Abstract:

According to the control allocation problem of near space vehicles, a control allocation method based on HOFSA(Hybrid Optimization Fish Swarm Algorithm) is studied. HOFSA fused by differential evolution and genetic evolution is applied to dynamic constrained control allocation problem by fully considering the dynamic constraints. The initial fishes are generated randomly according to the constraints of the control surfaces, and the fish swarm algorithm is used to achieve a global search. The fish swarm algorithm can converge rapidly in the initial stage, but the convergence speed will be slow down or keep stagnant when search local region. Due to its advantage in local optimization, the differential evolution algorithm is further employed to optimize for improving convergence speed and accuracy. And under the circumstance that differential evolution has not been able to get more optimal solution, the genetic algorithm is used to avoid the local optimal solution and to improve the efficiency of the whole allocation algorithm. The developed control allocation method based on HOFSA is applied to a near space vehicle and the simulation results show that it can effectively assign control instructions to each control surface and the tacking control performance is good.

Key words: near space vehicles, control allocation, dynamic constrained, fish swarm algorithm, differential evolution, genetic evolution, hybrid optimization