A Modular Method for Manufacturing Error Analysis of Linkages and Manipulators

This paper presents a simple and effective methodology to address the issues on the manufacturing error analysis and the tolerance design of linkages and manipulators. It assesses the effect of the dimension tolerances to the performance error and inversely determines the required dimensional tolerances for a prescribed performance tolerance. The methodology is adaptable to assess the effect of an individual tolerance as well as any combination of tolerances. Instead of using complex closed loop equations to describe the linkage geometry, the methodology is focused on using linkage topology. Complex linkages are broken down to basic RR, PR, and RP units. The error and tolerance computation of complex linkages are reduced to repeatedly or alternatively using forward and inverse analysis of basic RR, PR, and RP units. The methodology is exemplified by simple and complex linkages. For design and manufacturing engineers, the proposed method is most useful for quick tolerance allocation and performance error assessment.