Associate Professor of Mechanical Engineering
We have designed, implemented, and tested an electromagnetically driven fast tool servo for diamond turning precision contoured surfaces with nanometer resolution. Our device is based on a novel ultrafast motor utilizing permanent magnets for flux bias in conjunction with steering coils used to control the actuator force. Experimental results demonstrate that our ultrafast tool servo has a stroke of 30 micrometers, achieves 23kHz closed-loop bandwidth, as low as 1.7nm RMS tracking error, 500G peak acceleration at 10kHz open-loop operation, and 2.1nm (0.04%) error in tracking a 3kHz sinusoid of 16mm p-v. This talk will describe the electromagnetic design, operating principles, magnetic material consideration, mechanical design, and experimental results. To drive and control this ultrafast tool servo, a 1kW linear power amplifier and a high-speed real-time computer with 1MHz sampling rate have been designed and implemented. The key features of these devices will also be presented.