Orbit attitude control device, and method of controlling orbit attitude

Patent metadata

Field	Value
Publication number	US-9242745-B2
Application number	US-201314018667-A
Country	US
Kind code	B2
Filing date	Sep 5, 2013
Priority date	Nov 28, 2012
Publication date	Jan 26, 2016
Grant date	Jan 26, 2016

Abstract

An orbit attitude control device includes a divert thruster including a plurality of nozzles. First group nozzles inject combustion gas in opposite directions along a first axis. Second group nozzles inject combustion gas in opposite directions along a second axis. A control section calculates correction values for opening degree commands based on a detection value of a pressure of the combustion chamber and a command value of the pressure, and corrects the opening degree command values by the correction values. The device further includes a first axis acceleration sensor for detecting acceleration along the first axis and a second axis acceleration sensor for detecting acceleration along the second axis. The correction values for the opening degrees of the first group nozzles are determined by a first axis acceleration, and the correction values for the opening degrees of the second group nozzles are determined by a second axis acceleration.

First claim

What is claimed is:

1. An orbit attitude control device, comprising:
a pressure sensor configured to detect a pressure of a combustion chamber to generate a pressure detection value;
a first axis acceleration sensor configured to detect an acceleration in a first axis direction as a first axis acceleration;
a second axis acceleration sensor configured to detect an acceleration in a second axis direction as a second axis acceleration;
a plurality of nozzles respectively having a plurality of valves and configured to emit combustion gas generated in said combustion chamber through said plurality of valves, whose opening degrees are controlled based on valve opening degree control values, and wherein said plurality of nozzles comprises a first couple of nozzles respectively having a first couple of valves and emitting the combustion gas in opposite directions along a first axis and a second couple of nozzles respectively having a second couple of valves and emitting the combustion gas in opposite directions along a second axis;
a storage section configured to store an inertia model of an object whose orbit is controlled by said first couple of nozzles and said second couple of nozzles; and
a control section configured to:
calculate a relative thrust force of said first couple of nozzles along the first axis direction as an estimated first axis thrust force value and a relative thrust force of said second couple of nozzles along the second axis direction as an estimated second axis thrust force value, based on the inertia model, the pressure detection value, the first axis acceleration, and the second axis acceleration;
convert valve opening degree command values for said first couple of valves into a first axis thrust force command value and valve opening degree command values for said second couple of nozzles into a second axis thrust force command value,
calculate a first axis thrust force difference indicating a difference between the estimated first axis thrust force value and the first axis thrust force command value, and a second axis thrust force difference indicating a difference between the estimated second axis thrust force value and the second axis thrust force command value,
calculate a first axis valve opening degree difference for said first couple of valves based on the first axis thrust force difference, and a second axis valve opening degree difference for said second couple of valves based on the second axis thrust force difference,
estimate a total valve opening degree value of said valves of said first and second couples of valves based on the pressure detection value,
calculate the valve opening degree correction values which are correction values of the valve degree command values for said first and second couples of valves, based on the estimated total valve opening degree value, the first axis valve opening degree difference and the second axis valve opening degree difference,
wherein the valve opening degree correction values comprise pressure dependent correction values which are calculated based on the estimated total valve opening degree value, and acceleration dependent correction values which are calculated based on the first axis valve opening degree difference and the second axis valve opening degree difference,
calculate the valve opening degree control values from the valve opening degree command values and the valve opening degree correction values, and
output the valve opening degree control values to said first and second couples of valves to drive said valves of said first and second couples of valves based on the valve opening degree control values such that the combustion gas is emitted through said first and second couples of valves.

2. The orbit attitude control device according to claim 1 , wherein a summation of the first axis thrust force values for said first couple of nozzles is zero.

3. The orbit attitude control device according to claim 1 , wherein said control section is configured to calculate a total correction value that is a correction value for a total value of the valve opening degree command values so that a deviation between the total valve opening degree value estimated from the pressure detection value and the total value of the valve opening degree command values becomes smaller, and evenly distribute the total correction value to the pressure dependent correction values for said first and second couples of valves.

4. The orbit attitude control device according to claim 1 , wherein said control section is configured to calculate a total correction value that is a correction value for a total value of the valve opening degree command values so that a deviation between the total valve opening degree value estimated from the pressure detection value and the total value of the valve opening degree command values becomes smaller, and distribute the total correction value to the valve opening degree correction values for said plurality of nozzles in correspondence to a ratio of the valve opening degree command values of said plurality of nozzles.

5. The orbit attitude control device according to claim 1 , wherein said control section is configured to:
calculate a total correction value that is a correction value for a total value of the valve opening degree command values so that a deviation between the total valve opening degree value estimated from the pressure detection value and the total value of the valve opening degree command values becomes smaller,
calculate a total first couple opening degree value T1 that is a total value of the opening degree command values for said first couple of valves, and calculate a total second couple opening degree value T2 that is a total value of the valve opening degree command values for said second couple of valves,
distribute the total correction value to a first couple opening degree correction value in a ratio of T2/(T1+T2), and to a second couple opening degree correction value in a ratio of T1/(T1+T2).

6. A method of controlling an orbit attitude, comprising:
detecting a pressure of a combustion chamber to generate a pressure detection value;
detecting an acceleration of a first couple of nozzles in a first axis direction of a plurality of nozzles as a first axis acceleration, the first couple of nozzles respectively having a first couple of valves and emitting combustion gas in opposite directions along a first axis;
detecting an acceleration of a second couple of nozzles in a second axis direction of the plurality of nozzles as a second axis acceleration, the second couple of nozzles respectively having a second couple of valves and emitting the combustion gas in opposite directions along a second axis;
calculating a relative thrust force of the first couple of nozzles along the first axis direction as an estimated first axis thrust force value and a relative thrust force of the second couple of nozzles along the second axis direction as an estimated second axis thrust force value, based on an inertia model, the pressure detection value, the first axis acceleration, and the second axis acceleration, the inertia model indicating an object whose orbit is controlled by the first couple of nozzles and the second couple of nozzles;
converting valve opening degree command values for the first couple of valves into a first axis thrust force command value and valve opening degree command values for the second couple of nozzles into a second axis thrust force command value;
calculating a first axis thrust force difference indicating a difference between the estimated first axis thrust force value and the first axis thrust force command value, and a second axis thrust force difference indicating a difference between the estimated second axis thrust force value and the second axis thrust force

Assignees

• Mitsubishi Heavy Ind Ltd

Inventors

• Fujita Toshiharu
• Hayakawa Nobuaki

Classifications

• B64G1/26 Primary

  using jets · CPC title

• F02K9/86

  using nozzle throats of adjustable cross- section {(F02K9/978 takes precedence)} · CPC title

• B64G1/36

  using sensors, e.g. sun-sensors, horizon sensors · CPC title