Manipulator effecting 2D microdisplacements

Abstract

The study summarises the structural design of a manipulator mechanism effecting the micro-scale displacements in two directions on a plane. The mechanism, designed and engineered as a monolith cut out from a single steel sheet, incorporates the bar linkages connected via narrowed necks with a round undercut, operating as revolute joints with the constrained motion range. Bar linkages are connected to an immobile edge of the rigidly fixed link via necks. The end effector can be set in motion manually, through varying the input link’s position on the plane. Two displacements of the input link, orthogonal to each other, are separately transmitted and reduced by mutually symmetrical bar linkage mechanisms. Displacement reduction is effected through the use of classical bar linkage mechanisms and a regulated transmission ratio. The resultant of mutually orthogonal displacements, reduced to the micrometer range executes the complex displacement of the square-based effector link. In the extreme vertex of the square there is the tip of the end effector which performs the micro-tasks. The study explores the kinematic relationships of link positions, yielding the recommendations for geometric dimensions of the bar linkage and enabling the transmission ratios in the executed motions to be precisely determined. The analysis of displacements and stresses acting in the necks is supported by the FEM software. Simulation data indicate the occurrence of plastic strains in neck localised in the proximity of the driving link. The mechanism was tested under laboratory conditions to confirm its correctness of assumptions and functionality features.