A Synthesis of Pantograph Mechanisms for Robots Based on Working Spaces and Characteristic Charts of Statics

Kinematic and static characteristics of pantograph mechanisms have been analyzed and represented in the form of charts which enable rational syntheses of the mechanisms as robot arms and legs with two degrees of freedom. Namely, two factors concerning the maximum joint forces and bending moments of links when the mechanisms take arbitrary positions and attitudes have been proposed and the positions of output points where the each factor takes various values are plotted in dimensionless reachable regions of the output points. Making use of the characteristic charts, dimensions of working spaces, loading conditions, strokes and arrangement positions of actuators etc. can be directly considered in the determination of kinematic parameters of the robot mechanisms with the optimum joint forces and bending moments of links.