Satellite Reaction Wheel Momentum Dump Offset
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Solution Overview
Problem
Current momentum management techniques for geostationary orbit satellites require frequent thruster-based momentum dumps, which disrupt precise attitude control and increase satellite weight and cost due to the need for larger reaction wheels.
Innovation Solution
An offset-applied momentum dump method for satellite reaction wheels, where an appropriate offset is applied to the momentum dump cycle to delay the momentum dump time, allowing for extended mission performance without momentum dumping and reducing the required momentum capacity of the reaction wheels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the momentum dump cycle is shortened to prevent reaction wheel speed limits, then the reaction wheel reliability is improved, but the satellite mission efficiency deteriorates due to more frequent interruptions
Solution Approach 1:
The patent applies preliminary action by performing a partial momentum dump in advance to create a momentum offset before the reaction wheel reaches critical speed limits. This proactive approach removes a portion of accumulated momentum ahead of time, extending the interval before the next full momentum dump is required, thereby reducing the frequency of thruster activations and minimizing interruptions to satellite missions.
Solution Approach 2:
The patent implements dynamics by transitioning from a static, fixed momentum dump schedule to a dynamic, flexible scheduling system. The momentum dump timing and frequency are adjusted based on real-time reaction wheel momentum accumulation rates and satellite mission requirements, allowing optimization of both reaction wheel reliability and satellite productivity under varying operational conditions.
2Duration of action of moving object
If larger reaction wheels are used to increase momentum capacity, then the time between momentum dumps is extended, but the satellite weight and cost increase
Solution Approach 1:
The patent applies partial action by performing a partial momentum dump that removes only a portion of the accumulated momentum rather than completely emptying the reaction wheel. This creates a momentum offset that allows the reaction wheel to operate within an extended safe range, effectively increasing the duration between full momentum dumps without requiring larger reaction wheel capacity, thus avoiding increased satellite weight.
Solution Approach 2:
The patent implements parameter changes by modifying the momentum dump operation parameters, specifically introducing a momentum offset parameter that defines the target momentum level after dumping. This parameter adjustment allows flexible control of the reaction wheel momentum range, extending operational duration between dumps without physical changes to the reaction wheel size or satellite weight.
3Reliability
If more reaction wheels are used to ensure three-dimensional attitude control, then the attitude control reliability is improved, but the satellite weight and cost increase
Solution Approach 1:
The patent applies partial action by implementing a partial momentum dump strategy that removes only sufficient momentum to maintain safe operating margins with existing reaction wheels. This approach ensures attitude control reliability through optimized momentum management rather than through redundancy of additional reaction wheels, thereby avoiding increased satellite weight and cost.
4Reliability
If frequent momentum dumps are performed using thrusters, then the reaction wheel momentum accumulation is controlled, but the precise attitude control is disrupted and power consumption increases
Solution Approach 1:
The patent applies preliminary action by performing a partial momentum dump in advance to create a momentum offset that delays the requirement for subsequent full momentum dumps. This reduces the frequency of thruster activations, thereby lowering overall power consumption while maintaining effective momentum accumulation control within safe operational limits.
Solution Approach 2:
The patent implements periodic action by establishing an optimized momentum dump schedule that combines partial preliminary dumps with full periodic dumps. This structured periodic approach ensures reliable momentum control while minimizing the total number of thruster activations and associated power consumption compared to frequent full momentum dumps.
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 method enables safer and more efficient satellite operation by delaying momentum dumps, reducing the load on reaction wheels, and alleviating the need for increased momentum capacity, thereby lowering satellite weight, cost, and power consumption while extending the life of the reaction wheels.
Implementation Method 1
angular momentum, that is, momentum (on a Xs/Zs plane of the satellite in FIG. 1), is accumulated at a constant rate in a direction perpendicular (Xes axis in FIG. 1) to the earth/sun direction
Implementation Method 2
a torque generated as a solar radiation pressure continuously acts on a solar panel of the satellite
Implementation Method 3
The reaction wheel is a device that controls attitude by turning a wheel with a motor
Data Source
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AI summary
The present disclosure relates to an offset-applied momentum dump method for a satellite reaction wheel. The purpose of the present disclosure is to provide an offset-applied momentum dump method for a satellite reaction wheel, in which an appropriate offset is applied to an originally designed momentum dump to enable safer and more efficient operation of a satellite.