• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2002년도 ICCAS
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• pp.105.6-105
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• 2002

Contents 1We developed a new type of lower part of the human-sized BWR (biped walking robot) driven by a new actuator based on the ball screw which has high strength and high gear ratio. Each leg of the robot is composed of three pitch Joints and one roll joint. In all, a 8 degree-of-freedom robot was developed. A new type of actuator for the robot is proposed, which is composed of four bar link mechanism driven by the ball screw. The BWR was designed to walk autonomously by adapting small DC motors for the robot actuators and has an embeded controller system including host computer, batteries and motor drivers. In the performance test, we had basic stable walking data so far, but we f...

• Journal of the Korean Society for Precision Engineering
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• 제19권10호
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• pp.139-146
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• 2002

We developed a motion capture system to utilize informations on the human walking motion. The system is composed of the mechanical and electronic devices to obtain the joint angle data and the software to analyze the obtained data and to transform the data into the input for a biped walking robot. The mechanical system is composed of a pair of links with 3 revolute joints, on which potentiometers are attached on joint axes to sense rotation angles. Analog signals from potentiometers are transformed into the digital data through the low pass filter and the A/D converter, and then which are stored at the computer. We analyzed the walking characteristics by applying FFT to the digital data, and then performed a 3-D computer simulation using the data. Finally, We apply the processed data to a biped walking robot.

• Journal of the Korean Society of Industry Convergence
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• 제17권4호
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• pp.245-254
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• 2014

In this paper, stable and robust dynamic walking for a biped motion is proposed. To success this objective, the following structures are processed. In this paper, the proposed control method is one that adjusts actual zero moment position to move to the closest possible point in the stable area instead of following desired zero moment position. This minimizes energy consumption with the smallest joint movements. The proposed control method makes mechanical energy that drives lower limb of the bipedal robot efficient. In this paper, walking experiment is carried out with the three control structures mentioned above. The trajectory generated by off-line is illustrated by performing to walking on flat ground. experiment with an obstacle whose height is lower than that of trajectory is executed to validate dynamic motion.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2005년도 ICCAS
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• pp.2132-2137
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• 2005

This paper is concerned with computer simulations of a biped robot walking in dynamic gaits. To this end, a three-dimensional robot is considered possessing a torso and two identical legs of a kinematically ingenious design. Specific walking patterns are off-line generated meeting stability based on the ZMP condition. Subsequently, to verify whether the robot can walk as planned, a multi-body dynamics CAE code has been applied to the corresponding joint motions determined by inverse kinematics. In this manner, complex mass effects could be accurately evaluated for the robot model. As a result, key parameters to successful gaits are identified including inherent characteristics as well. Also, joint actuator capacities are found required to carry out those gaits.

• Journal of the Korean Institute of Intelligent Systems
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• 제16권5호
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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.

• Proceedings of the KIEE Conference
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• 대한전기학회 2002년도 합동 추계학술대회 논문집 정보 및 제어부문
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• pp.169-172
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• 2002

This paper is concerned with walking trajectory generation by applying the genetic algorithm. The walking trajectory is generated though three via-points and genetic algorithm is employed to find velocity and acceleration at each via-point. Also genetic algorithm is applied for balancing joint trajectory. Fitness function is used for minimizing the trajectory. As a result, new algorithm generated the smooth trajectory. The proposed algorithm is verified by the experiment of biped walking robot developed in our Control laboratory, and we compared the result with the previous walking algorithm. It showed that the new proposed algorithm generated the better walking trajectory.

• Journal of the Korean Society for Precision Engineering
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• 제23권4호
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• pp.75-82
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• 2006

In this paper, we propose an optimal trajectory for biped robots to move up-and-down stairs using a genetic algorithm and a computed-torque control for biped robots to be dynamically stable. First, a Real-Coded Genetic Algorithm (RCGA) which of operators are composed of reproduction, crossover and mutation is used to minimize the total energy. Constraints are divided into equalities and inequalities: Equality constraints consist of a position condition at the start and end of a step period and repeatability conditions related to each joint angle and angular velocity. Inequality constraints include collision avoidance conditions of a swing leg at the face and edge of a stair, knee joint conditions with respect to the avoidance of the kinematic singularity, and the zero moment point condition with respect to the stability into the going direction. In order to approximate a gait, each joint angle trajectory is defined as a 4-th order polynomial of which coefficients are chromosomes. The effectiveness of the proposed optimal trajectory is shown in computer simulations with a 6-dof biped robot that consists of seven links in the sagittal plane. The trajectory is more efficient than that generated by the modified GCIPM. And various trajectories generated by the proposed GA method are analyzed in a viewpoint of the consumption energy: walking on even ground, ascending stairs, and descending stairs.

• Journal of the Korean Institute of Intelligent Systems
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• 제24권5호
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• pp.477-481
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• 2014

Human has various types of emotions which affect speculation, judgement, activity, and the like at the moment. Specifically, walking is also affected by emotions, because one's emotion status can be easily inferred by his or her walking style. The present research on biped walking with humanoid robots is mainly focused on stable walking irrespective of ground condition. For effective human-robot interaction, however, walking pattern needs to be changed depending on the emotion status of the robot. This paper provides analysis and comparison of gait experiment data for the men and women in four representative emotion states, i.e., joy, sorrow, ease, and anger, which was acquired by a gait analysis system. The data and analysis results provided in this paper will be referenced to emotional biped walking of a humanoid robot.

• Transactions of the Korean Society of Mechanical Engineers A
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• 제30권6호
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• pp.643-652
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• 2006

This paper is concerned with computer simulations of a biped robot walking in static and dynamic gaits. To this end, a three-dimensional robot is considered possessing a torso and two identical legs of a typical design. For such limbs, a set of inverse kinematic solutions is analytically derived between the torso and the feet. Specific walking patterns are off-line generated meeting stability based on the VPCG or ZMP condition. Subsequently, to verify whether the robot can walk as planned in the presence of mass and ground effects, a multi-body dynamics CAE code has been applied to the resulting joint motions determined by inverse kinematics. As a result, the key parameters to successful gaits could be identified including inherent characteristics as well. Upon comparisons between the two types of gaits, dynamic gaits are concluded more desirable for larger humaniods.

• Proceedings of the KIEE Conference
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• 대한전기학회 1996년도 하계학술대회 논문집 B
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• pp.1228-1230
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• 1996

A neural network(NN) mechanism is proposed to modify the gait of a biped robot that walks on sloping surface using sensory inputs. The robot starts walking on a surface with no priori knowledge of the inclination of the surface. By accumulating experience during walking, the robot improves its walking gait and finally forms a gait that is adapted to the surface inclination. A neural controller is proposed to control the gait which has 72 reciprocally inhibited and excited neurons. PI control is used for position control, and the neurons are trained by a reinforcement learning mechanism. Experiments of static gait learning and pseudo dynamic learning are performed to show the validity of the proposed reinforcement learning mechanism.