JPH10244997A - Attitude controller for artificial satellite - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize the control of attitude with high accuracy, by estimating a periodical disturbance pattern generated on an orbit, from an angular speed detector of an artificial satellite, and installing a pattern feedforward compensator for the feedforward compensation. SOLUTION: An angular speed (a) detected by an angular speed detector 1 is input to a pattern feedforward compensator 8. A pattern of the input angular speed (a) is detected by a pattern detecting part, and the result of recording is transmitted to a command converting part. The command converting part generates a momentum command for compensating the disturbance on the basis of the recorded pattern, and transmits the same to a command correcting part. The correction command is transmitted to a command profile generating part, to be a command profile. The command profile is output from a pattern feedforward compensator 8, to be added to an angular momentum command.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to satellite attitude control.

[0002]

2. Description of the Related Art FIG. 6 is a block diagram showing a conventional attitude control device for an artificial satellite. In FIG. 6, 1 is an angular velocity detector for detecting the angular velocity of the satellite, 2 is an angle detector for detecting the attitude angle of the satellite, and 3 is an angular momentum command generated using the detected angular velocity and attitude angle. The control rule 4 is a speed loop for controlling the angular momentum of the wheel, and 5 is a wheel for controlling the satellite. 6 and 7 indicate the dynamics of the artificial satellite. Numeral 6 is for converting the torque applied to the artificial satellite into an angular velocity, and numeral 7 is for converting the angular velocity into an attitude angle. Numeral 14 denotes a subtractor for calculating the difference between the angular momentum command and wheel angular momentum. Numeral 15 denotes a gain, which is an element constituting a speed loop of 4.

[0003] The conventional satellite attitude control device is configured as described above, and the angular velocity h is detected by the angular velocity detector 1. The attitude angle i is detected by the angle detector 2. The detected angular velocity a and attitude angle b are input to the control law 3 to generate an angular momentum command c. The angular momentum command c is input to the speed loop 4 to generate a wheel torque command f to drive the wheel 5. The wheel 5 rotates to generate an angular momentum g. The angular momentum g of the wheel is fed back to the speed loop 4. The wheel torque command f generated by the wheel is applied to the dynamics 6 of the satellite and becomes an angular velocity h, and the angular velocity is further applied to the dynamics 7 to become an attitude angle i.

[0004]

Generally, disturbance (disturbance torque) is applied to an artificial satellite, and the attitude angle and the angular velocity fluctuate. These disturbances are corrected by the attitude control system. However, in the conventional attitude control device, the correction of the disturbance is performed only with a fixed value, so that there is a problem that high-precision attitude control accuracy cannot be realized.

[0005]

SUMMARY OF THE INVENTION A satellite attitude control apparatus according to a first aspect of the present invention estimates a periodic disturbance pattern generated in orbit from an angular velocity detector of the satellite and feed-forward compensates the pattern. A vessel is provided.

A satellite attitude control apparatus according to a second aspect of the present invention is provided with a pattern feedforward compensator for feedforward compensating for a periodic disturbance generated in orbit using an angular momentum command.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiment 1 FIG. FIG. 1 is a configuration diagram showing Embodiment 1 of the present invention. Descriptions of 1 to 7 are omitted because they are the same as those in the conventional attitude control device for artificial satellites. In addition, 1
Reference numeral 4 denotes a subtractor for calculating the difference between the angular momentum command and the wheel angular momentum, and 15 denotes a gain, which is an element constituting a speed loop. Reference numeral 8 denotes a pattern feedforward compensator that generates an angular momentum feedforward command using the angular velocity detected by the angular velocity detector 1. 13
Is an adder that combines the command generated by the pattern feed forward compensator 8 and the angular momentum command.

FIG. 2 shows the details of the inside of the pattern feedforward compensator. Reference numeral 9 denotes a pattern detection unit that stores an input signal (angular velocity detected by the angular velocity detector 1) as a pattern, 10 denotes a command conversion unit that generates a command for correcting the influence of disturbance from the detected pattern, and 11 denotes a command conversion unit. A command correction unit 12 for storing and correcting the generated command is a command profile generation unit that generates a pattern of the corrected command in a time profile.

The operations 1 to 7 in the attitude control device of the artificial satellite configured as described above are the same as the operations of the attitude control device of the conventional artificial satellite, and therefore the description is omitted. In FIG. 1, the angular velocity a detected by the angular velocity detector 1 is input to the pattern feedforward compensator 8. The input angular velocity a is the same as the input signal j in FIG. The input signal j is input to the pattern detection unit 9.
The pattern is detected. The pattern detector 9 records the input signal in units of clock o, and sends the recording result k to the command converter 10. The command conversion unit 10 generates a command for compensating the disturbance from the recorded pattern. In the embodiment, since the input of the pattern detection unit 9 is an angular velocity, the command conversion unit 10 generates a momentum command L by multiplying the moment of inertia of the satellite.
The command L is sent to the command correction unit 11, where it is stored. The switch 16 of the command correction unit 11 operates after all command conversions are completed, and the command conversion unit 10
Are added by the adder 17 to the command stored in the register 18. Command correction unit 11
The correction command m generated in is sent to the command profile generator 12. The command profile generation unit 12 sends out the transmitted correction command pattern according to the clock o, and becomes a command profile n. The command profile n becomes the output of the pattern feedforward compensator 8 and is added to the angular momentum command.

FIG. 4 shows an occurrence pattern of angular momentum disturbance and an operation example of a clock and a switch. As can be seen from the figure, the disturbance pattern is recorded according to the clock, and at the same time, a command profile for compensating the disturbance is generated to reduce the influence of the disturbance.

Embodiment 2 FIG. 3 is a configuration diagram showing a second embodiment of the present invention. Descriptions of 1 to 7 are omitted because they are the same as those of the configuration of the attitude control device of the conventional artificial satellite. Reference numeral 8 denotes a pattern feedforward compensator that generates an angular momentum feedforward command using the angular momentum command generated in the control law 3. FIG. 2 shows the details of the inside of the pattern feedforward compensator. 9 is an input signal (Embodiment 2)
Is a pattern detection unit that stores an angular momentum command generated according to a control law and generally indicates a periodic behavior) in a pattern. Reference numeral 10 denotes a command conversion unit that generates a command for correcting the influence of disturbance from the detected pattern. A command correction unit 11 stores and corrects the generated command. A command profile generator 12 generates a corrected command pattern in a time profile.

The operations of 1 to 7 in the attitude control device of the artificial satellite configured as described above are the same as the operations of the attitude control device of the conventional artificial satellite, and the description is omitted. In FIG. 3, the angular momentum command c generated in the control law 3 is input to the pattern feedforward compensator 8. The input angular momentum command c is the same as the input signal j in FIG. The pattern of the input signal j is detected by the pattern detector 9. The pattern detector 9 records the input signal in units of clock o, and sends the recording result k to the command converter 10. The command conversion unit 10 generates a command for compensating the disturbance from the recorded pattern. In the second embodiment, since the input of the pattern detection unit 9 is an angular momentum command, the command conversion unit 9 does not need any conversion processing. The command L is sent to the command correction unit 11, where it is stored. The switch of the command correction unit 11 operates after all the command conversions are completed, and the command transmitted by the command conversion unit 9 is added to the previously transmitted command. Command correction unit 11
The correction command m generated in is sent to the command profile generator 12. The command profile generation unit 12 sends out the transmitted correction command pattern according to the clock o, and becomes a command profile n. The command profile n becomes the output of the pattern feedforward compensator 8 and is added to the angular momentum command.

FIG. 5 shows an occurrence pattern of angular momentum disturbance and an operation example of a clock and a switch. As can be seen from the figure, the disturbance pattern is recorded according to the clock, and at the same time, a command profile for compensating the disturbance is generated to reduce the influence of the disturbance.

[0014]

According to the first aspect of the present invention, the angular velocity detector of the satellite can feedforward compensate the disturbance angular momentum with high accuracy. Therefore, it is possible to achieve high-accuracy attitude control without increasing the bandwidth of the control system.

According to the second aspect, the disturbance angular momentum can be accurately feedforward compensated by the angular momentum command. Therefore, it is possible to achieve high-accuracy attitude control without increasing the bandwidth of the control system.

[Brief description of the drawings]

FIG. 1 is a diagram showing Embodiment 1 of an attitude control device for an artificial satellite according to the present invention.

FIG. 2 is a detailed configuration diagram of a pattern feed forward compensator according to the present invention.

FIG. 3 is a diagram showing Embodiment 2 of the attitude control device for an artificial satellite according to the present invention.

FIG. 4 is a diagram showing a generation pattern of disturbance angular momentum and an operation example of a clock and a switch according to the first embodiment of the present invention.

FIG. 5 is a diagram showing a generation pattern of disturbance angular momentum and an operation example of a clock and a switch according to a second embodiment of the present invention.

FIG. 6 is a configuration diagram illustrating a conventional attitude control device for an artificial satellite.

[Explanation of symbols]

1 angular velocity detector, 2 angle detector, 3 control rules, 4
Speed loop, 5 wheel, 6 satellite dynamics (angular velocity), 7 satellite dynamics (attitude angle), 8
Pattern feed forward compensator, 9 pattern detector section, 10 command conversion section, 11 command correction section,
12 Command profile generator, 13 adder, 14
Subtractor, 15 gain, 16 switches, 17 adder, 18 registers.

Claims (2)

[Claims] An angular velocity detector for detecting an angular velocity of an artificial satellite, an angle detector for detecting an attitude angle of the artificial satellite, and an angular momentum command for controlling an attitude of the artificial satellite from the detected angular velocity and angle. And a pattern feedforward compensator for correcting angular momentum disturbance applied to the artificial satellite by the pattern using the detected angular velocity, and inputting the angular momentum command and the output of the compensator, A velocity loop for controlling angular momentum of a wheel for controlling the attitude of the satellite, the attitude control apparatus for the satellite. 2. An angular velocity detector for detecting the angular velocity of the satellite, an angle detector for detecting the attitude angle of the satellite, and an angular momentum command for controlling the attitude of the satellite based on the detected angular velocity and angle. A control law to be generated, a pattern feedforward compensator for correcting angular momentum disturbance applied to the artificial satellite by a pattern using the angular momentum command, and an input of the angular momentum command and the output of the compensator. A velocity loop for controlling angular momentum of a wheel for controlling the attitude of the satellite.