A synthesis problem for a class of multirate sampled-data systems is considered, where the design specifications consist of (i) the closed-loop system is stable, and (ii) the L₂-induced norm of the closed-loop system is less than one. A necessary and sufficient condition for the existence of a controller satisfying the specifications is given in terms of LMIs. A procedure for controller construction is also derived.

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In this paper we investigate some general properties of equilibrium points of finite quantum dynamics which provide fundamental results for designing a controller and a measurement apparatus. Firstly, the averaged quanturn dynamics is shown to be stable in the Lyapunov sense. This implies that the average behavior of the quantum dynamics is characterized by the set of the equilibrium points. Secondly, an explicit form of a unique equilibrium point associated with the controller and the measurement apparatus, which provides a practical procedure to attain a desired equilibrium point, is shown. A quantum state can be utilized as an information source quantified by “von Neumann entropy”. We derive a necessary and sufficient condition for the entropy of the equilibrium points to be maximum (or minimum).

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This paper proposes a new approach to solve the controllability (reachability) problem of sampled-data/discrete-time piecewise affine systems. First, an algebraic characterization for the system to be controllable (reachable) is derived. Next, based on this characterization, an approach to determine if the system is controllable (reachable) in a probabilistic sense is proposed based on a randomized algorithm. Finally, it is shown by numerical examples that the proposed approach is useful.

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This paper proposes a multivariable model predictive control system for a refuse incinerator with a boiler to stabilize recovery steam. This system is able to control steam generation rate and boiler drum pressure stably, because it predicts their behaviors more precisely by observing oxygen concentration in the incinerator. Experimental results at a real fluidized bed incinerator show the usefulness of the proposed method.

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In this paper, we propose a design method of an observer-based controller for nonlinear differential algebraic equation (DAE) systems. We transform a DAE system to an explicit ordinary differential equation (ODE) system that is restricted to an invariant manifold by differentiating the original DAE repeatedly. If the DAE is non-regular, we add integrators to inputs to avoid impulse modes. We design a state feedback law that incorporates redundant state variables and an observer that estimates all of these variables simultaneously. We also give a set of sufficient conditions for the global stability of the control system. The efficiency of the controller is demonstrated by computer simulation.

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In distributed intrusion detection systems, self monitoring is a subject of current research. One possibility is that each intrusion detection system is checked periodically by others, and then corrupted intrusion detection systems can be identified. In this paper, we employ both an immunity-based diagnosistic model and mobile agents for the self-monitoring. The immunity-based diagnosis, which was proposed by one of the authors in 1990, is performed by the mutual tests among units and the dynamic propagation of active states. In simulated distributed intrusion detection systems, we compare three methods: (1) a simple majority vote on host-to-host communication, (2) the immunity-based diagnosis on host-to-host communication, and (3) the immunity-based diagnosis with mobile agents. Some simulation results show that the immunity-based diagnosis can work better than the majority vote. We also clarify advantages and disadvantages of using mobile agents in comparison with the host-to-host communication.

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This paper discusses acquisition of knack included in symbols and patterns by a robot. Knack is defined as a rule or a sensed information that improve performance of robot drastically for a task execution. Concept of acquisition of knack included in symbols and patterns are discussed and the method to acquire the knack is presented. For acquisition of knack included in symbols, the robot acts in a new environment and success/failure data are clustered. For acquisition of knack contained in patterns, it acts in a new environment while a human modifies the output of its actuator directly, and data are clustered again. The knack in patterns is distinguished for us to interpret. Simulations using a mobile robot are done to demonstrate the acquisition of knack.

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A rectangle packing is a non-overlapping placement of given rectangles. The algorithm to optimize the rectangle packing can be required in a variety of application fields. However, since the optimization problem of rectangle packing is a combinatorial optimization problem and NP-hard, it is hard to solve it exactly in practical applications. To cope with this difficulty, a new coding scheme, sequence-pair, has been proposed, by means of which any possible packing can be represented. Tabu search is one of the powerful meta-heuristics, which can explore the solution space effectively in an intelligent manner. Thus a tabu search approach for rectangle packing problem based on sequence-pair should be powerful in practical applications, however any such approaches have not been reported. The purpose of this paper is to apply tabu search to rectangle packing based on sequence-pair, and evaluate this approach. First, rectangle packing problem is formulated, and the representation of each solution is defined. And then, the proposed method is described in detail, where first admissible move strategy and a concept of stochastic tabu restrictions are employed. The experimental result shows that the proposed method keeps providing good performance through the search process.

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Augmented Reality (AR) allows the user to see the real world, with annotations superimposed on the real scene. Therefore, it is effective to guide a user intuitive way. In this paper, we describe an application of head tracking method using a stereo camera pair and localization method using a laser range finder to AR. It is important to measure the position and the orientation of a user accurately in order to build an AR system. In our approach, the head position and orientation of the user is measured by a pair of stereo cameras, and the position of the user is estimated by a laser range finder. We conducted experiments to evaluate the usefulness of these methods for AR, and the effectiveness was confirmed. Finally we developed an AR-based guidance system for a wheelchair using both measurement methods. An experiment to guide the user was conducted and the usability of this system was confirmed.

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The paper presents newly developed dynamic simulation models of chillers for energy consumption evaluation of HVAC (heating, ventilating and air-conditioning) systems. The dynamic chiller simulation models are developed for absorption chillers and turbo chillers. The software makes energy consumption prediction not only for steady state operation, but also for start up and shut down operations possible. The tool also enables to test dynamic control stability of the HVAC systems precisely. Then it can be convenient to analyze the HVAC system and to improve the control performance. By the simulation tools with HVAC simulation tools such as HASP or HVACSIM+, we do believe the building commissioning will be become much more accurate.

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With increasing demand for high fuel efficiency, better exhaust control measures, comfort and high performance on current vehicles, electronic control of the throttle chamber which decides the engine output, is getting advanced day by day. It is expected that this trend will be maintained towards electronic control of the throttle chamber in conjunction with injection air-amount control, drive control, traction control, etc. A control method for electronic throttle servo system is proposed, which consists of a DC motor, a throttle valve and a return spring. The control method fulfills the demand for high robustness in nonlinear opening of the throttle. In this paper, a sliding-mode controller with prescribed transient response is designed for electronic throttle chamber systems. By using a function augmented sliding hyperplane, it is guaranteed that the output tracking error converges to zero in a finite time. Simulation and experimental results are shown for the confirmation of effectiveness of the sliding-mode controller with prescribed transient response.

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In scissors game, one should change his/her strategy when the opponent change his/her strategy. In this paper, we propose an scissors game playing system based on neural networks. We compare several possible arichitectures and conclude that a dual system with backpropagation method wins.

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The frequency and duration of induction heating required for the detection of surface defects on a non-magnetic square billet are investigated using finite element analysis. The results indicate that a heating frequency of 50-100kHz for approximately 200ms is optimum to detect the defect signal for shallow defects.

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