Masanori Itoh’s scientific contributions

A new method for designing a discrete time adaptive control system is presented for a single-input, single-output, time-varying plant with known dead time. It is assumed that the time-varying plant treated here has unknown time-varying parameters which are described by certain time function of the known form.The proposed method is based on an indirect model reference adaptive control algorithm with predictor of the future value of the plant output.In this paper, first, an adaptive controller is designed for the case where the plant has a stable inverse. Next, it is shown that the proposed adaptive control algorithm guarantees the convergence of the plant output to the reference sequence. Moreover, the structure of the control system is discussed and the modification of the control system is also mentioned.Finally, the result of computer simulation of adaptive control applied to a plant with time-varying parameters is included to illustrate the effectiveness of the proposed method.

The 4th District Port Construction Bureau has planned to develop the easy operation system for bucket dredger and committed the study and the basic design of the system to the Federation of Working Vessels. In 1984, NKK was ordered to develop this system. In 1985, it was installed in Chinzeimaru No. 2. The system showed good results in performance tests and was used in the daily operation now.

This paper describes an adaptive steering system for ships that was developed by Nippon Kokan K.K. in cooperation with Yokogawa Hokushin Electric Corporation. The purpose of the system is to improve a ship's automatic steering performance under a variety of operational and environmental conditions. The techniques of hill climbing and model reference adaptive control are used in the course-keeping and course-changing modes, respectively. The results of related full-scale experiments with ocean-bound bulk carriers are presented.

An electric fuel injection system is thought to be one of the most effective methods for improving thermal efficiency of the marine diesel engine. Nippon Kokan K.K. have developed a new type of fuel injection system, which uses a hydraulic servo-mechanism and injection control system, based on an optimal control algorithm for a higher speed engine. The performance of these systems examined on the test engine showed higher controllability and a large amount of reduction of fuel oil consumption. The control algorithm was established as being applicable to the practical system with no problems.