Second Order Task Specifications in the Geometric Design of Spatial Mechanical Linkages

This paper builds on the authors’ planar kinematic synthesis for contact task specifications and formulates the kinematic specification of the synthesis problem for spatial open-serial chains in which a desired acceleration of the endeffector is specified. Applications of this research focus on the design of spatial linkages to maintain specified local motion. A recently developed failure recovery strategy of a general six-degreeof-freedom TRS robotic arm is discussed and some experimental set up and tests of the proposed failure recovery are presented. The authors also briefly show another possible application of the geometric design of linkages using acceleration task specifications. It combines the second-order effects of the task with the particular kinematics of the chain to yield free parameters that allow for more than one system to accomplish one and the same task.