Performance evaluation and optimization of a fast tool servo for single point diamond turning machines
- Oak Ridge National Lab., TN (United States)
- Alabama Univ., University, AL (United States)
This paper describes a new, fast tool servo system for fabricating non-rotationally symmetric components using single point diamond turning machines. A prototype, designed for flexible interfacing to typical machine tool controllers, will be described along with performance testing data of tilted flat and off-axis conic sections. Evaluation data show that servo produced surfaces have an rms roughness less than 175 angstroms (2-200 {mu}m spatial filter). Techniques for linearizing the hysteretic effects in the piezoelectric actuator are also discussed. The nonlinear effects due to hysteresis are reduced using a dynamic compensator module in conjunction with a linear controller. The compensator samples the hysteretic voltage/displacement relation in real time and modifies the effective gain accordingly. Simulation results indicate that errors in the performance of the system caused by hysteresis can be compensated and reduced by 90%. Experimental implementation results in 80% reduction in motion error caused by hysteresis, but peak-to- valley errors are limited by side effects from the compensation. The uncompensated servo system demonstrated a peak-to-valley error of less than 0.80 micrometer for an off-axis conic section turned on-axis.
- Research Organization:
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
- Sponsoring Organization:
- Department of Defense, Washington, DC (United States); National Aeronautics and Space Administration, Washington, DC (United States)
- DOE Contract Number:
- AC05-96OR22464
- OSTI ID:
- 518769
- Report Number(s):
- CONF-970794-1; ON: DE97008448; CNN: Agreement 1855-1562-A1
- Resource Relation:
- Conference: SPIE symposium on optical science, engineering and instrumentation, San Diego, CA (United States), 27 Jul 1997; Other Information: PBD: [1997]
- Country of Publication:
- United States
- Language:
- English
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