Abstract:

Aiming at the terminal guidance problem of guided projectile attacking ground target, a finite time sliding mode guidance law with constraints of impact angle and field-of-view angle is proposed. Firstly, the field-of-view angle constraint is added to the traditional terminal sliding surface, and the tangent barrier Lyapunov function is constructed to solve the constraint problem of the reaching phase of the sliding mode surface to ensure the finite time convergence for the guidance system under the condition of limited state. Secondly, the extended state observer (ESO) is used to estimate and compensate the disturbance caused by target maneuver, which effectively weakens the chattering phenomenon of guidance command. Then, the guidance law is analyzed and proved based on the stability theory. Finally, the effectiveness and robustness of the guidance law are verified by comparative simulation. The simulation results show that the guidance law can not only meet the constraints of impact angle and field-of-view angle, but also has the advantages of continuous command, short guidance time and high hit accuracy.

Key words: guidance law, angle constraint, terminal sliding mode control, barrier Lyapunov function, extended state observer (ESO)