Influence of complex loads on multi-axis force sensor

Just as temperature affects the measurement accuracy of common sensors, complex loads significantly affect the measurement accuracy of multi-axis force sensors (MAFSs). In practical applications of MAFSs, complex loads are almost unavoidable; however, in conventional MAFS research, the influence of complex loads on measurement accuracy has often been overlooked. The fundamental manifestations of complex loads are first analyzed. The impact of complex loads on measurements is then intuitively illustrated using a one-axis force sensor, followed by an analysis of their influence on multi-axis force measurement. In essence, to acquire accurate multi-axis force data, it is imperative to precisely measure the three-axis stress at all points on an infinite (or closed) partition surface situated between the load region and the support region. Through a comparative analysis of RPB (or Stewart) structures, Maltese structures, and column-type structures, it is revealed that the RPB structure is more capable of constructing a favorable partition surface under complex load conditions and approximating the three-axis stress at all points on this surface. The RPB (Stewart) structure exhibits the advantage of a better resistance to multi-axis force measurement errors induced by complex loads. Nevertheless, due to issues such as the stability of compression members, the elastic beams of an RPB structure machined integrally from metal cannot be fabricated to an extremely slender dimension, leading to the problem of excessively low measurement sensitivity—a challenge that requires further research.