Actuator Error
Author: Tianjiang Says
Website: https://cislunarspace.cn
Definition
Actuator error refers to the deviation between the actual thrust and the desired thrust when a spacecraft's propulsion system executes a control command. Actuator error is an unavoidable error source in orbit control, constituting one of the main uncertainties in orbit keeping control alongside navigation error.
Error Sources
| Error Type | Description |
|---|---|
| Thrust magnitude error | Deviation of actual thrust magnitude from the nominal value |
| Thrust direction error | Deviation of actual thrust direction from the desired direction |
| Thrust duration error | Deviation in engine ignition time and duration |
| Attitude coupling error | Thrust direction error caused by attitude control deviations |
Impact on Orbit Keeping
In DRO orbit keeping control, the effects of actuator error include:
- Velocity increment deviation: The actual applied differs from the desired value
- Coupling with navigation errors: The combined effect of actuator and navigation errors accumulates and amplifies
- Fuel consumption uncertainty: Actual fuel consumption differs from theoretical predictions
Related Concepts
References
- Chen Yuju. DRO Orbit Design and Control Research for Cislunar Space Situation Awareness[D]. 2024.