• Journal of Drive and Control
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• v.17 no.1
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• pp.44-50
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• 2020

For the requirement of accurate tracking control and the safety of physical human-robot interaction, torque control is basically desirable for humanoid robots. Because of the complexity of humanoid robot dynamics, the TDC (time-delay control) is practical because it does not require a dynamic model. However, there occurs a considerable error due to discontinuous non-linearities. To solve this problem, the TDC-FLC (fuzzy logic compensator) is applied to humanoid robots. The applied controller contains three factors: a TDE (time-delay estimation) factor, a desired error dynamic factor, and FLC to suppress the TDE error. The TDC-FLC is easy to execute because it does not require complicated humanoid dynamic calculations and the heuristic fuzzy control rules are intuitive. TDC-FLC is implemented on the whole body of a humanoid, not on biped legs even though it is performed by a virtual humanoid robot. The simulation results show the validity of the TDC-FLC for humanoid robots.

• Proceedings of the IEEK Conference
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• 2008.06a
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• pp.1059-1060
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• 2008

In this paper, using a genetic algorithm, consisting of six to seven degrees of freedom links, walking robot to up-stair that can walk to optimize energy and stability to generate. Walking robot to up-stairs of the four-step segmentation of the various situations that match the pace and pattern so that it can generate. It also generated using genetic algorithms to test for Matlab into the Robot Simulation of the humanoid experiment was used.

• Journal of Institute of Control, Robotics and Systems
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• v.18 no.9
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• pp.837-844
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• 2012

We introduce a pattern generation method for a hopping one-legged robot and verify it experimentally. The pattern is derived from the liner and angular momentum of a COM (Center of Mass), which are pre-scheduled. Because of the relation between angular velocities of joints and momemtums of the COM, joint angle trajectories are easily obtained. In addition, the landing impact force is reduced by only adjusting the landing timing. In the experiment, the one-legged robot hops in place with 0.06 s of flying time, and makes continuous hopping. Based on our experimental results, the proposed method can be applied to hopping and running of biped humanoid robots.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.131-132
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• 2011

현 시대는 로봇의 시대라 할 만큼 다채로운 로봇들이 개발되고 있으며, 인간의 기능들을 본 떠 만든 로봇 암(Robot arm: manipulator)과 워킹로봇(Walking robot: biped robot, quadruped robot, popping robot, etc.)물체인식 및 물체 추적 로봇(Tracking robot with image processing -. Domo robot, MIT.)이나 곤충과 동물 등의 생체 로봇에 대한 개발 또한 진행하고 있다. 지능형 이동로봇에서 가장중요하고 기본이 되는 기술인 무선통신망을 이용한 통신 기술과 지표면을 걷는 워킹로봇이 아닌 개활지나 밀폐된 공간에서 주행이 자유롭고 속도 및 주변 반응에 대해서 즉시 반응할 수 있는 장점을 가져 개발이용이한 바퀴를 이용한 2축 이동로봇에 관하여 연구하였다. 본 연구는 무선통신망을 이용하여 인터넷이 되는 곧 이면 어디서든 원격제어를 통하여 이동로봇을 전진, 후진, 좌회전. 우회전 및 속도제어 위치제어를 할 수 있고 GPS로 로봇의 위치와, 카메라를 이용하여 영상자료를 수집하고 센서를 이용하여 장애물 감지 및 자율주행 하는 등 여러 분야에 응용 할 수 있는 로봇을 연구하였다.

• Journal of Institute of Control, Robotics and Systems
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• v.14 no.10
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• pp.1014-1021
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• 2008

This paper proposes an intelligent sliding mode control method for robotic systems with the unknown bound of model uncertainties. In our control structure, the unknown bound of model uncertainties is used as the gain of the sliding controller. Then, we employ the function approximation technique to estimate the unknown nonlinear function including the width of boundary layer and the uncertainty bound of robotic systems. The adaptation laws for all parameters of the self-recurrent wavelet neural network and those for the reconstruction error compensator are derived from the Lyapunov stability theorem, which are used for an on-line control of robotic systems with model uncertainties and external disturbances. Accordingly, the proposed method can not only overcome the chattering phenomenon in the control effort but also have the robustness regardless of model uncertainties and external disturbances. Finally, simulation results for the five-link biped robot are included to illustrate the effectiveness of the proposed method.

• Journal of the Korea Computer Graphics Society
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• v.23 no.2
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• pp.23-27
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• 2017

We propose an inter-leg collision avoidance method that compensates the disadvantage of the data-driven biped control method. The data-driven biped control technique proposed by Lee et. al [1] sometimes generates the movement that the two legs intersect with each other while walking, which can not be realized in walking of a real person or a biped robot. The proposed method changes the angle of the swing hip so that the swing foot can move inward only after passing the stance foot. This process introduces an additional angle adjustment algorithm to avoid collisions with the stance leg to the original feedback rule of the stance hip. It generates a stable walking simulation without any inter-leg collisions, by adding minimal changes and additional calculations to the existing controller behavior.

• Journal of the Korea Convergence Society
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• v.11 no.5
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• pp.175-182
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• 2020

The calculation of the optimal trajectory of the stepped top-down robot was made using a genetic algorithm and a computational torque controller. First, the total energy efficiency was minimized using the Red-Cold Generic Algorithm (RCGA) consisting of reproductive, cross, and mutation. The reproducibility condition related to the position assembly of the start and end of the stride and the joints, angles, and angular velocities are linear constraints. Next, the unequal constraint accompanies the condition for preventing the collision of the swing leg at the corner with the outer surface of the stairs, the condition of the knee joint for preventing kinematic peculiarity, and the condition of no moment in safety in the traveling direction. Finally, the angular trajectory of each joint is defined by fourth-order polynomial whose coefficient is to approximate chromosomes. This is to approximate walking. In this study, the energy efficiency of the optimal trajectory was analyzed by computer simulation through a biped robot with seven degrees of freedom composed of seven links.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2003.05a
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• pp.309-312
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• 2003

Though a legged robot has high terrain adaptability as compared with a wheeled vehicle, its moving speed is considerably low in general. For attaining a high moving speed with a legged robot, a dynamically stable walking, such as running for a biped robot and a trot gait or a bound gait for a quadruped robot, is a promising solution. However, energy efficiency of a dynamically stable walking is generally lower than the efficiency of a stable gait such as a crawl gait. In this paper, we present an experimental study on the energy efficiency of a quadruped walking vehicle. Energy consumption of two walking patterns for a trot gait is investigated though experiments using a TITAN-VIII.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2007.05a
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• pp.295-299
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• 2007

Biped robot requires that an energy source and a control part should be installed on the body to realize active system. So, we choose the DC motor having high torque in compact size in this study. In the DC motor serve system, we choose power amplifier with analog configuration, developed the module combined the controller and the driver. We applied this module to robot actuator and studied the response characteristics in an action and a return. Main controller with serve system, loading PIC micro controller, can be load on the robot with light weight.

• Proceedings of the KIEE Conference
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• 2006.10c
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• pp.205-207
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• 2006

Since a humanoid robot inherently suffers from instability and always risks tipping itself over, or topping to the ground, it is necessary to ensure high stability and reliability of walk. An unexpected ground condition is one of the principal factors of instability. This paper proposes a walk stabilization method consisting of a Fuzzy algorithm and geometry under uneven terrain. The ground reaction forces that are measured by the FSR sensors on the sole are used to check the ground condition and the robot posture. The effectiveness of proposed method is verified by computer simulations.