Structure Simulation Of Piezoelectric Six Axis Force Sensor And Design Of Signal Processing Circuit

Force sensor is the most basic sensor in robot, and six axis force sensor that can measure three axis force and three axis moment is indispensable sensor in robot. Researchers have studied multi-axis force sensor for more than forty years and have gained many achievements. But at present and before, multi-axis sensors are designed by applying different elastomers and changing the position where resistance stain gauges stick on. Because of the influence of patch technics and elastomer processing precision, produced sensors almost have the shortcomings of complex structure, difficult manufacture, and large volume. Dynamic responses of these sensors are poor.To overcome these shortcomings, this paper studies piezoelectric sensor with direct output. The sensor has small volume, light mass, high reliability, high natural frequency, high sensitivity and signal-to-noise, little delay. It doesn't need decoupling operation. It has great research significance and wide foreground to study this sensor.At first, principle of piezoelectric sensor is introduced in the paper. After compared many kinds of piezoelectric material, quartz is selected as the sensitive element material of sensor. The size of quartz wafer is decided by the measurement range of force. Arrangement of quartz wafer is designed to meet the requirement for measuring six axis force. The whole six axis force sensor is made up of two pieces of four axis force sensors. The structure is symmetric, which can avoid the interference of torque.In this paper, based on three-dimensional finite element theory, the model of the six axis piezoelectric sensor is built in ANSYS. Static analysis, electromagnetic analysis, and modal analysis of the sensor are done through the ANSYS software. The result of simulation shows that the sensor has good linearity, high sensitivity, little interference among each dimension, high natural frequency.At last, the requirement of charge amplifier is analyzed in the paper, and PCB of charge amplifier has been produced after studying circuit module.