Automated mill control using vibration signal processing

Historically many different signals have been employed in the quest for optimal automatic closed loop mill control. These include mill power, sound, elevator amps, bearing pressure and temperature as a few examples. However, within the last few years, a new technology is emerging that makes all these antiquated techniques obsolete. This new technology is mill control using vibration sensors, analog to digital converters and digital signal processing (DSP). This paper presents a brief but current overview of mill vibration analysis and control using signal processing techniques. It then also documents an actual 'before and after' case comparing mill control using classical techniques versus automate loop control using mill vibration to instantaneously estimate and control mill fill level. It will be shown that significant improvements in material throughput, reduced kilo-watt per ton numbers, improved material quality can all be realized with vibration control