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This paper presents a novel initial value compensation (IVC) using an additional input for semi-closed control systems. The authors have already proposed the IVC approach using the additional input for residual vibration suppression in the fast and precise positioning control. In the approach, however, an essential subject has remained, i.e., the positioning control in the load side could not satisfy the required performance because the systems have been constructed under the assumption of a semi-closed control system. An improvement of the control performance in load position, therefore, is discussed in this paper, where the appropriate assignments of poles and zeros in IVC are ensured, considering the transfer functions of position in both sensor and load for the control initial values. The effectiveness of the proposed approach has been verified by numerical simulations and experiments using a prototype. [ABSTRACT FROM AUTHOR]

In this paper, we propose a new robust congestion- control strategy for a differentiated-services (DiffServ) network. A sliding-mode-based variable structure control technique is utilized to design a congestion controller on the basis of a fluid flow model. The performance of our proposed scheme is then demonstrated on a DiffServ network. Our proposed algorithm is developed for an interconnected network as a hop-by-hop distributed-control approach. A formal analysis of the controlled network is conducted, where it is shown that the error dynamics of the overall time-delay-dependent system is ℒ∞ stable. Numerical simulations are provided to demonstrate the capabilities of our proposed methodology. [ABSTRACT FROM AUTHOR]

In elevator drive systems, the gains of a conventional proportional-integral (P1) speed controller cannot usually be set large enough because of its mechanical resonance. Consequently, the speed control performance deteriorates. In our work described in this paper, a fuzzy logic controller (FLC) was adopted for use in elevator drive systems in order to improve the speed control performance. The proposed FLC was compared with a conventional P1 controller with respect to speed dynamic responses and load torque. Simulation and experimental results demonstrated that the proposed FLC was superior over the conventional P1. This FLC can be a good solution for high-performance elevator drive systems. [ABSTRACT FROM AUTHOR]