• 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.

• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.1440-1443
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• 2004

Most previous robots had used the wheels as means for movement. These structures were relatively simple and easy to control and this is why the method had been used until currently. However, there are many realistic problems to move from one place to another in human life, for instance, steps and edges. So we need to develop the two-legged walking humanoid robot. The 2-legged walking Robot system has been vigorously developed in so many corporations and academic circles of several countries. However, 2-legged walking Robot has been mostly studied in view of the static walk. We design a stable humanoid Robot which can walk in high-speed through the research of the dynamic walk in this paper. Especially, worldwide companies have been interested in developing humanoid robots for a long time to solve the before mentioned problems so that they can become more familiar with the human form. The most important thing, for the novel two-legged walk, is to create a stable and fast walking in two-legged robots. For realization of this movement, an optimal mechanical design of 12 DOFS, a distributed control and a parallel processing control are implemented in this paper. This paper proves that high speed and stable walking can be achieved, through experiments.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.20 no.11
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• pp.74-79
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• 2021

Generally, multi-legged walking robots have excellent mobility in rough and uneven terrain, and they are deployed for the safety of rescuers in various disaster environments. However, as each leg is driven by a number of actuators, it leads to a complicated structure and high power consumption; therefore, it is difficult to put them into practical use. In this article, a new concept is proposed of a walking robot whose legs are driven by a complex linkage structure to overcome the deficiencies of conventional multi-legged walking robots. A double crank-rocker mechanism is proposed, making it possible for one DC motor to actuate the left and right movements of two neighboring thighs of the multi-legged walking robot. Each leg can also move up and down through an improved cam structure. Finally, each mechanism is connected by spur and bevel gears, so that only two DC motors can drive all legs of the walking robot. The feasibility of the designed complex linkage mechanism was verified using the UG NX program. It was confirmed through actual production that the proposed multi-legged walking robot performs the desired motion.

• The Journal of Korea Robotics Society
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• v.14 no.4
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• pp.278-284
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• 2019

Legged locomotion has high mobility on irregular surfaces by touching the ground at discrete points. Inspired by the creature's legged locomotion, legged robots have been developed to explore unstructured environments. In this paper, we propose a modular crawler that can easily adjust the number of legs for adapting the environment that the robot should move. One module has a pair of legs, so the number of legs can be adjusted by changing the number of modules. All legs are driven by a single driving motor for simple and compact design, so the driving axle of each module is connected by the universal joint. Universal joints between modules enable the body flexion for steering or overcoming higher obstacles. A prototype of crawler with three modules is built and the driving performance and the effect of module lifting on the ability to overcome obstacles are demonstrated by the experiments.

• The Journal of Korea Robotics Society
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• v.18 no.2
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• pp.143-154
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• 2023

In this study, a fast motion planning method for the swing motion of a 6x6 wheel-legged robot to traverse large obstacles and gaps is proposed. The motion planning method presented in the previous paper, which was based on trajectory optimization, took up to tens of seconds and was limited to two-dimensional, structured vertical obstacles and trenches. A deep neural network based on one-dimensional Convolutional Neural Network (CNN) is introduced to generate keyframes, which are then used to represent smooth reference commands for the six leg angles along the robot's path. The network is initially trained using the behavioral cloning method with a dataset gathered from previous simulation results of the trajectory optimization. Its performance is then improved through reinforcement learning, using a one-step REINFORCE algorithm. The trained model has increased the speed of motion planning by up to 820 times and improved the success rates of obstacle crossing under harsh conditions, such as low friction and high roughness.

• Proceeding of EDISON Challenge
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• 2016.03a
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• pp.429-433
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• 2016

Moving robot is divided 2 kinds; one is the robot using wheels and the other has leg structure. On plat terrain, the former is better than the latter because it has fast speed and simple method to control. But on non-plat terrain, the situation is reversed. The robot using legs has slow speed but it has advantage to adjust various environments. This robot is expected to contribute to human in many fields such as rescue and exploration and so on. So walking robot is worth enough to research. In this paper, we present the design of 4-legged walking robot based on Jansen mechanism using m-Sketch and Edison Designer.

• Proceedings of the IEEK Conference
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• 2003.07c
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• pp.2721-2724
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• 2003

This paper deals with a manipulability analysis of multi-legged walking robots in acceleration domain, that is the dynamic manipulability analysis of walking robot. Noting that the kinematic structure of the walking robot is basically the same with that of the multiple serial robot system holding one object, the analysis method for cooperating robot is converted to that of walking robot. With the proposed method, the bound of achievable acceleration of the moving body is easily derived from the given bounds on the capabilities of Joint torques. Several walking robot examples are analyzed with proposed method under the assumption of hard contact, and presented in the paper to validate the method.

• Journal of Internet of Things and Convergence
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• v.6 no.3
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• pp.59-65
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• 2020

The Internet of Things (IoT) era, in which all items used in daily life are equipped with a network connection function, and they are closely linked to increase the convenience of life and work, has opened wide. Robots also need to develop according to the IoT environment. A use of new type of evolved fuzzy machine (EFM) for generating legged robot trajectory in IoT enviornmentms is discussed in this paper. Fuzzy system has been widely used for describing nonlinear systems. In fuzzy system, determination of antecedent and consequent structures of fuzzy model has been one of the most important problems. EFM is described which carries out evolving antecedent and consequent structure of fuzzy system for legged robot. To generate the robot trajectory, parameters of each structure in the fuzzy system are tuned automatically by the EFM. The results demonstrate the performance of the proposed approach for the legged robot.

• Proceedings of the KIEE Conference
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• 2003.11b
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• pp.23-26
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• 2003

The vector field histogram(VFH) uses a two-dimensional Cartesian histogram grid as a world model. The VFH method subsequently employs a two-stage data-reduction process in order to compute the desired control commands for the vehicle. In the first stage the histogram grid is reduced to a one dimensional polar histogram that is constructed around the robot's momentary location. Each sector in the polar histogram contains a value representing the polar obstacle density in that direction. In the second stage, the algorithm selects the most suitable sector from among all polar histogram sectors with a low polar obstacle density, and the steering of the robot is aligned with that direction. We applied this algorithm to our four-legged robot.

• Journal of Mechanical Science and Technology
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• v.14 no.2
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• pp.131-140
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• 2000

For a walking robot with high constant body speed, the dynamic effects of the legs on the transfer phase are dominant compared with other factors. This paper presents a new force distribution algorithm to maximize walkable terrain without slipping considering the dynamic effects of the legs on the transfer phase. Maximizing the walkable terrain means having the capability of walking on more slippery ground under the same constraint, namely constant body speed. A simple force distribution algorithm applied to the proposed walking model with a pantograph leg shows an improvement in the capability of preventing foot-slippage compared with one using a pseudo-inverse method.