Topology optimization of stiffness constrained flexure-hinges for precision and range maximization

Abstract

Compliant hinges are one of the most widely used design elements in precision mechanism design. They enable higher precision rotation than multi-part hinges and facilitate the adaptation of macro-scale parallel mechanisms into micro-scale. Existing hinge designs offer either a large range at the expense of rotational accuracy or attempt to produce accuracy at the expense of range and stiffness. This paper investigates novel hinge structures which increases range, stiffness and precision and characterises the trade-off between the parameters. A computational topology optimization methodology is developed, and the effects of varying geometry and orientation investigated. Two novel hinges are proposed based on the results, which can be employed in heuristic mechanism designs and their enhanced performance demonstrated in a 3-PRR positioning mechanism.