Design of Resistance Measurement Equipment for Motor Commutator Segment Based on LabWindows/CVI

Abstract

Traditional resistance measurement for DC motor commutator segment is manual. The process is complicated, the efficiency is low, and the cost is high. In order to enhance efficiency and precision of the resistance measurement, we design an automatic measurement equipment using virtual instrument technique. The equipment consists on industrial compute, stepping motor drive transmission system, low resistance measuring meter, host compute software. Making the equipment universal and automated is the core of design. We discuss working principle of the equipment, hardware de- sign, software design, measurement experiment process and results analysis. Hardware design includes accurate position control of stepping motor, 4-wire method for resistance measurement, special fixture design for probe. Software design based on LabWindows/CVI platform includes serial communication, asynchronous timers, multi-thread, ActiveX control. The measurement experiment results indicate that the euipment can measure almost all kind of DC motor rotors accurate- ly, also can record and save measurement results automatically.