JP3160365B2 - Attitude control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an attitude control device used for controlling an attitude of a spacecraft such as an artificial satellite, including a change in attitude.

[0002]

2. Description of the Related Art Generally, an attitude control device determines an estimated attitude angle / estimated angular velocity based on an attitude angle / angular velocity, calculates a control torque based on the estimated attitude angle / estimated angular velocity, and converts the control torque into A corresponding drive signal is generated, the control actuator is driven, and the attitude control is performed. When the attitude of the spacecraft is changed, a constant bias value is set for the outputs of the angle sensor and the angular velocity sensor to drive the control actuator, or the attitude determination system in the attitude control logic. By setting a threshold value for the estimated attitude angle determined by (the attitude angle / angular velocity estimation logic unit), a method of driving a control actuator to change the attitude at a constant attitude angle / angular velocity corresponding to the threshold value is known. Taken.

However, in the above attitude control apparatus, in the former case, when the bias value is set, in the latter case, a so-called overshoot phenomenon occurs after the target attitude angle is reached, so that the energy consumption required for the attitude change is very large, and the attitude change is very large. It takes a long time to complete the process.
Such a problem becomes a serious problem particularly when the size of a spacecraft required in recent space development is to be increased.

[0004]

As described above, the conventional attitude control apparatus has a problem that when the attitude is changed, the energy consumption is large and it takes a long time to complete the attitude change. Was.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to provide an attitude control device which can speed up an attitude changing operation and save energy consumption. .

[0006]

According to the present invention, an estimated attitude angle / estimated angular velocity is determined based on at least an angular velocity of a spacecraft, and a control torque is calculated based on the estimated attitude angle / estimated angular velocity. In a posture control device that generates a drive signal according to a control torque, drives a control actuator, and controls a posture, a value in an angular velocity profile of the spacecraft based on the angular velocity of the spacecraft and the estimated attitude angle. Is constant T1, time T2 at which the posture change amount reaches about 1/2, and (time T2 × 2-T
1) Estimating the time T3 and, in accordance with these times T1 to T3, a posture changing means for sequentially decreasing and setting the threshold value for the estimated posture angle.

[0007]

According to the above configuration, the posture change is relatively reduced at the time T1 because the threshold value for the estimated posture angle is reduced in order at the times T1, T2, and T3 set based on the angular velocity profile. It is executed with a higher control torque, and is executed with a lower control torque in order from time T2 to T3. As a result, the posture can be quickly changed, and overshoot after the posture change can be reduced.

[0008]

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

FIG. 1 shows an attitude control apparatus according to an embodiment of the present invention.
1 detects the attitude angle θ and the angular velocity ω of the satellite dynamics 12 and outputs them to the attitude determination unit 13. A command is input to the attitude determination unit 13, and the estimated attitude angle θe and the estimated angular velocity ωe are determined based on the command. Posture determination unit 1
Reference numeral 3 has its estimated attitude angle output terminal connected to the control calculation unit 15 via the threshold value setting unit 14 and its estimated angular velocity output terminal connected to the control calculation unit 15. The control calculation unit 15 calculates a control torque based on the estimated attitude angle θe1 input via the threshold value setting unit 14 and the estimated angular velocity ωe from the attitude determination unit 13, generates a drive signal, and 16 is controlled to control the attitude of the satellite dynamics 12.

An output terminal of the angular velocity sensor 11 is connected to an attitude change time determination unit 17. The output terminal of the clock 18 is connected to the input terminal of the posture change time determination unit 17, and the estimated posture angle output terminal of the posture determination unit 13 is connected to the input terminal. The posture change time determination unit 17 is, for example, as shown in FIG.
The time T1 at which the value in the angular velocity profile of the satellite dynamics 12 becomes constant as shown in FIG.
/ 2 to reach T / 2, and (time T2.times.2-T1)
Is estimated based on the time T from the clock 18, the angular velocity ω from the angular velocity sensor 11, and the estimated attitude angle θe from the attitude determination unit 13, and these time T 1 to time T 3
Is set so that the threshold value with respect to the estimated attitude angle θe decreases in order as shown in FIG.

When the posture change time determination unit 17 detects the time T2 before detecting the time T1, for example, it is assumed that T2 = T1 and T1 = T2 = T.
Set as 3.

In the above configuration, when executing the posture change, first, a command for setting the posture change amount is input to the posture determination unit 13. The attitude determination unit 13 receives the attitude angle θ and the angular velocity ω from the angle sensor 10 and the angular velocity sensor 11, and determines the estimated attitude angle θe and the estimated angular velocity ωe based on the attitude angle θ and the angular velocity ω and the amount of change in the attitude. I do. Here, as described above, the attitude change time determination unit 17 determines the time T1 at which the value in the angular velocity profile of the satellite dynamics 12 is constant, the time T2 at which the amount of attitude change reaches about 1/2, and (time T2 × 2 −T1) is the time T3 from the clock 18, the angular velocity ω from the angular velocity sensor 11, and the estimated attitude angle θ from the attitude determination unit 13.
e at the time T1 to the time T3.
, The threshold value for the estimated attitude angle θe is set so as to decrease in order, and is output to the threshold value setting unit 14. Thereby, the control operation unit 1
5 is input with an estimated angular velocity ωe from an attitude determination unit 13 and an estimated attitude angle θe1 via a threshold value setting unit 14 in which a threshold value is variably set in a period of time T1 to T3. The drive signal is generated by calculation, and the control actuator 16 is set to the time T1 to T3.
Drive with strength. As a result, the angular velocity of the satellite dynamics 12 is changed as shown in FIG. 2, and the attitude change is completed.

As described above, the attitude control device performs the time T1 when the value in the angular velocity profile of the satellite dynamics 12 becomes constant based on the angular velocity ω and the estimated attitude angle θe of the satellite dynamics 12, and about 1/1/3 2 and a time T of (time T2.times.2-T1).
3 is estimated, and the threshold value for the estimated attitude angle θe is sequentially reduced and set according to the time T1 to the time T3, and the attitude is changed. According to this, the threshold value for the estimated attitude angle θe is set to the time T1 set based on the angular velocity profile.
, T2, and T3, the motor is executed with a relatively high control torque at the time T1, and the time T2 to T3
By executing the control torque sequentially in the lower order in step 3, energy consumption can be efficiently used to quickly change the attitude, and overshoot after the appropriate attitude change can be reduced.

In the above embodiment, the attitude angle θ of the satellite dynamics 12 is detected by using the angle sensor 10, and the attitude determination section 13 estimates the attitude angle θe based on the attitude angle θ.
Is determined, for example, the angular velocity sensor 11
The estimated attitude angle may be determined based on the angular velocity of the satellite dynamics 12 detected in the above.

Further, in the above embodiment, the case where the present invention is applied to a satellite has been described. However, the present invention is not limited to this, and the present invention can be applied to various space navigation vehicles including a spacecraft equipped with a manipulator. Therefore, it is needless to say that the present invention is not limited to the above-described embodiment, but can be variously modified without departing from the gist of the present invention.

[0016]

As described above in detail, according to the present invention, it is possible to provide a posture control device which can realize a quick posture changing operation and can save energy consumption.

[Brief description of the drawings]

FIG. 1 is a diagram showing a posture control device according to an embodiment of the present invention.

FIG. 2 is a diagram showing a profile of an angular velocity sensor output.

FIG. 3 is a diagram showing an example of a threshold value with respect to an estimated attitude angle.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 ... Angle sensor, 11 ... Angular velocity sensor, 12 ... Satellite dynamics, 13 ... Attitude determination part, 14 ... Threshold value setting part, 15 ... Control calculation part, 16 ... Control actuator, 17 ... Attitude change time determination part, 18 ... clock.

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int. Cl. ⁷ , DB name) B64G 1/24 G05D 1/08

Claims (1)

(57) [Claims] 1. An estimated attitude angle / estimated angular velocity is determined based on at least an angular velocity of a spacecraft, a control torque is calculated based on the estimated attitude angle / estimated angular velocity, and a drive signal corresponding to the control torque is generated. The attitude control device generates, drives a control actuator, and controls the attitude. The time T1 at which the value in the angular velocity profile of the spacecraft becomes constant based on the angular velocity of the spacecraft and the estimated attitude angle, Time T to reach about 1/2 of the change amount
2 and a time T3 of (time T2 × 2-T1) is estimated,
A posture control device comprising posture changing means for sequentially decreasing and setting a threshold value for the estimated posture angle in accordance with the time T1 to the time T3.