End-milling is intermittent cutting process performed by a tool with a number of teeth. Its cutting forces are commonly measured by the tool dynamometer which has rectangular coordinates. In this case, the pattern of cutting forces is different according to cutting conditions. At a certain cutting condition, the sign of cutting force changes from positive to negative during a revolution of one tooth. The change of force direction excites a cutting tool and severe vibration arises when radial depth of cut increases. In this study, cutting experiments and simulations were carried out in order to explain the cause of the change of the cutting force direction. In addition, the effect of the cutting force change was discussed in terms of chatter vibration in end milling.

This paper describes the development of a high-precision measuring device with DSP (digital signal processor) for the accurate measurement of the 6-axis force/moment sensor mounted to a humanoid robot’s ankle. In order to walk on uneven terrain safely, the foot should perceive the applied forces Fx, Fy, and Fz and moments Mx, My, and Mz to itself, and control the foot using the measured them. The applied forces and moments should be measured from two 6-axis force/moment sensors mounted to the feet, and the sensor is composed of Fx sensor, Fy sensor, Fz sensor, Mx sensor, My sensor and Mz sensor in a body (single block). In order to acquire output values from twelve sensors (two 6-axis force/moment sensor) accurately, the measuring device should get the function of high speed, and should be small in size. The commercialized measuring devices have the function of high speed, unfortunately, they are large in size and heavy in weight. In this paper, the high-precision measuring device for acquiring the output values from two 6-axis force/moment sensors was developed. It is composed of a DSP (150 ㎒), a RAM (random access memory), amplifiers, capacities, resisters and so on. And the characteristic test was carried out.

To measure water levels from remote cites using a narrowband channel, this paper developed a difference image based JPEG communication scheme and a water level measurement scheme using the sparsely sampled images in time domain. In the slave system located in the field, the images are compressed using JPEG after changed to difference images, among which in a period of data collection those showing larger changes are sampled and transmitted. To measure the water level from the images received in the master system which may contain noises caused by various sources, the averaging scheme and Gaussian filter are used to reduce the noise effects and the Y axis profile of an edge image is used to read the water level. Considering the wild condition of the field, a simplified camera calibration scheme is also introduced. The implemented slave system was installed at a river and its performance has been tested with the data collected for a month.

Because of the size and environment in the shipbuilding process, the portable type robot is required for the automatic seam tracking. For this reason, the structure of laser sensor should be considered in the initial design step and the coordinate transformation between welding robot and laser sensor, which is joint finder, must be identified exactly and the real time tracking algorithm based on these consideration could be developed. In this research, laser displacement sensor in which its structure is laser beam’s vertical projection, is developed to recognize the location of weld joint. In practical applications, however, images of weld joints are often degraded because of the surface specularity or spatter. To overcome the problem, the constrained joint finding algorithm is proposed. In the approach of coordinate conversion rule for the visual feedback control among welding torch, robot body and laser sensor is applied by the same reference point method. In the real time seam tracking algorithms we propose constrained sampling method which uses look ahead distance. The RLS(Recursive Least Square) filter is applied to obtain the smooth tracking path from the sensitive edge data. From the experimental results, we could see the possibility that the developed laser sensor with proposed processing algorithm and real time seam tracking method can be used as a welding under the shipbuilding condition.

The AMT(Automated Manual Transmission) has been developed by utilizing the auto clutch system and the automatic shift mechanism, to automate the clutch operation and shift operation of the existing MT(Manual Transmission). The use of hydraulic actuator for each actuator of the clutch and gear has realized a reduction of fuel consumption and exhaust emission. In this paper, we develop a simulator for the transmission control system of the AMT using AMESim. The developed simulator can be applied to design the hydraulic select actuator system of an AMT.

The vehicle dynamic control system needs to detect the yaw rate of vehicle and a yaw rate sensor is required as a central component. Therefore, A sensor on the basic of the “tuning fork method" for automotive controls is being developed. The sensor was fabricated by the surface micro machining process to miniaturize its size. The sensor output offset is 土 0.37˚sec in the room temperature. The resonance frequency of the fabricated yaw rate sensor is measured to 5.29㎑ for the drive mode. Tests of the sensor demonstrate that its performance is equivalent to that required for implementation of a yaw control system. Vehicle handling and safety are substantially improved using the sensor to implement yaw control.

This paper describes the development of the calibration system for a multi-axis force/moment sensor and its uncertainty evaluation. This calibration system can generate the continuous forces(土Fx, 土Fy and 土Fz) and moments(土Mx, 土My and 土Mz). Many kinds of multi-axis force/moment sensors in industries should be carried out the characteristic test or the calibration with the calibration system that can generate the forces and the moments. The calibration systems have been already developed are the disadvantages of the low capacity, the generation of step forces(10N, 20N …) and step moments(1Nm, 2Nm …) with weights, the high coasts in manufacture and so on. In this paper, the calibration system for a multi-axis force/moment sensor that can generate the continuous three forces and three moments was developed. Their ranges are 0~2000N in all force-directions and 0~400Nm in all moment-directions. And the system was evaluated in the expanded relative uncertainty. They were 土0.0004 in all forces 土Fx, 土Fy and 土Fz, and 土0.0004 in all moments 土Mx, 土My and 土Mz.

As the structure of a mobile phone becomes thin to catch up with a slim product trend, the reliability of a LCD module is on the rise as a big issue for a product design. A drop test is the most basic and important verification method for a mechanical quality control but it requires much time and cost during a product development process. Thus many manufacturers have considered design guide lines using CAE and simulation for more effective usage of limited resources on the market. In this paper, the Maximum Principle Stress of a LCD glass panel is calculated on the basis of explicit FE Analyses method and input conditions are determined according to the general test standard. The design guideline for reliability improvements are suggested on the basis of the results of FE Analysis.

Focused ion beams are a potential tool for micro/nano structure fabrication while several problems still have to be overcome. Redeposition of sputtered atoms limits the accurate fabrication of micro/nano structures. The challenge lies in accurately controlling the focused ion beam to fabricate various arbitrary curved shapes. In this paper a basic approach for the focused ion beam induced direct fabricate of fundamental features is presented. This approach is based on the topography simulation which naturally considers the redeposition of sputtered atoms and sputtered yield changes. Fundamental features such as trapezoidal, circular and triangular were fabricated with this approach using single or multiple pass box milling. The beam diameter(FWHM) and maximum current density are 68 ㎚ and 0.8 A/㎠, respectively. The experimental investigations show that the fabricated shape is well suited for the pre-designed fundamental features. The characteristics of ion beam induced direct fabrication and shape formation will be discussed.

The novel implant system was developed using osseo-integration technology which enable amputee to overcome skin troubles in use of previous socket system and was evaluated in view of biomechanics, radiology, histology, and pathology. The osseo-integrated implants were designed and manufactured using CT image of canine’s tibia and were applied to laboratory animals(canines). The follow-up studies were performed for 24 months with 10 canines. In radiology examination, we found that the relative low strain distribution caused medial and posterior bone resorption and then we verified them by biomechanical testing. In histological approach, the complete osseo-integration was observed through the activity of osteoblast cells around bone-implant interface and the radial outer region of bone due to peristeum reaction. Lastly in pathological aspect, the evidence of superficial infection was detected but that of deep infection was not. Therefore it is thought that infection problem will be overcome by immunity of body and good hygiene.