Electromechanical Actuator Development for Integrated Chatter Prediction on High Speed Machining Centers

Abstract

Machine tool chatter imposes limitations on the productivity and quality of modern high speed machining (HSM) operations. It has been shown that chatter prediction and avoidance strategies can lead to increased machining productivity if certain modal characteristics of the machine are known. The objectives of this research are to design and demonstrate an electromechanical actuator (EMA) to easily and accurately identify these characteristics. Design specifications for this actuator reflect a wide range of machine tools and operating conditions. A simulation-based design strategy is employed, based on traditional electromechanical analysis, finite element analysis (FEA), and computer simulations to ensure performance meets the design specifications. A prototype EMA system is built to validate the analytical results and demonstrate its capabilities as part of an automated chatter prediction and avoidance system. The EMA is shown to generate the required modal characteristics, namely frequency response functions (FRFs) and stability lobe diagrams (SLDs) quickly, accurately, and with fewer technical skill requirements than other vibration testing methods. Experimental machining tests demonstrate that the EMA can be an effective component of an integrated chatter prediction and avoidance system.