Abstract: To make the output response of the control system of precision linear motor displacement system (PLMDS) accu-rately track the input instructions and to eliminate the adverse influences introduced by the load disturbance and the cut-ting-force fluctuation from direct drive, a zero phase error tracking control (ZPETC) scheme based on least-beat and non-ripple control in PLMDS is proposed for the application to the CNC turning of non-circular cross-section part, which can eliminate the system phase error caused by the unstable zeros and enhance the system response rate as well. Simulation re-sults show that this method can effectively improve the system tracking performance. The steady-state sinusoidal signal track-ing error of the system can reach up to ±0.5 μm with rapid and accurate step response. Compared with general control strate-gies of PLMDS, this method increases the system tracking ac-curacy and possesses fine anti-disturbance ability, which is endowed with the potential for wide application.

Key words: Feedforward control, Least-beat and ripple disable control, Precision linear displacement, Zero phase error tracking control