Optimizing Deep Learning Parameters Using Genetic Algorithm for Object Recognition and Robot Grasping

The performance of deep learning(DL)networks has been increased by elaborating the network structures. However, the DL netowrks have many parameters, which have a lot of influence on the performance of the network. We propose a genetic algorithm(GA) based deep belief neural network(DBNN) method for robot object recognition and grasping purpose. This method optimizes the parameters of the DBNN method, such as the number of hidden units, the number of epochs, and the learning rates, which would reduce the error rate and the network training time of object recognition. After recognizing objects, the robot performs the pick-andplace operations. We build a database of six objects for experimental purpose. Experimental results demonstrate that our method outperforms on the optimized robot object recognition and grasping tasks.

Design and Prototyping of Micro Centrifugal Compressor for Ultra Micro Gas Turbine

In order to establish the design methodology of an ultra micro centrifugal compressor, which is the most important component of an ultra micro gas turbine unit, a 10 times size of the final target compressor （impeller outer diameter 40 mm, corrected rotational speed 220,000 r/min） was designed. The problems to be solved for downsizing were examined and a 2-dimensional impeller was chosen as the first model due to its productivity. The conventional 1D prediction method and CFD were used. The prototyped compressor was tested by using cold air at the reduced speed of 110,000 r/min. Following to the 10 times model, a 5 times size of the final target model having fully 3-dimensional shape （impeller outer diameter 20mm, corrected rotational speed 500,000 r/min） was designed and tested by using hot gas at the reduced speed of 250,000 r/min.

Investigation of Surge Behavior in a Micro Centrifugal Compressor

This paper reports the experimental and theoretical study of the surge occurred in prototyping an ultra micro centrifugal compressor. As the first step, the 10 times size model of an ultra micro centrifugal compressor having the 40 mm outer diameter was designed and manufactured. The detailed experimental investigations for the transient behavior of surge with several different values of B parameter were carded out. The experimental results during the surge were compared with those obtained by the non-linear lumped parameter theory in order to validate the effectiveness of the theoretical surge model for the micro centrifugal compressor. As a result, the quite different behavior of the surge appeared for the different values of B both in the experiment and in the analysis.

Influences of Incidence Angle on 2D-Flow and Secondary Flow Structure in Ultra-Highly Loaded Turbine Cascade

An increase of turbine blade loading can reduce the numbers of blade and stage of gas turbines. However, an increase of blade loading makes the secondary flow much stronger because of the steep pitch-wise pressure gradient in the cascade passage, and consequently deteriorates the turbine efficiency. In this study, the computations were performed for the flow in an ultra-highly loaded turbine cascade with high turning angle in order to clarify the effects of the incidence angle on the two dimensional flow and the secondary flow in the cascade passage, which cause the profile loss and the secondary loss, respectively. The computed results showed good agreement with the experimental surface oil flow visualizations and the blade surface static pressure at mid-span of the blade. The profile loss was strongly increased by the increase of incidence angle especially in the positive range. Moreover, the positive incidences not only strengthened the horseshoe vortex and the passage vortex but also induced a new vortex on the end-wall. Moreover, the newly formed vortex influenced the formation of the pressure side leg of horseshoe vortex.

Design and Prototyping of Micro Centrifugal Compressor

In order to establish the design methodology of ultra micro centrifugal compressor,wich is the most important component of ultra micro gas turbine unit,a 10 times of the final target size model was designed,prototyped and tested.The problems to be solved for downsizing were examined and 2-dimensional impeller was chosen as the first model due to its productivity.The conventional 1D prediction method.CFD and the inverse design were attempted.The prototyped compressor was driven by using a turbocharger and the performance characteristics were measured.

Development of Compressor for Ultra Micro Gas Turbine

The major problems for the development of an ultra micro gas turbine system were discussed briefly from the stand point of the internal flow and the performance characteristics. Following to these, the development of ultra micro centrifugal compression systems for the ultra micro gas turbine is explained with the design and the manufacturing processes. The measured results of ultra micro centrifugal compressors are shown.

Improvement of tribological responses of sputtered MoSx films by indium ion implantation

Molybdenum disulfide (MoS_2) has been applied to various space mechanisms as solid lubricant. The tribological characteristics of sputtered MoSx films have been improved by inert gas ion implantation. We tried to extend the wear life and reduce friction coefficient by high energy implantation of indium ions. In friction tests, a pin-on-disk tester was used to measure friction coeffi- cient and wear life in a vacuum, dry air and air of 30%, 50% and 80% RH. Indium ions implanted the film at a dose of 1×10^(16) ions/cm^2 exhibited friction coefficient of 0.008 and 5.0 times longer wear life than the unimplanted ones did. However, the wear life of this film tested in high humid air presented no im- provement.