Chattering‐free sliding mode control with unidirectional auxiliary surfaces for miniature helicopters

This article proposes a chattering‐free sliding mode control scheme with unidirectional auxiliary surfaces (UAS‐SMC) for small miniature autonomous helicopters (Trex 250).

The proposed UAS‐SMC scheme consists of a nested sequence of rotor dynamics, angular rate, Euler angle, velocity and position loops.

It is demonstrated that the UAS‐SMC strategy can eliminate the chattering phenomenon exhibiting in the convenient SMC method and achieve a better approaching speed.

The proposed control strategy is implemented on the helicopter and flight tests clearly demonstrate that a much better performance could be achieved, compared with convenient SMC schemes.