마그네슘은 20여년간 자동차 산업에서 휠소재로 사용되어 왔다. 마그네슘 휠은 무게가 알루미늄 휠보다 25% 가벼워서 주행성이 우수하다. 이 연구의 목적은 사형주조 및 영구금형주조 공정에 의한 AZ91D 합금제 췰을 개발하는 것이다 보호개스(SF6+CO2)를 사용하는 비플럭스 용해기술을 적용하여 용탕의 산화와 불순물의 유입을 배제하였다 마그네슘 용탕은 가압식 펌프시스템을 사용하여 가열된 파이프를 통하여 모울드에 자동으로 공급된다. 열처리 및 인고트의 조성에 따른 AZ91B 합금제 휠의 기계적 특성을 조사하였다.

2219 aluminum alloy bonded diamond wheels containing intermetallic compounds were fabricated by powder metallurgy method. Nickel and titanium were added in aluminum matrix piece. The hot pressing condition was and 20 Mpa in the furnace of the electric resistance type. The mechanical properties and grinding tests were carried out to confirm the wheel performance. Aluminum oxide ceramics were chosen for use in the grinding tests. The test proved that the heat resistance 2219 aluminum bonded diamond wheel containing 15 wt% nickel and 15 wt% titanium respectively showed the best performance.

본 논문에서는, 고속철도용 슬래브 궤도의 동특성을 파악하여 소음.진동 대책을 마련하기 위한 기초자료를 제시하기 위해 차륜과 레일의 상호작용을 고려한 슬래브 궤도의 진동해석을 수행하였다. 해석시 열차의 스프링아래 질량은 Hertzian스프링을 통해 레일과 접촉하는 것으로 가정하였으며, 궤도는 2중 탄성지지보로 모델링 하였다. 연구결과 궤도지지계의 탄성, 질량 및 강성 등을 적절히 조절하므로서 궤도에 발생하는 진동 및 하부구조물로 전달되는 분포력을 감소시킬 수 있음을 알 수 있었다.

A rover is a planetary surface exploration device designed to move across the ground on a planet or a planetary-like body. Exploration rovers are increasingly becoming a vital part of the search for scientific evidence and discoveries on a planetary satellite of the Sun, such as the Moon or Mars. Reliable behavior and predictable locomotion of a rover is important. Understanding soil behavior and its interaction with rover wheels—the terramechanics—is of great importance in rover exploration performance. Up to now, many researchers have adopted Bekker’s semiempirical model to predict rover wheelsoil interaction, which is based on the assumption that soil is deformable when a pressure is applied to it. Despite this basic assumption of the model, the pressure-sinkage relation is not fully understood, and it continues to present challenges for rover designers. This article presents a new pressure-sinkage model based on dimensional analysis (DA) and results of bevameter tests. DA was applied to the test results in order to propose a new pressure-sinkage model by reducing physical quantitative parameters. As part of the work, a new bevameter was designed and built so that it could be successfully used to obtain a proper pressure-sinkage relation of Korean Lunar Soil Simulant (KLS-1). The new pressure-sinkage model was constructed by using three different sizes of flat plate diameters of the bevameter. The newly proposed model was compared successfully with other models for validation purposes.

In a four-wheel independent drive platform, four wheels and motors are connected directly, and the rotation of the motors generates the power of the platform. It uses a skid steering system that steers based on the difference in rotational power between wheel motors. The platform can control the speed of each wheel individually and has excellent mobility on dirt roads. However, the difficulty of the straight-running is caused due to torque distribution variation in each wheel’s motor, and the direction of rotation of the wheel, and moving direction of the platform, and the difference of the platform’s target direction. This paper describes an algorithm to detect the slip generated on each wheel when a four-wheel independent drive platform is traveling in a harsh environment. When the slip is detected, a compensation control algorithm is activated to compensate the torque of the motor mounted on the platform to improve the trajectory tracking performance of the platform. The four-wheel independent drive platform developed for this study verified the algorithm. The wheel slip detection and the compensation control algorithm of the platform are expected to improve the stability of trajectory tracking.

When problems occurred in the unstable and/or extreme terrain environment, formal field-driving robots were unable to provide any other options such as the transformation of the wheel and body structure, and so on. For such reason, this paper proposed a novel type of integrated wheel mechanism that can be operated as a conventional driving wheel mode and hybrid wheel-leg mode in order to be negotiated in an unstable terrain environment. The mechanical effect of the proposed variable wheel mechanism was analyzed considering the geometric constraint and power requirement of the actuator for the transformation. In addition, we designed and manufactured the prototype of field-driving robot, which reliably control the variable wheel shape. Finally, the effectiveness of the variable wheel mechanism was verified by preliminary experimental approach.

꽃차의 경쟁력인 색은 심리, 커뮤니케이션 매체, 상품이미지를 구성하는 요소로 많이 사용되고 있으며 꽃차가 맛과 향에서는 커피, 녹차, 홍차 및 허브차를 따라가기 어렵지만 꽃차는 앞서 열거한 차 종류들과 비교할 수 없는 특유의 정체성인 색을 지니고 있음에도 아직도 소비자의 꽃차에 대한 의식은 맛, 향 및 기능성을 우선 찾는 것이 일반적이다. 본 연구는 먼셀 20색상환을 기본으로 한 꽃차의 색을 20색으로 꽃차식물 및 품종까지 분류해서 다른 차와의 차별성 및 정체성으로 뚜렷이 구별하여 꽃차색의 표준화를 목적으로 하고 연구방법으로 그에 해당되는 꽃차의 색 우림이 가능한 식물을 선별하여 다섯 종류로 색 분류를 하고 그들의 특성, 품종을 문헌을 통하여 조사한 결과는 다음과 같았다. 빨강(R)계열에서 빨간색(5R) 꽃 차는 맨드라미 품종 쿠루메 홍양 2호, 아미고 레드, 다홍색(10R) 꽃차는 노랑코스모스 품종 코스믹 레드, 자주색(5RP) 꽃 차는 맨드라미 품종 쿠루메 로즈, 연지색(10RP) 꽃차는 맨드라미 품종 썬데이 와인 레드가 사용되고 노랑(Y)계열의 색에서 주황색(5YR) 꽃차는 금계국 품종 썬 업, 귤색(10YR) 꽃차는 금어초 품종 스냅샷 옐로, 노란색(5Y) 꽃차는 메리골드 품종 핫팩 옐로, 국화는 품종 스카이폴 옐로, 노란연두색(10Y) 꽃차는 팬지 품종 프림로즈가 사용된다. 그린(G)계열의 색에서 연두색(5GY) 꽃차는 팬지 품종 레몬, 풀색(10GY) 꽃차는 팬지 품종 화이트블로치, 녹색(5G) 꽃차는 팬지 품종 옐로 블로치, 초록색(10G) 꽃차는 팬지 품종 오션이 사용되고 파랑(B)계열의 색에서 청록색(5BG) 꽃차는 팬지 품종 블루블로치, 바다색(10BG) 꽃차는 팬지 품종 딥블루블로치, 파란색(5B) 꽃차는 버터플라이피 품종 블루, 감청색(10B) 꽃차는 보라색 도라지가 사용되며 보라(P)계열의 색에서 남색(5PB) 꽃차는 비단향꽃무 품종 카츠 블루, 남보라색(10PB) 꽃차는 비단향 꽃무 품종 쿼테트 퍼플, 보라색(5P) 꽃차는 당아욱 딥퍼플, 붉은 보라색(10P) 꽃차는 천일홍 품종 핑퐁 퍼플이 사용된다. 꽃차는 맛이나 향보다 색이 우선하는 컬러차이므로 앞으로 꽃차의 정체성인 색에 대한 표준화, 메뉴얼화 및 상품화에 대한 후속 연구가 필요하다.

The purpose of this experimental study is to develop the waterborne silicon acrylic finishing material of parking lots. Resistance-Wheel moving load test was conducted in order to supply basic datum for developing the material by implementing modified polyamide resin. As a result, all the specimens were satisfied by the quality standard regarding dynamic wheel load resistance which is prescribed in KS F 4937. As conclusion, this study confirmed that developed finishing material could be an optimum surface finishing material capable of applying for parking lots’ floors.

In order to complement the defects of a ballasted track requiring continuous maintenance and a concrete track where the initial construction cost is expensive, research on an asphalt concrete track that is easy to maintain, economical and environmentally friendly is underway. In order to investigate the safety and the applicability of the asphalt concrete track, the test construction was carried out on the Kyeongbuk line. In this study, when the Mugunghwa train runs on the asphalt concrete track, the wheel load and lateral wheel load measured through the sensors installed at the rails were analyzed. As a result of the analysis, it was confirmed that the track performance test standard was satisfied.

This paper proposes a robust balance and driving control for omni-directional ball robot(generally called ball-bot) with two axis mecanum wheel. Slip between ball and mecanum wheel actuator inevitably occurs along diagonal axis due to its instantaneous strong torque. In order to reduce and saturate slip, exact distance calculation scheme especially for rotational movement is essential. So this research solved Euler-Lagrange dynamics for proposed two axis ball robot based on practical mechanical modeling. Robust balance control was carried out by PID controller according to the pitch and roll angles of ball robot by using sensor fusion between AHRS and wheel encoder. Proposed PID controller enhances stability by reducing steady state error and settling time. Proposed slip control algorithm for omni-directional ball robot has been demonstrated by experiments for balance control and arbitrary driving control.

Planetary exploration rovers are likely to make a trip on a winding and sloping road of irregular surfaces to the destination in order to accomplish scientific missions. One of the key technologies for rovers is a suspension for traveling and performing exploration missions; the suspension is an essential area of technology for a stable movement of a rover. In this study, an 8-wheel suspension is designed to enable efficient climbing of slopes on a passage to the destination. For the two front wheels among the eight wheels, the moment at the pivot connecting two wheels is derived when the distance between the wheels and the torque of wheels are same. A test experiment was performed to compare the magnitude of moment according to the change in tilt angle and the position of the pivot. Finally, a suspension design considering the position of the pivot was proposed to enhance the hill-climbing performance.