Development of an innovative, posture-independent dynamometer for robotic milling applications

Nowadays robotic milling is largely used in strategic industrial sectors such as aerospace. Unfortunately, robotic arms are characterized by a large, posture-dependent dynamic compliance, which limits the achievable performances of the cutting process. In-process, real-time knowledge of system dynamic compliance – for any generic robot posture – together with a good reconstruction of the input cutting forces would enable an effective optimization of robotic milling. For this purpose, a novel device for cutting force measurements in robotic milling was designed and developed in this work. Relatively cheap PVDF sensors have been selected as main sensing elements, in combination with piezoelectric accelerometers, according to the principles of the Universal Dynamometer that was recently presented in technical literature. In this work, the design, testing and preliminary validation of the new device will be presented, showing its outstanding potential advantages.