基于虚拟仪器技术的轮荷测量仪电测系统开发

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.

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

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.