A mode switching method applied to a variable speed control moment gyro

Abstract

The application discloses a mode switching method applied to a variable rotating speed control moment gyro, which clearly defines multiple working modes of the control moment gyro, switching logic between behaviors of the control moment gyro in the modes and the modes, can realize non-control, moment control and backup reaction wheel functions of the control moment gyro, and can make the control moment gyro effectively applied in satellite attitude control.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of satellite attitude and orbit control, and particularly relates to a mode switching method applied to a variable-speed control moment gyroscope. BACKGROUND

[0002] A variable-speed control moment gyroscope (CMG) is a component for satellite attitude control, which is composed of a low-speed frame and a high-speed rotor. The high-speed rotor can realize torque output through speed change, and the low-speed frame realizes torque output through rotation of the frame shaft. Since the high-speed component realizes torque output through speed increase and decrease of the rotor, the speed change is smooth, the torque output is small, and it is suitable for small-angle speed maneuvering. The torque output by the low-speed frame shaft directly acts on the satellite body, and a larger control torque can be obtained. Reasonable working mode planning can make it switch reasonably between torque control, backup reaction wheel and ground remote control functions according to the actual working condition of the satellite, so as to realize effective application of the variable-speed control moment gyroscope.

[0003] At present, there are few mode switching methods applied to control moment gyroscopes, and more research focuses on the dynamic control of control moment gyroscopes. CN116880525A proposes a combined attitude maneuvering control method of a flywheel and three control moment gyroscopes, taking the vertex of the flywheel angular momentum vector as the maneuvering starting point, finding the maximum available angular momentum motion space inside the control moment gyroscope group momentum body, and inversely calculating the bias speed required for the flywheel compensation and the corresponding control moment gyroscope group initial frame angle. According to the angular momentum motion space and torque output capacity of the control moment gyroscope group, the control moment gyroscope group is connected to the closed loop for attitude control, but the working modes of the control moment gyroscopes are not classified. CN118145017A proposes a long-term sun-pointing control method for a tilted solar panel satellite based on three control moment gyroscopes. This method calculates the attitude control three-axis command torque according to the determined sun-pointing attitude, designs the command speed of the three control moment gyroscopes based on the attitude control three-axis command torque, and realizes long-term sun-pointing control of the tilted solar panel satellite. It can realize sun-pointing of the solar panel installed at any tilt angle, but it does not involve the switching method of the working mode of the control moment gyroscope. SUMMARY

[0004] The application proposes a mode switching method applied to a variable-speed control moment gyroscope for the actual application of the variable-speed control moment gyroscope on a satellite. The method clearly defines the specific behavior of the control moment gyroscope in various working modes and the switching logic between the working modes, and realizes effective application of the control moment gyroscope in satellite attitude control.

[0005] The technical scheme of the present application is: a mode switching method applied to a variable speed control torque gyro, and the following nine working modes are designed: mode one is a non-control mode, mode two is a starting mode, mode three is a CMG mode, mode four is a recovery mode, mode five is a backup reaction wheel mode, mode six is an instruction reaction wheel mode, mode seven is a ground interface mode, mode eight is an orbit entry mode, and mode nine is a constant angle maintaining mode.

[0006] The mode one is a non-control mode: the high-speed rotor speed is 0 rpm, and the low-speed frame constant angle is maintained at 0°.

[0007] The mode two is a starting mode: the low-speed frame constant angle is maintained at 0°, when the torque gyro remote low-speed frame angle is less than the low-speed frame angle control deviation , if the torque gyro high-speed rotor speed is less than the use speed , then the fixed step is used to increase the rotor speed to the use speed .

[0008] The mode three is a CMG mode: the low-speed frame angular speed is controlled by an instruction, and the high-speed rotor maintains the speed.

[0009] The mode four is a recovery mode: the high-speed rotor speed instruction is 0 rpm, the rotor speed is 0 rpm and maintained for a period of time, and then the low-speed frame angle is recovered to 0°.

[0010] The mode five is a backup reaction wheel mode: the high-speed rotor receives a reaction wheel control instruction.

[0011] The mode six is an instruction reaction wheel mode: the high-speed rotor receives a reaction wheel control instruction, and the low-speed frame is to an instruction position.

[0012] The mode seven is a ground interface mode: the high-speed rotor and the low-speed frame both receive a ground single machine instruction, and no instruction is maintained at the last instruction.

[0013] The mode eight is an orbit entry mode: the low-speed frame is locked, and the high-speed rotor speed is set to 0 rpm.

[0014] The mode nine is a constant angle maintaining mode: the low-speed frame is to an instruction position and maintains the frame angle.

[0015] Further, when the current mode is the mode eight orbit entry mode, after the satellite separates from the rocket, the mode one non-control mode is switched in.

[0016] When the current mode is the mode one non-control mode, if the satellite and rocket separation signal is not separated, the mode eight orbit entry mode is switched in.

[0017] When the current mode is the mode one non-control mode, if the satellite working mode is a high-speed maneuvering mode and the CMG available identifier is all available, the mode two starting mode is switched in.

[0018] Further, the current mode is mode two start mode, when all CMGs satisfy the difference between the high-speed rotor telemetry speed and the target speed is less than the high-speed rotor speed error and the frame angle is less than the low-speed frame angle control deviation in a continuous period , mode three CMG mode is cut in;

[0019] The current mode is mode two start mode, when any of the CMGs satisfies that any available identifier is unavailable, any reaction wheel is unavailable, or the satellite working mode needs to cut out the fast maneuver mode, all CMGs are simultaneously cut into mode four recovery mode.

[0020] Further, the current mode is mode three CMG mode, when any of the CMGs satisfies that any available identifier is unavailable, any reaction wheel is unavailable, or the satellite working mode needs to cut out the fast maneuver mode in a continuous period, all CMGs are simultaneously cut into mode four recovery mode;

[0021] The current mode is mode three CMG mode, when any of the CMGs satisfies that any available identifier is unavailable, any reaction wheel is unavailable, or the satellite working mode needs to cut out the fast maneuver mode in a continuous period, all CMGs are simultaneously cut into mode four recovery mode.

[0022] Further, the current mode is mode four recovery mode, when all satisfy the difference between the high-speed rotor command speed and the high-speed rotor speed error and the difference between the telemetry frame angle and the target frame angle is less than the low-speed frame angle control deviation in a continuous period, mode one uncontrolled mode is cut in;

[0023] Wherein, when the CMG is unavailable, it is defaulted that the difference between the telemetry frame angle and the target frame angle is less than the low-speed frame angle control deviation .

[0024] Further, the current mode is mode one uncontrolled mode, when all satisfy the following conditions: condition one, only one reaction wheel is unavailable; condition two, if the CMG available identifier is available, the CMG low-speed frame fixed angle holding angle is set to the low-speed frame expected angle , and the current CMG is set to the fixed angle holding mode, and the other CMGs are set to the uncontrolled mode; mode nine fixed angle holding mode is cut in.

[0025] Further, the current mode is mode nine fixed angle holding mode, when all satisfy the difference between the telemetry frame angle and the target frame angle is less than the low-speed frame angle control deviation , the CMG available identifier is available, and the high-speed rotor telemetry speed is less than the high-speed rotor speed error in a continuous period, mode five backup reaction wheel mode is cut in.​

[0026] Further, the current mode is mode five backup reaction wheel mode or mode nine constant angle holding mode, when any of the continuous multiple attitude control periods satisfies the reaction wheel available or the CMG available identification is not available, the mode four recovery mode is cut in.

[0027] The beneficial effects of the present application are: a mode switching method applied to variable speed control moment gyroscopes is provided, the method defines multiple working modes of the control moment gyroscopes, the switching logic between the behaviors of the control moment gyroscopes in the modes and the modes, the functions of the control moment gyroscopes can be realized, the control moment gyroscopes can be effectively applied in satellite attitude control. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 It is a mode switching flowchart applied to variable speed control moment gyroscopes. DETAILED DESCRIPTION

[0029] The present application will be further described below in combination with the drawings.

[0030] Due to the violent vibration during the rocket launching process, the low-speed frame bearing of the CMG is a vulnerable component, therefore, before the satellite and rocket are separated, the working mode needs to be designed to lock the low-speed frame bearing to reduce the influence of the rocket vibration on the CMG. In the satellite on-orbit stage, considering the CMG as a reaction wheel hot standby component, in order to avoid the deflection of the frame shaft with the satellite attitude change, thereby affecting the whole satellite stable control, the working mode needs to be designed as the use mode of the CMG hot standby process. When the satellite needs to use the CMG for high maneuvering task, the working mode needs to be designed to pull up the speed of the high-speed component of the CMG, in order to prepare for the torque output control of the low-speed frame. When any reaction wheel of the satellite fails, the CMG needs to be used as a backup reaction wheel for small torque output, the working mode needs to be designed to transfer the high-speed rotor of the CMG to the appropriate angle for the variable speed control of the high-speed rotor component. In combination with the above application scenarios of the CMG in the satellite on-orbit process, the working mode of the CMG and the corresponding mode switching condition are designed.

[0031] In the mode switching method, nine working modes are designed, as follows:

[0032] (1) Non-control mode: the high-speed rotor speed is 0 rpm, and the low-speed frame constant angle holding is 0°;

[0033] (2) Start-up mode: the low-speed frame constant angle holding is 0°, when the torque gyro remote low-speed frame angle is less than the low-speed frame angle control deviation (the error between the actual low-speed frame angle of the current torque gyroscope and the target angle (0°)), if the high-speed rotor speed of the torque gyroscope is less than the use speed (3) CMG mode: low speed frame angle speed is controlled by command, high speed rotor maintains speed; (3) CMG mode: low speed frame angle speed is controlled by command, high speed rotor maintains speed;

[0034] (3) CMG mode: low speed frame angle speed is controlled by command, high speed rotor maintains speed;

[0034] (4) Recovery mode: high speed rotor speed command is 0 rpm, rotor speed is 0 rpm and maintains for a period of time, then low speed frame angle returns to 0°;

[0035] (4) Recovery mode: high speed rotor speed command is 0 rpm, rotor speed is 0 rpm and maintains for a period of time, then low speed frame angle returns to 0°;

[0036] (5) Backup reaction wheel mode: high speed rotor receives reaction wheel control command;

[0037] (6) Command reaction wheel mode: high speed rotor receives reaction wheel control command, low speed frame to command position;

[0038] (7) Ground control mode: high speed rotor and low speed frame both receive ground single machine command, no command then maintains last command;

[0039] (8) Orbit entry mode: low speed frame is locked, high speed rotor speed is set to 0 rpm;

[0040] (9) Fixed angle holding mode: low speed frame to command position and maintains frame angle.

[0041] Switching logic between working modes is as follows Table 1:

[0042] Table 1

[0043]

[0044]

[0045]

[0046]

[0047] The above working modes arrange the working modes of CMG from before orbit entry to in-orbit, so that the torque gyro realizes the torque output function when the satellite needs to quickly maneuver in a certain direction; can realize the function of backup reaction wheel when a single reaction wheel fails; and can realize torque control function according to ground command. The switching logic of working modes realizes the automatic application scene of CMG under different working conditions of the satellite, and provides a control strategy for the in-orbit application of CMG.

[0048] Embodiment one

[0049] Step one: when the satellite and the rocket are not separated, the torque gyro is in orbit entry mode, and after the satellite and the rocket are separated, it is switched to uncontrolled mode.

[0050] Step two: After entering the uncontrolled mode, the torque gyro can enter the torque control or reaction wheel working state. When the satellite enters the high-speed maneuvering working mode and the remaining conditions are met, the torque gyro enters the torque control state, first enters the starting mode, the gyro frame is kept at 0°, and the rotor speed is raised to a fixed value. When the rotor speed reaches the requirement, the CMG mode is entered, at this time the rotor speed is kept, and the gyro frame is rotated according to the frame axis angular velocity command to realize the high-speed maneuvering of the satellite on the certain axis of the warning satellite.

[0051] After entering the uncontrolled mode, if any of the satellite reaction wheels is unavailable, the backup reaction wheel mode is entered. First, a torque gyro frame is kept at a certain angle according to the torque required direction, and after meeting the requirement, the backup reaction wheel mode is switched, at this time the high-speed rotor receives the reaction wheel speed command to perform the backup reaction wheel function.

[0052] In the CMG mode, if the satellite needs to cut out the high-speed maneuvering working mode, or the reaction wheel is abnormal, or the like, the recovery mode is cut.

[0053] In the backup reaction wheel mode, if the reaction wheels are all available or the torque gyro is unavailable, the recovery mode is cut. In the recovery mode, the rotor speed is set to 0 rpm, the frame angle is turned back to 0° after the speed reaches 0 rpm, and then the torque gyro enters the uncontrolled mode.

[0054] Step three: The program-controlled mode other than the orbit insertion mode can be switched to the command reaction wheel mode or the ground takeover mode through the ground command. In the command reaction wheel mode, the frame angle is determined by the ground command, and the rotor receives the reaction wheel command to perform the self-defined reaction wheel function. In the ground takeover mode, the frame and the rotor are controlled by the ground command to perform the self-defined function.

[0055] The above only describes the preferred embodiments of the present application, and it should be noted that for those skilled in the art, without departing from the principles of the present application, a number of improvements and refinements can be made, and these improvements and refinements should also be considered as the protection scope of the present application.

Claims

1. A mode switching method applied to a variable speed control moment gyroscope, characterized in that, Nine modes are designed as follows: mode one is free mode, mode two is start mode, mode three is CMG mode, mode four is recovery mode, mode five is backup reaction wheel mode, mode six is instruction reaction wheel mode, mode seven is ground takeover mode, mode eight is orbit insertion mode and mode nine is constant angle mode; The mode one is free mode: the high speed rotor speed is 0 rpm and the low speed frame constant angle is 0°; The mode two starting mode: the low-speed frame angle is kept at 0°, and when the low-speed frame angle of the moment gyro remote measurement is less than the low-speed frame angle control deviation δ error , if the high-speed rotor speed of the moment gyro is less than the use speed n max0 , then the rotor speed is increased to the use speed n max0 by using a fixed step length. The mode three is CMG mode: the low speed frame angular speed is controlled by instruction and the high speed rotor maintains speed; The mode four is recovery mode: the high speed rotor speed instruction is 0 rpm, the rotor speed is 0 rpm and maintains for a period of time, and then the low speed frame angle is recovered to 0°; The mode five is backup reaction wheel mode: the high speed rotor receives reaction wheel control instruction; The mode six is instruction reaction wheel mode: the high speed rotor receives reaction wheel control instruction and the low speed frame is to instruction position; The mode seven is ground takeover mode: the high speed rotor and the low speed frame both receive ground single machine instruction, and no instruction is maintained to last instruction; The mode eight is orbit insertion mode: the low speed frame is locked and the high speed rotor speed is set to 0 rpm; The mode nine is constant angle mode: the low speed frame is to instruction position and maintains frame angle.

2. The mode switching method for a variable speed control moment gyro according to claim 1, characterized in that: When the current mode is the mode eight orbit insertion mode, the mode one free mode is cut in after the satellite separates from the rocket; When the current mode is the mode one free mode, the mode eight orbit insertion mode is cut in when the satellite and rocket separation signal is not separated; When the current mode is the mode one free mode, the mode two start mode is cut in when the satellite working mode is high speed maneuver mode and the CMG available identifier is available.

3. The mode switching method for a variable speed control moment gyroscope according to claim 1, characterized in that: The current mode is mode two start mode, when all CMG in the continuous period meet the difference between the high-speed rotor telemetry speed and the target speed is less than the high-speed rotor speed error R error And the frame angle is less than the low-speed frame angle control deviation δ error Mode three CMG mode is cut in. When the current mode is the mode two start mode, all CMGs are simultaneously cut into the mode four recovery mode when any of the following conditions is met: the CMG available identifier is not available, the reaction wheel is not available or the satellite working mode needs to be cut out of the fast maneuver mode.

4. The mode switching method for a variable speed control moment gyroscope according to claim 1, characterized in that: When the current mode is the mode three CMG mode, all CMGs are simultaneously cut into the mode four recovery mode when any of the following conditions is met in the continuous period: the CMG available identifier is not available, the reaction wheel is not available or the satellite working mode needs to be cut out of the fast maneuver mode. Current mode is mode three CMG mode, when either single meets star angular velocity greater than star angular velocity maximum δ w Or any reaction wheel speed over limit, all CMG simultaneously cut into mode four recovery mode.

5. The mode switching method for a variable speed control moment gyroscope according to claim 1, wherein: The current mode is mode four, the recovery mode, when all of the following conditions are met in consecutive periods: the high speed rotor command speed is less than the high speed rotor speed error R error and the CMG is available, the difference between the telemetry frame angle and the target frame angle is less than the low speed frame angle control bias δ error Mode one, the no control mode, is cut in. Wherein, when the CMG is unavailable, the difference between the telemetry frame angle and the target frame angle is less than the low-speed frame angle control deviation δ by default error .

6. The mode switching method for a variable speed control moment gyroscope according to claim 1, wherein: The current mode is mode one, no control mode, when all of the following conditions are met: condition one, there is only one reaction wheel unavailable; condition two, if the CMG available identifier is available, set the CMG low-speed frame fixed angle holding angle to the low-speed frame expected angle δ fix Set the current CMG to the fixed angle holding mode, and set the other CMG to the no control mode; cut into mode nine, the fixed angle holding mode.

7. The mode switching method for a variable speed control moment gyroscope according to claim 1, wherein: The current mode is mode nine constant angle hold mode, when all of the following conditions are met in consecutive periods: the difference between the telemetry gimbal angle and the target gimbal angle is less than the low speed gimbal angle control deviation δ error , the CMG available flag is available and the high speed rotor telemetry speed is less than the high speed rotor speed error R error , the mode five backup reaction wheel mode is engaged.

8. The mode switching method for a variable speed control moment gyroscope according to claim 1, wherein: When the current mode is the mode five backup reaction wheel mode or the mode nine constant angle mode, the mode four recovery mode is cut in when any of the following conditions is met in the continuous period: the reaction wheel is available or the CMG available identifier is not available.

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