The Study Of Detection System Of Milking Machine’s Vacuum And Pulsation System Based On ARM

Pulse system is the core of milking machine, and its performance and stability will directly influence the milking effect and efficiency of the machine, and in result, the health condition of cow’s breast, milk production, and the economic benefit of the rangeland/pasture. That is why the detection of pulse machine and pulsator is of great importance in improving milking efficiency, reducing cow mastitis morbidity, and boosting economic benefit. Nowadays the overall detection of pulse system is not available because the detection equipment, be it in China or abroad, can only detect the performance of pulsator, but not the changes of vacuum degree in the pipeline.In this paper I invented a detection system for the whole pulse system and explained the realization of it in software and hardware. The system is based on Processor STM32F103 and is capable of the detecting of both the performance of the pulsator and the changes of vacuum degree in the pipeline, waveform display, as well as data storage.For the hardware design, I combined touch panel with ARM, with touch panel taking charge of human-machine interaction and ARM data processing and analytical calculation. The core of ARM module is microcontroller STM32 which integrated Cortex-M3. The ARM design includes peripheral circuit, signal acquisition circuit, communication circuit RS485, and realtime clock circuit. Also there is a two-path supply circuit design, one is 5V and the other 24 V, for power supply to different parts, which ensures the stability of power supply.The design of software includes touch panel software design and processor software design. The touch panel design is mainly about graphical interface design and macro instruction design. Graphical interface includes master-control interface, vacuum degree display interface, and pulsing display interface. As to processor design, I took use of uC/OS-Ⅲ process system to get real-time task control. The processor can assign AD sampling task, data processing task and communication task, and by that realize sampling and processing of vacuum degree data detected in three places and pulsing data tested in two places as well as the communication with touch panel.Parameter calibration of the design is made in Beijing Institute of Metrology, and application test in China Agricultural Machinery Testing Centre. Discrepancy of vacuum degree measurement in pipeline is less than 0.6kPa, that of pulsing measurement is less than 0.2kPa, and environment degree detection discrepancy less than 1℃, which are all within the national standard. The measuring frequency of vacuum degree is 200 Hz, with updating frequency of measured pulsing parameter is 6s, and data recording interval 6s. That all leads to the conclusion that the measuring result is reliable, response time conforms to the requirement of detection and the system operation is stable enough.