Three-dimensional Robust Guidance Law with Impact Angle Constraint and Compensation of Channels Coupling

To deal with the coupling between channels in the guidance system for a bank-to-turn missile and the uncertainty of the measurement signal, a novel three-dimensional guidance law with impact angle constraint and compensation of channels coupling is proposed based on the robust control theory. Firstly, lineof- sight rate is described through vector description, and the representation of channels coupling is presented. Secondly, a guidance law which fulfills L2 performance index is designed by taking the measurement uncertainties as exogenous disturbance under the nonlinear robust control theory. A novel form of guidance law is obtained after joining the coupling term. Simulation results show that the proposed robust guidance law can guarantee the integrity of guidance information, also satisfy the requirements of guidance precision and impact angle constraint, and more robust than the traditional guidance law.