On Modelling and Control of Four Cable Suspended Robots

In this note, we investigate the problem of modeling and controlling four-cable-suspended robots during the motion of a platform carrying a given payload. Indeed, one of the challenges faced involves payload oscillations during motion. Initially, we elaborate on the dynamic model of the motion of the center of gravity of the platform-load assembly, which showcases this phenomenon. Subsequently, we establish an LQR type control law to achieve trajectory tracking where oscillations are reduced or eliminated. High performances of the proposed approach are shown through numerical simulations, including in the case of uncertain models.