Development And Decoupling Research Of Six-axis Force Sensor Based On Flexible Mechanism

The six-axis force sensor can simultaneously detect spatial six-axis force/torque information and has been widely used in aerospace,robotics,industrial production and medical fields.Taking the demand of high-performance six-axis force sensor in industrial production and robot field as the application background and considering the insufficiency of research on the measurement accuracy and decoupling performance of multi-axis force sensors in China,this paper develops a six-axis force sensor with high precision and high decoupling performance,which can be universally applied to the end of a robot wrist or arm.Firstly,the existing typical elastomer structure is analyzed,and a new type of elastomer with high sensitivity and high mechanical decoupling performance is proposed in combination with the flexible hinge mechanism.A reasonable strain gauge attachment scheme and output bridge are designed for this structure,and the sensor strain compliance matrix is derived.The sensor signal processing circuit design was also completed.Secondly,the most critical flexible mechanism in the elastomer is analyzed and optimized.The stiffness formula of the parallelogram flexible mechanism and the binocular flexible mechanism is established,and the influence of structural parameters on the stiffness performance of each flexible mechanism and the decoupling performance of the elastic body is analyzed.The response surface optimization design of the structural parameters of the elastomer is completed by using the response surface optimization module in ANSYS.Then,the performance of the sensor is simulated and analyzed.The stress,strain,modal and patch path simulations of the elastomer were carried out.The performance parameters of the elastomer were obtained,the rationality of the elastomer structure design was verified and the optimal patch position was determined.The six-axis force loading analysis of the sensor was also carried out,and the measurement and mechanical decoupling performance of the sensor were preliminarily verified.Finally,a six-axis force sensor prototype and a static calibration test system were built,and the sensor calibration test was completed.The calibration test data is decoupled by the least squares algorithm,the sensor calibration matrix is obtained,and the static performance indexes of the sensor are analyzed.The calibration decoupling study shows that the sensor meets the design specifications and has good measurement and decoupling performance.