基于虚拟仪器技术的轮荷测量仪电测系统开发

Development of Electric Measuring System of Wheel Load Measuring Instrument Based on Virtual Instrument Technology

依据电阻应变测量原理,应用机电一体化技术,开发测量汽车轮荷的测量仪电测系统.该系统由数采硬件电路和上位机车辆轮荷测量系统软件组成.应变传感器测得的电压信号,先后经过调理电路、A/D转换电路和光电隔离电路,传输给MCU.通过串口通信协议,MCU与上位机轮荷测量系统间进行指令和数据的传输,数据经过存储和运算处理后,通过上位机系统面板把轮荷值传达给用户,并将结果储存到PC机中.采用砝码加载,在可倾斜卡具上对测量仪进行了实验标定.根据实验数据算得测量仪的非线性误差为±0.72%,重复性误差为±1.37%,迟滞性误差为±1.47%,灵敏度误差为±1.67%,最终得到综合误差为±2.71%,满足轮荷测量仪预期设计的测量精度和功能要求.

With the application of mechatronies technology, electric measuring system of wheel load measuring instrument is developed based on resistance strain measurement principle. The electric measuring system is com- posed of data acquisition circuit and upper computer wheel load measuring system software. Voltage signals from strain sensor pass through signal conditioning circuit, A/D conversion circuit and optical isolation circuit, on to MCU ultimately. Instructions and data transfer between MCU and PC wheel load measuring system via serial com- munication protocols. Users get wheel load value after data is restored and operated or result is restored at a speci- fied directory as request. Weight as loading tool, the instrument is set above a tihable jig and calibration by experi- ment. Errors are gained according to experiment data in which non-liner error is ± 0. 72%, repeated error is ± 1.37% , hysteresis error is ± 1.47% and comprehensive error is ± 2. 71% ultimately. It confirms that measure- ment accuracy and function performance of the instrument meet the pre designed requirements.