation unit includes a CLARK coordinate transformation device (10) and a PARK coordinate transformation device (9) connected in sequence. The input end of the CLARK coordinate transformation device (10) is connected to the output end of the inverter (7). The input end of the PARK coordinate transformation device (9) is also connected to the permanent magnet synchronous motor (8) through an angle sensor (11). The angle sensor (11) is also connected to the IPARK coordinate transformation device (5). The output end of the PARK coordinate transformation device (9) is connected to the current loop PI control device.

7. The rocket engine valve servo controller speed feedback-free robust control method as described in any one of claims 1 to 6, characterized in that, The calculation method for the velocity estimation is as follows: ； in, This is the position differential velocity estimate; This represents the position at the current sampling time. This is the position at the previous sampling time. The system sampling period; This is the measurement scale conversion factor.

8. The rocket engine valve servo controller speed feedback-free robust control method as described in any one of claims 1 to 6, characterized in that, The data fusion specifically includes the following steps: A consistency detection method is used for fault detection; A locking and unlocking mechanism based on continuous counting is adopted to automatically switch states; A weighted fusion algorithm is used for speed fusion; The fused velocity is subjected to a first-order low-pass filter to obtain the composite velocity value.

9. The rocket engine valve servo controller speed feedback-free robust control method as described in claim 8, characterized in that, The locking and unlocking mechanism based on continuous counting is as follows: when When this happens, the sensor is determined to be faulty and enters a fault lockout state; when When the sensor is unlocked and resumed to normal operation, the status switches to normal. in, The number of consecutive anomalies; For consecutive normal counts; To lock the threshold; The threshold for unlocking.

10. The rocket engine valve servo controller speed feedback-free robust control method as described in claim 8, characterized in that, The speed fusion specifically refers to: ； in, For fusion speed; For fusion weighting coefficients; This is the position differential velocity estimate; This is the measurement value from the speed sensor.

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