Closed-Loop Control of an Underactuated Sheet Registration Device Using Feedback Linearization and Gain Scheduling

摘要

Over the past few decades, the two-wheeled driven cart, also known as the unicycle wheeled mobile robot or wheeled mobile robot with independently driven wheels, has been a favorite case study in the literature on nonholonomic control. In this paper, we show how input–output linearization of a cart can be leveraged for a novel and practical application, closed-loop control of a differential-drive sheet registration device. The current state of the art for control for such a device, typically found in xerographic engines like printers and copiers, is open-loop motion planning. We present a closed-loop method that achieves full-state trajectory tracking via input–output linearization and asymptotically stable internal dynamics. To achieve rapid convergence while satisfying acceleration constraints, we apply elementary gain scheduling to the output tracking controller of the linearized input–output system. Experimental results are presented to demonstrate the effectiveness of the discrete-time implementation of our control strategy, which is based on a kinematic model with acceleration as the control input.