• The Transactions of The Korean Institute of Electrical Engineers
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• v.63 no.5
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• pp.683-689
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• 2014

The paper introduces dynamic generation technique of foot trajectories for humanoid robots using CPG(Central Pattern Generator) and proposes adaptive walking method for slope terrains combining a feedback network. The proposed CPG based technique generates the trajectory of foot in the Cartesian coordinates system and it can change the step length adaptively according to the feedback information. To cope with variable slope terrains, the sensory feedback network in the CPG are designed using the geometry relationship between foot position and body center position such that humanoid robot can maintain its stability. To demonstrate the effectiveness of the proposed approach, the experiments on humanoid robot Nao are executed in the Webot simulation. The performance and motion features of the CPG based approach are compared and analyzed focusing on the adaptability in slope terrains.

• Journal of Advanced Navigation Technology
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• v.21 no.1
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• pp.132-137
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• 2017

This paper proposes a transformation method of the zero moment point (ZMP) and the center of mass (CoM) from one walking pattern to other patterns by considering the structure of a robot or walking situations in real time. In general, a humanoid robot has own structure characteristics like height and mass. The structure characteristics make the given CoM/ZMP walking pattern of one human or one humanoid robot to be difficult to apply to other robot directly. For this purpose, we analyze the characteristics of walking patterns according to the step length, duration of walking support phase and the CoM height by using the cart-table model as the simple humanoid robot model. A transformation equation is derived from the analyzation and it is verified with simulation.

• Journal of Platform Technology
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• v.6 no.3
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• pp.23-30
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• 2018

A motion pattern generation is a process of calculating a certain stable motion trajectory for stably operating a certain motion. A motion control is to make a posture of a robot stable by eliminating occurring disturbances while a robot is in operation using a pre-generated motion pattern. In this paper, a general method of motion pattern generation for a biped walking robot using universal approximator, learning neural networks, is proposed. Existing techniques are numerical methods using recursive computation and approximating methods which generate an approximation of a motion pattern by simplifying a robot's upper body structure. In near future other approaches for the motion pattern generations will be applied and compared as to be done.

• Proceedings of the KIEE Conference
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• 1998.11b
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• pp.552-554
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• 1998

This paper deals with the gait generation of IWR-III using a kick action to have a walking pattern like human. For this, trajectory planning with the consideration of kick action is done in each walking step, and the coordinate transformation is done for simplifying the kinematics. Balancing motion is analyzed by FDM during the walking, By combining 4-types of pre-defined steps, multi-step walking is done. Using numerical simulator, dynamic analysis, ZMP analysis and system stability is confirmed. Walking motion is visualized by 3D- graphic simulator. As a result, trunk ahead motion effect and impactless smooth walking is implemented by experiment. Finally walking with kick action is implemented the IWR-III system.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2013.05a
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• pp.1625-1626
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• 2013

• ETRI Journal
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• v.31 no.5
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• pp.565-575
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• 2009

This paper concerns the use of support vector regression (SVR), which is based on the kernel method for learning from examples, in identification of walking robots. To handle complex dynamics in humanoid robot and realize stable walking, this paper develops and implements two types of reference natural motions for a humanoid, namely, walking trajectories on a flat floor and on an ascending slope. Next, SVR is applied to model stable walking motions by considering these actual motions. Three kinds of kernels, namely, linear, polynomial, and radial basis function (RBF), are considered, and the results from these kernels are compared and evaluated. The results show that the SVR approach works well, and SVR with the RBF kernel function provides the best performance. Plus, it can be effectively applied to model and control a practical biped walking robot.

• 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.

• Journal of the Korean Institute of Intelligent Systems
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• v.23 no.4
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• pp.360-365
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• 2013

The paper introduces dynamic generation technique of foot trajectories using CPG(Central Pattern Generator). In this approach, the generated foot trajectories can be changeable according to variable outputs of CPG in various environments, because they are given as mapping functions of the output signals of the CPG oscillators. It enables to provide an adaptable foot trajectory for environmental change. To demonstrate the effectiveness of the proposed approach, experiments on humanoid robot Nao is executed in the Webot simulation. The performance and motion features of CPG based approach is analyzed.

• Proceedings of the KIEE Conference
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• 1999.07g
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• pp.3092-3094
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• 1999

This paper deals with the gait generation of Biped Walking Robot (IWR-III) to have a continuous walking pattern like human. For this, trajectory planning with the consideration of kick action is done in each walking step, and the coordinate transformation is done for simplifying the kinematics. The trunk moves continuously for all walking time and moves toward Z-axis. Balancing motion is acquired by FDM(Finite Difference Method) during the walking. By combining 4-types of pre-defined steps, multi-step walking is done. Using numerical simulator, dynamic analysis and system stability is confirmed. Walking motion is visualized by 3D-Graphic simulator. As a result, the motion of balancing joints can be reduced by the trunk ahead effect during kick action, and impactless smooth walking is implemented by the experiment.

• The Journal of Korea Robotics Society
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• v.2 no.4
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• pp.353-360
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• 2007

This paper proposes the trot gait pattern generation and online control methods for a quadruped robot to carry heavy loads and to move fast on uneven terrain. The trot pattern is generated from the frequency modulated pattern generation method based on the frequency modulated oscillator in order for the legged robots to be operated outdoor environment with the static and dynamic mobility. The efficiency and performance of the proposed method are verified through computer simulations and experiments using qRT-1/-2. In the experiments, qRT-2 which has two front legs driven by hydraulic linear actuators and two rear casters is used. The robot can trot at the speed up to 1.3 m/s on even surface, walk up and down the 20 degree inclines, and walk at 0.7 m/s on uneven surface. Also it can carry over 100 kg totally including 40 kg payload.