CN103171775B - Angular momentum coupling unloading method based on orbit control interference - Google Patents

Abstract

The invention discloses an angular momentum coupling and unloading method based on orbit control interference. The invention adopts the method of momentum wheel control to absorb the accumulated angular momentum generated in the process of satellite orbit control, and uses the orbit control interference torque to make the satellite X and Z direction momentum wheels The characteristic of the angular momentum exchanged every 1/4 cycle, through the X-direction jet unloading the orbit control accumulated angular momentum generated in the Z direction, to solve the problem of orbit control in the case of satellites without Z-direction jet control, through the Z-direction jet unloading the X-direction The generated orbit control accumulates angular momentum, which solves the problem of orbit control in the case of satellites without X-direction jet control, and realizes satellite high-precision trajectory capture. The momentum coupling unloading technology of orbit control interference can be adopted in the orbit control of general satellites, and it can also be applied to the orbit control of underactuated satellites that lose X-axis or Z-axis jet control in orbit. At the same time, it can be extended from jet coupling unloading to magnetic Unloading, reducing the jet volume during the satellite orbit control process, and improving the efficiency of satellite orbit change.

Description

An Angular Momentum Coupling Unloading Method Based on Orbit Control Disturbance

technical field

The invention relates to an angular momentum coupling unloading method, in particular to an angular momentum coupling unloading method based on orbit control interference, which is mainly used for momentum management and disturbance angular momentum unloading in the orbit control process of spacecraft, and belongs to aerospace orbit control technology.

Background technique

In order to realize the high-precision frozen return orbit capture of sun-synchronous orbit spacecraft, when determining the orbit change strategy, the double-pulse orbit change method is generally adopted to realize the coordinated control of orbit eccentricity and perigee angle to ensure that the spacecraft orbit meets the freeze return requirements. During the long-term orbit control process of the spacecraft, the direct jet attitude control method is generally adopted to eliminate the disturbance torque generated by the orbit control engine, realize the attitude control during the orbit control process of the spacecraft, and ensure that the attitude of the spacecraft orbit control process meets the requirements. Once the spacecraft loses the jet control capability of the orbit control engine in the direction of the larger disturbance torque, the spacecraft will not be able to perform orbit control, otherwise it will cause the attitude of the spacecraft to lose control and the orbit control will be suspended. At present, the disturbance angular momentum generated in the orbit control process is generally unloaded directly by the jet. The relevant literature on the orbit control method of the sun-synchronous orbit spacecraft and the angular momentum unloading of the spacecraft mainly includes: Wang Xudong et al. "The Orbit Acquisition and Trajectory Rendezvous Control of China-Brazil Earth Resources Satellite" published by China-Brazil Earth Resources Satellite No. "Journal of the Chinese Academy of Sciences" published "Study on the initial orbit acquisition strategy of sun-synchronous orbit satellites", the research results combined with the actual constraints of engineering applications, and designed the initial orbit acquisition strategy for sun-synchronous orbits with characteristics such as regression and freezing; Liu Hui et al. in 2004 22 The volume "Aerospace Control" published "Minimum working medium loss control of accumulating angular momentum of spacecraft unloaded by jet device", discussing the problem of realizing minimum loss of working medium in the process of unloading external disturbance angular momentum accumulated by spacecraft by using jet device. However, there is no report on the orbit control method using the momentum coupling unloading technology of orbit control interference for the loss of jet torque in a certain direction.

Contents of the invention

The technical problem of the present invention is: to overcome the deficiencies of the prior art, to provide an angular momentum coupling unloading method based on orbit control interference, and to solve the problem that long-term orbit control cannot be carried out when the satellite loses the jet control in the X-axis or Z-axis direction , to achieve satellite high-precision trajectory capture.

The technical solution of the present invention is: an angular momentum coupling unloading method based on orbit control disturbance, the steps are as follows:

(1) The ground sends remote control instructions to the satellite to heat the orbit control engine on the satellite;

(2) The ground injects the target orbit data into the satellite;

(3) The nominal angular momentum and unloading threshold of the momentum wheel injected into the satellite by the ground;

(4) The ground injects single-pulse or double-pulse orbit change into the satellite;

(5) Check the injected orbit change method on the ground, if it is correct, execute step (6), otherwise follow the process of step (4) to re-inject parameters into the satellite;

(6) The ground injects the orbit change data into the satellite, including the combination mode of the orbit control engine, the start time of the orbit change, the length of the orbit change time and the orbit change pulse interval;

(7) The ground remotely opens the self-locking valve on the star so that the orbital control engine can work normally;

(8) The satellite performs orbit control interference angular momentum coupling unloading according to the received orbit change method. If the received single-pulse orbit change method is received, when the satellite waits for the orbit change start time to arrive, the satellite performs orbit control engine combination and orbit change according to the received orbit control engine combination The length of time starts to change orbit autonomously. After 1/4 orbit period, the satellite independently judges whether the difference between the angular momentum of the momentum wheel in the X direction or the Z direction of the satellite and the nominal angular momentum exceeds the unloading threshold. When the satellite X direction or Z direction If the difference between the angular momentum of the directional momentum wheel and the nominal angular momentum exceeds the unloading threshold, the satellite autonomously uses the attitude control engine in the X direction or Z direction of the satellite to unload the jet to realize an orbit control interference angular momentum coupling unloading; if the double pulse is accepted In the orbit change mode, the satellite waits for the arrival of the second orbit change time after completing the above orbit change work. The second orbit change time is equal to the orbit change start time plus the orbit change pulse interval. When the second orbit change time arrives, The satellite starts to independently carry out the second orbit change according to the combination mode of the orbit control engine and the length of the orbit change time. After the orbit change passes 1/4 of the orbit period, the satellite independently judges the angular momentum and the nominal angle of the momentum wheel in the X direction or Z direction of the satellite. Whether the momentum difference exceeds the unloading threshold. When the difference between the angular momentum of the satellite’s X-direction or Z-direction momentum wheel and the nominal angular momentum exceeds the unloading threshold, the satellite autonomously uses the satellite’s attitude control engine in the X-direction or Z-direction to perform jet unloading. Secondary orbit control disturbance angular momentum coupling unloading;

(9) When the satellite completes the orbit change, the ground remotely closes the self-locking valve on the satellite and stops heating the orbit control engine;

(10) Complete the unloading of orbit control disturbance angular momentum coupling.

Compared with the prior art, the present invention has the beneficial effects that: the present invention adopts the mode of momentum wheel control to absorb the accumulated angular momentum generated during the orbit control process of the satellite, and utilizes the orbit control disturbance torque to make the angular momentum of the momentum wheel in X and Z directions of the satellite every The characteristics of the exchange every 1/4 cycle, through the X-direction jet unloading the orbit control generated in the Z direction to accumulate angular momentum, solve the orbit control problem in the case of satellites without Z-direction jet control, and unload the orbit control generated in the X direction through the Z-direction jet Accumulate angular momentum, solve the orbit control problem in the case of satellites without X-direction jet control, and realize satellite high-precision trajectory capture. The momentum coupling unloading technology of orbit control interference can be adopted in the orbit control of general satellites, and it can also be applied to the orbit control of underactuated satellites that lose X-axis jet control in orbit. At the same time, it can be expanded from jet coupling unloading to magnetic unloading, reducing The jet volume in the process of satellite orbit control improves the efficiency of satellite orbit change and has good market competitiveness.

Description of drawings

Fig. 1 is the relationship diagram of inertial coordinate system and satellite body coordinate system;

Fig. 2 is the realization flowchart of the present invention.

Detailed ways

Assuming the satellite's orbital angular velocity ω ₀ , the disturbance moment generated by the orbital thruster on the +Z axis of the star is T _d . Assuming that the orbit control engine works continuously on a circle of orbits, an inertial coordinate system is established at the beginning of orbit control. The relationship between this coordinate system and the satellite body coordinate system is shown in Figure 1, and Xb and Zb in the figure are corresponding to the satellite body coordinate system Coordinate axes, X and Z are the coordinate axes corresponding to the satellite inertial coordinate system, then the angular momentum generated by the orbit control disturbance moment is:

${\mathrm{<span\; class="notranslate">\; h</span>}}_{\mathrm{<span\; class="notranslate">\; x</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; d</span>}}{<span\; class="notranslate">\; \&Integral;</span>}_{\mathrm{<span\; class="notranslate">\; 0</span>}}^{\frac{\mathrm{<span\; class="notranslate">\; \&theta;</span>}}{{\mathrm{<span\; class="notranslate">\; \&omega;</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}}}\mathrm{<span\; class="notranslate">\; sin</span>}{\mathrm{<span\; class="notranslate">\; \&omega;</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}\mathrm{<span\; class="notranslate">\; tdt</span>}<span\; class="notranslate">\; =</span><span\; class="notranslate">\; (</span>\frac{\mathrm{<span\; class="notranslate">\; 1</span>}}{{\mathrm{<span\; class="notranslate">\; \&omega;</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}}<span\; class="notranslate">\; -</span>\frac{\mathrm{<span\; class="notranslate">\; 1</span>}}{{\mathrm{<span\; class="notranslate">\; \&omega;</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}}\mathrm{<span\; class="notranslate">\; cos</span>}\mathrm{<span\; class="notranslate">\; \&theta;</span>}<span\; class="notranslate">\; )</span>{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; d</span>}}$

${\mathrm{<span\; class="notranslate">\; h</span>}}_{\mathrm{<span\; class="notranslate">\; z</span>}}<span\; class="notranslate">\; =</span><span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; d</span>}}{<span\; class="notranslate">\; \&Integral;</span>}_{\mathrm{<span\; class="notranslate">\; 0</span>}}^{\frac{\mathrm{<span\; class="notranslate">\; \&theta;</span>}}{{\mathrm{<span\; class="notranslate">\; \&omega;</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}}}\mathrm{<span\; class="notranslate">\; sin</span>}{\mathrm{<span\; class="notranslate">\; \&omega;</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}\mathrm{<span\; class="notranslate">\; tdt</span>}<span\; class="notranslate">\; =</span><span\; class="notranslate">\; -</span>\frac{\mathrm{<span\; class="notranslate">\; sin</span>}\mathrm{<span\; class="notranslate">\; \&theta;</span>}}{{\mathrm{<span\; class="notranslate">\; \&omega;</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}}{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; d</span>}}$

Among them, H _x and H _z are the angular momentum accumulated in the X direction and the Z direction after the satellite travels at an angle of θ, respectively.

θ is the angle at which the satellite orbits.

It can be seen that the orbit control disturbance torque T _d causes the angular momentum of the satellite X and Z directions to be exchanged every 1/4 cycle, and the short-term orbit control disturbance torque also causes the angular momentum of the momentum wheels in the X and Z directions to be exchanged. In order to establish a fixed-point frozen orbit, there are strict restrictions on the orbit change start time, jet pulse length, and double pulse orbit change phase. The orbit control process considers the momentum management technology. By setting the jet unloading threshold and controlling the X and Y axes of the satellite, The coupling angular momentum is unloaded in time, so that the momentum wheel can restore the nominal speed in time before the next attitude control engine jet, otherwise the momentum wheel will be saturated if the track control is continued, and the three-axis wheel control ability will be lost. The design of the momentum coupling unloading technology should comprehensively consider the start-up and control point of the orbit control, the selection of the orbit control engine, the determination of the injection time, the magnetic unloading capability, the jet unloading threshold, and the injection interval, etc., in order to obtain high-precision fixed-point trajectory capture.

The above scheme is still applicable to the spacecraft that has lost the direct jetting moment in the X direction. By controlling the Z and Y axes of the star, the coupled momentum is unloaded in time to realize the long-term orbit control of the spacecraft.

The implementation process of the present invention is as shown in Figure 2, and is specifically described as follows:

(1) The ground sends remote control instructions to the satellite to heat the orbit control engine on the satellite;

(2) The ground injects the target orbit data into the satellite;

(3) The nominal angular momentum and unloading threshold of the momentum wheel injected into the satellite by the ground;

(4) The ground injects single-pulse or double-pulse orbit change into the satellite;

(5) Check the injected orbit change method on the ground, if it is correct, execute step (6), otherwise follow the process of step (4) to re-inject parameters into the satellite;

(6) The ground injects the orbit change data into the satellite, including the combination mode of the orbit control engine, the start time of the orbit change, the length of the orbit change time and the orbit change pulse interval;

(7) The ground remotely opens the self-locking valve on the star so that the orbital control engine can work normally;

(8) The satellite performs orbit control interference angular momentum coupling unloading according to the received orbit change method. If the received single-pulse orbit change method is received, when the satellite waits for the orbit change start time to arrive, the satellite performs orbit control engine combination according to the received orbit control engine combination method (in order to improve The orbit control capability of the satellite is designed to adopt a symmetrical layout of four orbit control engines around the center of mass on the installation surface along the axis of the satellite body. Through ground injection, different combinations of 1, 2 or 4 thrusters can be realized. ) and the length of the orbit change time, the orbit change will be carried out autonomously according to the target orbit. After the orbit change passes 1/4 of the orbit period, the satellite will independently judge whether the difference between the angular momentum of the momentum wheel in the X direction or the Z direction of the satellite and the nominal angular momentum exceeds the unloading threshold. , when the difference between the angular momentum of the momentum wheel in the X direction or Z direction of the satellite and the nominal angular momentum exceeds the unloading threshold, the satellite autonomously uses the attitude control engine in the X direction or Z direction of the satellite to perform jet unloading, and realizes an orbit control interference angular momentum coupling unloading ; If the double-pulse orbit change method is accepted, the satellite waits for the arrival of the second orbit change time after completing the above orbit change work. The second orbit change time is equal to the orbit change start time plus the orbit change pulse interval. When the time for the second orbit change arrives, the satellite starts to autonomously carry out the second orbit change according to the target orbit according to the combination mode of the received orbit control engine and the length of the orbit change time. Whether the difference between the angular momentum of the direction momentum wheel and the nominal angular momentum exceeds the unloading threshold. When the difference between the angular momentum of the momentum wheel in the X direction or the Z direction of the satellite and the nominal angular momentum exceeds the unloading threshold, the satellite will automatically use the satellite X direction or Z direction. The attitude control engine performs jet unloading to realize the second orbit control disturbance angular momentum coupling unloading;

The difference between the angular momentum of the momentum wheel in the X direction of the satellite and the nominal angular momentum exceeds the unloading threshold, and the satellite independently uses the attitude control engine in the X direction of the satellite for jet unloading, and the difference between the angular momentum of the momentum wheel in the Z direction of the satellite and the nominal angular momentum exceeds the unloading threshold. Threshold, the satellite autonomously uses the attitude control engine in the Z direction of the satellite to perform jet unloading.

(9) When the satellite completes the orbit change, the ground remotely closes the self-locking valve on the satellite and stops heating the orbit control engine;

(10) Complete the unloading of orbit control disturbance angular momentum coupling.

For example: a remote sensing satellite lost the -Z-axis jet torque failure in orbit, and the present invention was used to control the orbit 22 times, and the cumulative jet was 8563.8s, and satisfactorily completed satellite sun synchronization, homing, freezing orbit capture and trajectory rendezvous control tasks.

The content not described in detail in the present invention is well known to those skilled in the art.

Claims (1)

1. An angular momentum coupling unloading method based on orbit control disturbance, characterized in that the steps are as follows: (1) The ground sends remote control instructions to the satellite to heat the orbit control engine on the satellite; (2) The ground injects the target orbit data into the satellite; (3) The nominal angular momentum and unloading threshold of the momentum wheel injected into the satellite by the ground; (4) The ground injects single-pulse or double-pulse orbit change into the satellite; (5) Check on the ground whether the injected orbit change method is correct, and if it is correct, perform step (6), otherwise follow the process of step (4) to re-inject parameters into the satellite; (6) The ground injects the orbit change data into the satellite, including the combination mode of the orbit control engine, the start time of the orbit change, the length of the orbit change time and the orbit change pulse interval; (7) The ground remotely opens the self-locking valve on the star so that the orbital control engine can work normally; (8) The satellite performs orbit control interference angular momentum coupling unloading according to the received orbit change method. If the received single-pulse orbit change method is received, when the satellite waits for the orbit change start time to arrive, the satellite performs orbit control engine combination and orbit change according to the received orbit control engine combination The length of time starts to change orbit autonomously. After 1/4 orbit period, the satellite independently judges whether the difference between the angular momentum of the momentum wheel in the X direction or the Z direction of the satellite and the nominal angular momentum exceeds the unloading threshold. When the satellite X direction or Z direction If the difference between the angular momentum of the directional momentum wheel and the nominal angular momentum exceeds the unloading threshold, the satellite autonomously uses the attitude control engine in the X direction or Z direction of the satellite to unload the jet to realize an orbit control interference angular momentum coupling unloading; if the double pulse is accepted In the orbit change mode, the satellite waits for the arrival of the second orbit change time after completing the above orbit change work. The second orbit change time is equal to the orbit change start time plus the orbit change pulse interval. When the second orbit change time arrives, The satellite starts to independently carry out the second orbit change according to the combination mode of the orbit control engine and the length of the orbit change time. After the orbit change passes 1/4 of the orbit period, the satellite independently judges the angular momentum and the nominal angle of the momentum wheel in the X direction or Z direction of the satellite. Whether the momentum difference exceeds the unloading threshold. When the difference between the angular momentum of the satellite’s X-direction or Z-direction momentum wheel and the nominal angular momentum exceeds the unloading threshold, the satellite autonomously uses the satellite’s attitude control engine in the X-direction or Z-direction to perform jet unloading. Secondary orbit control disturbance angular momentum coupling unloading; (9) When the satellite completes the orbit change, the ground remotely closes the self-locking valve on the satellite and stops heating the orbit control engine; (10) Complete the unloading of orbit control disturbance angular momentum coupling.