Articulated Satellite Thrusters for Orbit Control and Wheel Desaturation
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Solution Overview
Problem
Current satellite orbit and attitude control methods, particularly for geostationary satellites with electric propulsion, face challenges in efficiently managing 3-axis desaturation of angular momentum storage devices, leading to overconsumption of propellant and increased stress on articulated arms, which can result in reduced controllability and increased failure probability.
Innovation Solution
A method involving a maneuver plan that includes discontinuous thrust maneuvers, where thrust sub-maneuvers are separated by non-zero duration intervals, allowing for 3-axis desaturation without increasing propulsion unit activation duration, thereby reducing propellant consumption and stress on articulated arms.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If continuous thrust maneuvers are used for orbit control and desaturation, then the desaturation capacity is sufficient, but the propellant consumption increases and stress on articulated arms increases
Solution Approach 1:
The patent divides a continuous thrust maneuver into multiple discrete thrust sub-maneuvers separated by non-zero duration intervals. This segmentation allows the satellite to achieve the same desaturation capacity while reducing cumulative propellant consumption and stress on articulated arms by utilizing orbital mechanics and gravitational forces during the intervals between sub-maneuvers.
Solution Approach 2:
The patent implements periodic thrust sub-maneuvers with specific timing intervals that align with the satellite's orbital period. By scheduling thrust events periodically at optimal orbital positions (near ascending and descending nodes), the system achieves efficient desaturation while minimizing propellant usage and mechanical stress through the natural periodicity of orbital motion.
2Productivity
If thrust maneuvers are concentrated in short duration, then the orbit control efficiency is high, but the desaturation capacity is insufficient
Solution Approach 1:
The patent segments the desaturation process into multiple short-duration thrust sub-maneuvers distributed over time, rather than using a single long continuous thrust. Each sub-maneuver maintains high orbit control efficiency, while the cumulative effect of multiple sub-maneuvers achieves sufficient desaturation capacity.
Solution Approach 2:
The patent performs preliminary planning of thrust sub-maneuvers to optimize their timing and duration. By pre-calculating the optimal schedule of sub-maneuvers based on orbital parameters and desaturation requirements, the system ensures that each short thrust event is highly efficient while the overall sequence achieves the required desaturation capacity.
3Force
If articulated arms are stressed heavily during thrust maneuvers, then the thrust force is sufficient for desaturation, but the failure probability increases
Solution Approach 1:
The patent divides the total thrust requirement into multiple smaller thrust sub-maneuvers, reducing the peak stress on articulated arms during each individual maneuver. This segmentation maintains sufficient cumulative thrust force for desaturation while keeping stress levels during any single maneuver below critical thresholds, thereby reducing failure probability.
Solution Approach 2:
The patent incorporates non-zero duration intervals between thrust sub-maneuvers that allow the articulated arms and satellite structure to recover from stress. These intervals act as a cushioning mechanism, preventing cumulative fatigue and reducing the probability of structural failure during the mission lifetime.
4Duration of action of moving object
If propellant consumption is reduced, then the mission duration is extended, but the desaturation capacity may be insufficient
Solution Approach 1:
The patent schedules thrust sub-maneuvers periodically throughout the mission at optimal orbital positions, maximizing the efficiency of each propellant unit. By aligning thrust events with favorable orbital mechanics (near nodes), the system achieves sufficient desaturation capacity over extended mission durations with reduced propellant consumption compared to continuous or non-optimized thrusting.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach enhances the controllability and desaturation capacity of satellites by spreading thrust maneuvers over time, reducing propellant consumption, and minimizing stress on articulated arms, thus improving the efficiency and reliability of orbit control and attitude maintenance.
Implementation Method 1
the thrust forces generated by these thrusters during the various thrust maneuvers
Implementation Method 2
an angular momentum storage device. This device typically includes at least three reaction wheels with linearly independent axes of rotation. By controlling the rotational speed of these reaction wheels, it is possible to generate moments that oppose the disturbing moments.
Implementation Method 3
two articulated arms, each having at least three degrees of freedom, carrying respective thrusters and arranged on either side of a satellite body
Data Source
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AI summary
The present invention relates to a method (50) for orbit control of a satellite (10) orbiting Earth and desaturation of a device for storing kinematic momentum of the satellite, the satellite (10) comprising two articulated arms (20, 21) each supporting a propulsion unit (30, 31), the method (50) comprising: - determining (51) a manoeuvre plan comprising at least two thrust manoeuvres, wherein a first thrust manoeuvre is to be executed using the propulsion unit on one of the articulated arms and a second thrust manoeuvre is to be executed using the propulsion unit on the other articulated arm, - controlling (52) the articulated arms (20, 21) and the propulsion units (30, 31) depending on the manoeuvre plan, at least one of the first and second thrust manoeuvres being a thrust manoeuvre referred to as a discontinuous thrust manoeuvre which is made up of at least two separate consecutive thrust sub-manoeuvres.