Vibration-Based Operating Status Monitoring of a Production Line with Low-Cost IoT Devices

Many production lines still in use today have been designed without provisions or machine interfaces for data recording and data analysis. An efficient solution for generating operation metrics for these brownfield lines is smart retrofitting with Internet of Things (IoT) devices. We present a cost-efficient, nonintrusive IoT solution for monitoring the operating status of modules of an assembly line based on the measured background vibrations. In contrast to existing solutions which often examine a single machine or process step, our solution monitors entire production modules with many moving components on a higher, business-focused level. The vibration is measured by a wireless network of low-cost IoT devices. A middleware software processes the sensor data for later analysis with unsupervised machine learning. Experiments at an assembly line have proven that low-cost IoT solutions are capable of identifying normal operation, state transitions, and standstill of production modules from the background vibrations. The monitoring of the actual operating status is necessary for deriving key indicators for business questions or maintenance optimization.