Unified approach for tolerance analysis, synthesis, and compensator selection.

Abstract

Tolerancing is a necessary task for practical designs. The system Jacobian is utilized here for the three sub-tasks of tolerancing. The first is tolerance analysis, which is evaluation of the perturbed system. Second is tolerance allocation, also known as tolerance budgeting and more widely known as error budgeting. The automatic allocation of tolerances is tolerance synthesis. The algorithm described accomplishes this by fitting an orthotope inside an ellipsoid. Third is compensator selection. Metrics are presented that correlate with the looseness of the allocated tolerances and hence with the effectiveness of the compensator set, thus enabling identification of the most optimum combination of compensators.