Dual-redundancy spaceflight permanent magnet motor redundancy switching method based on online torque observation

Abstract

The invention discloses a dual-redundancy spaceflight permanent magnet motor redundancy switching method based on online torque observation, and the method comprises the steps: constructing an online torque observer, and achieving the real-time estimation of the output electromagnetic torque of a main channel motor; comparing the observed torque with a historical reference torque, and extracting an output capability recession characteristic; and a switching criterion is formed according to the torque reduction degree, and redundancy switching is completed in time before the performance of the main motor is insufficient. According to the invention, the actual electromagnetic torque output of the main channel motor can be obtained in real time by constructing the on-orbit operation on-line torque observer. The main channel motor performance reduction degree can be accurately calculated by comparing the observed torque with the historical reference torque in the healthy state, a switching decision is formed according to the performance reduction degree, advanced switching can be completed before obvious function failure of the main channel motor does not occur, and advanced, active and measurable redundancy switching is achieved. The execution control is stable, the real-time performance is high, and the on-orbit reliability and the task continuity of a spaceflight permanent magnet motor system are effectively improved.

Description

TECHNICAL FIELD

[0001] The application relates to a dual-redundancy space permanent magnet motor redundancy switching method based on online torque observation and belongs to the technical field of space permanent magnet motor control. BACKGROUND

[0002] In key actuating mechanisms such as spacecraft attitude control mechanisms, solar wing driving mechanisms, antenna pointing mechanisms and load scanning mechanisms, permanent magnet motors have become core driving components widely used in spacecrafts due to their compact structure, high control precision and strong low-temperature starting capability. With the increasing requirements of space missions on long-term reliability on-orbit, mission continuity and redundancy of actuating mechanisms, the single-channel driving architecture has been difficult to meet the needs of fault-free operation of deep space exploration, long-life satellites and high-reliability attitude control platforms. Therefore, more and more space actuating mechanisms adopt dual-redundancy permanent magnet motor configurations, and through parallel or series-parallel structures of the main and backup driving links and actuating units, the redundancy fault tolerance of key information flow and torque output is realized, so that the system can still maintain uninterrupted task functions in the case of single-channel performance degradation or local failure.

[0003] The core of the dual-redundancy permanent magnet motor lies in redundancy switching. The main purpose of redundancy switching is to ensure that when the performance of the main channel motor appears a degradation trend, the standby channel can be switched in time to avoid the actuating mechanism from stalling or causing irreversible damage. However, the existing redundancy switching strategies in space actuating mechanisms generally make macroscopic judgments based on the response characteristics of the actuating mechanism, for example, by monitoring the angular deviation, speed ripple anomaly, tracking error increase or failure to actuate of the mechanism to determine whether the main motor has failed to maintain normal operation. Such methods are essentially passive switching after observable behavior failure, and switching is usually triggered only when the actuating mechanism is obviously abnormal or even cannot implement the command action. The disadvantage is that it cannot reflect the motor performance degradation process and is not sensitive to early performance degradation, and the switching timing is lagging, which may cause task interruption or structural damage, not meeting the requirements of high reliability and continuity control of spacecrafts. SUMMARY

[0004] The application aims to solve the problem of the prior art that the traditional redundancy switching observation cannot reflect the motor performance degradation, resulting in lagging switching timing and causing task interruption or even equipment damage. The application provides a dual-redundancy space permanent magnet motor redundancy switching method based on online torque observation.

[0005] To achieve the above-mentioned purpose, the technical solution adopted by the application is as follows: The dual-redundancy space permanent magnet motor redundancy switching method based on online torque observation comprises the following steps: S1 state measurement and voltage current conversion, the rotor position information and speed are measured by using the position sensor in the dual-redundancy aerospace permanent magnet motor system, the current information of the main channel motor winding is measured by using the current sensor, the voltage information of the main channel motor winding is measured by using the voltage sensor, and the conversion current and conversion voltage are converted; S2 constructing an online torque observer, the online torque observer is constructed by the conversion voltage and the conversion current; S3 calculating torque, the torque is calculated according to the online torque observer; S4 torque comparison and degradation feature extraction, the performance degradation degree is calculated by comparing the calculated torque with the historical benchmark torque of the aerospace permanent magnet motor under the healthy state corresponding to the working condition; S5 forming redundancy switching decision, setting the performance degradation degree threshold, when the performance degradation degree continuously exceeds the set threshold, switching from the main channel to the standby channel; when the performance degradation degree continuously does not exceed the set threshold, maintaining the main channel.

[0006] Preferably, in the step S1, the rotor position information is θ and the rotor speed is ω m , the current information of the main channel motor winding is i a , i b , i c , and the voltage information of the main channel motor winding is u a , u b , u c ; The conversion equation is constructed as follows: , , Wherein, u d and u q are the conversion voltage, i d and i q are the conversion current.

[0007] Preferably, in the step S2, the equation of the online torque observer is as follows: , wherein p is the pole pair number of the dual-redundancy aerospace permanent magnet motor, ψ f is the permanent magnet flux linkage, B is the friction factor, J is the moment of inertia, ω m * is the estimated speed of the torque observer, is the difference between the estimated speed ω m * and the real speed ω m of the motor, k is the proportional factor of the torque observer, F( ) is the approaching law function, and d / dt is the differential operator of the variable change rate with respect to time.

[0008] Preferably, k=21.2, .

[0009] Preferably, in the step S3, the torque of the main channel motor is T l .

[0010] Preferably, in the step S4, the historical reference torque T his of the space permanent magnet motor in the healthy state corresponding to the working condition is observed, and the performance degradation degree is η, .

[0011] Preferably, the performance degradation degree threshold η th = 23% is set. When the performance degradation degree continuously exceeds the set threshold η th = 23%, the main channel is switched to the standby channel; when the performance degradation degree continuously does not exceed the set threshold η th = 23%, the main channel is maintained.

[0012] The beneficial effects of the present application mainly include: 1. By constructing an online torque observer running on orbit, the actual electromagnetic torque output of the main channel motor can be obtained in real time, thereby meeting the data comparison redundancy switching strategy requirement.

[0013] 2. The performance degradation degree of the main channel motor can be accurately calculated by comparing the observed torque with the historical reference torque in the healthy state, and the switching decision is made according to the performance degradation degree, so that the advance switching can be completed before the main channel motor appears obvious functional failure, and the advance, active and measurable redundancy switching is realized.

[0014] 3. The execution control is stable and real-time, and the on-orbit reliability and task continuity of the space permanent magnet motor system are effectively improved. BRIEF DESCRIPTION OF DRAWINGS

[0015] Other features, objects and advantages of the present application will become more apparent from the following detailed description of non-limiting embodiments made with reference to the accompanying drawings: Figure 1 is a flowchart of the dual-redundancy space permanent magnet motor redundancy switching method based on online torque observation of the present application. DETAILED DESCRIPTION

[0016] In order to make the purpose, technical scheme and advantages of the embodiments of the present application more clear, the technical scheme in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.​

[0017] The present application will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, only the parts relevant to the invention are shown in the accompanying drawings. It should be noted that, unless otherwise specified, the embodiments and features described in the present application can be combined with each other.

[0018] This invention provides a redundancy switching method for dual-redundant aerospace permanent magnet motors based on online torque observation, such as... Figure 1 As shown: Construct and inject high-frequency signal state measurement and voltage-current conversion; The rotor position information θ and velocity ω are measured using position sensors in a dual-redundant aerospace permanent magnet motor system. m The current information of the main channel motor winding is measured using a current sensor. a i b i c The voltage information u of the main channel motor winding is measured using a voltage sensor. a u b u c And use the following formula to convert current and voltage: , , Among them, u d and u q For the conversion voltage, i d and i q To convert current.

[0019] Constructing an online torque observer: Convert voltage u d u q , conversion current i d i q The number of pole pairs p of a permanent magnet motor, and the flux linkage ψ of a permanent magnet. f Substituting the friction coefficient B and moment of inertia J into the following formula, an online torque observer is constructed: , Where, ω m * represents the estimated speed from the torque observer. To estimate the rotational speed ω m *With the actual motor speed ω m The difference, the scaling factor k of the torque observer is set to 21.2, F( Let d be the reaching law function, and d / dt be the differential operator of the rate of change of the variable with respect to time, which satisfies: .

[0020] The torque is calculated: When the constructed torque observer is stable, the torque Tl* of the main channel motor can be calculated by the following formula: .

[0021] Torque comparison and performance degradation feature extraction: The online observed torque T l * is compared with the historical baseline torque T his of the space permanent magnet motor under the corresponding working condition in the healthy state, and the performance degradation degree η is calculated: .

[0022] The historical baseline torque of the main motor under the corresponding working condition in the healthy state can be obtained by ground testing, specifically, by applying different working conditions (different speeds and different loads) instructions on the calibration test bench, recording the stable output torque of the motor in the healthy state, and forming a working condition-torque correspondence table.

[0023] Forming a margin switching decision: According to the performance degradation degree, the margin switching decision is established: First, when η continuously exceeds the set threshold ηth=23%, switch from the main channel to the standby channel; second, when η continuously does not exceed the set threshold ηth=23%, there is no need to switch from the main channel to the standby channel.

[0024] As can be seen from the above description, by constructing an online torque observer running on orbit, the actual electromagnetic torque output of the main channel motor can be obtained in real time, thereby meeting the data comparison margin switching strategy requirement. The performance degradation degree of the main channel motor can be accurately calculated by comparing the observed torque with the historical baseline torque under the healthy state, and the switching decision is made according to the performance degradation degree, so that the early switching can be completed before the main channel motor appears obvious functional failure, realizing the early, proactive and measurable margin switching. The execution control is stable and real-time, effectively improving the on-orbit reliability and mission continuity of the space permanent magnet motor system.

[0025] The term "comprising" or any other similar word is intended to encompass non-exclusive inclusion, so that the process, method, article or equipment / device including a series of elements not only includes those elements, but also includes other elements not explicitly listed, or includes the elements inherent to the process, method, article or equipment / device.

[0026] The technical solution of the present invention has been described above with reference to the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of the present invention is obviously not limited to these specific embodiments. Without departing from the principles of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after such changes or substitutions will all fall within the scope of protection of the present invention.

Claims

1. A redundancy switching method for dual-redundancy aerospace permanent magnet motor based on online torque observation, characterized in that The method comprises the following steps: S1, state measurement and voltage-current conversion, rotor position information and speed are measured by using a position sensor in a dual-redundancy aerospace permanent magnet motor system, current information of a main channel motor winding is measured by using a current sensor, voltage information of the main channel motor winding is measured by using a voltage sensor, and the voltage information is converted into converted current and converted voltage; S2, constructing an online torque observer, the online torque observer is constructed by using the converted voltage and the converted current; S3, calculating torque, the torque is calculated according to the online torque observer; S4, torque comparison and degradation feature extraction, the calculated torque is compared with historical reference torque of the aerospace permanent magnet motor under a healthy state, and a performance degradation degree is calculated; S5, forming a redundancy switching decision, a performance degradation degree threshold is set, when the performance degradation degree continuously exceeds the set threshold, switching from a main channel to a backup channel is performed; When the performance degradation degree continuously does not exceed the set threshold, the main channel is maintained.

2. The dual-redundancy aerospace permanent magnet motor redundancy switching method based on online torque observation according to claim 1, characterized in that: In the step S1, the rotor position information is θ and the rotor speed is ω m , the current information of the main channel motor winding is i a , i b , i c , the voltage information of the main channel motor winding is u a , u b , u c ; a conversion equation is constructed: ， ， where u d and u q are the conversion voltages, i d and i q are the conversion currents.

3. The dual-redundancy aerospace permanent magnet motor redundancy switching method based on online torque observation according to claim 2, characterized in that: in the step S2, an equation of the online torque observer is: where p is the pole pair number of the dual-redundancy space permanent magnet motor, ψ f is the magnetic flux of the permanent magnet, B is the friction factor, J is the moment of inertia, ω m * is the estimated speed of the torque observer, is the estimated speed of the torque observer ω m * and the real speed of the motor ω m , k is the proportional factor of the torque observer, F( ) is the reaching law function, and d / dt is the differential operator of the variable change rate with respect to time.

4. The dual-redundancy space permanent magnet motor redundancy switching method based on online torque observation according to claim 3, characterized in that: k=21.2， 。 5. The dual-redundancy aerospace permanent magnet motor redundancy switching method based on online torque observation according to claim 3, characterized in that: In the step S3, the torque of the main channel motor is T l .​ 6. The dual-redundancy aerospace permanent magnet motor redundancy switching method based on online torque observation according to claim 5, characterized in that: In the step S4, the aerospace permanent magnet motor corresponds to the historical reference torque T of the working condition under the healthy state his The performance degradation degree is η, .

7. The dual-redundancy aerospace permanent magnet motor redundancy switching method based on online torque observation according to claim 6, characterized in that: Setting a performance degradation degree threshold value η th = 23% When the degree of performance degradation continuously exceeds a set threshold η th = 23%, switch from the main channel to the standby channel; When the degree of performance degradation continuously does not exceed the set threshold η th = 23%, the main channel is maintained.

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