Limitations imposed by single DOF actuators on discrete actuator arrays

The Modular Distributed Manipulator System (MDMS) is an array of actuators that is capable of manipulating objects in the plane [1]. Each actuator in the array consists of two closely spaced, orthogonally mounted motorized roller wheels whose combined action approximates a programmable vector force. This paper first derives the equations of motion for transported objects by explicitly considering the traction force from each wheel of the actuator. This contrasts with prior work, which assumed an ideal single point of contact for each actuator [2]. A translational velocity field is developed based on these dynamics and is compared with the discrete elliptic field derived in [2]. Errors in translational dynamics under an elliptic velocity field are discussed. This paper then presents simulation results that demonstrate some of the difficulties encountered when using non-ideal actuators.