The roller rig tester for safety performance evaluation of wheel derailment is a test facility which can give the test load condition to the test wheel, similar to the actual dynamic condition in actual running condition. This study describes the evaluation result on the durability of the resilient wheel equipped with the ring damper and the damping material, and installed in the half part of a full scaled bogie in combination with the primary spring when it rotates under the dynamic condition. The evaluation result on durability of resilient wheel after load test of 2 million cycles shows that the safety of wheel is not affected by the applied load in visual inspection and nondestructive test, however, in the bolt used for fastening the ring damper to the wheel the loosening was found. Accordingly the use of self-locking nut and washer is recommended.

In this paper, we studied the steering performance of wheelset with primary suspension characteristics of railway vehicle. We carry out dynamic analysis and experimental study for the vehicle models which are different primary suspension characteristics. The steering angle of a vehicle model (Case 1) operating in domestic subway lines is insufficient compared with an objective steering angle for curved track. And the steering angle of a vehicle model (Case 2) with improved self-steering performance of wheelset is a little improved compare to previous vehicle model. But also Case 2 model is still insufficient compared with an objective steering angle and has its limit in steering performance. So to overcome this limit of steering performance of passive type railway vehicle, an active steering technology is being developed. In case of vehicle model with active steering system, the steering performance is improved remarkably compared to passive type vehicle model.

Railway vehicles driven by wheels obtain force required for propulsion and braking by adhesive force between wheels and rails, this adhesive force is determined by multiplying adhesion coefficient of the friction surface by the applied axle load. Because the adhesion coefficient has a peak at certain slip velocity, it is important to determine the maximum values of the friction coefficient on the contact area. But this adhesive phenomenon is not clearly examined or analyzed. Thus we have developed new test procedure using the scaled adhesion test-bench for analyzing of the adhesion coefficient between wheel and rail. This adhesion test equipment is an experimental device that contacts mutually with twin disc which are equivalent to wheels and rails of railway vehicles.

In the development of a vibration-based condition monitoring system in gearbox, one of the most important research topics is a quantitative analysis and test of the effect of gear damage on vibration of gearbox. This paper presents the evaluation result of vibration condition indicator according to the gear tooth damage through the vibration test of gearbox. The dynamic load test was performed with high speed railway (KTX)’s gearbox. The vibration of gearbox was measured according to a rotational speed change with the common gear fault modes, such as pitting and tooth breakage. The characteristics and the possibility of applying of vibration condition indicator on condition monitoring system were analyzed. As a result, the value of most condition indicator is gradually increased with the severity of gear faults. The NA6 indicator shows a low variation with the rotational speed change and high sensitivity in accordance with the gear fault.

There is a large interest to find reliable and automatic methods for crack detection and quantification in the railway bogie frame. The non-destructive inspection of railway bogie frame has been performed by ultrasonic and magnetic particle testing in general inspection. The magnetic particle method has been utilized in the defect inspection of the bogie frame but the grinding process is required before inspection and the dust is developed resulting from the processing. The objective of this paper is to apply the inspection method of bogie frame using infra-red thermography. The infra-red thermography system using the excitation of eddy current was performed for the defect evaluation of weld specimen inserted artificial defects. The result shows that the infra-red thermography method can detect the surface and inner defects in weld specimen for bogie frame.

Conventional etching technology is in the face of problems such as dishing, erosion resulting from non-uniform removal of film. Advanced printed circuit board (PCB) requires accurate wire formation with the aid of planarization by chemical mechanical polishing (CMP). Linear roll CMP is a line contact continuous process which removes the film by pressurization and rotation while slurry is supplied to polishing pad attached to the roll. This paper focuses on the design of floating nozzle on the linear roll CMP equipment which makes the slurry supply uniformly on the roll pad. Experimental results show that removal rate using the floating nozzle increases 3 times higher than that without it and non-uniformity is less than 15%.

In this study, we proposed a three-dimensional (3D) scanning system based on laser-vision technique and rotary mechanism for automatic 3D model reconstruction. The proposed scanning system consists of a laser projector, a camera, and a turntable. For laser-camera calibration a new and simple method was proposed. 3D point cloud data of the surface of scanned object was fully collected by integrating extracted laser profiles, which were extracted from laser stripe images, corresponding to rotary angles of the rotary mechanism. The obscured laser profile problem was also solved by adding an addition camera at another viewpoint. From collected 3D point cloud data, the 3D model of the scanned object was reconstructed based on facetrepresentation. The reconstructed 3D models showed effectiveness and the applicability of the proposed 3D scanning system to 3D model-based applications.

Multi-axis magnetic and accelerometer sensor are widely used in consumer product such as smart phones. The vector output of multi-axis sensors have errors on each axis such as offset error, scale error, non-orthogonality. These errors cause many problems on the performance of the applications. In this paper, we designed the effective inline compensation algorithm for calibrating of 3 axis sensors using ellipsoid for mass production of multi-axis sensors. The outputs with those kinds of errors can be modeled by ellipsoid, and the proposed algorithm makes sequential mappings of the virtual ellipsoid to perfect sphere which is calibrated function of the sensor on three-dimensional space. The proposed calibrating process composed of four main stages and is very straightforward and effective. In addition, another imperfection of the sensor such as the drift from temperature can be easily inserted in each mapping stage. Numerical simulation and experimental results shows great performance of the proposed compensation algorithm.

This paper describes the design of the force measuring system for an industrial robot’s deburring work. The force measuring system is composed of a three-axis force sensor, a measuring device, a housing and a cover. The three-axis force sensor can detect x-direction force, y-direction force and z-direction force at the same time. The measuring device is designed using DSP(Digital Signal Processor), and have a RS-232 and a RS-485 communication port for sending force data to PC or other controller. As a result of test, the repeatability error and the non-lineality error of the three-axis force sensor are less than 0.03%, and the interference error of the sensor is less than 0.95%. It is thought that the force measuring system can be used for an industrial robot’s deburring work.

This paper presents control performance improvement by modifying center of gravity (COG) of an underwater robotic platform. To reduce the oscillation or to increase the positioning accuracy, it is important to accurately know the COG of an underwater robotic platform. The COG is determined by the three measured tilting angles of the platform in different postures. The tilting angle is measured while the platform is hanged by two strings. Using coordinate transformation, the plane of intersection is defined from the angle of the platform and the position of the string. The COG of the robotic platform is directly calculated by the intersected point in three defined planes. The measured COG is implemented to the control algorithm that is pre-designed in the previous research, and the empirical result on tilting gives 48.26% improved oscillation performance comparing to the oscillation result with the ideal COG position.