A general approach for geometrical calibration of machinery and its application to a parallel kinematic manipulator

Geometric machine calibration is a widespread technique used to increase machine accuracy thanks to a set of measures and adequate algorithms that permit identification and, generally, compensation of all relevant repetitive errors in the structure. Traditional strategies are challenged by the vast kinematic variety of Parallel Kinematic Machines, today under development for industrial applications. An original approach is proposed and implemented to calibrate machine with generic architectures and varying geometrical errors. The analysis time is very short because the kinematic model is numerically obtained from a customized multi-body package and then automatically elaborated with numerical routines. As an example, the methodology is applied, in simulation, to a PKM with 3 translational degrees of freedom.