Three-dimensional guidance method for air to ground missile with impact time constraint

This paper presents a three-dimensional guidance method based on sliding mode control (EMC) theory for attacking fixed target with time constraint. Assuming the configuration is axisymmetric, the missile movement is decomposed to the lateral plane and longitudinal plane. In the lateral plane: a guidance law is proposed based on the SMC theory, which controls the impact time and the miss-distance simultaneously. In the longitudinal plane, another SMC-based guidance law is implemented to converge the line-of-sight(LOS) rate rapidly. The convergence for both the lateral and longitudinal guidance law is proved by the Lyapunov theory. Simulation results indicate that the proposed three-dimensional guidance method has high control precision for both the impact time and miss-distance. The proposed guidance method is also demonstrated to have the ability to salvo attack.