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ACTA AERONAUTICAET ASTRONAUTICA SINICA ›› 2017, Vol. 38 ›› Issue (1): 320168-320168.doi: 10.7527/S1000-6893.2016.0183

• Electronics and Electrical Engineering and Control • Previous Articles     Next Articles

Minimum-fuel spacecraft transfer trajectories solved by direct/indirect hybrid continuation method

MENG Yazhe1,2   

  1. 1. Key Laboratory of Space Utilization, Technology and Engineering Center for Space Utilization, Chinese Academy of Sciences, Beijing 100094, China;
    2. University of Chinese Academy of Sciences, Beijing 100049, China
  • Received:2016-02-26 Revised:2016-06-06 Online:2017-01-15 Published:2016-06-27
  • Supported by:

    National Natural Science Foundation of China (11372311); Project of the Space Science Academy, Chinese Academy of Sciences

Abstract:

A continuation method is proposed for fixed-time minimum-fuel spacecraft trajectory optimization given initial and terminal states. The continuation method, based on the direct/indirect hybrid method, starts with a transfer solution with two impulses, followed by calculating firstly the full-propelling transfers and then the fuel-optimal transfers (including continuous and impulsive thrust ones) with continuation on thrust amplitude. All fuel-optimal solutions solved satisfy the necessary optimality conditions derived from the primer vector theory. A thrust switching presetting method based on the variational trends of switching function curves and a simple step-length adaptation rule based on the previous calculation results are proposed to enable the continuation automatic. The necessary optimality conditions for the impulsive trajectory expressed by the modified equinoctial orbit elements are given and verified, and the state transition matrix of costates of modified equinoctial orbit elements for coast arcs is derived. Three numerical examples are given to represent various transfer scenarios. Continuation can be regarded as improvement and extension of the direct/indirect hybrid trajectory optimization method. Continuation procedure and results can help to improve our understanding of the relations of the optimal control trajectories to system parameters.

Key words: modified equinoctial orbit elements, fuel-optimal trajectory, direct/indirect hybrid method, continuation, thrust switching sequence presetting, step-length adaptation

CLC Number: