The use of an intelligent, adaptive sensor/actuator module for machine tools has prevented vibration and improved heat control. The result is higher quality and improved productivity.
Key elements of Industry 4.0 are machines capable of adapting autonomously to changing ambient conditions. The EU’s HARCO project has developed components for metal-working machinery which are able to compensate automatically for tool vibration. This enables much higher quality of the machined item and improves productivity.
Vibration is actively reduced
Cutting operations, such as in milling machines, create vibration as soon as the tool touches the surface of the workpiece. The precision and quality of the finished surface is heavily dependent on the control of such vibration. Companies and research institutions from Italy, Germany, the UK, Spain and Belgium have developed an adaptive component that connects the chisel to the machine’s tool fixture and is able to actively reduce vibration.
This “adaptronic” component is equipped with sensors and intelligent actuators. The sensors measure the vibration level and relay the information to the internal controller. Intelligent algorithms use that information to compute a strategy for control of the actuators, which eliminate the unwanted vibration by their movements. The system is thus able to predict the active damping needed for the specific process.
Additional modules complete the system
Vibration damping is only one part of the machine tool solution developed by the HARCO project however: additional modules provide adaptive tool fixing as well as compensation for thermal expansion resulting from the machining process. The intelligent, modular adaptronic components – known as Adaptive Smart Components, or ASCs – can be configured as required.
Fast, precise robot positioning
Spanish research organisation Tecnalia uses ASC technology to provide vibration damping for robots with serial and parallel kinematics, highlighting the benefits of a holistic design approach. The specific goal was to cut the cycle times of parallel robots developed for fast, high-accuracy pick-and-place tasks. The high acceleration means that the actuator – such as the robot’s gripper arm – is subject to unwanted vibration at its stop position. This results in longer cycle times. Tecnalia adopted two strategies to enhance the accuracy and productivity of the robots: Firstly, an adaptive torque controller was developed and implemented. And secondly, the company developed a Smart Device capable of damping the vibration of the robot’s mobile platform at the placement position.
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