Performance Analysis And Experimental Research Of Fault-tolerant Flexible Six-axis Force Sensor

In order to meet the critical task requirement of high precision and high reliable six-axis force sensor during the key task of areas such as aerospace, biomedical, deep-sea exploration etc, the idea of fault tolerance is introduced in the research of six-axis force sensor and the traditional ball joint is replaced by elastic hinges. Measurement model, performance analysis, optimal design, and calibration algorithms are conducted. The research of the paper will provide not only theoretical basis but also practical significance for the study on the six-axis force sensor in our country. The main contents of the paper are presented as follows:Firstly, based on the deformation superposition principle and the deformation compatibility condition, the whole stiffness matrix of elastic parallel six-axis force sensor is established. Thus, taking the whole stiffness matrix as the ligament, the force mapping relationship between the six-axis external force of sensor and the axial force of each limb is built. Further, the whole measurement model with signal fault, structural damage fault and fault-free model are set up respectively.Secondly, the performance of six-axis force sensor is introduced and the relationship between six-axis sensor parameter and the performance of six-axis force sensor is analyzed. Furthermore, with Workbench software, six-axis sensor is optimized. Linear error matrix is gained by the method of virtual calibration, which is based on calibration experiments. The linear error matrix proves the superiority of the structure.Thirdly, the six-axis sensor is designed. The 3D models of the setting, roof and platform about fault flexible six-axis sensor are designed by 3D Software Solid Works. Also, the spare parts are checked. Meanwhile designing seal, determining hybrid junction, identifying processing methods, and selecting material are described. On this basis, the whole 3D-model of six-axis sensor is gained. Ultimately, the prototype of six-axis sensor is machined.Finally, based on the previous study, the calibration system is established on the basis of the prototype of six-axis force sensor. Next, the static calibration experiments including signal fault and fault-free model are carried out, and the linear error matrix is gained.