Chamber Pressure and Mixture Ratio Estimation and Control for a Staged Combustion Rocket Engine
(2024)Department of Automatic Control
- Abstract
- Ever since the end of the second world war, Europe has been lagging behind the United States in rocket development. In particular in the last 10 years, the technological gap and American competitive advantage have grown thanks to SpaceX’s development of reusable launch vehicles. A key enabler for the reusability of booster stages is precise rocket engine control. This thesis addresses the objectives of developing, analyzing, and testing a closed loop controller for combustion chamber pressure and propellant mixture ratio in the European aspiring launcher company Rocket Factory Augsburg’s Helix engine. Central difficulties which are addressed are nonlinearities in both the control valves and engine dynamics, and indirect realtime estimation... (More)
- Ever since the end of the second world war, Europe has been lagging behind the United States in rocket development. In particular in the last 10 years, the technological gap and American competitive advantage have grown thanks to SpaceX’s development of reusable launch vehicles. A key enabler for the reusability of booster stages is precise rocket engine control. This thesis addresses the objectives of developing, analyzing, and testing a closed loop controller for combustion chamber pressure and propellant mixture ratio in the European aspiring launcher company Rocket Factory Augsburg’s Helix engine. Central difficulties which are addressed are nonlinearities in both the control valves and engine dynamics, and indirect realtime estimation of mixture ratio.
A robust control framework was developed that demonstrated stable performance across different operating points. The chamber pressure controller showed consistent behavior regardless of the mixture ratio setpoint, effectively handling large reference steps with rapid settling times and minimal overshoot. The introduction of a transformed mixture ratio controller addressed nonlinearities in the engine, ensuring consistent mixture ratio control authority and maintaining robustness against disturbances across the operating domain. Potential challenges such as switching oscillations and noise amplification were identified, but the controllers overall performed as intended under the simulated conditions. An extended Kalman filter provided reliable real-time estimation of the mixture ratio. The design methodology is pragmatic throughout, in line with the goal of developing a practical framework for implementation in future hot-fire tests. (Less)
Please use this url to cite or link to this publication:
http://lup.lub.lu.se/student-papers/record/9183792
- author
- Åberg Garcia, Elias
- supervisor
- organization
- year
- 2024
- type
- H3 - Professional qualifications (4 Years - )
- subject
- report number
- TFRT-6263
- other publication id
- 0280-5316
- language
- English
- id
- 9183792
- date added to LUP
- 2025-02-04 15:00:26
- date last changed
- 2025-02-04 15:00:26
@misc{9183792,
abstract = {{Ever since the end of the second world war, Europe has been lagging behind the United States in rocket development. In particular in the last 10 years, the technological gap and American competitive advantage have grown thanks to SpaceX’s development of reusable launch vehicles. A key enabler for the reusability of booster stages is precise rocket engine control. This thesis addresses the objectives of developing, analyzing, and testing a closed loop controller for combustion chamber pressure and propellant mixture ratio in the European aspiring launcher company Rocket Factory Augsburg’s Helix engine. Central difficulties which are addressed are nonlinearities in both the control valves and engine dynamics, and indirect realtime estimation of mixture ratio.
A robust control framework was developed that demonstrated stable performance across different operating points. The chamber pressure controller showed consistent behavior regardless of the mixture ratio setpoint, effectively handling large reference steps with rapid settling times and minimal overshoot. The introduction of a transformed mixture ratio controller addressed nonlinearities in the engine, ensuring consistent mixture ratio control authority and maintaining robustness against disturbances across the operating domain. Potential challenges such as switching oscillations and noise amplification were identified, but the controllers overall performed as intended under the simulated conditions. An extended Kalman filter provided reliable real-time estimation of the mixture ratio. The design methodology is pragmatic throughout, in line with the goal of developing a practical framework for implementation in future hot-fire tests.}},
author = {{Åberg Garcia, Elias}},
language = {{eng}},
note = {{Student Paper}},
title = {{Chamber Pressure and Mixture Ratio Estimation and Control for a Staged Combustion Rocket Engine}},
year = {{2024}},
}