• Proceedings of the KIEE Conference
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• 2001.11c
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• pp.80-83
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• 2001

이족로봇이 stand-alone 형태를 가지기 위해서는 기계적인 구조가 중요할 뿐만 아니라 하드웨어시스템이 간결하게 잘 설계되어야 한다. 이렇게 하드웨어시스템이 가볍고 간결하여 설계되어야 쉽게 로봇에 장착할 수가 있다. 본 논문에서는 FPGA(Field Programmable Gate Array)를 이용해 모터 제어기를 구성해서 이족로봇을 설계하는 방법을 다루고자 한다. 본 논문에서 구성하는 하드웨어 시스템은 메인 CPU로 AM186ES를 사용하며 FPGA는 Altera사의 FLEX EPF10K20TC144-3을 사용하였다. 이와 같이 FPGA를 사용하는 하드웨어시스템은 기본적으로 VHDL언어를 사용하여 유연하게 하드웨어를 구성 할 수 있으며, 이족로봇의 여러 가지 보행 알고리즘에 능동적으로 대처할 수 있다. 뿐만 아니라 하드웨어가 간단해 지면서 가볍고 전력소모가 적으며 신뢰성 있는 시스템을 구축할 수 있다.

• Journal of KIISE:Software and Applications
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• v.36 no.2
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• pp.131-143
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• 2009

Based on the fact that a human being walks naturally and stably with consuming a minimum energy, this paper proposes a new method of generating a natural gait of 5-link biped robot like human by analyzing a COG (Center Of Gravity) trajectory of human's gait. In order to generate a natural gait pattern for 5-link biped robot, it considers the COG trajectory measured from human's gait images on the sagittal and frontal plane. Although the human and 5-link biped robot are similar in the side of the kinematical structure, numbers of their DOFs(Degree Of Freedom) are different. Therefore, torques of the human's joints cannot are applied to robot's ones directly. In this paper, the proposed method generates the gait pattern of the 5-link biped robot from the GA algorithm which utilize human's ZMP trajectory and torques of all joints. Since the gait pattern of the 5-link biped robot model is generated from human's ones, the proposed method creates the natural gait pattern of the biped robot that minimizes an energy consumption like human. In the side of visuality and energy efficiency, the superiority of the proposed method have been improved by comparative experiments with a general method that uses a inverse kinematics.

• Journal of the Korean Institute of Intelligent Systems
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• v.20 no.6
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• pp.793-798
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• 2010

In this paper we propose a low-power walking compensation method for biped robot based on consumption energy analysis. Firstly, basic walking motions that can reduce energy consumption of robot movements are implemented based on consumption energy analysis according to robot axes. We define knee bent motion as a basic walking motion. It can improve energy consumption and motion stability by lowering center of gravity of the biped robot. We analyze consumption energy of left and right leg of the robot using motor currents and propose a compensation method of walking motions to reduce unbalance of consumption energy between left leg and right leg. It can also improve energy consumption and walking stability of the robot. The proposed low-power compensation method based on consumption energy analysis is verified by walking experiments of a small biped robot with an embedded system.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.48 no.4
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• pp.33-39
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• 2011

Biped robot with high DOF has instability in mechanism. Therefore, it is important to guarantee walking stability of biped robot. Biped robot can stably walk on the flat ground using static walking patterns. However, walking stability of robot becomes increasingly worse on the uneven terrain. In the paper, we propose a robust walking algorithm of biped robot with motion stabilization to solve the problem The proposed algorithm was designed to stabilize walking motions based on the inclination of robot body using a gyro sensor and a accelerometer equipped in the center of the upper body. If unstable motions are recognized, angles of each joints are modified to increase stability by using compensation of angles of lower legs. The experimental results show that biped robot performs stable walking on the uneven terrain.

• Journal of Digital Contents Society
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• v.19 no.4
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• pp.815-819
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• 2018

In this study, we investigate balance of a biped robot applying Foot Placement Estimator (FPE) in simulation. FPE method is used to determine a stable foot location for balancing the biped robot when an initial orientation of the robot body is statically unstable. In this case, the 6-DOF biped robot with point foot is modelled considering contact and friction between foot and the ground. For simulation, the mass of the robot is 1 kg assuming the center of robot mass (COM) is located at the center of the robot body. The height from the ground to the COM is 1 m. Robot balance is achieved applying stable foot locations calculated from FPE method using linear and angular velocities, and the height of the COM. The initially unstable angular postures, $5^{\circ}$ and $-5^{\circ}$, of the robot body are simulated. Simulation results confirm that the FPE method provides stable balance of the robot for all given unstable initial conditions.

• Journal of the Korean Institute of Intelligent Systems
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• v.16 no.4
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• pp.389-395
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• 2006

This paper proposes the controller for biped robot using intelligent control algorithm. In order to simplify the complexity of biped robot control, manipulator of biped robot is divided into four modules. These modules are controlled by intelligent algorithm with Hierarchical Mixture of Experts(HME) using neural network. Also neural network having direct control method learns the inverse dynamics of biped robot. The HME, which is a network of tree structure, reallocates the input domain for the output by learning pattern of input and output. In this paper, as a result of learning HME repeatedly with EM algorithm, the controller for biped robot operating safety walking is designed by modelling dynamics of biped robot and generating virtual error of HME.

• Proceedings of the Korean Information Science Society Conference
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• 2007.06b
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• pp.363-367
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• 2007

본 논문에서는 Micro 내장형 운영체제상의 실시간 객체 엔진으로 개발한 TMO-eCos를 기반으로 TMO를 이용한 이족로봇 제어 프레임워크와 이를 활용한 실제 사람의 동작과 유사하게 이족로봇을 제어할 수 있는 응용모델에 대해 기술한다. TMO 모델을 이용한 이족로봇 제어 프레임워크는 시스템 개발을 위한 객체 기반의 규격적 단층을 제공하여 모션캡춰장비의 시그널을 분석 처리할 수 있도록 설계 구현되었다.

• Journal of the Korean Institute of Intelligent Systems
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• v.16 no.5
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• pp.601-607
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• 2006

This paper proposes a novel balance control scheme of a biped robot to predict the next position of ZMP using Kalman Filter. The mathematical model of the biped robot is generally approximated by 3D-LIPM(3D-Linear Inverted Pendulum Mode), but it cannot completely express the robot's dynamics. The stability of the biped robot depends on whether the ZMP(Zero Moment Point) position is in the stability region or out of. And the internal error between the robot mechanism and its model could affect the stability of a robot. Therefore, the proposed balance control not reduces the internal error, but also timely generates the proper control. The experiment of the proposed balance control is simulated on the virtual workspace where the biped robot may encounter with various difficulties.

• Journal of the Korean Institute of Intelligent Systems
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• v.23 no.3
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• pp.238-243
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• 2013

This paper analyzes a virtual work of the knee and hip joints of bipedal walking robots. For the purpose, we consider a model of bipedal leg mechanism with a compliant foot and a typical walking pattern. We also check the torque characteristics at the joint space propagated from the space of the foot contacting a flat and stiff surface, and present the works accumulated at the joint space. As a result, it is shown that this analysis is useful for evaluating the fatigue of the leg mechanism by the physical walking contact between the foot and the surface, and it is applicable for improving the compliant characteristics at the foot space by employing a proper footgear.

• Journal of the Korean Institute of Intelligent Systems
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• v.18 no.1
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• pp.100-108
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• 2008

This paper proposes a method of adaptively generating a gait pattern of biped robot. The gait synthesis is based on human's gait pattern analysis. The proposed method can easily be applied to generate the natural and stable gait pattern of any biped robot. To analyze the human's gait pattern, sequential images of the human's gait on the sagittal plane are acquired from which the gait control values are extracted. The gait pattern of biped robot on the sagittal plane is adaptively generated by a genetic algorithm using the human's gait control values. However, galt trajectories of the biped robot on the sagittal Plane are not enough to construct the complete gait pattern because the bided robot moves on 3-dimension space. Therefore, the gait pattern on the frontal plane, generated from Zero Moment Point (ZMP), is added to the gait one acquired on the sagittal plane. Consequently, the natural and stable walking pattern for the biped robot is obtained.