The Micro DC Motor Testing System Based On The Spectral Analysis Of Steady-state Current

Misco DC motor has characteristics of simple structure、easy to control、working stably、low manufacturing cost, So it’s widely used as critical execution unit and principal drive element in Electro-Mechanical systems, Misco DC motor covers many fields of industrial manufacture and social life. With the improvement of the degree of automation and the quality of Misco DC motor, it can expand considerably the range of application of Misco DC motor, this means a huge increase in production of Misco DC motor. Misco DC motor is a key element in system device, it will cause a series of problems once Misco DC motor breaks down, therefore it is a very important step to test Misco DC motor quality before the factory prepares sale their product to the dealer. At present, in order to ensure the high quality, the manufactures totally rely on the manual detecting, to address this issue, this paper designed a automatic test equipment to detect Misco DC motor online.We found that DC motor armature’s Starting current and Stead-state current will be abnormal if there is a manufacturing defect during manufacture. Based on detailed analysis of permanent magnet DC motor’s mathematical model in this paper, we take the steady-state current as the main object of study and collect a large amount of signal waveform in time domain and frequency spectrum in frequency domain. Our analysis focused on the difference of the steady-state current in the time domain and frequency domain between the defective motor and the non-defective motor. Eventually this paper proposed a detection model based on detection template which is composed by5characteristic parameters in frequency domain. Furthermore, we proved this detection model correctness.With the foundation of detection and overall design of system, in this paper,a DC motor testing system which took STM32F107VCT as core processor is designed, we completed the design of system hardware and system software debugging, the overall debugging and self-learning of the prototype are made. This system can provides the steady-state current signal acquisition、filtering、extraction of characteristic parameters in frequency domain and comprehensive judgment, finally sends the testing result to the PLC via the serial port and removes non-defective motor with the completion of the mechanical control unit. The experiment proved this system high testing precision, so this system can basically take the place of the manual detecting, the manufactures are satisfied with the testing precision.