Attitude Control of an Object Commonly Held by Multiple Robot Arms: A Lyapunov Approach

Multiple robot arms moving a commonly held object can be viewed as complex actuators whose purpose is to provide net forces and moments to the object. These forces and moments can be used to control the orientation, or attitude, of the object via the Euler equation describing attitude evolution in response to applied moments at the mass center. In contrast to the common approach that feedback linearizes the attitude dynamics to a double integrator form with respect to some 3-parameter local representation of orientation, we control the object using a globally nonsingular representation. Using an energy motivated Lyapunov function, globally stable control of attitude can be shown.