R&D When industrial robots overheat
A research team at Saarland University has developed an early warning system for industrial assembly, handling and packaging processes. It keeps a constant eye on the condition of the machine, it carries out diagnostic analyses and it notifies the operator when a part needs to be replaced.
Intelligent sensors continuously collect a wide range of measurement data from inside plant machinery and compare the signal patterns against those for normal operating conditions. If the system detects a difference in the patterns that indicates a potential fault, it immediately notifies the equipment operator about what remedial measures should be taken. This helps engineers to plan maintenance more effectively and protects them from unpleasant surprises and unexpected production losses.
Robots in production lines work tirelessly and with micrometre precision – unless of course a component fails. If, for example, the linear actuator used to precisely position a car body in front of an assembly robot is damaged, the robotic arm will no longer be able to position the car door as exactly as it normally does. The result is a door that is misaligned. Or, to take another example, the sudden failure of a machine component due to material fatigue could well result in the complete shutdown of a production line. A team of engineers led by Andreas Schütze, an expert in sensor systems from Saarland University and the Center for Mechatronics and Automation Technology, is working with a group of academic and industrial partners to prevent this sort of situation from arising.
Their system subjects machines to what is effectively a continuous medical check-up. The human equivalent would be equipping a person with an activity tracker, a continuous digital ECG and blood pressure monitor so that their state of health could be analysed at any time. "Our system makes it possible to continuously visualise the current condition of plant machinery and provide advance warning of potential damage. To do this, we fit sensors inside the machines and these sensors are able to interact with each other and with existing process sensors. This enables us to register even the smallest of changes," explains Andreas Schütze. The researchers make use of the phenomenon that technical equipment will begin to make a different noise, or will vibrate or overheat long before it actually fails. The trick here is that the characteristic manner in which a machine hums or vibrates during normal operation is different to that observed when something has changed within the machine, though these differences can be very subtle and undetectable to normal senses.