车辆电气系统智能故障诊断仪的研制

车辆电气系统智能故障诊断仪由电参量、继电器状态、发动机起动和蓄电池测试电路,信号调理板、数据采集卡、工控机组件及专家系统组成.设置扫描方式、采样频率和点数并进行A/D转换后,通过程序可绘制起动电流、电压曲线,计算起动时间,单位时间内电池端电压变化率及蓄电池剩余电量.基于诊断基元和产生式规则的专家系统,根据初始故障现象找出最底层故障基元,通过多层正反向混合推理实现故障最终定位.

Intelligent Fault Diagnosis Instrument for Electric System of Vehicle

The intelligent fault diagnosis instrument for electric system of vehicle is composed of circuit of electric parameter measure, state test circuits of relay and engine start-up and storage cell, signal adjust circuit, data acquisition card, industry control computer and expert system. The curves of started-up current and voltage were drawn, and start-up time, voltage change-rate and remain capability of storage cell in unit-time was computed with program by setting scan mode, sampling frequency and A/D conversion. The diagnosis basic unit of lowest layer found out with fault diagnosis expert system based on diagnosis basic unit and rule according to initial fault phenomenon. The final fault orientation was realized by mixed reasoning of positive and reversed direction of multiplayer.