This paper presents the results of experimental study on the effects of synchronization systems for a thyristor controlled series capacitor (TCSC). A comparison has been made between two different synchronization schemes : synchronization with respect to zeros of TCSC capacitor voltage and synchronization with respect to zeros of line current. No such comprehensive investigation has been reported in the literature yet. A laboratory-scale TCSC has been designed, produced and installed in a laboratory power system. Effects of the two synchronization systems on the performances of TCSC have been investigated on the experimental system. Steady-state impedance characteristics, dynamic response, and instability of TCSC in a variety of operating conditions have been compared. Both advantages and disadvantages of the two synchronization systems have been clarified in this paper.
It is a point in dispute whether “Shinsou-Senjimon”, which is one of ancient manuscripts written by writing-brushes, is a work that was written originally or a traced one. On the other hand, it is clearly handed down that “Souranjo” was written by “toumo” which was one of unknown skilled techniques for copying. In this paper, we compare several characters from these two ancient manuscripts by writing-brushes from viewpoints of the distribution of gray values and their gradient in the direction of making strokes by writing-brush. It is observed from the result of comparison that in the case of characters in Sinsou-Senjimon the difference in gray values of pixels in each character is large compared with that in the Souranjo.
We have proposed a task-level teaching system, in which operators can make programs for robots as if giving directions to persons to do so. This system has three main features. First, by describing the main task and the failure recovery sequence separately, operators can get detailed command sequence with parts sending a signal from the robot to peripheral equipment and vice versa. Second, operators don't have to make a dedicated menu on each task, because our system automatically generates the menu. Third, our language has the function to generate a collision avoidance trajectory. So the entire operation time could be short. This paper will introduce the basic idea of our new system, and demonstrate its availability by showing a prototype system.
In this paper we consider a J-spectral factorization problem for a rational spectral matrix. The problem considered here is called the standard J-spectral factorization problem (S-J-SFP) since it is applicable to the standard H∞ control problem for a descriptor system (DS). Based on DS representation of the spectral matrix, we derive a solution to the S-J-SFP using a stabilizing solution of an indefinite generalized algebraic Riccati equation (GARE). The main result of this paper includes the well-known solution to the canonical J-spectral factorization problem (C-J-SFP).
A new gauge control system for hot finishing mills has been developed to distribute the mill motor power of each stand. The new system has the following features : (a) Interstand exit gauge is calculated based on the law of mass flow constancy using the exit thickness gauge. (b) The design strategy of the new system are to cope with a detection time delay, and to simplify the controller to easily tune during actual implementation. (c) The H∞, controller with two degrees of freedom is designed to obtain high responses of the reference and disturbance. The performance of the controller is evaluated by numerical simulation. The effectiveness of the new system has been shown by application in an actual plant.
This paper deals with a method of keeping production smoothing in JIT production systems with machine breakdowns. In general, when the production smoothing is disturbed by machine breakdowns in a JIT production system, all processes are suspended in order to keep the production smoothing. However, if the suspended time becomes very long, the production cost becomes large. To cope with the problems occurred in the production smoothing system, we propose a method to minimize the production cost and to keep the production smoothing. In this paper, we develop the two kind models of production smoothing systems and evaluate the method by computer simulations.
In this paper, we study supervisory control of partially observed discrete event systems with arbitrary control patterns. We assume that the desirable behavior is specified as a nonempty and closed language. We present a necessary and sufficient condition for the existence of a supervisor which achieves the desirable behavior under partial observation. We also consider the case that there does not exist a supervisor for a given specification language under the assumption that the set of control patterns is closed under union. We present a sublanguage of the specification language for which a supervisor exists.
The principle and the results of an experimental study concerning a new high-power and high-performance inverter drive system will be presented. One usual method of supplying large vector-controlled a.c. drives rated at more than several thousands kW is to combine the outputs of the two inverters using inter-phase reactors. But inter-phase reactors have problems of acoustic noise and high losses, and in addition, are bulky and expensive. Therefore, the new proposal we present offers a new approach to the solution of the above-mentioned problems. In this paper, the principle of the γ-δ decoupling current controller using matrix theory, the experimental setup of the system, the software of the DSP, and experimental results will be explained. The experimental results show a completely γ-δ decoupling current control of the primary and the secondary magnetizing and torque currents.