The next generation coastal ship "Shige-Maru" has a new onboard LAN (Local Area Network) system configured to achieve labor savings. In the deck department, a control LAN system was developed to effectively support each phase of ship operation, such as navigation, maneuvering, anchoring, berthing, mooring and cargo handling. On the other hand, in the engine and ship management departments, an information LAN system was developed to comprehensively handle and manage voyage data, machinery data, running maintenance information, onboard affairs data, etc. The control and information LAN systems are mutually connected and designed to exchange various data. In this paper, the required specifications, research tasks and results of the Integrated Control and Information LAN System are described
Efforts to improve engine performance have led to a tendency to increase the maximum combustion pressure (Pmax) in an engine. This leads to the cylinder head gasket sealing being exposed to tough conditions which can result in gas leakage. This problem has become important in recent years and its solution is required. In the present study, the relationship between the deformation in the lower surface of the cylinder head due to Pmax and the primary seal part of a gasket which is the edge of the circumference of a cylinder is discussed. The reinforcement of the secondary seal part in the gasket structure which is a new viewpoint in gasket sealing and its validity are also discussed.
In a previous paper, the authors proposed a new system for ship stability, i.e., a horizontal slider type parallel mechanism, and presented its performance based on a kinematic model. In this paper, the construction of the actual system and the control method by which to effectively move the mechanism are introduced. The application of this system for assisting a pilot getting on/off ships by decreasing motion such as rolling, pitching, yawing, and heaving was discussed. The performance of this system was confirmed with simulation based on the test results of the actual system. The results showed good potential for practical application.
The authors proposed and designed a robot for underwater work. The underwater robot has a rectangular plane body with 4 legs at each corner. The parallel link leg mechanism consists of 2 or 3 cylinders whose ends are attached to the robot body with free rotational joints. The ends of both piston rods are connected with pin joints. The movement of the leg which is composed of 2 cylinders is restricted to the forward and backward directions. However, the 3 cylinder leg can move in any direction. The authors studied the walking control scheme for this robot considering smooth and steady movement without rolling, pitching, yawing, and heaving motion while keeping the robot's body horizontal. The authors also confirmed the validity of the control scheme through simulation and experiments.
The cyclone separator has been used for the separation of particles or dust in a gas or liquid stream. High separation efficiency can be obtained at the high centrifugal region with a high nozzle velocity when the density of the separated material is much larger than that of the working fluid. The decrease of the separation efficiency at the low centrifugal region was studied using a liquid cyclone separator where the separated particle density is near that of the liquid. A special eddy breaker was proposed to increase the separation efficiency at the low centrifugal region. An improvement of over 20% was obtained with the insertion of an eddy breaker at the appropriate location in the liquid cyclone separator.
With regard to global warming, the reduction of carbon dioxide (CO2) emissions is a problem of great urgency. Since the thermal efficiency of a marine diesel engine is high, it is difficult to reduce CO2 emissions simply by the improvement of its thermal efficiency. For this reason, it is realistic to limit the use of fossil fuels by using bio-fuels (raw vegetable oil, waste cooking oil) as a countermeasure against global warming. The aim of this study is to develop basic technology for the clean and safe use of bio-fuels (raw vegetable oil, waste cooking oil) and blended fuels of bio-fuel and heavy oil for marine diesel engines. In this paper, the emission characteristics of a 4 stroke cycle, medium speed marine diesel engine using gas oil, marine diesel fuel (MDF), and raw rapeseed oil were investigated. The findings are as follows: (1) The CO emissions and smoke of rapeseed oil were lower than that of gas oil or MDF at high load conditions (75, 100% load), but these were higher at low load conditions (25% load). (2) Compared to that of gas oil or MDF, the NOx emissions of rapeseed oil were higher at high load conditions and lower at low load conditions.