New interceptor guidance law using LOS rate only

A new guidance strategy using only the line-of-sight (LOS) rate measurement is proposed for the missiles with passive seekers. The initial relative range, initial closing velocity and their error boundaries are utilized to obtain their estimations according to the missile-target kinematics. A guidance law based on sliding mode control (SMC) theory is firstly presented, in which the boundary of target maneuvering ability is needed and the chattering phenomenon inevitably exists. In order to overcome the disadvantages above, an expression with a time-varying parameter is introduced to the new guidance law and the stability analysis is included. One of the main features of the proposed guidance strategy is that it reduces the influence of the relative range and the closing velocity on the interception and enhances the effect of LOS rate. The performance of the new guidance law is studied via a computer simulation. The effectiveness of the new guidance law is illustrated through intercepting two kinds of maneuvering target successfully.