Performance of pseudo-elastic flexure hinges in parallel robots for micro-assembly tasks

This paper presents the application of pseudo-elastic flexure hinges in parallel robots for micro-assembly tasks. The material used for the flexure hinges is a shape memory alloy permitting angular deflections of +/- 30degrees. Based on this flexibility sufficiently large workspaces of the robots can be achieved. Simulations show that kinematic deviations caused by flexure hinges are reducing the absolute positioning accuracy of compliant mechanisms. Likewise the simulations indicate that the kinematic behaviour of compliant mechanisms differs only slightly from their counterparts with conventional joints, which are analytically described by means of a rigid-body model. Experimental measurements with two compliant robots show the possibility to increase repeatability and resolution by using flexure hinges.