BACKSTEPPING BOUNDARY CONTROL OF FLEXIBLE-LINK ELECTRICALLY DRIVEN GANTRY ROBOTS

Gantry robots are used for precision manufacturing and material handli ng in the electronics, nuclear, and automotive industries, Light, flex ible links require less power, but may vibrate excessively, In this pa per, an implementable boundary controller is developed to damp out und esirable vibrations in a flexible-link gantry robot driven by a brushe d de motor. Hamilton's principle produces the governing equations of m otion and boundary conditions for the flexible link, The electrical su bsystem dynamics for a permanent magnet brushed de motor couple with t he link dynamics to form a hybrid system of partial and ordinary diffe rential equations, A boundary voltage control law is de,eloped based o n Lyapunov theory for distributed parameter systems, Through an embedd ed desired-current control law, the integrator backstepping controller generates the desired control force on the mechanical subs,stem, A ve locity observer estimates the gantry velocity, eliminating one feedbac k sensor, Modal analysis and Galerkin's method generate the closed-loo p modal dynamics. Numerical simulations demonstrate the improved vibra tion damping characteristics provided by the backstepping boundary con trol law, Experimental results confirm the theoretical predictions, sh owing the high performance of backstepping boundary control.