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Three-Parameter Motion

Common 3DOF motions include pure translation (3T) and pure orientation or rotation (3R). Less familiar motions involving both translation and rotation, i.e., (1T2R) and (2T1R), are difficult to classify, analyze and design. We call (1T2R) tasks ``mining'' since these involve following a space curve or ``tunnel'' while the end effector is capable of 2DOF orientation or ``excavation''. 2T1R tasks are called ``sculpting'' since freedom of movement on some surface as well as a 1DOF rotation is implied. A special case, planar motion, is the only familiar member of this class. 3DOF manipulation is useful in manufacturing where such reduced mobility is sufficient and a stiff, simple and accurate mechanism is desired. The design of parallel manipulators for this pupose is particularly interesting.
P. Zsombor-Murray, M. Husty, J. Hayes, P. Gervasi

Thierry Baron
Mon Nov 13 10:43:02 EST 1995