Research of multi-rudder trimming technology for sub-orbital reusable launch vehicle based on optimal algorithm

Aerodynamic characteristics of sub-orbital reusable launch Vehicle (SRLV) is complicated. Generally algorithm of trimming is not applicable for SRLV. This paper studies on the optimal method using the steepest descent algorithm. Construct the optimal object function by squaring the moment coefficient of the three channels. Calculate the searching method through gradient direction. Obtain the trimming result through iteration algorithm. By comparing different trimming algorithm, it proved validity and advantage of the trimming algorithm based on the steepest descent algorithm.