This study attempted to experimentally confirm the change in damping force for a prototype self-leveling damper with a pump rod and a leveling port applied with a new spiral flow path for small and medium-sized electric SUVs. The faster the excitation speed of the piston rod, the higher the damping force during compression and rebound and it can be seen that the graph shape appears in a similar pattern. Based on this, it can be used as basic data for additional characteristic tests such as temperature, sliding resistance, and operating sound test, etc.

A spiral flow path was applied to solve the problem of the existing straight flow path in the leveling shaft, a key component of the self-levelizer that can maintain the height according to the change in payload in EV, SUV. In this study, flow analysis was performed to check the velocity, pressure drop, and flow direction of oil according to the main operating conditions of the leveling shaft with a spiral flow path. As a result of the study, a leveling shaft with a spiral flow path is likely to improve fluid properties around the orifice and inlet valve under compression conditions, and it is judged to have a development application effect.

To make a satisfactory decision regarding project scheduling, a trade-off between the resource-related cost and project duration must be considered. A beneficial method for decision makers is to provide a number of alternative schedules of diverse project duration with minimum resource cost. In view of optimization, the alternative schedules are Pareto sets under multi-objective of project duration and resource cost. Assuming that resource cost is closely related to resource leveling, a heuristic algorithm for resource capacity reduction (HRCR) is developed in this study in order to generate the Pareto sets efficiently. The heuristic is based on the fact that resource leveling can be improved by systematically reducing the resource capacity. Once the reduced resource capacity is given, a schedule with minimum project duration can be obtained by solving a resource-constrained project scheduling problem. In HRCR, VNS (Variable Neighborhood Search) is implemented to solve the resource-constrained project scheduling problem. Extensive experiments to evaluate the HRCR performance are accomplished with standard benchmarking data sets, PSPLIB. Considering 5 resource leveling objective functions, it is shown that HRCR outperforms well-known multi-objective optimization algorithm, SPEA2 (Strength Pareto Evolutionary Algorithm-2), in generating dominant Pareto sets. The number of approximate Pareto optimal also can be extended by modifying weight parameter to reduce resource capacity in HRCR.

This study is implemented the impact analysis of leveling system used to maintain the level of jacket structure in construction of jacket structure for wind turbine which widely used in offshore wind power. The major problem during the construction of offshore wind power is that a tower or bottom structure which are supporting structures of the generator are passing above the jacket, and it is necessary to maintain its leveling by accurately measuring the level of the jacket while constructing. Due to its purpose, the level of jacket is adjusted with the leveling system which operates hydraulically, but the leveling system inevitably exposed to the impact load during the pile drive. This study interpreted the influences of impact during the design or construction of the leveling system by considering the interaction between the ground and the jacket structures.

In this paper, we developed the hydraulic leveling jack(HLJ) with double-tube type structure which could be applicable to excessive lateral load area. In order to develop HLJ, the design requirements, such as the vertical and lateral loads where applied to hydraulic jack, were selected. To verify the structural stability of the HLJ, the structure analysis was performed. In order to verify the operational performance and structural stability of the developed HLJ, test bench was designed. The performance of HLJ was verified via various test using test bench.

In this paper, the design of hydraulic system for leveling control of a large vehicle was developed. The hydraulic system for leveling control was consisted of four hydraulic actuators and two gravity referenced inclinometer. In order to verify the effectiveness of leveling system via simulation, Hydraulic actuators, vehicle and control algorithm were modeled using ADAMS which is a commercial dynamic analysis software for multi-body system. The test and simulation results of hydraulic actuator were compared and it showed the properness of simulation model. The effectiveness of hydraulic system and leveling control algorithm were verified via simulation results.

본 연구에서는 공리적 설계 방법론에서 중요한 2가지 공리 중 독립공리를 시스템 개발에서 설계 기준으로 적용하였다. 기능 요구사항과 대응하는 설계 파라메터는 설계행렬을 구성하고 이를 이용하여 독립공리에 부합하는 설계 파라메터의 순서를 정한 후 블록 레벨링 시스템에서의 독립적 구성요소를 판별하였다. 이러한 공리적 설계의 결과로서 설계 순서에 맞는 블록 레벨링 시스템 구성을 도출하였다. 도출된 블록 레벨링 시스템 구성의 검증과 확인을 위해 블록 조립 현장에서 사용하고 있는 3차원 좌표 측정기인 토털 스테이션을 사용하여 실제 조립이 완료된 블록에 대하여 구현된 블록 레벨링 시스템을 적용하여 데이터를 비교하는 시험을 수행하였다. 토털 스테이션의 측정 데이터와 블록 레벨링 시스템의 수신 데이터를 비교하여 1 mm 이내의 정밀도로 블록 레벨링 시스템이 동작함을 검증하고 확인하였다.

This study was conducted to investigate the effects of the pasture types and the leveling methods of winding slope land for seedbed on the runoff, soil loss, botanical composition, dry matter yield of forage and economical value at the Experimental Field

수중에서 로봇으로 사석 고르기 작업을 실시할 경우 로봇 주위의 지형 정보를 실시간으로 제공해야 원격조종이 가능하다. 현 위치로 부터 주변지형의 높낮이를 보여줘야 운전자가 작업 계획을 수립하고, 전복과 같은 사고도 예방할 수 있다. 지금까지 지형인식은 멀티 빔 소나에 의해 이뤄졌는데 이는 작업 전후의 품질을 평가하는 용도만 사용되었지 원격조종에서 필요한 실시간 정보로는 사용될 수 없었다. 본 연구는 수중 사석 고르기 작업을 위한 실시간 지형인식 방법을 개발한다. 버킷이 지면을 누를 때 전달되는 힘을 측정해 접촉여부를 판단하고, 실린더의 길이를 읽어 접촉위치를 계산한다. 버킷의 위치제어를 위해 가변 뱅뱅제어 알고리즘을 적용하고 숙련된 굴삭기 운전자의 작업패턴을 프로 그램화해 지형인식, 긁기, 밀기, 전진 등의 작업을 자동으로 수행하도록 한다. 개발된 방법은 로봇 몸체로부터 버킷의 거리에 따라 3차원 격자 지형을 상대적으로 보여줌으로써 작업자가 쉽게 지형을 인식하고 지형에 따라 작업계획을 세우도록 한다.