• Proceedings of the Korean Society of Precision Engineering Conference
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• 2013.05a
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• pp.397-398
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• 2013

• Journal of Electrical Engineering and Technology
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• v.11 no.6
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• pp.1787-1792
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• 2016

Previous walking pattern generation methods could generate walking patterns that allow only straight walking on flat and uneven terrain. They were unable to generate modifiable walking patterns whereby the sagittal and lateral step lengths and walking direction can be changed at every footstep. This paper proposes a novel walking pattern generation method to realize modifiable walking of humanoid robots on unknown uneven terrain. The proposed method employs a walking pattern generator based on the 3-D linear inverted pendulum model (LIPM), which enables a humanoid robot to vary its walking patterns at every footstep. A control strategy for walking on unknown uneven terrain is proposed. Virtual spring-damper (VSD) models are used to compensate for the disturbances that occur between the robot and the terrain when the robot walks on uneven terrain with unknown height. In addition, methods for generating the foot and vertical center of mass (COM) of the 3-D LIPM trajectories are developed to realize stable walking on unknown uneven terrain. The proposed method is implemented on a small-sized humanoid robot platform, DARwIn-OP and its effectiveness is demonstrated experimentally.

• Journal of the Korean Society for Precision Engineering
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• v.28 no.4
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• pp.446-454
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• 2011

In terms of the anatomy and mechanics of the human foot, a flexible robot foot with toes and heel joints is designed for a bipedal walking robot. We suggest three design considerations in determining foot design parameters which are critical for walking stability. Those include the position of the frontal toe, the stiffness of toes and heels, and the position of the ankle joint. Compared with the conventional foot with flat sale, the proposed foot is advantageous for human-like walking due to the inherent structural flexibility and the reasonable parameter values. Simulation results are provided to determine the design parameters and also show that the proposed foot enables smaller energy consumption.

• Proceeding of EDISON Challenge
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• 2017.03a
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• pp.540-546
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• 2017

Bipedal robots tend to have greater mobility than conventional treaded or wheeled robots yet they are commonly complicated by instabilities in balance. This paper presents a bipedal robot based upon Jansen's locomotive mechanism which addresses these challenges in stability and efficiency. In order to achieve a functioning robot, we considered a multitude of variables in its motion including, the Ground Score, Drag Score, step size, foot lift, stride, and instantaneous speed of the Jansen mechanism. Matlab and Jansen Opt solver were used to optimize the legs of the robot. A trial and error experimental method was used to determine the best combination of link lengths, and m.Sketch was used to model our results. Finally, we drew the entirety of the robot's figure by using the Edison design.

• 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 the Korean Society of Industry Convergence
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• v.17 no.4
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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.

• Journal of Institute of Control, Robotics and Systems
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• v.17 no.10
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• pp.1029-1036
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• 2011

An energy-efficient reference walking trajectory generation algorithm is suggested utilizing allowable ZMP (Zero-Moment-Point) region, which maxmizes the energy efficiency for cyclic gaits, based on three-dimensional LIPM (Linear Inverted Pendulum Model) for biped robots. As observed in natural human walking, variable ZMP manipulation is suggested, in which ZMP moves within the allowable region to reduce the joint stress (i.e., rapid acceleration and deceleration of body), and hence to reduce the consumed energy. In addition, opimization of footstep planning is conducted to decide the optimal step-length and body height for a given forward mean velocity to minimize a suitable energy performance - amount of energy required to carry a unit weight a unit distance. In this planning, in order to ensure physically realizable walking trajectory, we also considered geometrical constraints, ZMP stability condition, friction constraint, and yawing moment constraint. Simulations are performed with a 12-DOF 3D biped robot model to verify the effectiveness of the proposed method.

• 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 Institute of Intelligent Systems
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• v.23 no.1
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• pp.24-28
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• 2013

In this paper, a procedure of design and development of a child-sized humanoid robot is described. The design concept for a humanoid robot was proposed and the mechanism of the humanoid robot which is more than 1 meter tall was designed by using 3D design tools. By considering the lightweight of the robot, the hardware for the robot was designed for optimal performance. The frames and links of the robot designed by 3D design tools was manufactured through precision machining with the material which is light and have a good strength. The manufactured child-sized humanoid robot was experimented with basic motions applied inverse kinematics and balance control, and the performance of the motions were verified.