Nonlinear Contour Tracking of a Voice Coil Motors-Driven Dual-Axis Positioning Stage Using Fuzzy Fractional PID Control with Variable Orders

<div>Window contour tracking results of the VCMs-driven dual-axis positioning stage using PID, FFPID, and VOFPID controllers in Case 1. (a) Tracking errors; (b) drive currents.</div>

Mathematical Problems in Engineering

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Figure 11

Figure 11: Nonlinear Contour Tracking of a Voice Coil Motors-Driven Dual-Axis Positioning Stage Using Fuzzy Fractional PID Control with Variable Orders 

Figure 11 | Nonlinear Contour Tracking of a Voice Coil Motors-Driven Dual-Axis Positioning Stage Using Fuzzy Fractional PID Control with Variable Orders 