JPH02117498A - Orbit control unit for artificial satellite - Google Patents

Abstract

PURPOSE:To normally control inclinations of its attitude during movement on an orbit perpendicular to a spin shaft, by loading a spin type solar sensor and an orbit control computer on a spin type artificial satellite so as to find at the satellite the amount of residual torque between radial direction thrusters. CONSTITUTION:In a satellite carrying thereon a plurality of radial direction thrusters 1, 2 for providing thrust perpendicular to a spin shaft 5, a chemical propulsion valve 11 for performing switching of fuel to be supplied to the radial direction thrusters 1, 2, a spin type solar sensor 8 for detecting both the strength of sunlight and a spin solar angle defied by the spin shaft 5 and by the incident line of the sunlight, and an orbit control computer 3, the orbit control computer 3 computes residual torque according to changes in spin solar angle signals and, in addition to control signals produced according to the commands of injection from a terrestrial station, sends actuating and control signals to the chemical propulsion valve 11 of the radial direction thrusters 1, 2, so that the residual torque is 0. Fluctuations of the satellite are thus reduced to small amount.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an orbit control device for an artificial satellite, in which the radial thrusters 1 and 2 are required to give velocity in a certain direction in inertial space based on the special KK. However, the operation for appropriately matching the two will be explained with reference to the configuration diagram in FIG.

The spin type solar sensor 8 detects sunlight and once transmits this detection signal to a control station on the ground. The control station calculates the position of the satellite from this detection signal and calculates the deviation from a predetermined orbit. Based on this result, a command signal corresponding to the timing until the injection of the radial direction thrusters 1 and 2 and the number of injections is sent to the satellite.

The orbit control unit 7 of the satellite converts this command signal into a signal that controls the opening/closing time and number of times of the propellant valve 11, controls the propellant valve 11, and sends and injects fuel to the radial direction thrusters 1 and 2. .

The magnitude of the speed caused by this injection can be adjusted by the pulse width and the number of pulses ejected in one spin, that is, the number of spins to execute the injection. By simultaneously injecting the two radial direction thrusters 1 and 2 using such an injection method, the torque applied to the satellite body 4 is effectively canceled out, and the velocity in a predetermined direction can be obtained without changing the attitude of the satellite. I'm trying to be able to do that.

[Problem to be solved by the invention]

The conventional satellite orbit control device described above is designed so that no torque is generated when two radial thrusters are injected simultaneously, but in reality, the unique thrust force of the two radial thrusters is This difference in torque and the movement of the center of gravity of the satellite due to fuel consumption cause a difference in torque, which has the disadvantage of generating torque that changes the attitude of the satellite.

[Means to solve the problem]

An orbit control device for an artificial satellite according to the present invention includes a plurality of radial thrusters having thrust in a direction perpendicular to the spin axis of a spin-type artificial satellite, and a thruster that opens and closes fuel supplied to each of the radial thrusters. a spin-type solar sensor that detects the intensity of sunlight and a spin-sun angle formed between the spin axis and the direction of incidence of the sunlight; and a plurality of propellant valves based on a signal of the spin-sun angle. at least one of
The computer is equipped with a computer that calculates and controls the control signal to open the two.

〔Example〕 Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a block diagram of one embodiment of the present invention.

The overall configuration diagram of the artificial satellite according to this embodiment is the same as the general configuration diagram of the artificial satellite shown in FIG. 2 except that the orbit control computer 3 is mounted in place of the orbit control section 7.

The embodiment shown in FIG. 1 includes radial thrusters 1 and 2 that provide thrust in a direction perpendicular to the spin axis of the satellite, a propellant valve 11 operated by a propellant valve opening/closing signal 12, a spin type solar sensor 8, and an orbit. It is composed of a control computer 3.

The orbit control computer 3 is a radial direction thruster l.

The operation of this embodiment will be explained with reference to the inherent difference in thrust between the two thrusters and the radial direction thruster 1° below.

As in the conventional example, the detection signal of the spin type solar sensor 8 is transmitted to a control station on the ground, and the control station calculates the position of the satellite from this detection signal and processes the deviation from a predetermined orbit. Based on this result, a command signal corresponding to the timing of the injection of the radial thruster 1.2 and the number of injections is sent to the satellite.
It is input to the orbit control computer 3.

On the other hand, the spin-type sunlight sensor 8 has a pattern of planes parallel to the spin axis 5, such as the solar field of view 8A shown in FIG. 2, and when the spin axis 5 is not parallel to this spin plane,
A signal 6 of the spin solar angle θ, which is a deviation from this parallelism, is detected by the spin solar sensor 8. A detection signal proportional to the spin solar angle θ signal 6 is input to the orbit control computer 3.

In addition to the control signal based on the injection command from the ground control station, the orbit control computer 3 calculates the residual torque from the change in the signal 6 of the spin solar angle θ, and calculates the residual torque from the radial thruster so that the residual torque becomes zero. A control signal is sent to adjust the opening time of propellant valves 1 and 2.

For example, if the torque of radial thruster 1 is
If the torque is smaller than that of the radial thruster 1, the opening time of the thrust valve 11, which is different from the radial thruster 1, is made longer than that of the radial thruster 2 so that the torque becomes the same. When the magnitude of the torque is opposite, the opening/closing operation is performed in the opposite direction. In this way, by controlling the injection of either of the two radial direction thrusters using the orbit control computer, the tilt of the satellite's attitude can be made normal. In this embodiment, the case where there are two thrusters in the radial direction is illustrated, but the present invention can also be applied to the case where there are a plurality of thrusters.

〔Effect of the invention〕

As explained above, the present invention is capable of controlling orbital movement in a direction perpendicular to the spin axis by installing an orbit control computer on a satellite and determining residual torque between radial thrusters within the satellite in orbit. This has the effect of keeping satellite fluctuations to a minimum when executing

゛°゛Spin type solar sensor, 8A... View in the sun direction, 9... Piping, 1o... Fuel tank, 11... Propellant valve, 12...Propellant valve opening/closing signal.

Claims (1)

[Claims] A plurality of radial thrusters that generate thrust in a direction perpendicular to the spin axis of a spin-type satellite, a propellant valve that opens and closes the fuel supplied to each of the radial thrusters, and detects the intensity of sunlight. At the same time, a spin type solar sensor detects a spin solar angle formed between the spin axis and the direction of incidence of sunlight, and a control signal for opening at least one of the plurality of propellant valves is calculated from the signal of the spin solar angle. An orbit control device for an artificial satellite, comprising: a computer for controlling the orbit of an artificial satellite;