A configuration design approach to the capacitive six-axis force/torque sensor utilizing the compliant parallel mechanism

• Published in: Measurement : journal of the International Measurement Confederation 2024-09, Vol.237, p.115205, Article 115205
• Main Authors: Pu, Minghui, Luo, Chengxuan, Wang, Yaozong, Yang, Yukun, Zhao, Rendong, Tian, Longxiang
• Format: Article
• Language: English
• Subjects: Capacitive sensor; Compliant parallel mechanism; Sensor configuration design; Six-axis force/torque sensor
• ISSN: 0263-2241
• DOI: 10.1016/j.measurement.2024.115205

•Compliant parallel mechanisms were applied for the design of capacitive six-axis F/T sensors.•A method of configuration design based on the compliant parallel mechanism is proposed.•Construct the POC sets for fulfilling the demands of six-axis capacitive F/T sensors, and exemplify its use with instances.•Simulation and prototype structure proved that the sensor indices meet the design requirements, with an accuracy of 0.66%FS in the experiment of six-axis F/T measurements. The configuration of capacitive six-axis force/torque (F/T) sensors significantly impacts their performance, and there are few studies on the configuration design method of the sensor. By analyzing the signal conversion model of the sensor, this paper proposes that the key to obtaining a reasonable configuration is that the configuration can easily achieve sensitivity isotropy. To achieve sensitivity isotropy, the six-degree-of-freedom sensitive part must be available. The compliant parallel mechanism is easier to meet this requirement. Based on the position and orientation characteristic (POC) set theory, the flexure building blocks applicable to compliant sensitive part configurations are analyzed, and we investigate a methodology for synthesizing compliant parallel sensor configurations that satisfy sensitivity isotropy. The results show that the precision is 0.66%FS in the physical prototype experiment, the fabricated sensor has good performance. The proposed configuration design methodology proposed can effectively guide the design of the capacitive six-axis F/T sensor.