Satellite Thruster Groups for Odd-Firing Stability
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Solution Overview
Problem
Existing electric propulsion systems for artificial satellites face challenges in avoiding momentum around the center of gravity when an odd number of thrusters are simultaneously fired, which hinders directional travel.
Innovation Solution
The system employs two thruster groups with different operating numbers, where the ratio of distances from the center of gravity to each group is inversely related to the ratio of operating thrusters, allowing for controlled thruster firings to maintain directional stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If an odd number of electric propulsion thrusters are simultaneously made to perform firings to obtain larger thrust, then the thrust force is improved, but momentum is produced around the center of gravity causing the satellite to deviate from target travel direction
Solution Approach 1:
The thruster system is segmented into multiple groups (first thruster group, second thruster group, third thruster group) with different dispositions around the satellite. This segmentation allows selective operation of odd numbers of thrusters while maintaining balance through coordinated firing of thrusters in different groups, resolving the contradiction between obtaining large thrust and maintaining directional stability.
Solution Approach 2:
The patent employs asymmetric thruster disposition where thrusters are arranged in multiple groups at different positions and orientations around the satellite. This asymmetric arrangement enables flexible selection of thruster combinations, allowing odd numbers of thrusters to fire while compensating for momentum production through coordinated operation of thrusters in different asymmetric groups.
2Productivity
If more electric propulsion thrusters are operated to increase thrust, then the productivity is improved, but the complexity of controlling thruster operations to avoid momentum production increases
Solution Approach 1:
The patent implements dynamic control of thruster operations where the operation status of each thruster group is adjusted based on real-time satellite state and mission requirements. The control system dynamically selects which thrusters to operate and in what combinations, enabling flexible achievement of desired thrust levels while automatically maintaining momentum balance through coordinated operation of multiple thruster groups.
Solution Approach 2:
The patent incorporates feedback control mechanisms where the operation status of each thruster group is monitored and adjusted based on the overall thrust requirement and momentum balance considerations. The control system receives feedback on satellite attitude and thrust production, and automatically adjusts thruster group operations to maintain optimal performance while avoiding unwanted momentum production.
Data Source
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AI summary
When a first operating number being the number of thrusters in a first thruster group (115) that are operated and a second operating number being the number of thrusters in a second thruster group (125) that are operated are different, a ratio between a first distance D1 in a +Y direction from a satellite gravity center (101) to the first thruster group (115) and a second distance D2 in a -Y direction from the satellite gravity center (101) to the second thruster group (125) becomes inverse to a ratio between the first operating number and the second operating number.