Study on Dynamic Characteristics of Six-Axis Wrist Force/Torque Sensor

Abstract

It is necessary to detect complex force and torque components of three-dimensional space in research and manufacture, therefore the multi-axis force and torque sensors are developed rapidly. For examples, the six-axis wrist force/torque sensor for robot assembling and automated polishing [1,2], the multi-component strain gauge balance for wind tunnel testing to determine loads on models [3], the multi-axis measuring force platform for biomedical research and development, and so on [4]. Now the dynamic performances of multi-axis force and torque sensors are demanded strictly because these sensors are used in robot operation, dynamic testing and process control. However, the dynamic performances of multi-axis force sensor are not satisfied with the needs of applications. First, due to the small damped ratio and low natural frequency of sensor, the dynamic response of sensor is slow, and the time to reach steady state is long. Secondly, there are dynamic couples among various directions of multi-axis force and torque sensor because the elastic body of sensor is an integer structure and the interaction of various directions can not be avoided completely. Thirdly, the multi-axis force sensor possesses the nonlinear dynamic characteristics under some conditions, which will affect the measurement accuracy. It is necessary to study and solve these key problems. Therefore, this chapter focuses on the six-axis wrist force sensor, and introduces the dynamic calibration experiments, dynamic modeling, dynamic compensation and dynamic decoupling. Finally, it presents some researches on the nonlinear dynamic characteristics of the six-axis wrist force sensor.