Spacecraft Fault Diagnosis Based on Improved A* Algorithm
Sheng Gao, Wei Zhang, Xu He, Yongming Zou, Wei Li · 2020
The development of fault diagnosis systems has received more and more attention from countries and regions, especially the fault diagnosis of spacecraft. In this paper, the fault diagnosis search problem is also compared to a relationship of finding a path. An inference search tree is established. By finding the fault point in the inference search tree, a constraint condition-cost function is added to expand the branch in the search tree. At the time, the cost function is used to judge and filter, so that it can reduce many unnecessary searches and search for the optimal solution with the least amount of time. In this paper, the traditional A* algorithm is improved. By adding constraints, that is, the cost function, based on the traditional A* algorithm and adding additional structure, especially considering the state in the variable assignment, and the constraint set is Decomposed into a set of constraints. By using mutual priority independence (MPI) to solve the optimal constraint satisfiability problem (OCSP), the optimal constraint satisfiability problem is constructed as a state space search problem, and each search state corresponds to the partial allocation of decision variables. Combine the cost of each allocation to calculate the invalidity, and achieve the purpose of fast fault search.