Smooth Second Order Sliding Mode Guidance Law with Disturbance Observer against High Maneuvering Targets with Impact Angle Constraint

A smooth second order sliding mode controller that guarantees a desired impact angle with a proper speed and impact time. This method is capable of intercepting high maneuvering targets. The desired impact angle is defined in terms of a time-varying desired line of sight angle for a maneuvering target. To solve the problem of the unknown target acceleration when intercepting maneuvering targets, an extended state observer (ESO) based guidance law is presented, and the target maneuver is compensated using the smooth sliding mode controller. Numerical simulations demonstrate the effectiveness of the proposed guidance law and show that this method has a better performance against high maneuvering targets in comparison with previous methods.