• Journal of the Korean Society for Precision Engineering
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• v.19 no.7
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• pp.43-50
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• 2002

This paper presents the new gait implementation of a biped robot with smooth walking using 3-dimensional continuous trunk motion and kick action of ankle joints. Trajectory generation ova trunk is performed not on a unit gait but on a whole walking interval. In applying kick action such as heel-touch or toe-off, varying coordinate system was employed for the simplification of the kinematic analysis. Desired ZMP (zero moment point) is also changed to implement the efficient kick action. As a result, balancing motion of the proposed gait was much more decreased than that of conventional one. Moreover, robot\\`s walking behavior is very smooth, natural and similar to the pace of a human. The walking experiment system is composed of eight AC servo motors and a DSP controller. The walking simulation and the experimental results are shown using the proposed new walking algorithm.

• Journal of Institute of Control, Robotics and Systems
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• v.16 no.10
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• pp.963-968
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• 2010

This paper handles ZMP based control that is inspired by neural networks for humanoid robot walking on varying sloped surfaces. Humanoid robots are currently one of the most exciting research topics in the field of robotics, and maintaining stability while they are standing, walking or moving is a key concern. To ensure a steady and smooth walking gait of such robots, a feedforward type of neural network architecture, trained by the back propagation algorithm is employed. The inputs and outputs of the neural network architecture are the ZMPx and ZMPy errors of the robot, and the x, y positions of the robot, respectively. The neural network developed allows the controller to generate the desired balance of the robot positions, resulting in a steady gait for the robot as it moves around on a flat floor, and when it is descending slope. In this paper, experiments of humanoid robot walking are carried out, in which the actual position data from a prototype robot are measured in real time situations, and fed into a neural network inspired controller designed for stable bipedal walking.

• Journal of Mechanical Science and Technology
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• v.20 no.5
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• pp.602-611
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• 2006

This paper proposes a locomotion pattern and a control method for biped robots with curved soles. First, since the contact point of a supporting leg may arbitrarily move back and forth on the ground, we derived the desired trajectory from a model called the Moving. Inverted Pendulum Model (MIPM) where the Zero Moment Point (ZMP) exists at the supporting point and can be moved intentionally. Secondly, a biped robot with curved soles is an under-actuated system since the supporting point contacting with a point on the ground has no actuator during the single supporting phase. Therefore, this paper proposes a computed-torque control for this under-actuated system using decoupled dynamic equations. A series of computer simulations with a 7-DOF biped robot with curved soles shows that the proposed walking pattern and control method are effective and allow the biped robot to walk fast and stably, and move more like human beings. Also, it is shown that the curved sole shape has superior energy consumption compared to flat soles, and greater efficiency in ascending and descending the stairs.

• Proceedings of the KIEE Conference
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• 2008.04a
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• pp.75-76
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• 2008

In oder for the robot to walk with stability, trajectory generation method for the biped robot is important. In this paper proposed the genetic algorithm to optimize biped robot motion parameters. Because most of trajectory generation, the walking parameters determined arbitrarily. Formulating the constraints of the motion parameters, and the trajectory is derived by cubic spline function. Finally walking patterns are described through simulation studies. When the ZMP(zero moment point) and DSM(dynamic stability margin) are satisfied, the walking pattern is chosen.

• Advances in robotics research
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• v.2 no.2
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• pp.151-159
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• 2018

The evolution of bipedal robots was the foundation stone for development of Humanoid robots. The highly complex and non-linear dynamic of human walking made it very difficult for researchers to simulate the gait patterns under different conditions. Simple controllers were developed initially using basic mechanics like Linear Inverted Pendulum (LIP) model and later on advanced into complex control systems with dynamic stability with the help of high accuracy feedback systems and efficient real-time optimization algorithms. This paper illustrates a number of significant mathematical models and controllers developed so far in the field of bipeds and humanoids. The key facts and ideas are extracted and categorized in order to describe it in a comprehensible structure.

• Journal of the Korean Society for Precision Engineering
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• v.22 no.3 s.168
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• pp.38-45
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• 2005

In this paper, a bird type biped robot for entertainment controlled by R/C servo motors, is built using the embedded RTOS (Real Time Operating System). ${\mu}C/OS-II$ V2.00 is used fur RTOS and the board 80C196KC for main CPU. A control algorithm of R/C servo motors is proposed on ${\mu}C/OS-II's$ preemptive and deterministic property without any extra PWM module. The realized biped robot has 19DOF, that is, 12DOF for both legs, 6DOF for both arms and 1DOF for neck. To verify the proper walking process, ZMP(Zero Moment Point) theory is applied and the simulation has been done by ADAMS.

• Journal of Electrical Engineering and Technology
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• v.10 no.6
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• pp.2368-2375
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• 2015

To accommodate various navigational commands, a humanoid should be able to change its walking motion in real time. Using the modifiable walking pattern generation (MWPG) algorithm, a humanoid can handle dynamic walking commands by changing its walking period, step length, and direction independently. If the humanoid is given a command to perform an infeasible movement, the algorithm substitutes the infeasible command with a feasible one using binary search. The feasible navigational command is subsequently translated into the desired center-of-mass (CM) state. Every sample time CM reference is generated using a zero-moment-point (ZMP) variation scheme. Based on this algorithm, various complex walking patterns can be generated, including backward and sideways walking, without detailed consideration of the feasibility of the navigational commands. In a previous study, the effectiveness of the MWPG algorithm was verified by dynamic simulation. This paper presents experimental results obtained using the small-sized humanoid robot platform DARwIn-OP.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.15 no.5
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• pp.29-36
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• 2006

The hydraulic excavators are mainly applied for excavating, public works, quarrying, etc. In some of the construction site, however, they are used for crane works of relatively light materials, although the crane works by the hydraulic excavators are forbidden by law due to the safety reasons. The major construction equipment companies in forward countries have been developing the new systems, e.g. crane works by the hydraulic excavators, and they are working in the construction site. Therefore, the new system of crane works by the hydraulic excavators should be developed for the domestic construction site in order to prevent the accident. In this paper, the fundamental study and experiment are accomplished for the crane system application on the hydraulic excavators.

• Proceedings of the KIEE Conference
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• 2006.07d
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• pp.1937-1938
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• 2006

최근 들어 안정적인 보행 패턴 생성을 위해서 많은 방법들이 제안 되고 있다. 대부분의 논문에서 주기적인 보행에 대한 연구는 이루어지고 있으나 첫 보행 구간과 마지막 보행 구간에 대한 분석은 이루어지지 않고 있다. 본 논문은 첫 보행 구간과 마지막 보행 구간에 대한 분석을 통해 기존의 역 진자 모델(Inverted pendulum model)을 기반으로 부드러운 무게 중심의 궤적을 생성하는 해석적 방법을 제안한다. 이를 위해 먼저 정현파 함수를 이용해 영 모멘트 위치(ZMP, Zero Moment Point) 궤적을 설계한다. 영 모멘트 위치 궤적 설계 시 첫 보행 구간과 마지막 보행 구간에 대해 영 모멘트 위치와 무게 중심 간의 비 최소 위상(non-minimum phase) 시스템의 특성을 이용한다. 제안된 방법을 이용하여 주기적인 보행 구간 및 첫 보행 구간과 마지막 보행 구간에서 부드러운 무게 중심 궤적이 생성됨을 시뮬레이션을 통해 구현하여 제안된 방법의 유효성을 보인다.

• Journal of Institute of Control, Robotics and Systems
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• v.13 no.4
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• pp.358-364
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• 2007

Intelligent walking modeling of humanoid robot using learning based neuro-fuzzy system is presented in this paper. Walking pattern, trajectory of the zero moment point (ZMP) in a humanoid robot is used as an important criterion for the balance of the walking robots but its complex dynamics makes robot control difficult. In addition, it is difficult to generate stable and natural walking motion for a robot. To handle these difficulties and explain empirical laws of the humanoid robot, we are modeling practical humanoid robot using neuro-fuzzy system based on the two types of natural motions which are walking trajectories on a t1at floor and on an ascent. Learning based neuro-fuzzy system employed has good learning capability and computational performance. The results from neuro-fuzzy system are compared with previous approach.