9522815 Tsao Recent advances in tool materials and spindle technology have the potential to dramatically increase material removal rates. To achieve this requires high dynamic rigidity and precise motion and speed control to maintain accuracy. Direct drive technology eliminates the gear reduction between servo and the tool or spindle motion. Potentially this means high performance, but it also eliminates the means by which the servo and the final motion can be decoupled. This means that to achieve the potential of direct drives in machining systems, the drive dynamics have to be included in the dynamic model of the system. This research will complete the theoretical design of an inner loop robust feedback control, outer loop repetitive control and control tracking control, and optimal feedforward/preview control. Dynamic mechanistic models of the machining process represent the loads presented to a direct drive machining system during operation. Two experiments to test these direct drive control concepts are part of the research: two axes high feed rate milling, and variable spindle speed machining for chatter suppression. These results will provide fundamental understanding of the dynamics and control of direct drive machining that can be used to design the next generation of high performance direct drive machining systems. ***
