Fast steering mirrors (FSMs), which are mounted on observation satellites to realize a shake correcting function, are required to have large aperture, high responsivity and multi control axes. This paper presents a tip-tilt motion controlled FSM having an 80 mm diameter mirror driven by four compact voice coil motors and supported by an elastic rod made of super elastic alloy called GUMMETAL®. Four rubber dampers are also attached to the mirror to suppress an unexpected low-frequency vibrational mode. To evaluate the effect of the elastic rod and rubber dampers on the static and dynamic performance, tip-tilt range and open-loop frequency responses of the FSM were measured with or without dampers. Each PID controller for tip-tilt and axial motion was designed based on the FSM dynamic model. The control result showed that the bandwidth of more than 2,500 Hz in the tip-tilt direction was achieved suppressing the low-frequency vibrational mode.
We have proposed automatic inspection robot mechanism to enable the inner images in facilities only by operation from the ground without a person entering. To move the camera module at the observing point, we examined the positioning mechanism as a key device. The positioning mechanism with the robot arm and L-shape guide part was developed.
We applied the robot mechanism to image the manhole inside space of telecom-infrastructure facilities. We confirmed that a whole high-resolution image of the upper floor slab in a manhole could be obtained.
This research aims to support stable operation of the plant based on time-series data obtained from sensors attached to refuse incineration plant. In this paper, for the development of advanced technology for garbage incineration, factors related to exhaust-gas, namely Nitrogen Oxides (NOx) and Carbon mono Oxide (CO) contained in the exhaust gas are analyzed with forecast error variance decomposition, based on the novel modeling focusing on common frequency of time-series sensor data. The proposed modeling and analysis method are evaluated and confirmed that causal relationship can be revealed through the actual complex data.
This paper proposes an automatic part recognition technology for 3D point cloud data of elevator shaft. The measurement system is used for elevator renewal proposal. The 3D point cloud data is measured by 3D laser scanner. A conventional method using 3D point cloud data are required by GUI-based human instruction. In order to reduce lead-time of elevator renewal proposal, Hitachi Ltd. has developed an automatic parts recognition technology and an automatic measurement technology for the 3D point cloud data of elevator shaft. The automatic parts recognition technology is characterized by graph network on voxel representation of point cloud data. These developed technologies enable to reduce 80% of field study time and drawing creation time.
In the CAM field, a lot of strategies for tool path generation are proposed. CAM operators have to select an appropriate strategy in accordance with the characteristics of the cutting surface. Then, if the generated tool path based on the selected strategy were judged as insufficient to the cutting result, i.e., surface roughness and homogeneity, another strategy have to be attempted repeatedly. Therefore, large amount of effort are required until a satisfactory tool path is obtained. In order to solve this problem, a new method of tool path generation with addable and modifiable that can be calculated with low cost is proposed in this study. This novel method enables fast addition and modification of tool paths by calculating on parametric domain of cutting surfaces expressed as parametric surfaces. Using this method, it can be expected that the CAM operators can avoid confusion in strategy selection and reduce the effort to obtain the satisfactory tool path. This report describes the basic principle and implementation of the proposed method.
In this research, a measurement system was established to simultaneously measure the demolding force, the mold temperature and the mold pressure when releasing a molded product from the core of an injection mold. By using this system, experiments were carried out to find the relationship among the demolding force, the mold temperature and the internal pressure of the mold. Further, detailed analysis of the demolding force waveforms was performed to examine the phenomenological meaning of the time historical transition in waveforms. As the result, the demolding force was derived from the measured force waveform, based on the relationship between the mold motion and the measured force signal during releasing. By examining the demolding force, mold temperature and pressure, it was found that the demolding force is greatly influenced by the mold temperature, and the relationship with the mold internal pressure was also clarified.
The purpose of this study is the proposition of a high efficient processing method of a dimple texture to promote boiling with low superheat. And, we produce a system evaluating a nuclear boiling start of the dimple texture. Using these, we compare the start of nucleate boiling and the behavior of bubbles under the condition that the aspect ratio and the contact angle of the surface are changed according to the shape parameter of the dimple. At least the aspect ratio of 0.1 is necessary for the dimple to improve the heat transfer performance of the surface. In addition, by changing the arrangement of the dimples and imparting a gradient of the contact angle, heat transfer performance is improved.