Design of a Three-Degree-of-Freedom Robotic Worktable With Prescribed Entire-Motion Characteristics

Abstract

This paper presents the analysis and design of a robotic worktable with a structure based on two platforms connected by three four-bar linkages. The worktable has three rotational degrees-of-freedom and is designed for special motion generators, such as gyroscope calibration instruments and flight simulators. Of primary interest is the influence of the characteristics of a single four-bar linkage on the entire-motion characteristics of the worktable. This involves an investigation of the effects of limit positions, rotatability of cranks, transmission-angle characteristics and the variation of design parameters of the four-bar linkages on the characteristics of the compound platform mechanism. Based on the analytical results, some physical insights are interpreted and general guidelines can be drawn on the design of this robotic worktable with prescribed motion characteristics.