Spatio-geometric impedance control of Gough-Stewart platforms

This paper looks at the control of mechanical impedance of the so-called Go ugh-Stewart class of parallel platforms. Two methods of compliance control are presented. One is based on global potential energy functions that have previously been applied to controlling serial manipulators and electrodynam ically levitated platforms. The second uses the exponential map to associat e finite displacements of the platform from equilibrium with twist displace ments. Compliant wrenches are then proportional to the twist displacements. Control of spatial damping is addressed as well, justifying the classifica tion as impedance control, Control algorithms and simulation results are gi ven.