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In this paper, we present a control strategy for an axially moving web system that regulates transverse vibration and ensures that the web speed tracks a desired trajectory. The control strategy is implemented using roller torque inputs applied at the boundary and a pair of control forces applied to the web via a mechanical guide. Given the hybrid model of the web system (i.e. the distributed parameter field equation coupled to discrete actuator equations), Lyapunov-type arguments are utilised to design a model-based control law that exponentially regulates the axial speed tracking error and the web displacement. The proposed control law is based on measurements of the web speed and displacement, slope, and slope rate at the mechanical guide. Experimental results demonstrate the speed tracking and vibration damping provided by the control strategy.

In this paper, we present the design of boundary controllers for a two-dimensional, spinning flexible rotor system. Specifically, we develop a model-based boundary controller which exponentially regulates the rotor's displacement and the angular velocity tracking error, and an adaptive boundary controller which asymptotically achieves the same control objective while compensating for parametric uncertainty. As opposed to previous boundary control work, which focused on the velocity setpoint problem and placed restrictions on the magnitude of the desired angular velocity setpoint, the proposed control architecture achieves angular velocity tracking with no restrictions on the magnitude of the desired velocity trajectory. Experimental results conducted on a flexible rotor tested are presented to illustrate the feasibility of implementing the proposed boundary control laws. Copyright © 2001 John Wiley & Sons, Ltd.

In this paper, we propose a robust near output feedback (which refers to the fact that the control scheme uses dynamic feedback of the output but requires knowledge of the initial conditions of other states) link position tracking controller for a class of robotic systems, which includes the rigid-link flexible-joint (RLFJ) robot manipulator and the rigid-link electrically-driven (RLED) robot. The method uses a bank of dynamic filters, with the link position tracking error as the input, to generate surrogates for the unmeasurable system states. One of these generated filter states is then used in the feedback control strategy. The method is distinguished from previous results by the limited amount of modelling information required, the utilization of only link position measurements and knowledge of the initial conditions, and the overall simplicity of the controller. Even though the approach only requires link position measurements and knowledge of initial conditions, the controller exhibits good robustness properties while ensuring semiglobal uniformly ultimately bounded link position tracking.