Title :
Modelling and control of a 2 D.O.F. high-precision positionning system
Author :
Boichot, J. ; Delaleau, E. ; Diep, N.V. ; Levine, J. ; Parzy, E.
Author_Institution :
Lab. des Signaux et Syst., Supelec, Gif-sur-Yvette, France
fDate :
Aug. 31 1999-Sept. 3 1999
Abstract :
We present a hierarchical controller for a set of two linear synchronous motors with permanent magnets moving in two orthogonal directions for a two degree of freedom high-precision positionning system developed by Newport-France. This system is supposed to realize relatively fast linear displacements from 1 count (4 nm) to 400 mm. A linear displacement of 25mm must be achieved in less than 0.2 s with maximum acceleration of 1 g and current and voltage limitations, and with an error in the final position less than 1 count. A nonlinear model of the plant is obtained, consisting of two independent subsystems, representing the two linear drive dynamics. Flatness based motion planning and tracking design are proposed. Each motor´s tracking controller is then realized in a hierarchical way by a high level force control loop and a low level current loop.
Keywords :
control system synthesis; force control; hierarchical systems; linear synchronous motors; machine control; nonlinear control systems; path planning; permanent magnets; position control; DOF high-precision positioning system; current limitations; flatness based motion planning; hierarchical controller; high level force control loop; independent subsystems; linear drive dynamics; linear synchronous motors; low level current loop; nonlinear model; orthogonal directions; permanent magnets; tracking controller; tracking design; two degree of freedom; voltage limitations; Acceleration; Adaptation models; Force; Planning; Synchronous motors; Tracking; Trajectory; Flatness; hierarchical control; linear synchronous motor; nonlinear control; position control;
Conference_Titel :
Control Conference (ECC), 1999 European
Conference_Location :
Karlsruhe
Print_ISBN :
978-3-9524173-5-5
