JP2002087396A - Attitude determining device for spacecraft - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide high-accuracy attitude determination by achieving reliable compensation for perturbation rates. SOLUTION: The perturbation rates about the roll axis and the yaw axis of a spacecraft 10 generated by the rotation of an orbital plane on which the spacecraft 10 flies are calculated by first and second perturbation rate calculating parts 18, 19, a compensation roll attitude rate and a compensation yaw attitude rate which are compensated for the perturbation rates in accordance with information for the roll attitude rate and the yaw attitude rate are calculated, and then the attitude determination amount of the spacecraft 10 about a control axis is calculated in accordance with information for the compensation roll attitude rate and the compensation yaw attitude rate and information for an attitude angle.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an attitude determination device for a spacecraft deployed in orbit around the earth such as an artificial satellite.

[0002]

2. Description of the Related Art Generally, a spacecraft 10 has a roll axis (X) in its orbit around the earth 11 and a pitch substantially perpendicular to its orbit plane as shown in FIG. An axis (Y) and the earth direction as a yaw axis (Z). In such a spacecraft 10, for example, an earth sensor (ES) is used as a posture detection sensor for detecting a posture angle around three axes (a roll axis, a pitch axis, and a yaw axis).
A) and an inertial reference unit (IRU) are mounted, and a three-axis attitude determination amount is calculated using an attitude determination apparatus that determines the attitude of the spacecraft 10 based on the detection information of the attitude detection sensor. Attitude control around three axes is performed.

The attitude determination device of the spacecraft acquires roll axis attitude angle information by its earth sensor, acquires roll axis rate information and yaw axis rate information by an inertial reference device, and is constituted by a well-known Kalman filter. Roll axis
A so-called roll / yaw strap down attitude determination filter for determining the yaw axis estimated attitude angle / estimated attitude rate is employed.

In such a spacecraft attitude determination apparatus, the estimated attitude angle of the pitch axis is determined by the pitch axis attitude angle information acquired by the earth sensor using a pitch strap down attitude determination filter for determining the estimated attitude rate. , And the pitch axis rate obtained by the inertial reference device.

However, in the above spacecraft attitude determination device, when applied to the attitude determination of a spacecraft orbiting in a sun-synchronous orbit, the attitude rate information includes an attitude called a perturbation rate generated by rotation of the orbital surface. Since the rotation is included, if the posture is determined based on the posture rate information, the perturbation rate becomes an error component, and there is a problem that the posture determination accuracy is reduced.

[0006] The problem of increasing the accuracy of the attitude determination is one of the important issues in realizing various operation modes of a spacecraft including an artificial satellite in space with high accuracy.

[0007]

As described above, in the conventional attitude determination apparatus for a spacecraft, the perturbation rate is included in the attitude rate information of the spacecraft, so that the attitude determination accuracy is reduced. Have a problem.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and provides a spacecraft attitude determination device capable of realizing a reliable compensation of a perturbation rate and improving the accuracy of attitude determination. The purpose is to:

[0009]

SUMMARY OF THE INVENTION The present invention relates to a spacecraft which calculates an attitude determination amount about three orthogonal control axes of a spacecraft based on the attitude rate and attitude angle information of the spacecraft. In the attitude determination device for a navigation vehicle, a perturbation rate calculation means for calculating a perturbation rate around the control axis of the spacecraft generated by rotation of the orbital plane on which the spacecraft flies, and the perturbation rate calculation means calculate the perturbation rate. The perturbation rate,
Attitude determining means for compensating for the attitude rate information about the control axis and calculating an attitude determination amount of the spacecraft about the control axis based on the compensated attitude rate and the attitude angle information. An attitude determination device was constructed.

According to the above configuration, the perturbation rate calculation means calculates the perturbation rate around each control axis generated by the rotation of the orbit plane on which the spacecraft flies, and outputs the calculated perturbation rate to the attitude determination means. The attitude determining means compensates a perturbation rate from the attitude rate information of the spacecraft, and calculates an attitude determination amount about the control axis of the spacecraft based on the attitude rate and the attitude angle information that compensated for the perturbation rate. With this, the attitude determination amount calculated by the attitude determination means is calculated based on the true attitude rate and attitude angle information of the spacecraft that does not include the error component due to the perturbation rate, and thus, the attitude determination with high accuracy is performed. Becomes possible.

Further, the present invention is configured to calculate the perturbation rate given around the control axis based on the orbital element and the orbital position information of the spacecraft. According to this, it is possible to calculate the perturbation rate applied around the control axis of the spacecraft by simple arithmetic processing.

[0012]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 shows an attitude determination device for a spacecraft according to an embodiment of the present invention.
As shown in FIG. 1, the traveling direction of the spacecraft 10 is defined as a roll axis (X), a direction substantially perpendicular to the orbital plane is defined as a pitch axis (Y), and the earth direction is defined as a yaw axis (Z). The attitude determination amount about each control axis that orbits the orbit is calculated.

However, the spacecraft 1 orbiting the polar orbit
In the case of 0, the attitude rotational movement called the perturbation rate generated by the rotation of the orbital plane is given a negligible perturbation rate around the pitch axis, and the roll axis and the yaw axis are A relatively large amount of perturbation rate is provided. Therefore, in FIG. 1, a perturbation rate compensating system, which is a feature of the present invention, is provided for the two axes of the spacecraft 10 such as the roll axis and the yaw axis.

That is, in FIG. 1, reference numeral 12 denotes a roll / yaw attitude determination unit, and one input terminal thereof is connected to an output terminal of an attitude angle sensor 13 constituted by, for example, an earth sensor. The attitude angle sensor 13 detects a roll attitude angle around the roll axis and a pitch attitude angle around the pitch axis of the spacecraft 10, and outputs the roll attitude angle to the roll / yaw attitude determination unit 12, The pitch attitude angle is output to the pitch attitude determination unit 23.

The output terminals of the first and second adders 14 and 15 are connected to the other input terminal of the roll / yaw posture determination unit 12. These first and second adders 14, 1
The output end of a roll attitude rate sensor 16 for detecting an attitude rate about the roll axis and an output end of a yaw attitude rate sensor 17 for detecting an attitude rate about the yaw axis are connected to one of the input terminals.

The roll attitude rate sensor 16 and the yaw attitude rate sensor 17 are constituted by, for example, an inertial reference device, and detect the roll attitude rate and the yaw attitude rate of the spacecraft 10 to obtain the first and second yaw attitude rates. Adder 1
Output to one of the input terminals 4 and 15. The other input terminals of the first and second adders 14 and 15 are connected to first and second perturbation rate calculators 18 and 19, respectively.

The first and second perturbation rate calculators 1
8 and 19 have, for example, a command receiving unit 2 at their input terminals.
0 is connected. The command receiving unit 20 receives, for example, the orbital element information of the spacecraft 10 measured by the ground station and transmitted from the ground station as a command, and converts the orbital element information into first and second perturbation rate calculation units. 18 and 19 respectively.

The first and second perturbation rate calculators 1
The output terminals of the track position calculation unit 21 composed of, for example, a timer are connected to the input terminals of 8, 8. The trajectory position calculating unit 21 is connected to the command receiving unit 20, and receives the trajectory element received by the command receiving unit 20. Then, the orbital position calculating unit 21 obtains the orbital position of the spacecraft 10 from the orbital elements, and uses the orbital position information as the first and second perturbation rate calculating units 18 and 19.
Respectively.

The first and second perturbation rate calculators 18, 1
9, when the orbital element and the orbital position information are input, respectively, based on the function f perturbation rate = f (orbital element, orbital position) using these orbital element and orbital position information as input variables, Calculating the perturbation rates of the spacecraft 10 around the roll axis and the yaw axis, which are attitude rotation motions generated by the rotation of the orbit, and calculating the first and second adders 14,
15 is output.

Here, the first and second adders 14 and 15
Is a perturbation rate around the roll axis and the yaw axis input through the first and second perturbation rate calculation units 18 and 19,
The roll attitude rate and the yaw attitude rate obtained by adding the roll attitude rate and the yaw attitude rate from the roll attitude rate sensor 16 and the yaw attitude rate sensor 17 to the so-called feedforward compensation of the perturbation rate included in each attitude rate information. Is calculated.

The first and second adders 14, 1
The output end of the roll / yaw attitude determination unit 12
Is connected to the other input terminal. The first and second adders 14 and 15 calculate the compensating roll posture rate and the compensating yaw posture rate by adding the roll posture rate and the yaw posture rate and the perturbation rate around the roll axis and the yaw axis. Output to the roll / yaw attitude determination unit 12.

An attitude control section 22 is connected to the output end of the roll / yaw attitude determination section 12. The roll / yaw attitude determination unit 12 calculates the attitude determination amounts around the roll axis and the yaw axis based on the input roll attitude angle and yaw attitude angle, the compensated roll attitude rate, and the compensated yaw attitude rate, and calculates the attitude control unit. 22. At the same time, the attitude control unit 22 receives the amount of attitude determination about the pitch axis of the spacecraft 10 calculated by the pitch axis attitude determination unit 23. A pitch attitude rate sensor 24 is connected to the pitch axis attitude determination unit 23, and the pitch attitude rate from the pitch attitude rate sensor 24 and the attitude angle sensor 1
Based on the pitch attitude angle information from No. 3, a pitch axis attitude determination amount is calculated and output to the attitude control unit 22.

Here, the attitude control unit 22 calculates the attitude determination amounts around the roll axis and the yaw axis determined by the roll / yaw attitude determination unit 12 and the pitch axis attitude determination amount calculated by the pitch axis attitude determination unit 23. Based on the above, an actuator drive signal is generated to drive and control an attitude drive actuator (not shown) to control the attitude of the spacecraft 10 around three axes of a roll axis, a pitch axis, and a yaw axis.

In the above configuration, when the spacecraft 10 flies on the orbit, the attitude angle sensor 13 detects the roll attitude angle and the yaw attitude angle to determine the roll / pitch attitude determining unit 1.
Output to 2. Here, the roll attitude rate sensor 16 and the yaw attitude rate sensor 17 detect the roll attitude rate and the yaw attitude rate of the spacecraft 10 and output them to the first and second adders 14 and 15.

At the same time, the orbital elements and the orbital position information of the spacecraft 10 are input to the first and second perturbation rate calculating units 18 and 19 via the command receiving unit 20 and the orbital position calculating unit 21. Then, the first and second perturbation rate calculation units 18 and 19 use the input trajectory element and trajectory position information as input variables and rotate around the roll axis and the yaw axis generated by the rotation of the track surface based on the above equation (1). The respective perturbation rates are calculated and output to the first and second adders 14 and 15.

The first and second adders 14 and 15 are:
The input perturbation rates about the roll axis and the yaw axis are added to the roll attitude rate and the yaw attitude rate, and a compensated roll attitude rate and a compensated yaw attitude rate that compensate for the perturbation rate are calculated. Part 12
Output to

Then, the roll / yaw posture determination unit 12
Based on the input compensating roll posture rate and compensating yaw posture rate and the roll posture angle information from the posture angle sensor 13, each posture determination amount around the roll and yaw axes is determined and output to the posture control unit 22. At the same time, the pitch attitude determination unit 23 calculates an attitude determination amount around the pitch axis based on the pitch attitude rate from the pitch attitude rate sensor and the pitch attitude angle from the attitude angle sensor, and
Output to

Here, the attitude control unit 22 generates an actuator drive signal based on the determined amount of each attitude around the three axes of the roll axis, the yaw axis and the pitch axis to generate the attitude drive actuator (not shown). To control the attitude of the spacecraft 10 around three axes of a roll axis, a pitch axis, and a yaw axis.

As described above, the attitude determining device for the spacecraft 10 determines the perturbation rates of the spacecraft 10 around the roll axis and the yaw axis generated by the rotation of the orbital plane on which the spacecraft 10 flies. Second perturbation rate calculators 18, 19
Compensation of each perturbation rate from the roll attitude rate and yaw attitude rate information to calculate a compensation roll attitude rate and a compensation yaw attitude rate, and the compensation roll attitude rate and the compensation yaw attitude rate information, The attitude determination amount of the spacecraft 10 around the control axis is calculated based on the attitude angle information.

According to this, the calculated attitude determination amount about the roll axis and the yaw axis is calculated based on the true attitude rate and attitude angle information of the spacecraft 10 which does not include an error component due to the perturbation rate. This makes it possible to easily and easily realize a highly accurate posture determination.

In the above embodiment, the first and second perturbation rates of the two axes around the roll axis and the yaw axis are applied to the attitude determination system of the spacecraft 10 orbiting the polar orbit of the earth orbit. 2, the perturbation rate calculators 18 and 19 calculate the perturbation rate about the two axes from the attitude rate about the two axes. However, the present invention is not limited to this. The present invention can also be configured to be applied to the attitude determination system of the spacecraft 10 flying in an orbit, and in each case, substantially the same effect is expected.

As a compensation configuration of the perturbation rate,
In the above-described embodiment, the two axes of the roll axis and the yaw axis are compensated. However, the present invention is not limited to this, and the perturbation rates of the three axes of the roll axis, the yaw axis, and the pitch axis are compensated from each attitude rate. Such a configuration is also possible. According to this, it is possible to further promote the accuracy of the posture determination amount.

When the perturbation rate of one of the three control axes of the spacecraft is so large that the perturbation rates of the other two axes are negligible, only the perturbation rate of the single axis is compensated. You may comprise.

Further, in the above embodiment, the orbital element and the orbital position information transmitted from the ground station are received by the spacecraft, and the perturbation rate is calculated based on the orbital element and the orbital position information. The configuration is described above, but the present invention is not limited to this. For example, a GPS (Global Position) not shown in the spacecraft 10 may be used.
oning System) receiver, this G
It is also possible to adopt a configuration in which the orbital element and the orbital position information of the spacecraft are acquired in the outer space using the PS receiver.

Further, in the above-described embodiment, a case has been described where the present invention is applied to the system for determining the attitude of the spacecraft 10 flying in orbit around the earth. However, the present invention is not limited to this, and other astronomical objects may be used. The present invention is also applicable to the determination of the attitude of the spacecraft 10 flying in an orbit, and substantially the same effect is expected.

In the above embodiment, the space vehicle 1
Although the description has been given of the case where the attitude determination amounts around the three axes of 0 are calculated and the attitude of the spacecraft 10 is controlled based on the attitude determination amounts around the respective axes, the present invention is not limited to this. The present invention is also applicable to a system for evaluating the attitude of the spacecraft 10.

For example, the attitude angle and attitude rate information about the three axes of the spacecraft 10 are transmitted by telemetry from the spacecraft side to a ground station or the like, and the perturbation rate included in the attitude rate around the control axis is similarly determined. The attitude determination amount for attitude / evaluation of the spacecraft 10 is calculated based on the compensated attitude rate around the control axis.

According to this, since the attitude of the spacecraft 10 can be evaluated with high accuracy, it is possible to promote the diversification of the operation of the spacecraft and improve the operational reliability. It is possible to contribute to.

Further, in the above-described embodiment, the case has been described where the perturbation rate about the control axis is calculated based on the orbital element and the orbital position. However, the present invention is not limited to this, and may be calculated by other methods. It may be configured as follows.

Therefore, it is needless to say that the present invention is not limited to the above-described embodiment, and that various modifications can be made without departing from the scope of the present invention.

[0042]

As described in detail above, according to the present invention, there is provided an attitude determination device for a spacecraft capable of realizing reliable compensation of a perturbation rate and improving the accuracy of attitude determination. can do.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a spacecraft attitude determination device according to an embodiment of the present invention.

FIG. 2 is a diagram shown for explaining a schematic configuration of a space navigation body operating method to which the present invention is applied;

[Explanation of symbols]

 10 ... Spacecraft. 11 ... the earth. 12 ... Roll / Yaw attitude determination unit. 13 ... attitude angle sensor. 14 1st adder. 15 Second adder. 16 Roll attitude rate sensor. 17 ... Yaw attitude rate sensor. 18 1st perturbation rate calculation part. 19: second perturbation rate calculator. 20 Command receiving unit. 21 ... orbital position calculating unit. 22 ... posture control unit. 23 ... pitch axis attitude determination unit. 24 ... pitch attitude rate sensor.

Claims (5)

[Claims] 1. A spacecraft attitude determination device which calculates an attitude determination amount of three substantially orthogonal control axes of a spacecraft based on attitude rate and attitude angle information of the spacecraft, A perturbation rate calculating means for calculating a perturbation rate around the control axis of the spacecraft generated by the rotation of the orbital plane on which the spacecraft flies, and a perturbation rate calculated by the perturbation rate calculating means, Attitude determination means for compensating the attitude rate information of the spacecraft and calculating the attitude determination amount of the spacecraft around the control axis based on the compensated attitude rate and the attitude angle information. Body posture determination device. 2. The spacecraft according to claim 1, wherein said perturbation rate calculating means calculates a perturbation rate around at least two control axes among three control axes of said spacecraft. Attitude determination device. 3. The attitude determination device for a spacecraft according to claim 1, wherein the perturbation rate calculation means calculates the perturbation rate based on orbital elements and orbital position information of the spacecraft. . 4. The apparatus according to claim 1, further comprising detecting means for detecting said orbital element and orbital position information.
The attitude determination device for a spacecraft according to any one of claims 1 to 3. 5. The perturbation rate calculating means and the attitude determining means are provided in a base station, wherein the perturbation rate calculating means calculates a perturbation rate around a control axis of the spacecraft, and at least an attitude from the spacecraft. In a state where the rate and the attitude angle information are transmitted by telemetry, the attitude determination means compensates the perturbation rate calculated by the perturbation rate calculation means from the attitude rate, and based on the compensated attitude rate and the attitude angle information. The attitude determination device for a spacecraft according to any one of claims 1 to 4, wherein the attitude determination quantity of the spacecraft is calculated.