• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회A
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• pp.1195-1200
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• 2007

It is desirable that the guard robot should be small-sized and light-weighted to increase its portability. In addition, it should be able to overcome a relatively high obstacle to cope with different situations. The jumping robot can reach a higher place more rapidly than other locomotion methods. This research proposes the jumping mechanism based on the conical spring for a small robot. Both the clutch mechanism and conical spring are incorporated into the jumping mechanism. In the clutch mechanism, the spring can be immediately compressed and released by one actuator with the planetary gear train and one-way clutch. The robot equipped with the jumping mechanism can overcome the obstacles which are higher than its height. In this paper, the characteristic of the conical spring for the jumping robot is determined and the small-sized, lightweight jumping mechanism is developed. The validity of the jumping mechanism was verified by various experiments. It is shown that the robot using this mechanism can provide good mobility in the rough terrain.

• 제어로봇시스템학회논문지
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• 제15권11호
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• pp.1108-1114
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• 2009

Mobility is one of the most important features for a guard robot since it should be operated in rough places. A wheel-based mobile robot capable of jumping is an appropriate structure for a guard robot because it can easily satisfy the requirements for small guard robots. The jumping robot can reach a higher place more rapidly than other locomotion methods. This research proposes a small robot equipped with the jumping mechanism based on the conical spring with the variable length endtip. The variable length endtip enables the independent control of the jump force and jump angle which are related to the jump height and jump distance, respectively. Various experiments demonstrated that the proposed jumping mechanism can provide the independent control of jump force and jump angle, and improve the mobility of a small robot to overcome an obstacle. Furthermore, a combination of the jumping mechanism and the PSD sensor to measure the distance to the step enable the jumping robot to autonomously climb stairs.

• 한국군사과학기술학회지
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• 제12권5호
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• pp.563-570
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• 2009

In the future, most military activities will be replaced by robots. Because of many dangerous factors in battlefield, reconnaissance should be performed by robot. Reconnaissance robot should be small for not being detected, be light and simple structure for personal portability and overcome unexpected rough terrain for mission completion. In case of small and light robot, it can't get enough friction force for movement. Therefore small reconnaissance robot need jumping function for movement. In this paper we proposed a biologically inspired jumping mechanism. And we adjusted moment and jumping angle by using four bar linkage, especially varying coupler length.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2010년도 춘계학술대회 논문집
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• pp.317-318
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• 2010

• 대한기계학회논문집A
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• 제34권9호
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• pp.1145-1151
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• 2010

본 논문은 형상기억합금 와이어에 의해 구동되는 점핑로봇에 대한 연구로서 기구의 설계와 컴퓨터 시뮬레이션을 포함하고 있다. 인간과 같은 척추동물 하지 근골격계의 구조와 기능을 모방한 구조의 점핑 기구를 설계하였다. 점핑 기구의 각 다리는 대퇴부, 정강이, 발의 세 부분으로 구성되고, 점핑에 필수적인 단일관절근육인 대둔근, 양관절근육인 대퇴직근과 비복근을 포함하는 구조이다. 각 근육을 형상기억합금 와이어로 대체한 컴퓨터 모델로 시뮬레이션한 결과, 로봇의 최대 점핑 높이가 로봇 신장의 약 4 배임을 확인하였다. 또한 구조가 보다 단순화된 로봇 모델과 점핑 성능을 비교하였고, 그 결과 근골격계를 모방한 모델이 점핑 높이 면에서 3.3 배 우수한 것으로 나타났다. 이러한 컴퓨터 시뮬레이션을 통하여 형상기억합금이 소형 점핑로봇의 작동기로 사용하기에 적합함을 확인하였다.

• 로봇학회논문지
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• 제8권2호
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• pp.136-142
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• 2013

In nature, many small insects are using jumping as a survival strategy. Among them, fleas jump in a unique method. They use an elastomer, 'Resilin', an extensor muscle and a trigger muscle. By contracting the extensor muscle, the elastic energy, that makes a flea to jump, is stored in the resilin. After storing energy, the trigger muscle begins contracting and pulling the extensor muscle. When the extensor muscle crosses the rotational joint, direction of torque generated from the extensor muscle reverses, 'torque reversal mechanism'. Simultaneously, the elastic energy stored in the resilin releases rapidly and is converted into the kinetic energy. It makes a flea to jump 150 times its body length. In this paper, miniaturized jumping robot using flea-inspired catapult mechanism is presented. This mechanism is based on the 4-bar linkage and the reversal joint and is actuated by Shape Memory Alloy (SMA) coiled springs describing the flea's muscle. The robot prototype is fabricated by SCM process using glass fiber prepregs and a sheet of polyimide film. The prototype is 20mm link length, 34mm width and 2.0g weight and can jump 103cm.

• Earthquakes and Structures
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• 제3권5호
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• pp.675-694
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• 2012

The 2008 Iwate-Miyagi Nairiku earthquake ($M_w$ 6.9, $M_{jma}$ 7.2) occurred on 14 June 2008 in Japan. The amplification and asymmetric waveform of the vertical acceleration at the ground surface recorded by accelerometers at station IWTH25, situated 3 km from the source, were remarkable in two ways. First, the vertical acceleration was extremely large (PGA = 38.66 $m/s^2$ for the vertical component, PGA = 42.78 $m/s^2$ for the sum of the three components). Second, an unusual asymmetric waveform, which is too far above the zero acceleration axis, as well as large upward spikes were observed. Using a multidegree-of-freedom (MDF) system consisting of a one-dimensional continuum subjected to vertical acceleration recorded at a depth of 260 m below ground level, the present paper clarifies numerically that these singular phenomena in the surface vertical acceleration records occurred as a result of the jumping and collision of a layer in vertical motion. We herein propose a new mechanism for such jumping and collision of ground layers. The unexpected extensive landslides that occurred in the area around the epicenter are believed to have been produced by such jumping under the influence of vertical acceleration.

• 한국통신학회논문지
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• 제22권5호
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• pp.1116-1125
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• 1997

본 논문에서는 UPC(Usage Parameter Control) 기법의 하나인 Leaky Bucket 알고리즘에 Jumping Window 기법을 적용하여 평균비트율을 감시할 수 있는 새로운 사용 파라메터 제어 알고리즘을 제안한다. 본 논문에서 제안 알고리즈은 먼저 Leaky Bucket를 사용하여 최대비트율을 위반한 셀을 표시한 후, 만약 망으로 전송된 셀들의 평균비트율이 협약을 이하라면 표시된 셀들을 망으로 재전송한다. 평균비트율의 측정은 Jumping Window와 같은 윈도우 메카니즘을 응용하였다. 제안된 알고리즘의 성능평가를 위하여 On/Off 트래픽 소스 모델을 가정하고 시뮬레이션을 한 결과에 의하면, 제안한 알고리즘이 기존 Leaky Bucket 기법보다 셀 손실율이 저하되었고, 버킷 크기도 감소시킬 수 있었다.

• 한국운동역학회지
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• 제22권1호
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• pp.25-34
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• 2012

The purpose of this study was to determine the effects of landing height on the lower extremity during a counter movement jump. Fourteen healthy male subjects (age: $27.00{\pm}2.94$ yr, height: $179.07{\pm}5.03$ cm, weight: $78.79{\pm}6.70$ kg) participated in this study. Each subject randomly performed three single-leg jumps after s single-leg drop landing (counter movement jump) on a force platform from a 20 cm and 30 cm platform. Paired t-test (SPSS 18.0; SPSS Inc., Chicago, IL) was performed to determine the difference in kinematics and kinetics according to the height. All significance levels were set at p<.05. The results were as follows. First, ankle and knee joint angles in the sagittal plane increased in response to increasing landing height. Second, ankle and knee joint angles in the frontal plane increased in response to increasing landing height. Third, there were no significant differences in the moment of each segment in the sagittal plane for the jumping height increment. Fourth, ankle eversion moment and knee valgus moment decreased but hip abduction moment increased for the jumping height increment. Fifth, Ankle and knee joint powers increased. In percentage contribution, the ankle joint increased but the knee and hip joints decreased at a greater height. Lastly, as jumping height increased, the power generation at the ankle joint increased. Our findings indicate that the height increment affect on the landing mechanism the might augment loads at the ankle and knee joints.

• Journal of Information Processing Systems
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• 제18권3호
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• pp.332-343
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• 2022

To address the problems of the gravitational search algorithm (GSA) in which the population is prone to converge prematurely and fall into the local solution when solving the single-objective optimization problem, a sine map jumping gravity search algorithm based on asynchronous learning is proposed. First, a learning mechanism is introduced into the GSA. The agents keep learning from the excellent agents of the population while they are evolving, thus maintaining the memory and sharing of evolution information, addressing the algorithm's shortcoming in evolution that particle information depends on the current position information only, improving the diversity of the population, and avoiding premature convergence. Second, the sine function is used to map the change of the particle velocity into the position probability to improve the convergence accuracy. Third, the Levy flight strategy is introduced to prevent particles from falling into the local optimization. Finally, the proposed algorithm and other intelligent algorithms are simulated on 18 benchmark functions. The simulation results show that the proposed algorithm achieved improved the better performance.