Improving the coupling errors of a Maltese cross-beams type six-axis force/moment sensor using numerical shape-optimization technique. (October 2018)

• Record Type: Journal Article
• Authors: Akbari, Hossein; Kazerooni, Afshin
• Is Part Of: Measurement. Volume 126(2018)
• Page Start: 342
• Page End: 355
• Publication Date: 2018-10
• Subjects: Numerical shape-optimization -- Finite element method -- Six-axis force/moment sensor -- F/M Sensor's coupling errors; Weights and measures -- Periodicals; Measurement -- Periodicals; Measurement; Weights and measures; Periodicals; 530.8
• DOI: 10.1016/j.measurement.2018.05.074
• Languages: English
• ISSNs: 0263-2241

Abstract

Highlights: Expounds concept of coupling errors of multi-axis force/moment sensors in detail. Explains why acceptable range of coupling error (1–3%) is not enough in rated load. Special focus on reasons behind the coupling phenomenon by finite element analysis. Illustrates the effect of involving all coupling errors on optimization problem. More measurement accuracy resulting structural modification and shape-optimization. Abstract: In this paper, the optimal design of the elastic structure of a mechanically decoupled six-axis force/moment sensor is considered, with the aim of reducing the coupling errors of the sensors designed based on Maltese cross-beams geometry to negligible values. The reasons behind the creation of the coupling phenomenon in the Maltese cross-geometry are first analyzed using finite element and the design changes are made based on observations. After that, the numerical shape-optimization process is implemented by selecting eight design variables and a new objective function including all important coupling errors. The results show that the largest coupling error of the proposed optimal design decreases to less than 0.019% in rated load while the safe operation is secured and good isotropy of sensitivity is observed (condition number of normalized compliance matrix is 1.41), which are expected to provide design guideline for self-decoupled multi-axis force/moment sensors with measurement accuracy better than 0.1%.