Control of a heavy-duty robotic excavator using time delay control with switching action with integral sliding surface

The control of a robotic excavator is difficult from the standpoint of the following problems: parameter variations in mechanical structures, various nonlinearities in hydraulic actuators and disturbance due to the contact with the ground. The more the size of robotic excavators increase, the more the length and mass of excavator´s links; the more the parameters of a robotic excavator vary. A time-delay control with switching action (TDCSA) using an integral sliding surface is proposed for the control of a heavy-duty robotic excavator. The proposed controller is applied to straight-line motions of a robotic excavator with a speed level at which skilful operators work. Experiments, which were designed for surfaces with various inclinations and over broad ranges of joint motions, show that the proposed controller exhibits good performance.