Robust control synthesis for CNC machine spindle

Abstract

This paper aims to analyze the dynamic stability and build the robust controller for motorized spindle system under parametric variations, external disturbances and measurement noises. A nonlinear model has been established for the machine tool spindles. The phase portrait and bifurcation analyses are provided to show dynamical behaviors for spindle machining. The spindle operations can be dynamically stables or unstable under parameter variations and disturbances. By using the robust control synthesis, the system designers can shape the frequency responses of the desired model which satisfies both transient response and robustness against various uncertainties. In fact, the robust controller can effectively attenuate exogenous disturbances and sensor noises during machining process. Finally, the simulations results demonstrate that the presented controller provides robust stability for the spindle speeds, along with excellent abilities of noise as well as disturbance attenuations.

Keywords:

• Bifurcation
• CNC spindle machine
• machining process
• robust controller
• stability analysis

Additional information

Funding

This research was supported by a grant (17LRP-B079281-04) from Transportation & Logistics Research Program funded by Ministry of Land, Infrastructure and Transport of Korean government.