An Accurate Guidance Algorithm for Implementation Onboard Satellite Launch Vehicles

Abstract

An algorithm for guiding a launch vehicle carrying a small satellite to a sun synchronous LEO is presented. Before the launch, a nominal path and the corresponding nominal control law for the entire journey are computed. For each sampling instant during the guided ight, a linear equation approximately relating the di erences between the actual and nominal values is considered, and a Least- Squares formula using data from on-line state measurements is applied to compute the actual control. The coe cient matrices of the Least-Squares formula can be determined by o -line computations. The method enjoys simplicity of implementation by onboard computers, as well as robust accuracy against strong winds and uncertainties in thrust magnitude.