• 제어로봇시스템학회논문지
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• 제19권12호
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• pp.1152-1159
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• 2013

This paper proposes an effective walking system for a hexapod robot on uneven terrain. To overcome the deficiencies of two-pair walking systems, which are effective on even terrain, the use of only three legs changes the steps required for movement. The proposed system receives feedback data from switches attached to the bottom of the legs and gyro sensor to carry out stable walking using the Bezier curve algorithm. From the coordinates of the Bezier curve, which guarantees the circular motion of legs, the motor's angle value can be obtained using inverse kinematics. The angle values are sent to each motor though RS-485 communication. If a switch is pushed by the surface during navigation in the Bezier curve pattern, the robot is designed to change its circular course. Through the changed course, each leg can be located on an optimal surface and the wobble phenomenon is reduced by using a normal vector algorithm. The simulation and experiment results show the efficiency of the proposed algorithm.

• 대한인간공학회지
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• 제35권5호
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• pp.319-341
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• 2016

Objective:This research analyzed the lower-limb motion in kinetic and kinematic way while walking on various terrains to develop Foot-Ground Contact Detection (FGCD) algorithm using the Inertial Measurement Unit (IMU). Background: To estimate the location of human in GPS-denied environments, it is well known that the lower-limb kinematics based on IMU sensors, and pressure insoles are very useful. IMU is mainly used to solve the lower-limb kinematics, and pressure insole are mainly used to detect the foot-ground contacts in stance phase. However, the use of multiple sensors are not desirable in most cases. Therefore, only IMU based FGCD can be an efficient method. Method: Orientation and acceleration of lower-limb of 10 participants were measured using IMU while walking on flat ground, ascending and descending slope and stairs. And the inertial information showing significant changes at the Heel strike (HS), Full contact (FC), Heel off (HO) and Toe off (TO) was analyzed. Results: The results confirm that pitch angle, rate of pitch angle of foot and shank, and acceleration in x, z directions of the foot are useful in detecting the four different contacts in five different walking terrain. Conclusion: IMU based FGCD Algorithm considering all walking terrain possible in daily life was successfully developed based on all IMU output signals showing significant changes at the four steps of stance phase. Application: The information of the contact between foot and ground can be used for solving lower-limb kinematics to estimating an individual's location and walking speed.

• 정보처리학회논문지:소프트웨어 및 데이터공학
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• 제12권5호
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• pp.237-242
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• 2023

고성능의 보행 로봇에 관한 연구가 활발하게 이루어지고 있으며 4족 보행 로봇은 비평탄 지형에서 이동성과 적응력이 뛰어나 많은 관심을 받고 있지만 높은 비용으로 도입과 활용성에 어려움이 있다. 본 논문에서는 저비용의 4족 로봇에 지능적 기능을 적용하여 활용도를 높이기 위해 임베디드 보드에 IMU와 강화학습을 탑재하여 비평탄 지형 극복능력을 개선하고 카메라와 딥러닝을 이용하여 객체를 자동으로 검출하는 방법을 제시한다. 로봇은 4족 포유류 동물의 다리 형태로 구성되고 각 다리는 3 자유도를 가진다. 설계된 3D 모델로 시뮬레이션 환경에서 복잡한 지형을 학습시키고 실제 로봇에 적용한다. 본 연구방법의 적용을 통해 평탄 지형과 비평탄 지형의 보행 능력에 크게 차이가 나지 않음을 확인하였으며 제한된 실험조건에서 실시간으로 사람 검출을 수행하는 동작을 확인하였다.

• 한국지능시스템학회논문지
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• 제21권1호
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• pp.42-48
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• 2011

본 논문은 비평탄 지형에서 능동형 보행보조기를 구동하고자 할 때, 바닥 지형에 의해 발생하는 보행의지 센서의 영향을 줄이기 위한 논문이다. 최근 보행보조기에 대한 관심이 증가되고 있으며, 외부 경사지형, 둔턱, 계단 등의 비평탄 지형에서도 안정적으로 차량을 이동시킬 수 있도록 고안된 능동형 보행보조기에 대한 연구가 진행되고 있다. 이러한 실외에서 사용되는 능동형 보행보조기에 있어 진동해석 및 비평탄 지형을 이동하면서 발생하는 기계적 충격을 줄일 수 있는 알고리즘의 개발은 능동형 보행보조기에 있어 해결해야 할 문제 중 하나이다. 이에 본 논문에서는 비평탄 지형에서의 진동을 해석할 수 있도록 가속도 센서를 적용하였으며, 둔턱을 넘을 때 발생하는 진동에 의해 보행의지 센서에 가해지는 진동에 의한 충격을 감쇠시킬 수 있는 알고리즘을 제안하였으며, 이를 실험을 통해 검증하였다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1991년도 추계학술대회 논문집
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• pp.146-154
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• 1991

As the application of robotic systems expand its scope, more research efforts are given in providing mobility to the robotic systems so that they can travel across various paths including those with formidable obstacles such as stairways or rough terrains. Legged locomotion is mainly concerned because the walking motion, like that of animal behavior, has many advantages over wheel type or track type locomotion especially in rough terrain. Walking robot, in general, having a discrete number of legs, have inherently low static stability. Static stability can be increased to a certain degree, by improving walking method, but it has many limitations such as reduced travel speed. A very promising possibility lies in the use of balancing weight, nevertheless its actual implementation is very rare. In this study, a 4-legged walking machine is developed and the static stability margin is increased with the balancing weight. In the future, this robot will be used to take an experiment on the walking in mush terrain.

• 한국정밀공학회지
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• 제16권4호통권97호
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• pp.138-147
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• 1999

For autonomous navigation, a legged robot should be able to walk over irregular terrain and adapt itself to variation of supporting surface. Walking through slope is one of the typical tasks for such case. Robot needs not only to change foot trajectory but also to adjust its configuration to the slope angle for maintaining stability against gravity. This paper suggests such adaptation algorithm for stable walking which uses feedback of reaction forces at feet. Adjusting algorithm of foot trajectory was studied with the estimated angel of slope without visual feedback. A concept of virtual slope angle was introduced to adjust body configuration against slope change of the supporting terrain. Regeneration of foot trajectory also used this concept for maintaining its stable walking against unexpected landing point.

• Journal of Mechanical Science and Technology
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• 제14권2호
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• pp.131-140
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• 2000

For a walking robot with high constant body speed, the dynamic effects of the legs on the transfer phase are dominant compared with other factors. This paper presents a new force distribution algorithm to maximize walkable terrain without slipping considering the dynamic effects of the legs on the transfer phase. Maximizing the walkable terrain means having the capability of walking on more slippery ground under the same constraint, namely constant body speed. A simple force distribution algorithm applied to the proposed walking model with a pantograph leg shows an improvement in the capability of preventing foot-slippage compared with one using a pseudo-inverse method.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2000년도 제15차 학술회의논문집
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• pp.42-42
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• 2000

This paper concerns an efficient aperiodic static crab walking algorithm for quadruped walking machine in rough terrain. In this algorithm, the requirements for forward stability margin and backward stability margin could be given differently in order to consider the slope of terrain and disturbances resulting from moving velocity. To restrict the searing regions for motion variables, such as moving distances until a leg is lifted or is placed, the standard leg transferring sequence is decided to be that of wave gaits. standard support pattern is also proposed that enables the quadruped to continue forward motion using the standard leg transferring sequence without falling into deadlock.

• 대한기계학회논문집A
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• 제22권4호
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• pp.768-778
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• 1998

Human beings usually absorb a shock from terrain during walking through the damping effects of joints, muscles and skin. With this analogy, a robot-leg with a shock absorber is built to absorb the impact forces at its foot during high-speed walking on irregular terrain. To control the hip position while walking, the dynamic controller suitable for high speed walking is designed and implemented based on a dynamic model by Kane's equation. The hip position tracking performances of various controllers (PID controller, computed torque controller and feedforward torque controller) are compared through the experiments of the real robot-leg.

• EDISON SW 활용 경진대회 논문집
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• 제5회(2016년)
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• pp.429-433
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• 2016

Moving robot is divided 2 kinds; one is the robot using wheels and the other has leg structure. On plat terrain, the former is better than the latter because it has fast speed and simple method to control. But on non-plat terrain, the situation is reversed. The robot using legs has slow speed but it has advantage to adjust various environments. This robot is expected to contribute to human in many fields such as rescue and exploration and so on. So walking robot is worth enough to research. In this paper, we present the design of 4-legged walking robot based on Jansen mechanism using m-Sketch and Edison Designer.