A method and device for maintaining the speed of a satellite reaction flywheel after power failure and restart

Abstract

A method and device for maintaining the speed of a satellite reaction flywheel after power failure and restart can solve the problem that the speed of the existing reaction flywheel returns to zero during initialization after power failure and power is restored, resulting in unstable satellite attitude control. The method comprises: (1) after the reaction flywheel is powered on, the system is initialized and self-checking begins; (2) during the self-checking period, it is determined whether the reaction flywheel receives a correct remote control command, if so, the speed maintenance function of the flywheel after power failure and restart is turned off and step (4) is executed, otherwise, the speed maintenance function of the flywheel after power failure and restart is turned on and step (3) is executed; (3) the current speed is read, and then the current speed is set as the target speed, the speed mode is entered, the speed of the reaction flywheel is stabilized at the current speed, the satellite attitude is stabilized, and the step (5) is jumped; (4) the reaction flywheel responds to the correct remote control command; (5) ends.

Description

Technical Field

[0001] The present invention relates to the technical field of aerospace vehicle attitude control, and in particular to a method for maintaining the rotation speed of a satellite reaction flywheel after power failure and restart, and a device for maintaining the rotation speed of a satellite reaction flywheel after power failure and restart. Background Art

[0002] With the vigorous development of the commercial aerospace industry, the number of commercial satellites is increasing. The reaction flywheel is one of the important executive components of the satellite attitude and orbit control system. It controls the satellite attitude based on the principle of angular momentum exchange and generates torque through the acceleration or deceleration of the flywheel to achieve satellite attitude control. The reaction flywheel product is a high-precision space application product that integrates precision machinery, power electronics, automatic control, and space reliability design.

[0003] When the reaction flywheel is working normally in the satellite, it is always powered on. However, if some special circumstances occur, such as the single-particle latch effect of the flywheel, and it cannot communicate normally with the satellite computer, the reaction flywheel needs to be powered off and restarted. Currently, after the reaction flywheel is powered off and restarted, the flywheel controller will perform power-on initialization, and the speed of the flywheel will be set to the initial value of 0 speed. If the speed of the reaction flywheel before power failure is ω 0, then after the reaction flywheel is powered off and restarted, the speed change is ω 0, the moment of inertia of the flywheel is J The change in flywheel angular momentum caused by the change in flywheel speed is J · ω 0. The change of the flywheel angular momentum will affect the satellite's angular momentum, which is J · ω 0. According to the principle of conservation of angular momentum, the change in satellite angular momentum is - J · ω 0, the change of the satellite's angular momentum will cause the satellite's attitude to change, and the speed of the flywheel before power failure ω The higher the 0, the greater the change in satellite attitude.

[0004] This change in satellite attitude caused by the power failure and restart of the reaction flywheel is undesirable in actual satellite applications, as it will affect the normal operation of the satellite. Summary of the invention

[0005] In order to overcome the defects of the prior art, the technical problem to be solved by the present invention is to provide a method for maintaining the speed of a satellite reaction flywheel after power failure and restart, which can solve the problem that the speed of the existing reaction flywheel returns to zero during initialization after power failure and then power is restarted, resulting in unstable satellite attitude control.

[0006] The technical solution of the present invention is: the speed maintaining method of the satellite reaction flywheel power-off restart comprises the following steps:

[0007] (1) After the reaction flywheel is powered on, the system is initialized and starts self-test;

[0008] (2) During the self-test, determine whether the reaction flywheel receives the correct remote control command. If so, turn off the flywheel power-off restart speed holding function and execute step (4); otherwise, turn on the flywheel power-off restart speed holding function and execute step (3);

[0009] (3) Read the current speed, then set the current speed as the target speed, enter the speed mode, stabilize the reaction flywheel speed at the current speed, achieve satellite attitude stabilization, and jump to step (5);

[0010] (4) The reaction flywheel responds to the correct remote control command;

[0011] (5) End.

[0012] The present invention can ensure that the rotation speed of the reaction flywheel remains basically unchanged or the rotation speed change is very small before and after the power is cut off, so that the influence of the power-off and restart operation of the reaction flywheel on the attitude of the entire satellite can be ignored, and the satellite can maintain normal operation throughout the whole process of the power-off and restart of the reaction flywheel.

[0013] Another method for maintaining the rotation speed of a satellite reaction flywheel after power failure and restart is also provided, which comprises the following steps:

[0014] (I) The reaction flywheel is powered on and the control system is initialized;

[0015] (II) the controller detects the rotation speed of the reaction flywheel;

[0016] (III) if the rotation speed of the reaction flywheel is within a preset range, executing step (IV), otherwise executing step (II);

[0017] (IV) The counter starts and counts normally, and the communication module works normally;

[0018] (V) determining whether the communication module receives the target speed signal, if yes, executing step (VIII), otherwise executing step (VI);

[0019] (VI) determining whether the timing time reaches a preset time, if yes, executing step (VII), otherwise executing step (V);

[0020] (VII) The controller starts the power-off restart speed holding function and uses the current speed as the target speed;

[0021] (VIII) The controller performs PI control and outputs a control signal;

[0022] (IX) The motor runs according to the control signal to complete the speed control.

[0023] A speed maintaining device for restarting a satellite reaction flywheel after power failure is also provided, comprising:

[0024] Initialization module, which is configured to initialize the system and start self-checking after the reaction flywheel is powered on;

[0025] A judgment module, which is configured to judge whether the reaction flywheel receives the correct remote control command during the self-check period, and if so, turns off the flywheel power-off restart speed holding function and executes the response module, otherwise turns on the flywheel power-off restart speed holding function and executes the speed setting module;

[0026] The speed setting module is configured to read the current speed, then set the current speed to the target speed, enter the speed mode, stabilize the reaction flywheel speed at the current speed, and achieve satellite attitude stability;

[0027] A response module is configured to cause the reaction flywheel to respond to the correct remote control command. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 A flow chart of an embodiment of a method for maintaining rotation speed after power failure and restart of a satellite reaction flywheel according to the present invention is shown.

[0029] Figure 2 A flow chart showing another embodiment of a method for maintaining rotation speed upon power-off and restart of a satellite reaction flywheel according to the present invention.

[0030] Figure 3 This is the block diagram of the reaction flywheel speed control module.

[0031] Figure 4 This is a line chart for the reaction flywheel power-off speed maintenance state test.

[0032] Figure 5 Test line graph for receiving speed control signal when reaction flywheel is powered off. DETAILED DESCRIPTION

[0033] like Figure 1 As shown, the method for maintaining the rotation speed of the satellite reaction flywheel after power failure and restart includes the following steps:

[0034] (1) After the reaction flywheel is powered on, the system is initialized and starts self-test;

[0035] (2) During the self-test, determine whether the reaction flywheel receives the correct remote control command. If so, turn off the flywheel power-off restart speed holding function and execute step (4); otherwise, turn on the flywheel power-off restart speed holding function and execute step (3);

[0036] (3) Read the current speed, then set the current speed as the target speed, enter the speed mode, stabilize the reaction flywheel speed at the current speed, achieve satellite attitude stabilization, and jump to step (5);

[0037] (4) The reaction flywheel responds to the correct remote control command;

[0038] (5) End.

[0039] The present invention can ensure that the rotation speed of the reaction flywheel remains basically unchanged or the rotation speed change is very small before and after the power is cut off, so that the influence of the power-off and restart operation of the reaction flywheel on the attitude of the entire satellite can be ignored, and the satellite can maintain normal operation throughout the whole process of the power-off and restart of the reaction flywheel.

[0040] Preferably, in step (1), system initialization includes: clock initialization, IO initialization, serial port initialization, CAN initialization, timer initialization, and ADC / DAC initialization; the clock is to provide a signal of a certain frequency to the controller chip so that the controller chip works at a fixed rhythm; the timer provides timing; IO initialization is the initialization of the pin function of the controller chip; the serial port and CAN are used for the controller chip to communicate with the external control device; the ADC collects the motor current and feeds it back to the controller chip; the controller chip outputs the current to the motor through the DAC.

[0041] Preferably, in the step (3), if the current speed is within the flywheel control speed range, the measured speed signal is stable, otherwise the speed signal is unstable; if the speed signal is stable, the reaction flywheel enters the speed mode; if the speed signal is unstable, the motor is given 0 current by default when powered on, and the reaction flywheel enters the coasting mode.

[0042] Preferably, if Figure 3 As shown, in the step (3), after entering the speed mode, the timer starts timing, and after the preset time is reached, the flywheel power-off restart speed holding function is entered, the current speed value is first read, and then the current speed is set to the target speed to enter the speed mode control loop. The speed mode control loop uses the PI control method to control the device output current to stabilize the flywheel speed at the current speed.

[0043] Preferably, in step (3), the preset duration is 1 second.

[0044] It is understandable that different types of flywheels have different speeds of speed reduction after power failure. In theory, the preset time lengths of flywheels of different types also need to be configured differently. The 1-second duration in this solution is the longest safe time measured for all flywheels. Considering the uniformity of the program functional modules and facilitating industrialization, the preset time length in this solution is set to 1 second.

[0045] like Figure 2 As shown, another method for maintaining the rotation speed of a satellite reaction flywheel after power failure and restart is also provided, which includes the following steps:

[0046] (I) The reaction flywheel is powered on and the control system is initialized;

[0047] (II) the controller detects the rotation speed of the reaction flywheel;

[0048] (III) if the rotation speed of the reaction flywheel is within a preset range, executing step (IV), otherwise executing step (II);

[0049] (IV) The counter starts and counts normally, and the communication module works normally;

[0050] (V) determining whether the communication module receives the target speed signal, if yes, executing step (VIII), otherwise executing step (VI);

[0051] (VI) determining whether the timing time reaches a preset time, if yes, executing step (VII), otherwise executing step (V);

[0052] (VII) The controller starts the power-off restart speed holding function and uses the current speed as the target speed;

[0053] (VIII) The controller performs PI control and outputs a control signal;

[0054] (IX) The motor runs according to the control signal to complete the speed control.

[0055] Those skilled in the art can understand that all or part of the steps in the above-mentioned embodiment method can be completed by instructing the relevant hardware through a program, and the program can be stored in a computer-readable storage medium. When the program is executed, it includes the steps of the above-mentioned embodiment method, and the storage medium can be: ROM / RAM, disk, CD, memory card, etc. Therefore, corresponding to the method of the present invention, the present invention also includes a speed maintenance device for power-off restart of a satellite reaction flywheel, which is usually represented in the form of functional modules corresponding to the steps of the method. The device includes:

[0056] Initialization module, which is configured to initialize the system and start self-checking after the reaction flywheel is powered on;

[0057] A judgment module, which is configured to judge whether the reaction flywheel receives the correct remote control command during the self-check period, and if so, turns off the flywheel power-off restart speed holding function and executes the response module, otherwise turns on the flywheel power-off restart speed holding function and executes the speed setting module;

[0058] The speed setting module is configured to read the current speed, then set the current speed to the target speed, enter the speed mode, stabilize the reaction flywheel speed at the current speed, and achieve satellite attitude stability;

[0059] A response module is configured to cause the reaction flywheel to respond to the correct remote control command.

[0060] Preferably, in the initialization module, system initialization includes: clock initialization, IO initialization, serial port initialization, CAN initialization, timer initialization, ADC / DAC initialization; the clock provides a signal of a certain frequency to the controller chip so that the controller chip works at a fixed rhythm; the timer provides timing; IO initialization is the initialization of the pin function of the controller chip; the serial port and CAN are used for the controller chip to communicate with the external control device; the ADC collects the motor current and feeds it back to the controller chip; the controller chip outputs current to the motor through the DAC.

[0061] Preferably, in the speed setting module, the current speed is within the flywheel control speed range and the measured speed signal is stable, otherwise the speed signal is unstable; if the speed signal is stable, the reaction flywheel enters the speed mode; if the speed signal is unstable, the motor is given 0 current by default when it is powered on, and the reaction flywheel enters the coasting mode.

[0062] Preferably, in the speed setting module, the timer starts timing after entering the working mode, and enters the flywheel power-off and restart speed holding function after the preset time is reached. The current speed value is read first, and then the current speed is set to the target speed to enter the speed mode control loop. The speed mode control loop uses the PI control method to control the output current of the device to stabilize the flywheel speed at the current speed. The preset time is 1 second.

[0063] Figure 4 This is the line graph of the reaction flywheel power-off speed maintenance state test. Among them,

[0064] The first stage is the normal working stage, the target speed is 1000rpm, that is, the first flat speed segment, and the speed count number is 37.

[0065] The second stage is the power-off stage. Because the flywheel speed cannot be tested during power-off, the flywheel is in the coasting stage, that is, the speed is decreasing linearly, and the speed count is 0 (the speed is 927.24rpm when powered on, and the power-off time is 4.7s).

[0066] The third stage is the power-on stage, during which the control system performs self-check again and the flywheel continues to be in the coasting stage, i.e. the oblique line segment where the speed slowly decreases, and the speed count number is 11.

[0067] The fourth stage is the speed maintenance stage, and the flywheel maintains the speed with the current speed as the target speed (912.71rpm in the figure), that is, the second speed flat line segment, and the speed count number is 163.

[0068] Figure 5 It is a line chart for testing the speed control signal of the reaction flywheel when it is powered off.

[0069] The first stage is the normal working stage, the target speed is 1000rpm, that is, the first speed flat line segment, and the speed count number is 13.

[0070] The second stage is the power-off stage. Because the flywheel speed cannot be tested during power-off, the flywheel is in the coasting stage, that is, the speed is decreasing linearly, and the speed count is 0 (the speed is 905.95rpm when powered on, and the power-off time is 6.1s).

[0071] The third stage is the power-on stage, when the control system receives the control signal again and the flywheel continues to control the speed with 1000 rpm as the target speed, that is, the oblique line segment where the speed rises rapidly, and the speed count number is 11.

[0072] The fourth stage is the speed maintenance stage, and the flywheel maintains the speed at 1000 rpm as the target speed, that is, the second speed flat line segment, and the speed count number is 43.

[0073] Among them, when measuring the flywheel speed, the average counting interval of the controller is about 0.1s.

[0074] The beneficial technical effects of the present invention are as follows:

[0075] 1. This method can maintain the stability of the satellite attitude without obtaining the remote control command value.

[0076] 2. The implementation time of this method is much shorter than other technical solutions. The stable control of the satellite attitude can be completed within 3 seconds after the flywheel is powered on again.

[0077] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Any simple modification, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention are still within the protection scope of the technical solution of the present invention.

Claims

1. A method for maintaining the speed of a satellite reaction flywheel after power failure and restart. Features: It includes the following steps: (1) After the reaction flywheel is powered on, the system is initialized and starts self-test; (2) During the self-test, determine whether the reaction flywheel receives the correct remote control command. If so, turn off the flywheel power-off restart speed holding function and execute step (4); otherwise, turn on the flywheel power-off restart speed holding function and execute step (3); (3) Read the current speed, then set the current speed as the target speed, enter the speed mode, stabilize the reaction flywheel speed at the current speed, achieve satellite attitude stabilization, and jump to step (5); (4) The reaction flywheel responds to the correct remote control command; (5) End; Wherein, in the step (3), the current speed is within the flywheel control speed range and the measured speed signal is stable, otherwise the speed signal is unstable; if the speed signal is stable, the reaction flywheel enters the speed mode; if the speed signal is unstable, the motor is given 0 current by default when powered on, and the reaction flywheel enters the coasting mode; after entering the speed mode, the timer starts timing, and after the preset time is reached, the flywheel power-off restart speed holding function is entered, the current speed value is first read, and then the current speed is set to the target speed to enter the speed mode control loop, and the speed mode control loop controls the device output current through the PI control method to stabilize the flywheel speed at the current speed.

2. The method for maintaining the rotation speed of a satellite reaction flywheel after power failure and restart according to claim 1, Features: In the step (1), the system initialization includes: clock initialization, IO initialization, serial port initialization, CAN initialization, timer initialization, and ADC / DAC initialization; the clock provides a signal of a certain frequency to the controller chip so that the controller chip works at a fixed rhythm; the timer provides timing; IO initialization is the initialization of the pin function of the controller chip; the serial port and CAN are used for the controller chip to communicate with the external control device; the ADC collects the motor current and feeds it back to the controller chip; the controller chip outputs the current to the motor through the DAC.

3. The method for maintaining the rotation speed of a satellite reaction flywheel after power failure and restart according to claim 2, Features: In step (3), the preset duration is 1 second.

4. A speed maintaining device for satellite reaction flywheel power failure restart, Features: It includes: Initialization module, which is configured to initialize the system and start self-checking after the reaction flywheel is powered on; A judgment module, which is configured to judge whether the reaction flywheel receives the correct remote control command during the self-check period, and if so, turns off the flywheel power-off restart speed holding function and executes the response module, otherwise turns on the flywheel power-off restart speed holding function and executes the speed setting module; The speed setting module is configured to read the current speed, then set the current speed to the target speed, enter the speed mode, stabilize the reaction flywheel speed at the current speed, and achieve satellite attitude stability; a response module configured to cause the reaction flywheel to respond to a correct remote control command; In the speed setting module, the current speed is within the flywheel control speed range when the measured speed signal is stable, otherwise the speed signal is unstable; if the speed signal is stable, the reaction flywheel enters the speed mode; if the speed signal is unstable, the motor is given 0 current by default when it is powered on, and the reaction flywheel enters the coasting mode; after entering the working mode, the timer starts timing, and after the preset time is reached, the flywheel power-off and restart speed holding function is entered, the current speed value is read first, and then the current speed is set to the target speed to enter the speed mode control loop, and the speed mode control loop uses the PI control method to control the output current of the device to stabilize the flywheel speed at the current speed, and the preset time is 1 second.

5. The satellite reaction flywheel power-off restart speed maintaining device according to claim 4, Features: In the initialization module, system initialization includes: clock initialization, IO initialization, serial port initialization, CAN initialization, timer initialization, ADC / DAC initialization; the clock provides a signal of a certain frequency to the controller chip so that the controller chip works at a fixed rhythm; the timer provides timing; IO initialization is the initialization of the pin function of the controller chip; the serial port and CAN are used for the controller chip to communicate with the external control device; the ADC collects the motor current and feeds it back to the controller chip; the controller chip outputs the current to the motor through the DAC.

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