A high-precision pitch control method and system for an electric propulsion aircraft

Abstract

The present application discloses a high-precision pitch control method and system for an electric propulsion aircraft. The method includes: after the motor starts, it rotates clockwise until it moves to the lower limit of the pitch-changing screw and stalls, and records the first resolver position reading at this time; rotates counterclockwise until it moves to the upper limit of the pitch-changing screw and stalls, and records the second resolver position reading at this time, and calculates the resolver difference corresponding to the upper and lower heights of the screw; performs three-loop position control of position-speed-current on the motor; according to the target position command, the motor runs to the command position through three-loop control, interpolates the target position and the screw height value, calculates the actual position at this time, and calibrates the three-loop control of the motor through the difference between the actual position and the target position. The present application can achieve high-precision control of the pitch-changing screw position without adding additional hardware, and avoid position errors caused by screw thread clearance.

Description

Technical Field

[0001] This application relates to the high-precision pitch control technology of electric propulsion aircraft, and specifically relates to a high-precision pitch control method and system for electric propulsion aircraft. Background Art

[0002] Electric propulsion aircraft have the advantages of high efficiency and large thrust-to-weight ratio, and have become an important research object for many scientific research institutions and enterprises. Especially in the fields of unmanned aerial vehicles, small aircraft, etc., electric propulsion systems are favored because of their high performance and low noise characteristics. With the development of technology, variable pitch has become one of the key technologies to improve the performance of aircraft, which can change the pitch in real time according to different load conditions of the aircraft, so as to improve flight performance. However, the accuracy of pitch change has a great impact on flight performance. If the position of pitch change cannot be guaranteed, serious problems such as falling will occur. Therefore, the position accuracy control of pitch change is particularly important.

[0003] Existing pitch control methods usually rely on external position sensors to detect the position change of the propeller blade. Although these sensors can provide relatively accurate data, they also bring many problems. On the one hand, installing additional sensors will increase the weight and volume of the aircraft, which is an obvious disadvantage for modern aircraft pursuing lightweight and compact design. On the other hand, the environmental adaptability and reliability of sensors are also a major challenge. Especially in bad weather conditions or extreme environments, sensors may be interfered with, resulting in inaccurate measurement results, which will affect the safety and stability of the aircraft.

[0004] In order to achieve high-precision pitch control without adding additional hardware, in the prior art, there is a method of using a resolver (resolver) built in the motor for position detection. Although the resolver has high stability and strong anti-interference ability and is suitable for applications that require high reliability, relying solely on the resolver for position control has certain limitations. Especially when there is a thread clearance in the screw, it will cause errors in position detection and affect the final control accuracy. This kind of error will not only affect the performance of the aircraft, but also may bring potential safety hazards. Therefore, it is necessary to develop a high-precision pitch control method based on the resolver, which can not only avoid the problems of high cost and large space occupation caused by installing sensors, but also eliminate the errors caused by the thread clearance of the screw to ensure high-precision pitch control. Summary of the Invention

[0005] In order to achieve high-precision pitch control without adding additional hardware, this application provides a high-precision pitch control method and system for electric propulsion aircraft.

[0006] In the first aspect, this application provides a high-precision pitch control method for electric propulsion aircraft, including:

[0007] S1. Start the motor and control it to rotate clockwise. Monitor the rotation of the motor. When the motor moves below the pitch-changing screw and jams, record the first resolver position reading at this time.

[0008] S2. Control the motor to rotate counterclockwise. Monitor the rotation of the motor. When the motor moves above the pitch-changing screw and jams, record the second resolver position reading at this time.

[0009] S3. Calculate the resolver difference corresponding to the heights above and below the pitch-changing screw according to the recorded first and second resolver position readings.

[0010] S4. Perform three-loop servo control of position - speed - current on the motor.

[0011] S5. According to the target position command, control the motor to run to the command position through three-loop servo control; combine the resolver difference corresponding to the heights above and below the pitch-changing screw, perform interpolation processing on the target position and the pitch-changing screw height value to obtain the actual position obtained through interpolation processing, calculate the difference between the actual position and the target position, and perform cumulative compensation with the motor running position, and then perform three-closed-loop position control again to achieve calibration of the motor three-loop servo control.

[0012] By adopting the above scheme, start the motor and record the resolver position readings when jamming occurs below and above the pitch-changing screw, calculate the resolver difference, and determine the position range of the pitch-changing screw; perform three-loop servo control on the motor, improve the position control accuracy of the motor, and eliminate the error caused by the screw thread clearance; combine the target position command, the motor runs to the command position through three-loop control, obtain the actual position through interpolation processing, calculate the difference between the actual position and the target position, and perform cumulative compensation, further improving the accuracy of position control and achieving high-precision control of the pitch-changing screw position of the electric propulsion aircraft.

[0013] Preferably, when the motor moves below the pitch-changing screw and jams in step S1, the relationship between the corresponding jamming current and time is:

[0014] Wherein, is the jamming current at the current moment, is the jamming current coefficient, is the jamming time and is the total jamming time, is the rated current of the motor; analyze the waveform and peak value of the jamming current to adjust the control parameters of the current loop and optimize the current response.

[0015] By adopting the above solution, the relationship between the locked-rotor current and time is analyzed to precisely control the locked-rotor process of the motor, accurately identify the moment when the locked-rotor occurs, and further adjust the control parameters of the current loop by analyzing the waveform and peak value of the locked-rotor current, optimize the current response, and improve the stability and accuracy of the motor position control.

[0016] Preferably, the formula for calculating the resolver difference corresponding to the upper and lower heights of the variable pitch screw in step S3 is:

[0017] Wherein, is the resolver difference corresponding to the upper and lower heights of the variable pitch screw, is the number of turns of resolver rotation when the motor moves from the lower part to the upper part of the screw, is the number of resolver pole pairs; is the first resolver position reading; is the second resolver position reading.

[0018] By adopting the above solution, calculating the resolver difference corresponding to the upper and lower heights of the variable pitch screw can accurately reflect the height change range of the screw, thus providing an accurate data basis for the subsequent interpolation processing of the target position command and the actual position.

[0019] Preferably, the position-speed-current three-loop servo control of the motor in step S4 includes:

[0020] Controlling the output of the position loop, and the discrete equation of the position loop output is:

[0021] Wherein, is the output value of the position loop at the current moment, is the position loop proportional gain, is the position feed value at the current moment, is the position feed value of the previous cycle, is the current position feedback value, is the feedforward gain, is the control period;

[0022] Controlling the output of the speed loop, and the discrete equation of the speed loop output is:

[0023] Wherein, is the output value of the position loop at the current moment, is the speed loop proportional gain, is the speed loop integral gain, is the given speed of the speed loop, is the feedback speed of the speed loop, is the output of the speed loop of the previous cycle, is the control period, It is the output of the speed loop; it controls the output of the current loop and realizes the control of the motor torque and speed by controlling the duty cycle of PWM.

[0024] By adopting the above scheme, the position loop proportional gain and feedforward gain are set to accurately calculate the discrete equation of the position loop output, enabling the motor to accurately follow the target position command; the proportional gain and integral gain of the speed loop are set to accurately calculate the discrete equation of the speed loop output, enhancing the stability and robustness of the control output; the output calculation of the current loop is completed and the PWM duty cycle is controlled to effectively control the motor torque and speed.

[0025] Preferably, the current loop output control specifically includes: designing a bias-free current predictive control based on an extended state observer for the current loop;

[0026] The discrete state equation of the dq-axis extended state observer current is:

[0027] Among them, is the calculation transition amount of the motor dq axis current, is the resistance value of the motor stator winding, is the control period, is the motor d axis inductance value, is the motor q axis inductance value, is the motor angular velocity, is the feedback value of the d-axis current, is q axis current feedback value, is the motor magnetic flux, is the observer coefficient; is the voltage output at time t of the d-axis, is the voltage output at time t of the q-axis;

[0028] For the bias-free current predictive control, the voltage output equation is:

[0029] Among them, is the calculation transition amount of the motor dq-axis current, is the resistance value of the motor stator winding, is the control period, is the motor d axis inductance value, is the motor q axis inductance value, is the motor angular velocity, is d axis current given value, is qAxis current given value, is d the voltage output at time t+1 of axis, is q the voltage output at time t+1 of axis.

[0030] By adopting the above scheme, unbiased predictive control of the dq-axis current is carried out by an extended state observer, effectively coping with the situation of distorted motor resistance and inductance parameters, and ensuring high current control accuracy under various working conditions.

[0031] Preferably, in step S5, the formula for calculating the difference between the actual position and the target position and accumulating and compensating it with the motor operating position is:

[0032] Wherein, is the motor three-closed-loop operating position, is the actual position command, is the position error, is the position compensation value at the current moment, is the actual position obtained by screw interpolation, is the resolver difference corresponding to the upper and lower heights of the screw, is the resolver reading of the motor three-closed-loop operation.

[0033] By adopting the above scheme, the actual position is obtained by combining the resolver reading and performing screw height interpolation, accurately identifying the position error between the current actual position and the desired position, accumulating the position error with the motor three-closed-loop operating position, generating a new position compensation value and applying it to the motor three-closed-loop control, effectively eliminating the displacement error caused by factors such as screw thread clearance, and improving the accuracy and stability of the motor position control.

[0034] Preferably, in step S1 or step S2, it further includes:

[0035] When starting the motor and controlling the motor to rotate clockwise or counterclockwise, environmental data is synchronously collected and the judgment threshold for blocking rotation is dynamically adjusted according to the collected environmental data. The dynamic adjustment process includes: inputting the collected environmental data into the neural network for obtaining the blocking rotation threshold, and obtaining the judgment threshold for blocking rotation corresponding to the currently collected environmental data; the neural network for obtaining the blocking rotation threshold is trained by the judgment threshold for historical blocking rotation corresponding to the historical blocking state judgment accuracy greater than the preset accuracy and the environmental data at the corresponding historical moment.

[0036] By adopting the above scheme, environmental data is collected and the judgment threshold for blocking rotation is dynamically adjusted when the motor rotates clockwise or counterclockwise, realizing accurate judgment of the blocking rotation state of the motor under different environmental conditions and improving the accuracy of resolver difference calculation.

[0037] In a second aspect, the present application provides a high-precision pitch control system for an electric propulsion aircraft, including:

[0038] A first resolver position reading recording module, which is used to start the motor and control the motor to rotate clockwise, monitor the rotation of the motor, and record the first resolver position reading at this time when the motor moves below the pitch screw and stalls;

[0039] A second resolver position reading recording module, which is used to control the motor to rotate counterclockwise, monitor the rotation of the motor, and record the second resolver position reading at this time when the motor moves above the pitch screw and stalls;

[0040] A resolver difference calculation module, which is used to calculate the resolver difference corresponding to the heights above and below the pitch screw according to the recorded first resolver position reading and the second resolver position reading;

[0041] A motor three-loop servo control module, which is used to perform position-speed-current three-loop servo control on the motor;

[0042] A motor three-loop servo control calibration module, which is used to, according to the target position instruction, control the motor to run to the instruction position through three-loop servo; combine the resolver difference corresponding to the heights above and below the pitch screw, perform interpolation processing on the target position and the pitch screw height value to obtain the actual position obtained through interpolation processing, calculate the difference between the actual position and the target position, and perform cumulative compensation with the motor running position, and perform three-closed-loop position control again to achieve motor three-loop servo control calibration.

[0043] By adopting the above solution, high-precision control of the pitch screw position is achieved, the response speed and stability of the motor in a complex environment are improved, the position error caused by the screw thread clearance of the screw is reduced, and the overall performance and safety of the aircraft are further improved.

[0044] In a third aspect, the present application provides a computer-readable storage medium, where the computer-readable storage medium includes a stored computer program, and wherein, when the computer program runs, it controls the device where the computer-readable storage medium is located to execute the method as described above.

[0045] In a fourth aspect, the present application provides a computer device, where the computer device includes a memory, a processor, and a program stored on the memory and executable, and when the program is executed by the processor, it implements the steps of the method as described above.

[0046] In summary, the present application has the following beneficial effects:

[0047] 1. The resolver of the screw propulsion motor itself is used as the position sensor, which avoids the problems of increased cost, increased weight, and occupied space caused by adding external sensors, and improves the overall performance and reliability of the aircraft. By performing three-loop servo control of position-speed-current on the motor and combining interpolation processing and dynamic compensation of the resolver difference corresponding to the heights above and below the variable pitch screw, the error caused by the screw thread clearance is eliminated, high-precision variable pitch position control is achieved, and the handling performance and safety of the aircraft are improved.

[0048] 2. The unbiased current predictive control method based on the extended state observer enhances the robustness of the control under the condition of distorted motor resistance and inductance parameters, and further improves the stability and response speed of the control.

[0049] 3. Considering the influence of environmental changes on stall, environmental data is collected and the stall judgment threshold is dynamically adjusted when the motor rotates clockwise or counterclockwise, so as to accurately judge the stall state of the motor under different environmental conditions, laying a foundation for subsequent precise control. Description of the Drawings

[0050] Figure 1 It is a flowchart of the high-precision variable pitch control method for the electric propulsion aircraft described in the specific embodiment.

[0051] Figure 2 It is a schematic diagram of the principle of the three-loop control of motor position-speed-current in the high-precision variable pitch control method for the electric propulsion aircraft described in the specific embodiment.

[0052] Figure 3 It is a schematic structural diagram of the high-precision variable pitch control system for the electric propulsion aircraft described in the specific embodiment. Detailed Embodiments

[0053] In order to make the purpose, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0054] As Figure 1 shown, the embodiment of the present application discloses a high-precision variable pitch control method for an electric propulsion aircraft, and the specific steps include:

[0055] S1. Start the motor and control the motor to rotate clockwise, monitor the rotation of the motor, and when the motor moves below the variable pitch screw and stalls, record the first resolver position reading at this time.

[0056] Specifically, monitor the clockwise rotation of the motor to obtain the status information of the motor rotation, including key data such as the motor speed, rotation direction, torque, and motor temperature. When the motor moves below the pitch-changing screw and stalls, for example, when the speed is lower than the preset speed threshold or the output current is greater than the preset current threshold, record the first resolver position reading at this time as 。

[0057] S2. Control the motor to rotate counterclockwise, monitor the rotation of the motor, and when the motor moves above the pitch-changing screw and stalls, record the second resolver position reading at this time;

[0058] Specifically, similarly, monitor the counterclockwise rotation of the motor to obtain the status information of the motor rotation, including key data such as the motor speed, rotation direction, torque, and motor temperature. When the motor moves below the pitch-changing screw and stalls, record the second resolver position reading at this time as 。

[0059] S3. Calculate the resolver difference corresponding to the heights above and below the pitch-changing screw according to the recorded first resolver position reading and the second resolver position reading.

[0060] The specific formula is:

[0061] Wherein, is the resolver difference corresponding to the heights above and below the pitch-changing screw, is the number of turns of resolver rotation when the motor moves from the lower part of the screw to the upper part, is the number of resolver pole pairs, which is determined in advance during the design stage; is the first resolver position reading; is the second resolver position reading.

[0062] S4. Perform three-loop servo control of position-speed-current on the motor.

[0063] Specifically, in order to eliminate the error caused by the screw thread clearance, perform three-loop servo control of position-speed-current on the motor to ensure that the motor can accurately reach the target position.

[0064] As Figure 2 shown, the three-loop servo control system includes a position loop, a speed loop, and a current loop.

[0065] According to the deviation between the set target position and the actual feedback position, control the output of the position loop through PID adjustment (the position loop proportional gain and feedforward gain are designed in this embodiment); the discrete equation of the position loop output is:

[0066] Wherein, is the position loop output value at the current moment, is the position loop proportional gain, is the position feed value at the current moment, is the position feed value in the previous cycle, is the current position feedback value, is the feedforward gain, is the control period;

[0067] The set value of the speed loop is formed according to the output of the position loop. The output of the speed loop is controlled by PID regulation (the speed loop proportional gain and the speed loop integral gain are designed in this embodiment). The discrete equation of the speed loop output is:

[0068] Among them, is the output value of the position loop at the current moment, is the speed loop proportional gain, is the speed loop integral gain, is the given speed of the speed loop, is the feedback speed of the speed loop, is the output of the speed loop in the previous cycle, is the control period, is the output of the speed loop; The set value of the current loop is formed according to the output of the speed loop. The duty cycle of PWM is finally controlled by PID adjustment to directly control the motor torque and speed.

[0069] In addition, in order to avoid the problem of reduced control performance caused by the distortion of the motor body resistance and inductance parameters, and thus improve the robustness of the three-loop control system; in this embodiment, the current loop output control further includes: designing a bias-free current prediction control based on an extended state observer for the current loop; specifically including:

[0070] An extended state observer is introduced to observe and compensate in real time for the control deviation caused by the change of motor parameters. For example, the current of the dq axis is observed. The discrete state equation of the current of the dq axis extended state observer is:

[0071] Among them, is the motor dq axis current calculation transition amount, is the resistance value of the motor stator winding, is the control period, is the motor d axis inductance value, is the motor q axis inductance value, is the motor angular velocity, is the d-axis current feedback value, is q axis current feedback value, is the motor magnetic flux, is the observer coefficient; is the voltage output at time t on the d-axis, is the voltage output at time t on the q-axis;

[0072] Unbiased current predictive control is introduced to predict the current value at the next moment, and the optimal control voltage is calculated through an optimization algorithm, so that the actual current can quickly track the given value; the current-voltage output equation is:

[0073] where, is the calculation transition amount of the motor dq-axis current, is the resistance value of the motor stator winding, is the control period, is the motor d axis inductance value, is the motor q axis inductance value, is the angular velocity of the motor, is d the given value of the current on the axis, is q the given value of the current on the axis, is d the voltage output at time t + 1 on the axis, is q the voltage output at time t + 1 on the axis.

[0074] S5. Implement the calibration of the motor three-loop servo control.

[0075] Specifically, according to the target position command, the motor runs to the command position through the three-loop servo control; among them, the three-closed-loop operating position of the motor is and the actual position command is Combined with the resolver difference corresponding to the upper and lower heights of the variable pitch screw, the target position and the variable pitch screw height value are interpolated to obtain the actual position obtained after the difference processing, calculate the difference between the actual position and the command position and accumulate it with the three-closed-loop operating position of the motor to get and perform the three-closed-loop position control again to achieve the calibration of the motor three-loop servo control.

[0076] Among them, the formula for accumulating and compensating to get includes:

[0077] The formula for accumulating and compensating the running command position is:

[0078] where, is the three-closed-loop operating position of the motor, is the actual position command, is the position error, is the position compensation value at the current moment, is the actual position obtained by screw interpolation, is the resolver difference corresponding to the upper and lower heights of the screw, is the initial resolver reading below the variable pitch screw; is the resolver reading during the three-closed-loop operation of the motor.

[0079] In a specific embodiment, in order to achieve control stability and performance, the control parameters of the current loop can be adjusted to optimize the current response. The method includes:

[0080] In step S1, the motor moves below the variable pitch screw and stalls. The relationship between the stall current and time is:

[0081] where, is the stall current at the current moment, is the stall current coefficient, is the stall time and is the total stall time, is the rated current of the motor;

[0082] Analyze the waveform and peak value of the stall current to adjust the control parameters of the current loop and optimize the current response. Specifically, it includes: identifying the waveform characteristics of the collected stall current waveform, marking the peak value of each stall current, and analyzing its change trend. Based on the results of waveform analysis and peak detection, adjust the control parameters such as the proportional gain, integral time, and differential time of the current loop, select an optimization algorithm, and obtain the parameter combination with the fastest current response and the smallest overshoot.

[0083] In a specific embodiment, considering different environmental conditions, accurately capture the stall state of the motor, and ensure more accurate calculation of the resolver difference. In step S1 or step S2 of the method, it further includes:

[0084] When starting the motor and controlling the motor to rotate clockwise or counterclockwise, synchronously collect environmental data; the environmental data includes temperature, humidity, vibration, etc.

[0085] Dynamically adjust the stall judgment threshold according to the collected environmental data. The dynamic adjustment process includes:

[0086] Input the collected environmental data into the stall threshold acquisition neural network to obtain the judgment threshold for stall corresponding to the currently collected environmental data; the input of the stall threshold acquisition neural network is the collected environmental data, and the output is the judgment threshold for stall, including: a preset rotational speed threshold and a preset current threshold, which are specifically generated by training the judgment threshold for historical stall corresponding to a historical stall state judgment accuracy greater than the preset accuracy and the environmental data at the corresponding historical moment; wherein, the historical stall state judgment accuracy is determined according to the actual stall state (stall occurs, no stall occurs) and the judged stall state.

[0087] As Figure 3 shown, this embodiment provides a high-precision pitch control system for an electric propulsion aircraft, specifically including:

[0088] The first resolver position reading recording module 101 is used to start the motor and control the motor to rotate clockwise, monitor the rotation of the motor, and record the first resolver position reading at this time when the motor moves below the pitch screw and stalls.

[0089] The second resolver position reading recording module 102 is used to control the motor to rotate counterclockwise, monitor the rotation of the motor, and record the second resolver position reading at this time when the motor moves above the pitch screw and stalls.

[0090] The resolver difference calculation module 103 is used to calculate the resolver difference corresponding to the heights above and below the pitch screw according to the recorded first resolver position reading and the second resolver position reading.

[0091] The motor three-loop servo control module 104 is used to perform position-rotation speed-current three-loop servo control on the motor.

[0092] The motor three-loop servo control calibration module 105 is used to, according to the target position command, control the motor to run to the command position through three-loop servo; combine the resolver difference corresponding to the heights above and below the pitch screw, perform interpolation processing on the target position and the pitch screw height value to obtain the actual position obtained through interpolation processing, calculate the difference between the actual position and the target position, and accumulate and compensate it with the running position, and perform three-closed-loop position control again to achieve motor three-loop servo control calibration.

[0093] In a specific embodiment, the first resolver position reading recording module 101 in the system is further used to, when starting the motor and controlling the motor to rotate clockwise, synchronously collect environmental data and dynamically adjust the judgment threshold for stall according to the collected environmental data. The process of dynamic adjustment includes: inputting the collected environmental data into the stall threshold acquisition neural network to obtain the judgment threshold for stall corresponding to the currently collected environmental data; the stall threshold acquisition neural network is generated by training the judgment threshold for historical stall corresponding to a historical stall state judgment accuracy greater than the preset accuracy and the environmental data at the corresponding historical moment.

[0094] In a specific embodiment, the first resolver position reading and recording module 102 in the system is further configured to, when starting the motor and controlling the motor to rotate counterclockwise, synchronously collect environmental data and dynamically adjust the judgment threshold for stalling according to the collected environmental data. The process of dynamic adjustment includes: inputting the collected environmental data into a stalling threshold acquisition neural network to obtain the judgment threshold for stalling corresponding to the currently collected environmental data; the stalling threshold acquisition neural network is generated by training the judgment threshold for historical stalling corresponding to the historical environmental data at the corresponding moment when the historical stalling state judgment accuracy rate is greater than a preset accuracy rate.

[0095] The embodiment of the present application also discloses a computer-readable storage medium.

[0096] Specifically, the computer-readable storage medium stores a computer program that can be loaded and executed by a processor, such as the high-precision pitch control method for an electric propulsion aircraft as described above. The computer-readable storage medium includes, for example, various media that can store program codes, such as USB flash drives, mobile hard disks, read-only memories (ROMs), random access memories (RAMs), magnetic disks, or optical discs.

[0097] The embodiment of the present application also discloses a computer device.

[0098] Specifically, the computer device includes a memory and a processor. The memory stores a computer program that can be loaded and executed by the processor, such as the high-precision pitch control method for an electric propulsion aircraft as described above.

[0099] The above are all preferred embodiments of the present application. Without limiting the protection scope of the present application accordingly, any feature disclosed in this specification (including the abstract and drawings), unless specifically described, can be replaced by other equivalent or similar-purpose alternative features. That is, unless specifically described, each feature is only an example in a series of equivalent or similar features.

Claims

1. A high-precision variable pitch control method for an electric propulsion aircraft, characterized in that: include: S1, start the motor and control the motor to rotate clockwise, monitor the rotation of the motor, and when the motor moves to the bottom of the variable pitch screw and is blocked, record the first rotary position reading at this time; S2, control the motor to rotate counterclockwise, monitor the rotation of the motor, and when the motor moves to the top of the variable pitch screw and is blocked, record the second resolver position reading at this time; S3, calculating the resolution difference corresponding to the upper and lower heights of the variable pitch screw according to the recorded first resolution position reading and the second resolution position reading; S4, perform position-speed-current three-loop servo control on the motor; S5. According to the target position command, the motor is controlled to run to the command position through the three-ring servo control; the target position and the variable pitch screw height value are interpolated in combination with the resolver difference corresponding to the upper and lower heights of the variable pitch screw, and the actual position obtained after the interpolation is obtained. The difference between the actual position and the target position is calculated, and accumulated compensation is performed with the motor running position, and closed-loop position control is performed again to realize the motor three-ring servo control calibration; The formula for calculating the rotation difference corresponding to the upper and lower heights of the variable pitch screw in step S3 is: in, is the rotation difference corresponding to the upper and lower heights of the variable pitch screw, is the number of revolutions of the motor from the lower part of the screw to the upper part of the rotary transformer. is the number of resolver pole pairs; is the first resolver position reading; is the second resolver position reading; In step S5, the difference between the actual position and the target position is calculated and the formula for cumulative compensation with the motor running position is: in, is the three closed-loop operating position of the motor, is the actual position instruction, is the position error, is the current position compensation value, is the actual position obtained by screw interpolation, is the rotation difference corresponding to the upper and lower heights of the screw, It is the resolver reading of the motor's three closed loop operation.

2. The high-precision variable pitch control method for an electric propulsion aircraft according to claim 1, characterized in that: In step S1, the motor moves to the bottom of the variable pitch screw and stalls. The corresponding relationship between the stall current and time is: in, is the stall current at the current moment, is the locked-rotor current coefficient, is the stall time and is the total stall time, is the rated current of the motor; the waveform and peak value of the stall current are analyzed to adjust the control parameters of the current loop and optimize the current response; specifically, the following steps are performed: identifying the waveform characteristics of the collected stall current waveform, marking the peak value, and based on the results of waveform characteristic identification and peak value detection, adjusting the control parameters of the current loop, including proportional gain, integral time and differential time, to obtain a parameter combination with the fastest current response and the smallest overshoot.

3. The high-precision variable pitch control method for an electric propulsion aircraft according to claim 1, characterized in that: The position-speed-current three-loop servo control of the motor in step S4 includes: Control the position loop output, the position loop output discrete equation is: in, is the output value of the position loop at the current moment, is the position loop proportional gain, is the position feed value at the current moment, is the position feed value of the previous cycle, is the current position feedback value, is the feedforward gain, To control the cycle; Control the speed loop output. The speed loop output discrete equation is: in, is the output value of the position loop at the current moment, is the speed loop proportional gain, is the speed loop integral gain, The speed loop sets the speed. is the speed loop feedback speed, is the speed loop output of the previous cycle, To control the cycle, It is the speed loop output; it controls the current loop output and realizes the control of motor torque and speed by controlling the duty cycle of PWM.

4. The high-precision variable pitch control method for an electric propulsion aircraft according to claim 1, characterized in that: The current loop output control specifically includes: designing an unbiased current predictive control based on an extended state observer for the current loop; The current discrete state equation of the dq-axis extended state observer is: in, For motor dq The shaft current calculates the transition amount, is the resistance value of the motor stator winding, To control the cycle, For motor d Shaft inductance value, For motor q Shaft inductance value, is the motor angular velocity, is the d-axis current feedback value, for q Shaft current feedback value, is the motor flux, is the observer coefficient; is the voltage output of the d-axis at time t, is the voltage output of the q-axis at time t; Without bias current prediction control, the voltage output equation is: in, Calculate the transition amount for the motor dq axis current, is the resistance value of the motor stator winding, To control the cycle, For motor d Shaft inductance value, For motor q Shaft inductance value, is the motor angular velocity, for d Shaft current setpoint, for q Shaft current setpoint, for d Axis voltage output at time t+1, for q Axis voltage output at time t+1.

5. The high-precision variable pitch control method for an electric propulsion aircraft according to claim 1, characterized in that: Step S1 or step S2 also includes: When starting the motor and controlling the motor to rotate clockwise or counterclockwise, environmental data is collected synchronously and the stall judgment threshold is dynamically adjusted according to the collected environmental data. The dynamic adjustment process includes: inputting the collected environmental data into the stall threshold acquisition neural network to obtain the stall judgment threshold corresponding to the currently collected environmental data; the stall threshold acquisition neural network is generated by training the historical stall judgment threshold corresponding to the historical stall state judgment accuracy rate greater than the preset accuracy rate and the historical corresponding environmental data.

6. A high-precision variable pitch control system for an electric propulsion aircraft, characterized in that: include: The first resolver position reading recording module is used to start the motor and control the motor to rotate clockwise, monitor the rotation of the motor, and record the first resolver position reading when the motor moves below the variable pitch screw and is blocked; The second resolver position reading recording module is used to control the counterclockwise rotation of the motor and monitor the rotation of the motor. When the motor moves to the top of the variable pitch screw and is blocked, the second resolver position reading is recorded at this time. The resolver difference calculation module is used to calculate the resolver difference corresponding to the upper and lower heights of the variable pitch screw according to the recorded first resolver position reading and the second resolver position reading; the resolver difference formula for calculating the upper and lower heights of the variable pitch screw is: in, is the rotation difference corresponding to the upper and lower heights of the variable pitch screw, is the number of revolutions of the motor from the lower part of the screw to the upper part of the rotary transformer. is the number of resolver pole pairs; is the first resolver position reading; is the second resolver position reading; The motor three-loop servo control module is used to perform position-speed-current three-loop servo control on the motor; The motor three-ring servo control calibration module is used to control the motor to run to the command position through the three-ring servo according to the target position command; the target position and the variable pitch screw height value are interpolated in combination with the resolver difference corresponding to the upper and lower heights of the variable pitch screw, the actual position obtained after the difference processing is obtained, the difference between the actual position and the target position is calculated, and the accumulated compensation is performed with the motor running position, and the closed-loop position control is performed again to realize the motor three-ring servo control calibration; the formula for calculating the difference between the actual position and the target position and accumulating the compensation with the motor running position is: in, is the three closed-loop operating position of the motor, is the actual position instruction, is the position error, is the current position compensation value, is the actual position obtained by screw interpolation, is the rotation difference corresponding to the upper and lower heights of the screw, It is the resolver reading of the motor's three closed loop operation.

7. A computer-readable storage medium, characterized in that: The computer-readable storage medium includes a stored computer program, wherein when the computer program is executed, the device where the computer-readable storage medium is located is controlled to execute the method according to any one of claims 1 to 5.

8. A computer device, characterized in that: The computer device comprises a memory, a processor and a program stored and executable on the memory, and the program implements the steps of the method according to any one of claims 1 to 5 when executed by the processor.

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