一种智能助力车力矩感测系统设计与实现

Design and realization of torque sensing system for an intelligent e-bike

针对目前助力车力矩感测系统开发难度大、成本高等问题,设计一种基于敏感元件的新型助力车力矩感测系统。以敏感元件电阻应变片为核心的力矩传感器、以差分放大和A/D转换电路为主的信号处理单元、以低功耗无线射频芯片CC1110为核心的数据处理及无线收发单元等部件置于助力车中轴,实现力矩信号的采集;软件上运用加权递推平均滤波增强数据采集的稳定性,采用零点补偿和最小二乘法拟合矫正来确保数据的采集精度。利用感应耦合供电和无线数字传输技术实现了对位于中轴力矩采集部件电能与信号的非接触传输。最后在模拟实际骑行的基础上对系统的精度及耐久性进行了测试,结果表明,该系统工作稳定,测量精度较高,在20 000 km测试范围内,满量程误差小于1%,具有很好的推广价值。

Since the torque sensing system of e-bike has high development difficuhy and cost, a sensitive component based novel torque sensing system for e-bike was designed. The torque sensor taking the sensitive component （resistance strain gage） as its core, the signal processing unit mainly composed of differential amplifier and A/D conversion circuits, and the data processing and wireless transceiving unit taking lower-power consumption RF chip CClll0 as its core are installed on the middle axle of the e-bike to realize torque signal acquisition. In the software, the weighted recursion average filtering algorithm is used to enhance the stability of data acquisition, and the zero-point compensation and least square method for fitting and correction are used to ensure the high precision of data acquisition. The inductive coupled power transfer （ICPT） and wireless digital transmission technology are used to realize the non-contact transmission of electric power and signal of torque acquisition components locating at the middle axis. On the basis of simulating the practical riding, the accuracy and durability of the system were tested. The result shows that the system works stably and has high detection precision, and its error is less than 1% within the testing range of 20 000 kin.