This paper describes the design method used in motion planning for a manipulator provided in a Remotely Operated Vehicle (ROV) . The method incorporates path planning for the manipulator tip and posture planning for the manipulator in a workspace divided into cubes. Each type of planning employs two kinds of genetic algorithms. One is used to generate suitable tip positions. The other is used to generate candidates for a secure manipulator posture that will be consistent with the tip positions. The secure manipulator posture, which avoids obstacles, is chosen from among generated candidates on the basis of an evaluation considering the drag force. The manipulator motion is planned by repeatedly executing this process. To confirm the validity of this method, an experiment was performed using the manipulator with seven degrees of freedom in an environment that included large obstacles.
In response to recent requirements for diesel engines with higher output, IHI has started developing a turbocharger having a higher pressure-ratio and volume-flow rate. One important technology for design of the turbocharger is a means of accurately evaluating the strength of turbine blades at resonance operating condition, in which serious accidents may occur through a failure of the blades now on the market. In this study, we measured resonance stress, resonance frequency, and logarithmic decrement for fluctuating flow and for non-fluctuating flow in the turbine scroll of the turbine casing. We describe the result of blade vibration measurements that were performed to clarify the influence of fluctuating flow on the resonance stress. The acquired results will contribute to safe design of a new turbine casing and turbine blade.
To improve exhaust emission characteristics of gas engine by controlling heat release rate, a multi-combustion zone model was applied to a cycle simulation program. The program was examined with the results of the single combustion test. The test results have shown to be proper for estimating the change of NOx emission when the heat release rate is changed. By inspecting with the various rates, the longer duration of high temperature in the heat release process resulted in the higher NOx emission. From the results of simulation, it has been shown to be able to improve the exhaust emission characteristics of the gas engine by controlling the heat release rate.