In this study, a four-axis platform capable of rolling, pitch, and yaw rotation was created for rehabilitation and exercise. Based on this, a virtual coach and a virtual reality game system were developed. The virtual coach is a 3D person model created with the Unity program that allows the user to exercise in the correct posture with the virtual coach, and recognizes the correct posture with the Kinect. Additionally, a virtual reality game has been developed, and in conjunction with this, the actual platform also moves to increase the rehabilitation effect. The upper body and lower body movement and plantar pressure measurement were used to associate with the four-axis platform to maintain strength and balance the body.

In this paper, we studied a new vacuum caterpillar drive system that can be used for solar panel cleaning robots. The conventional vacuum caterpillar structure has an issue, in that the vacuum hose becomes twisted. As a result, we designed a new vacuum caterpillar structure with no vacuum hose kinks. Also, we verified that no issues concerning flow analysis exist with this new system. We found that this system with the proposed vacuum caterpillar structure has an appropriate performance as a solar panel cleaning robot for practical use.

A design and analysis for new foot sensor that measures pressure distribution while walking or running in daily life is introduced. In the process of the sensor design, the shape, mechanism composing of the sensor, and variables that dominate sensor’s sensitivity are investigated. Through these variables analysis, an optimal shape and dimension were determined. The effects of variables on sensor’s sensitivity and the relationship between each variable are proved by analyses and experiments.

The purpose of this study is to establish the analysis method for prediction of temperature during cryogenic heat treatment. Experimental cryogenic heat treatment is conducted to observe the phenomena such as boiling of fluid, ice layer on the material surface and to measure the temperature distribution of Al6061 tube. The CFD analysis considering the observed phenomena in the experiment is performed to predict the temperature distribution and convection heat transfer coefficient at each stage of cryogenic heat treatment, in which the boiling of fluid is considered as the multi-phase condition of vapour and liquid. The formation of ice layer on the tube surface is also modeled between material and fluid. The predicted results are in good agreement with the experimental ones. From the results, it is shown that the analysis method can predict the temperature distribution and convection heat transfer coefficient during cryogenic heat treatment.

This paper deals with the aspects of die design for the multistage fine tooth hub gear in the cold forging process. In order to manufacture the cold forged product for the precision hub gear used as the ARD 370 system of bicycle, it examines the influences of different designs on the metal flow through experiments and FE-simulation. To find the combination of design parameters which minimize the damage value, the low gear length, upper gear length and inner diameter as design parameters are considered. An orthogonal fraction factorial experiment is employed to study the influence of each parameter on the objective function or characteristics. The optimal punch shape of fine tooth hub gear is designed using the results of FE-simulation and the artificial neural network. To verify the optimal punch shape, the experiments of the cold forging of the hub gear are executed.

In this study, to improve the formability of the rear floor in series stamping process, the method for predicting the temperature of tools and steel sheet is proposed using FE analysis. To do this, tensile tests and straight pulling friction tests of three steel sheets are carried out at temperatures up to 300℃, and the effect of temperature on the tensile properties and the characteristics of friction are examined. The steel sheets have a higher n-value in the temperature range of about 50℃ and it is related to the maximum uniform elongation. Also, the blue shortness occurs in the temperature range of about 150℃. When the temperature is higher than 200℃, the friction coefficient increase with increasing temperature. From the FE-simulation, the effects of the punch temperature considering heat expansion in the number of stamping are examined and discussed. The technique developed in this study for estimating tool temperature can be used to develop more feasible ways to improve continuous productivity in series stamping process.

In the hot forging process lubricant influences on frictional condition only, but in the warm forging process it influence on the formability such as dimensional accuracy, filling state and frictional condition and it is important to estimate a lubricating characteristic of lubricants in the warm forging. In this paper, in order to evaluate the formability of billet in warm forging process according to the lubricant and lubricating method, lubricant and lubricating test have been performed using oil-based and water-based lubricant which were widely used in the hot and warm forging processes. The surface roughness of initial billet was measured to evaluate the influence on the formability of billet and the forming load and dimensional accuracy were compared and evaluated. From the experimental results, it can be known that water-based lubricants are more excellent than oil-based lubricants for warm forging of complex shape like a bevel gear. Also, in this study characteristics of deformation have been investigated according to surface treatment of initial billet.

Die design to minimize the die wear in the cold forging process is very important as it reduce the production cost and the increase of the production rate. The quantitative estimation for the die wear is too hard because the die wear is caused by many process variables. So, in this paper, the optimal shape of the backward extrusion punch is newly designed through the FE-analysis considering the surface expansion and Archard wear model in order to reduce the rapid wear rate that is generated for the backward extruded products exceeding the forming limit. The main shape variables of the backward extrusion punch are the flat diameter, angle, and round of the punch nose part. As the flat diameter and angle of the punch nose are larger, the surface expansion is reduced and the wear rate is decreased according to the reduction of the punch round. These results obtained through this study can be applied to the real manufacturing process.