M. S. Thesis Abstract

Development of an In-Parallel Actuated End Effector

Dharmen Shah

December 1986

Traditionally, robots are anthropomorphic open chain mechanisms. These mechanisms are series actuated. An alternate solution is to use closed kinematic chain mechanisms in which the joints are actuated in parallel rather than in series.

The kinematic and dynamic analysis of a three degrees of freedom closed chain mechanism have been investigated. In the kinematic analysis, the forward and inverse kinematic equations are developed. The constraints on the motion imposed by the joints are discussed. The results of kinematic simulation to predict the range of motion are presented.

In the dynamic analysis, the Lagragian approach is chosen to formulate the equations of motion. The system is treated as non-holonomic and a total of six generalized coordinates are selected. This gives rise to three Lagrange multipliers to solve the equations of motion.

Its coordination with a spherical motor and also with an X-Y table are discussed. As a numerical example of simulation, a helical motion by the end effector is studied and its kinematic and dynamic simulation results are presented.

Finally, its advantages, limitations and areas of future development are mentioned.