Ascent adaptive guidance for power system fault of heavy lift launch vehicle
- Paper number
IAC-17,D2,5,6,x40884
- Year
2017
- Abstract
With the demand for future large payload launch missions, especially for manned lunar landing, as well as further manned deep space exploration missions, heavy lift launch vehicles are of considerable interest all over the world. The increase of the carrying capacity means a more complex power system, which leads to a higher probability of power system fault. What’s more, power system faults have significantly bad influence on the launch missions. To deal with the power system fault in the ascent phase of the heavy lift launch vehicle, this paper presents a guidance method which applies different methods based on the occurring moment of the power system fault. By autonomously and periodically reconstructing the remaining trajectory based on the current conditions, the completion of the transport task can be guaranteed. To solve the problems of exo-atmospheric power system fault, iterative guidance method with orbit injection point adaptive updated in each guidance cycle is adopted. The argument of latitude of the orbit injection point is adjusted online to acquire higher accuracy of other five orbital elements. In order to handle the endo-atmospheric fault of power system in the dense atmosphere, a rapid trajectory optimization closed-loop guidance algorithm based on indirect method is applied to minimize fuel consumption. Considering the real-time requirement of online trajectory reconstruction, finite element method is used to transform the optimal atmospheric ascent problem into root-finding problem of algebraic equations through discretizing the necessary conditions. The derived root-finding problem is finally solved by Newton Iteration. For a two stage heavy lift launch vehicle, the proposed guidance algorithm is tested under a series of cases with variations on the moment and degree of the engine failures. The results showed that the reliability of heavy lift launch vehicle against power system faults is effectively enhanced. The impact of failure moment and degree of failure on fuel consumption is analyzed, and the permissible bound of the power system fault degree is investigated. The outcome of this study will be beneficial to design of heavy lift launch vehicle for future missions.
- Abstract document
- Manuscript document
IAC-17,D2,5,6,x40884.pdf (🔒 authorized access only).
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