JP3001912B2 - Attitude control device - Google Patents

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial application field) The present invention is applied to a transition orbit (transfer orbit) of an orbit around the earth by a rocket, for example, and a propulsion device such as an apogee engine while performing attitude control. The present invention relates to an artificial satellite to be put into a geosynchronous orbit by using a satellite, and particularly to an attitude control device for the satellite.

(Prior art) As a method of controlling the three-axis attitude at the time of orbit insertion, a method of detecting and controlling the attitude angle of all three axes by an optical sensor (sun sensor + earth sensor) and obtaining an inertia reference by an inertia reference device There is a way to control. In the former case, it is difficult to use the earth sensor for stationary geosynchronous orbital control because of the configuration of the satellite, and a dedicated earth sensor for changing the orbit is required, resulting in an increase in weight.

The latter integrates the gyro output based on the gyro inertia criterion and integrates the attitude angles φ, θ, ψ around the roll (X), pitch (Y), and yaw (Z) axes of the satellite 10 (see FIG. 3). To control the attitude of the satellite. In such an attitude control device, since the gyro itself has a drift rate, in order to achieve high-accuracy attitude control at the time of orbit insertion, a sun sensor for initial and reacquisition and a stationary orbit attitude are required. It is necessary to selectively use the output of the control earth sensor to perform earth acquisition and drift correction. As shown in FIG. 4, the drift correction and the earth capture are performed for attitude control in accordance with the detection values of the earth sensor and the sun sensor in the AB section where the earth sensor can observe the earth in the transition orbit 12 orbiting the earth 11. This is performed by driving the actuator. Thereafter, orbit change attitude control is performed in accordance with the attitude angles φ, θ, and た obtained based on the inertia reference of the inertia reference apparatus whose drift rate has been corrected, and an apogee point (orbit change point O) on the transition orbit is performed. , The on-board propulsion device 10a such as an apogee kick engine is driven and put into a geostationary orbit.

However, in the above attitude control device, since both the earth capture and the drift correction must be performed in a short period of the AB section where the earth sensor can observe the earth, the capture and correction work is very complicated, and the attitude accuracy is high. There is a risk of causing deterioration of the

In particular, in the scanning type earth sensor, the earth image becomes large in the vicinity of the point A, and there is a section where it is not possible to recognize that the earth cannot be captured even if the earth is out of sight. It was time-consuming and had a problem that it was difficult to insert the track with high accuracy.

(Problems to be Solved by the Invention) As described above, in the conventional attitude control device, the operations of capturing the earth and correcting the drift are extremely complicated, and there is a possibility that the attitude accuracy is deteriorated.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and provides a posture control device that can achieve high accuracy of posture accuracy with a simple configuration, capable of reliably realizing earth capture and drift correction. The purpose is to provide.

[Constitution of the Invention] (Means for Solving the Problems) The present invention is based on the inertia criterion of an inertial criterion device for a satellite which is put into a transition orbit and then changed into a geostationary orbit by using an onboard propulsion device. In a posture control device that controls a posture by driving and controlling a posture driving actuator, a sun sensor that observes the sun and detects a posture angle at the time of initial / recapture for the orbit control of the satellite or the posture control, and the geostationary orbit. An earth sensor arranged to detect the attitude angle of the satellite by observing the earth above, and when changing the orbit of the satellite from a transition orbit to a geosynchronous orbit, the earth sensor is on the transition orbit and the earth In the first section in which the earth sensor can be observed, the actuator is driven on the basis of the detection value of the earth sensor and the detection value of the sun sensor to execute earth capture, and then the earth sensor on the transition orbit is executed. Until the second section in which earth observation is possible, the attitude is controlled by driving and controlling the actuator based on the roll attitude information obtained from the inertia reference of the inertia reference apparatus and the detection value of the sun sensor. And performing drift correction of the inertial reference device based on the detection values of the sun sensor and the earth sensor in a state in which the second section has been reached, and then performing drift correction based on the inertia reference of the inertial reference device. And control means for controlling the attitude by driving and controlling the actuator.

(Operation) According to the above configuration, a satellite is firstly captured in the earth in a transition orbit in a section substantially symmetric to the earth observation section,
The attitude is controlled in accordance with the roll attitude information obtained based on the inertial reference of the inertial reference apparatus, and the attitude is controlled based on the corrected inertial reference apparatus in which the drift correction of the inertial reference apparatus is performed in the earth observation section. Meanwhile, the orbit change is performed. Therefore, the orbit change of the satellite is performed in a state where the earth capture and the drift correction have been performed reliably, and a high-accuracy attitude accuracy at the time of the orbit change is ensured.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 shows an attitude control device according to an embodiment of the present invention. An attitude control unit 21 is connected to an output end of an inertial reference device, for example, a gyro 20. The output terminals of a sun sensor 22 for detecting the attitude angle at the time of initial / resupplement and an earth sensor 23 for detecting the attitude angle at the time of the stationary orbit steady control are connected to the attitude control unit 21. The attitude control unit 21 integrates the gyro output based on the inertia reference of the gyro 20, obtains an attitude angle, generates drive signals T _cx , T _cy , and T _cz to drive and control the attitude control actuator 24 to control the satellite. (See Fig. 3)
Realize the attitude control of At this time, the attitude control unit 21 selects the outputs φ, θ, の of the sun sensor 22 for initial / recapture and the earth sensor 23 for geostationary orbit attitude control based on the attitude angles Δφ, Δθ, Δψ obtained from the gyro 20. Used for earth capture and drift correction.

In the above configuration, when the satellite 10 inserted on the transition orbit 12 as shown in FIG.
When 10 reaches the point C in the CD section substantially symmetrical to the AB section of the earth sensor 23 that can be observed with respect to the earth 11 in the transition orbit 12, the attitude control unit 21 calculates the earth capture value from the detection value φ of the earth sensor 23. Then, the actuator 24 is driven and controlled by T _cx , T _cy , and T _cz corresponding to the captured value and the attitude angle obtained from the sun sensor 22, thereby controlling the attitude of the satellite 10 to capture the earth.
At this time, the earth sensor 23 realizes reliable capture without the scan being buried inside the earth even when a known scan type is used, for example.

Then, when the attitude control unit 21 completes capturing the earth, for the roll, the gyro output is integrated based on the inertia reference of the gyro 20 at that time to obtain an attitude angle Δφ, and thereafter, the roll attitude is φ _i , and the initial attitude determination is performed. The value is φ _o = φ _E −φ
_Assuming that _cal , the gyro output integration attitude angle increment value (during the control calculation cycle) is Δφ _gyro , and the earth sensor output at the time of completion of capturing is φ _E , the following calculation is performed: φ _i = φ _i-1 + Δφ _gyro (1) The posture is calculated, and the drive of the actuator 24 is controlled by T _cx , corresponding to the roll posture information, to control the roll posture in the DA section on the transition trajectory 12. At this time, the gyro 20 has a drift, and a slight error actually occurs. During this time, the attitude of the pitch / yaw is controlled based on the angle detected by the sun sensor 22. Since the error is very small as compared with the field of view of the earth sensor, it does not hinder the acquisition of the earth 11 at the point A of the transition orbit 12.

Incidentally, the attitude determination initial value phi _o If you pointing to the earth 11, in the CD section and AB interval, and phi _E -.phi _cal in DA interval since the roll attitude differ by phi _cal.

Next, the satellite 10 can observe the earth on the transition orbit 12
When the vehicle reaches the point A in the AB section, the attitude control unit 21 performs drift correction of the gyro 20 in accordance with the outputs φ, θ, and 太陽 of the sun sensor 22 and the earth sensor 23. Based on the gyro 20 inertia standard,
The attitude angles Δφ, Δθ, Δψ are obtained from the gyro output, and the actuator 24 is drive-controlled by T _cx , T _cy , T _cz corresponding to the attitude angles Δφ, Δθ, Δψ to control the attitude of the satellite 10. Then, with the satellite 10 reaching the orbit change point O in the transition orbit 12, the onboard propulsion device 10a is driven by the satellite 10 to change the orbit to the geosynchronous orbit.

As described above, when the orbit of the satellite 10 is changed, the attitude control device detects the earth sensor 23 in the CD section that is substantially symmetric with the AB section in which the earth sensor 23 for attitude angle detection in the transition orbit 12 can observe the earth.
After driving the actuator 24 in accordance with the detected value of, the earth is captured and the gyro is moved to the AB section where the earth can be observed.
The roll attitude is controlled by driving and controlling the actuator 24 based on the roll attitude information obtained based on 20 inertia criteria, and corresponds to the detection values of the sun sensor 22 and the earth sensor 23 for attitude angle detection in AB section where the earth can be observed Then, the drive of the actuator 24 is controlled to perform drift correction of the gyro 20. According to this, the earth capture and drift correction are performed in different CD and AB sections on the transition orbit 12, respectively,
Since each of these operations can be performed reliably with sufficient time, a high-accuracy posture accuracy at the time of orbit change is ensured, which contributes to the realization of an accurate orbit change.

It should be noted that the present invention is not limited to the above-described embodiment, and it goes without saying that various modifications can be made without departing from the spirit of the present invention.

[Effects of the Invention] As described in detail above, according to the present invention, it is possible to reliably realize the earth capture and drift correction with a simple configuration, and to achieve high accuracy of attitude. An attitude control device can be provided.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an attitude control device according to an embodiment of the present invention, FIG. 2 is a diagram showing the operation of FIG. 1, and FIG. Diagram,
FIG. 4 is a view for explaining a problem of the conventional attitude control device. 10 ... satellite, 10a ... onboard propulsion, 11 ... earth, 12 ...
Transition trajectory, 20 ... Gyro, 21 ... Attitude control unit, 22 ...
Sun sensor, 23 ... Earth sensor, 24 ... Actuator.

Claims (1)

(57) [Claims] A satellite which is orbitally changed into a geosynchronous orbit after being put into a transition orbit by an onboard propulsion device is driven and controlled by an attitude driving actuator based on an inertia reference of an inertial reference device to control an attitude. In the attitude control device, a sun sensor for observing the sun and detecting the attitude angle at the time of initial / recapture for the orbit control or attitude control of the satellite, and observing the earth in the geosynchronous orbit to determine the attitude angle of the satellite An earth sensor arranged to detect, when the orbit changes from a transition orbit of the satellite to a geosynchronous orbit, the earth sensor in the first section where the earth sensor can observe the earth on the transition orbit. After driving the actuator based on the detection value and the detection value of the sun sensor to execute the earth capture, and before reaching the second section where the earth sensor of the earth sensor can be observed on the transition orbit. The,
The attitude control is performed by driving and controlling the actuator based on the roll attitude information obtained from the inertia reference of the inertia reference apparatus and the detection value of the sun sensor, and the sun sensor and the Control means for performing drift correction of the inertial reference device based on the detection value of the earth sensor, and thereafter controlling the attitude by driving and controlling the actuator based on the inertia reference of the inertial reference device subjected to the drift correction. An attitude control device characterized in that: