基于TMS570的数控高精度电流源设计与实现

The Design and Implementation of Numerically Controlled High-Precision Current Source Based on TMS570

针对传统Howland电流源电路受输出负载影响,稳定性差、控制精度低以及分辨率低的问题,以TMS570为控制核心,设计上位机软件控制12 bits数模转换器(Digital to Analog Converter,DAC)产生电压基准,实时控制改进型Howland电流源电路。同时通过软硬件实时采样、比较,精确控制、补偿、反馈电流值,提高了整个电路的安全性和准确性。测试结果表明,该电流源输出不受负载影响,安全性、电流精度以及分辨率适用于力矩电机等高精度和高安全性要求,并且易于扩展升级。

The traditional Howland current source circuit is affected by output load,and with the problem of bad stability、low control accuracy and low resolution;This paper uses TMS570 as the control core,12 bits DAC is controlled by computer software to generate voltage reference,so the improved Howland current source circuit is controlled in real time.At the same time,Sampling and comparison through software and hardware which control,compensate,feedback current value precisely,so the safety and accuracy are improved.It is implicated by test result that current source circuit is not affected by output load,safely,accuracy and resolution are suitable for high-precision and high-security requirements such as torque motors,and this circuit is easy to expand and upgrade.