FOPID Control with Parameter Optimization for Hydrostatically-Actuated Autonomous Excavators

This article presents our recent work towards development of a controller for the new class of modernized excavators. There is an increasing demand to develop autonomous earth-moving machines that are: more efficient than the conventional ones and capable of operating with minimal supervision by operators. A fractional-order pro-portional-integral-derivative (FOPID) control is applied to a newly designed electro-hydrostatic actuator (EHA) circuit for these machines. We further employ the Oustaloup recursive method for which the parameters of the controller are chosen based on the modified Nelder-Mead optimization algorithm. Our experimental results indicate that the proposed controller is capable of controlling the speed of the link with a negligible error. This work paves the road for development of autonomous, energy efficient, off-road mobile machines.