JPH0379499A - Thruster controlling method of space flying body - Google Patents

Abstract

PURPOSE:To activate the maximum ability of a thruster by monitoring the ON/OFF modulation calculating part output by a simultaneous ON command detecting part, and changing the input route to a thruster selecting and driving signal generating part depending on whether or not the ON command of a control shaft is simultaneously outputted. CONSTITUTION:The outputs of ON/OFF modulation calculating parts 13, 14 are regularly monitored by a simultaneous ON command detecting part 26. It is judged whether or not the ON command of a control shaft to which thrusters 4-7 are coupled is simultaneously outputted. The outputs of the ON/ OFF modulation calculating parts 13, 14 are inputted to a thruster selecting and driving signal generating part 16 directly while no simultaneous output is conducted, and through a thruster ON/OFF time division processing part 15 when the simultaneous output is conducted. According to this constitution, the maximum ability of the thrusters can be utilized.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a thruster control method for a spacecraft. [Prior Art] Hereinafter, the attitude of a spacecraft with a thruster arrangement 0 shown in FIG. This will be explained using a control system as an example. In fig.

(11, +21. +31 is the roll axis and pitch axis of the spacecraft.

Yaw axis, (41, +51. +61. +71. +
8+ and +91 are the thrusters 1 and 1 attached to this spacecraft. Thruster 2. Thruster 3. Thruster 4. They are thruster 5 and thruster 6. Here, thruster 5 (81,
Thruster 6 (91) is used alone to generate ■yaw and e-yaw torques, respectively, but thruster 1 (4), thruster H51, thruster 3 (6), and thruster 4 (7) are , the two thrusters are used simultaneously to generate the desired torque for the control shaft.

The relationship between the desired control torque command and the thrusters to be turned on is as follows: (i) When roll torque is applied, thruster 1°2 is turned on, and when e-roll torque is applied, thrusters 3 and 4 are turned on.

■When the pitch torque is applied, the thruster is turned on by 2.3, and when the e-pitch torque is applied, the thruster is turned on by 1.4.

FIG. 4 is for a spacecraft with the thruster arrangement shown in FIG. 3. A block diagram of a conventional thruster %15D system is shown focusing on the two axes of roll and pitch. (12 is a roll control torque command calculation unit and a pitch control torque command calculation unit for inputting the output signal of the attitude sensor αO and calculating a control torque command; αJ and α4 are converting the torque command signal into an on/off signal. The roll on/off modulation meter xi and the pitch on/off modulation calculation section are used for conversion, and the thruster on/off signal is used for time-sharing processing of the thruster on/off signal based on the output of the on/off modulation calculation section. Time division processing unit.

αω is a thruster selection and drive signal generation unit that selects a thruster to be turned on based on the output signal of the thruster on/off time division processing unit and generates a cooperation signal.

(LD is Spacecraft Dynamics.

In order to obtain a desired control torque, this thruster control system is provided with an on/off modulation section, a thruster on/off time division processing section, and a thruster selection and drive signal generation section. A control torque corresponding to a torque command around each axis is generated. The roll on/off modulation calculation section 3 inputs the roll control torque command signal which is the output of the roll control torque command calculation section α9, and outputs the roll thruster on signal and the roll thruster on signal.

Similarly, the pitch control torque command signal that is the output of the pitch control torque command calculation section az is input to the pitch on/off modulation calculation section α.

■Outputs pitch thruster on signal and e pitch thruster on signal. The thruster on/off time division processing unit a divides 0 time into two: roll on/off time and pitch on/off time, and turns on the roll thruster only during the roll on/off signal processing time. is now performed only during pitch-on/off signal processing time. Therefore, ON commands for the two control axes, roll and pitch, are not output to the thruster selection and drive signal generation unit αG at the same time. FIG. 5 shows the relationship between input signals and output signals using time waveforms in order to explain the processing of the thruster on/off time division processing unit α9.

In the figure, αg, αI# (a), and ai+ are input signals to the thruster on/off time division processing unit α9. Waveforms of ■roll command, e-roll command, ■pitch command, and e-pitch command (c), @ , 04. □□□
teeth.

The output signals of the thruster on/off time division processing unit α have the following waveforms: (1) Roll thruster on, (2) Roll thruster on, (2) Pitch thruster on, and (e) Pitch thruster on. As can be seen from Fig. 5, the thruster on/off time division processing unit α is time divided into roll on/off signal processing time periods and pitch on/off signal processing time periods.
Even if the on command of the input signal to the thruster on/off time division processing unit (I) overlaps in roll and pitch.

The roll thruster is turned on during the roll on/off signal processing time period, and the pitch thruster is turned on during the pitch on/off signal processing time period shifted by half a cycle.

From this, the output of the thruster on/off time division processing unit t19 is [F]/e roll thruster C, on and ■/e
The pitch thruster will never turn on.

In the thruster selection and drive signal generation section ae, the above-mentioned on/off
The output signal of the off-thruster time-division processing unit α is optimized,■
When the roll thruster is on, thruster N41° thruster 2 (
5) is on, ○ When the roll thruster is on, thruster 3f6
1. Thruster 4 (7) is on, ■ When pitch thruster is on, thruster 2 (5) and thruster 3 (6) are on, e When pitch thruster is on, thruster 1 (4) and thruster 4 (7) are on.
) is turned on, and a drive signal is generated.

[Problem to be solved by the invention]

In the conventional thruster control system as described above, the thruster on/off time division processing unit divides the time period in which on/off processing should be performed for each control axis, and the thruster is always turned on/off outside of the corresponding time period. To turn off the command, the effective maximum torque of the thruster averaged over 2 hours is 2II4I when selecting a thruster that couples (2 time split). When using a thruster that couples 7 degrees of torque during continuous injection on 3 axes (
There was a problem in that the torque during continuous injection (during 3-time split) was reduced to 7.

This invention was made to solve the above-mentioned problem, and when the on-commands of each control axis do not overlap, the time-averaged effective control torque of the thruster is continuously Qlq
The objective is to obtain a thruster control method that can generate torque up to the maximum torque at the time of launch.

[Means to solve the problem]

Thruster control method for spacecraft 11 flying object according to this invention +1
．． A simultaneous on command detection section and an on/off command signal selection section are provided.

[Effect]

In the thruster control method for a spacecraft according to the present invention, the output of the on/off modulation calculation section is monitored by the simultaneous on-command detection section, and the on-commands of the thrusters are coupled, and the on-commands of the thrusters are simultaneously output. is on/
The output of the off-modulation calculation section is directly input to the thruster selection and drive signal generation section [7. If the ON commands of the above control axes are output at the same time, when the thruster is on/off/
1. The on/off command signal selection section is switched so that the division processing section is activated 41 and its output is input to the thruster selection and drive signal generation section.

〔Example〕

FIG. 1 is a block diagram showing an embodiment of the thruster control method according to the present invention.
(Iη is the same as the conventional thruster control method.

In this invention, the simultaneous on command detection section (to) and the on/off
The difference from conventional thruster control methods is that an off-command signal selection unit penalty is provided. The simultaneous on command detection unit (c) monitors the outputs of the roll on/off modulation calculation unit α3 and the pitch on/off modulation calculation unit I, and when the roll and pitch on commands are output simultaneously, the thruster on/off time division processing unit f
At the same time as activating 1s, a thruster time division processing execution flag is output to the on/off command signal selection section fin. The thruster on/off time division processing unit α9 activated by the simultaneous on command detection unit (to) performs one time division roll on/off based on the output of the on/off modulation calculation unit.
A roll on/off command signal is sent during the off signal processing period, and a pitch on/off command signal is sent during the pitch on/off signal processing period.

The on/off command signal selection section @ determines which on/off command signal to use based on the thruster time division processing execution flag from the simultaneous on command detection section. Roll from the on/off modulation calculation section,
If the pitch on command is not output at the same time, use the output of the on/off modulation calculator directly,
If on commands are output at the same time, the thruster on/off
Off time division processing unit (selects the output of I!9. Figure 2 shows thruster on/off time division processing unit a'3. Processing of simultaneous on command detection unit (to) and on/off command signal selection unit 艷) In order to specifically explain the content between songs, the relationship between the output of the on/off modulation calculation section and the output of the on/off command signal selection section is shown as a time waveform.
The commands corresponding to the input signals in the figure are the same as in FIG. 5 for comparison. In the flX2 diagram (to)
, (to), (to), onh on/off modulation calculation section (I3.■Roll command which is the output of α4, e
Waveforms of the roll command, ■pitch command, and e-pitch command, 0'3 is the waveform of the thruster time-sharing processing execution flag, which is the output of the simultaneous on command detection unit (a), o3
．． coo, (to), (to) are the waveforms of (1) roll thruster on, (e) roll thruster on, (2) pitch thruster on, and (theta) pitch thruster on, which are outputs of the on/off command signal selection unit. As can be seen from the figure, the thruster time-sharing processing execution flag is in execution only when the roll command is on and the pitch command is on, and the thruster time-sharing processing is executed. Meanwhile roll.

Also, when the ON and pitch commands do not overlap, the thruster time-division processing execution flag becomes non-execution, so the output of the ON/OFF command signal selection section or the ON/OFF modulation calculation section is selected.

In Figures 2 and 5, ■ The waveform of the roll thruster on ((c) in Figure 2 and @ in Figure 5) and the waveform of the e pitch thruster (
If you compare (to) in Figure 2 with (c) in Figure 5, the difference will become clear. In other words, if this invention is applied, when the ON of the roll command and the pitch command do not overlap,
The control torque can be increased up to the maximum torque generated during continuous thruster injection.

In the above embodiment, a thruster in which the two axes of roll and pitch are coupled is used.

The present invention can be similarly applied when using a thruster that couples two axes of pitch and yaw or roll and yaw, and more generally when using a thruster that couples three axes of roll, pitch, and yaw. [Effect of the Invention] As explained above, the present invention has a simultaneous on command detection section and an on/off command signal selection section, so that thruster on/off time division processing fM can be performed. The effective control torque can be prevented from decreasing, the control torque can be generated until it becomes equal to the maximum torque during continuous injection, and the thruster can be used effectively up to a maximum of 1 jL force.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing one embodiment of the present invention. FIG. 2 is a time waveform diagram of a signal for explaining the processing contents of the system to which the present invention is applied, and FIG. 3 is a roll diagram. Fig. 4 is a block diagram of the attitude control system applying the conventional thruster control method; Fig. 5 is a diagram showing the arrangement of thrusters with pitch couples; It is a waveform diagram. In the figure, (4) to (7) are thrusters, 01 is an attitude sensor, αD, α2 are a roll control torque command calculation unit and a pitch control torque command calculation unit, ai, (1
41 is a roll on/off modulation calculation unit and a pitch on/off modulation calculation unit, αS is a thruster on/off time division processing unit, αG is a thruster selection and drive signal generation unit, (1) is a simultaneous on command detection unit, @ is on /Off command signal selection section 0 Note 1 In the figures, the same reference numerals indicate the same or corresponding parts. Figure 2

Claims (1)

[Claims] a plurality of thrusters having torque components for two or more of the control axes of the spacecraft, roll, pitch, and yaw, and arranged so that two or more thrusters are used in combination to generate torque around a desired control axis; A control torque command calculation section for calculating the control torque to be generated by this thruster, an on/off modulation calculation section for converting this control torque command signal into an on/off signal, and a timer for converting the on/off signal. A thruster on/off time division processing unit that performs divided processing to prevent common thruster on commands from overlapping, and an on/off signal for the on/off modulation calculation unit, or an on/off signal for the thruster on/off time division processing unit. /On/Off signal to select which signal to select.
a simultaneous on command detection section that monitors the outputs of the off command signal selection section and the on/off modulation calculation section to check whether a simultaneous on command has occurred;
It consists of a thruster selection and drive signal generation section that selects the corresponding thruster based on the output of the on/off command signal selection section and generates a drive signal, and the simultaneous on command detection section selects the corresponding thruster and generates a drive signal. The output of the calculation unit is monitored, and while the ON commands of the control axes to which the thrusters are coupled are not output at the same time, the output of the on/off modulation calculation unit is directly input to the thruster selection and drive signal generation unit, and the control axis A thruster control for a spacecraft, characterized in that when on commands are simultaneously output, a thruster on/off time division processing section is activated and its output is used as an input to a thruster selection and drive signal generation section. Method.