Nonlinear path following for unmanned helicopter

This paper presents a new nonlinear path following control method for unmanned helicopter. The algorithm of the line-of-sight guidance law previously extended by Park is improved to address the control problems of the unmanned helicopter creatively. Aiming at the issues that the traditional PID control methods cannot obtain ideal nonlinear control effects and performance of anti-disturbance, a new nonlinear control method is designed. First of all, on the basis of the line-of-sight guidance law, the new control law adopting dual-loop structure, including an outer guidance loop and an inner loop for attitude control, is implemented in unmanned helicopter. To provide a number of key parameters for path following, the calculation methods are proposed. Numerical simulations are performed to verify the effectiveness and superiority of the proposed guidance law.