Abstract:

Abstract: To reduce electromagnetic disturbance of nanopositioning caused by direct actuation of cylindrical
permanent magnet synchronous linear motor (TPMSLM), the actuation mode of rotor and stator’s eccentric
installation of TPMSLM is studied. The actuation mode changes the interior space magnetic field distribution
of TPMSLM, therefore the axial electromagnetic force containing electromagnetic disturbance is decreased and
the radial electromagnetic force containing electromagnetic disturbance is produced. When guide damping is
added, a large amount of electromagnetic disturbance can be absorbed. Further more, to prevent large positioning
overshooting, a PI control algorithm with variable coefficients is studied, which changes dynamical
and static actuation characteristics of system in real-time to supply optimal control parameters for large travel
range actuation and nanopositioning actuation. Experimental results indicate that, using the eccentric actuation
mode and variable coefficient PI control algorithm, large travel range positioning actuation without
overshooting and accurate positioning with errors less than 10 nm are achieved.

Key words: TPMSLM, PI control algorithm with variable coefficients, actuation without overshooting, nanopositioning