This paper presents a novel design of spatial compliant device with variable stiffness. The main concept of the device is to have two elastic trapezoid four-bar linkages arranging in orthogonal. The tool side of the device can switch between totally stiff and compliant by changing the arrangement of leaf springs and passive joints. Based on the principal axes decomposition of structural compliance matrix, the leaf springs are approximated by hyper-redundant linkages with rigid bodies connected by passive elastic joints. Hence, the nonlinear large deflection problems of the leaf springs can be solved efficiently in a mechanism way. In order to demonstrate the compliance of the proposed device, a numerical simulation is provided using the proposed approach. The result shows that the leaf springs in the compliant device are easy to be deformed and can not generate great force. Due to these characteristics, as an end-of-arm tool, the device has the ability to prevent hard collisions under the compliant status and finish precise positioning under the stiff status.

This content is only available via PDF.
You do not currently have access to this content.