Research On Automatic Feeding Control System Of Flour Mill

Currently, the automatic feeding control system in domestic food machine factories, the level sensor widely adopted capacitive level sensor, the automatic adjustment of material flow widely adopted frequency control technology. Capacitive sensor could achieve continuous measurement of material and it has high sensitivity. In practice, the material dielectric constant change frequently, it needs automatic compensating circuit to adjust error. Thus, designing a level sensor with less influencing factors, lower cost and better working stability is very significant to reduce the costs and improve stability.Firstly, according to flour mill structure and material properties, the paper designs a type of multi-point infrared level sensor that it has infrared anti-interference function.Secondly, the paper completes hardware selection and software design. Hardware selection mainly contains the selection for controller, frequency converter and motor of feeding roller. Software design mainly contains time-sharing controlling of the level sensor driving signal, measuring and processing the effective material level signal, and implementing level sensor fault self-diagnosis function by software.Finally, it achieves frequency control technology by RS-485 bus in the way of communication. According to communication protocol that the frequency converter supported, it finishes the communication programming between controller and frequency converter. It validates the level sensors'practicability and acquires the curve between material level and frequency.The feeding system of flour mill configures multi-point infrared level sensor and open-loop frequency control system, it could responds quickly for different conditions of material fluctuation, and it helps to adjust smoothly the whole flour route flow. This integrate automatic feeding control system not only saves cost, but also brings great convenience to flour milling deploying.