Design and calibration of a novel piezoelectric six-axis force/torque sensor

This paper describes the design and the calibration of a novel parallel piezoelectric six-axis force/torque sensor. A new force-sensing cell distribution model has been investigated: eight piezoelectric quartz crystal cells are uniformly distributed along one circle line to get the spatial force information. The mathematic model of the method has been deeply researched, established and calculated. In this paper, the negative step response method is calibrated to evaluate the dynamic response of the sensor: the calibration force acting on the sensor is suddenly removed by breaking a brittle material. Based on the experimental data of the calibration, the natural frequency, dynamic range as well as coupling interference of the sensor are analyzed and discussed. The new force-sensing cell distribution model may overcome some disadvantages of present six-axis force sensor, such as improving the overall stiffness of the sensing system, and meanwhile, reducing the coupled interference.