A New Torque Sensor on System Identification

• Main Authors: E.Su Lee, 李易書
• Other Authors: S.B. Jiang
• Format: Others
• Language: zh-TW
• Published: 1995
• Online Access: http://ndltd.ncl.edu.tw/handle/96784206109729071231

碩士 === 國立中央大學 === 機械工程研究所 === 83 === A torque sensor based on system identification is proposed in this thesis. The proposed torque sensor is constructed of two encoders and signal processing firmware.The encoders are magnetic type with sinusoid outputs and connected with a torsion bar. With this arrangement, the phase difference between these two encoders is proportional to the torque loaded on the torsion bar.To estimate the phase difference,the signal processing firmware acquires data,use identification algorithm to construct a 2'nd order FIR model, and then use the FIR model parameters to estimate the phase difference. To varify the proposed approach, both simulation and experimental results are provided. The simulation data are constructed of sinusoid waves added with some distortion terms.To simulate the nonlinearity, the distortion terms are triangular waves. To simulate the disturbance of noise, the distortion term is pseudo random noise. To simulate the unbalance of analogy circuite cause by temperature or ageing,constant shift is added to sinusoid waves. The non-perfect data are feed to both proposed approach and Kunio's method for evaluation and comparison. The experiment is performed on the testing mechanism designed in this thesis.The testing mechanism is constructed of constant speed servo motor, torque sensor clamp,reduction gear,and off-central loading. With constant speed rotation,the loading will be a sinusoid torque over sensor. The frequency of sinusoid loading can be adjusted through setting the rotation speed of servo motor. Treat the sinusoid torgue as input and the phase difference as output, then the transfer function of our sensor is easy to get.