Approach for decoupling the non-linear cross-talk in a six-dimensional force platform

Abstract

As the primary equipment for balance function assessment, the six-dimensional force platform (SDFP) should maintain its quality for long term use. Unfortunately the inevitable cross-talk will deteriorate its comprehensive performance. Obtaininga new sensitivity coefficient matrix through re-calibration is an effective way to guarantee the measurement accuracy. Generalized force loading can be used for in-situ calibration, but the calibration result depends on the selected set of loading point when the components are nonlinearly coupled.This study attempts to find an appropriate loading point set to obtain the optimal decoupling matrix for the SDFP when non-linearcoupling exists. The decoupling design of strain gauge layout and the non-linear coupling resulting from the bending deformation of the top plate are analyzed. Based on the analysis, a digital simulation is conducted to investigate the relationship between the decoupling performance and the selection of the loading points. The simulation results show that the center distance of the loading point is the primary factor affecting the decoupling performance. An in-situ calibration is conducted, and the orthogonal test rule is used to evaluate the performance of the system. A comparison of the results shows that the experimental results agree with those of the simulations.