An integral sliding mode terminal guidance law based on trajectory linearization control for space interception system

For the space interception problem of a missile, a novel terminal guidance law structure is mentioned by using trajectory linearization control method and the sliding mode technology. In this structure, the sliding mode control is added into the trajectory linearization control loop to avoid the performance of the system getting worse, because the solving of the pseudo-dynamic inverse controller fully depends on the analytic model of the system. Also an error tracking integral sliding mode terminal guidance law under this structure is deduced by Lyapunov function. The new nonlinear integral sliding surface realizes the consistency of the order between the equations of the sliding mode and the equations of the relative motion of a missile and a target. Simulation results indicate that the law not only has good performance of playing the steadiness error of the tracking down, but also has strong robustness and adaptability to a maneuvering target.