MODELING OF CONTROL FORCES FOR KINEMATICAL CONSTRAINTS IN MULTIBODY SYSTEMS DYNAMICS - A NEW APPROACH

Conventionally kinematical constrains in multibody systems are treated similar to geometrical constraints and are modeled by constraint reaction forces which are perpendicular to constraint surfaces. However, in reality, one may want to achieve the desired kinematical conditions by control forces having different directions in relation to the constraint surfaces. In this paper the conventional equations of motion for multibody systems, subject to kinematical constraints, are generalized by introducing general direction control forces. Conditions for the selection of the control force directions are also discussed. A redundant robotic system subject to prescribed end-effector motion is analyzed to illustrate the methods proposed.