Design of non-smooth guidance law with terminal line-of-sight constraint

For the guidance law with terminal line-of-sight (LOS)constraint in the interception against maneuvering target, non-smooth control approach was applied to design a continuous nonlinear guidance law. The guidance law guarantees the finite-time stability of LOS rate and the error of LOS angle with respect to its reference value. In the implementation of the guidance law, high-gain observer was used to estimate necessary guidance information. The state of observer was augmented to estimate the maneuvering acceleration of target. Numerical simulation was carried out. The results show that the non-smooth guidance law guarantees the stability of guidance system in finite time.