• The Journal of Korea Robotics Society
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• v.18 no.2
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• pp.172-181
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• 2023

This paper presents research on the stability of control for a quadruped robot with two different leg structure designs. The focus of the research is on the design and analysis of the leg structures in terms of their impact on the stability and robustness of the robot's motion. First, a static analysis was performed in the simulation to compare the structural strength of the legs when the same force was applied. Secondly, two quadruped robots were built, each equipped with differently designed legs, and performed trot gait walking in the real world. And the states of the robots and the torques of each joint were analyzed and compared. In conclusion, based on the results of structural analysis in simulation and the actual walking experiments with the robots, it was demonstrated that the legs designed to be structurally robust improved the control stability of the quadruped robot.

• Transactions of the Korean Society of Mechanical Engineers
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• v.14 no.6
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• pp.1455-1463
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• 1990

In this study the feasibility of a dynamic gait for a given quadruped walking robot is investigated through a computer simulation of the walking with certain drivings of the actuators. Two planar inverted pendulums are used to represent the dynamic model of the leg of the walking robot. It's gait motion is assumed to be periodic and symmetric between left and right sides only with half cycle delay. The dynamics of the walking robot is simplified by introducing two virtual legs to produce two planar inverted pendulums in two orthogonal planes and on the basis that certain legs in pair act as one. The feasibility of the dynamic gait motion is established from the following two necessary conditions:(1) The position and velocity of a foot must satisfy the stroke and velocity requirements.(2) The gait motion should be periodic without falling down. The gait feasibility test was applied to a walking robot design showing the specific acceptable speed range of the robot in trot. Also it showed that the higher body height may produce the faster trot gait.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.58 no.3
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• pp.614-620
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• 2009

The force distribution in multi-legged robots is a constrained, optimization problem. The solution to the problem is the set points of the leg contact forces for a particular system task. In this paper, an efficient and general formulation of the force distribution problem is developed using linear programming. The considered walking robot is a quadruped robot with a locked-joint failure, i.e., a joint of the failed leg is locked at a known place. For overcoming the drawback of marginal stability in fault-tolerant gaits, we define safety margin on friction constraints as the objective function to be maximized. Dynamic features of locked-joint failure are represented by equality and inequality constraints of linear programming. Unlike the former study, our result can be applied to various forms of walking such as crab and turning gaits. Simulation results show the validity of the proposed scheme.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.04a
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• pp.78-81
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• 1997

In this study, we prepose the dynamic gait in consideration of emerge efficiency. The proposed dynamic gait is applied to the quadruped walking robot and experiments are performed for real robot. We proposed the dynamic gait is diagonal gait which is modified the trot gait in consideration of energy efficiency. The proposed gait is composed of two steps. In one step, the robot walks in the trot gait. In the other step, the robot walks with making the center of gravity lie on the two legs supporting line. Realization of the diagonal intermittent trot gait is performed by open loop contal and motion planning of the proposed gait. The validity of the purposed gait is confirmed by our experiment.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.6 no.2
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• pp.300-308
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• 2002

This paper deals with the remote control of a quadruped robot by using network concept. In case we have to work out the designed plan under the irregular terrains and have the human friendly actions,. our robot will be required to have walking capability, and patterns with legs, which are designed like gaits of insert, dog and human. Our quadruped robot(called SERO) has not only the basic actions operated with sensors and actuators but also the various advanced walking trajectories, which are generated by Genetic Algorithm In addition, it has the remote controller in order to operate the remote actions such as generation of command via web browser and monitoring the robot status. In this paper the body and the controller structures are suggested and the results of kinematics analysis are also presented, All of the suggested motions of SERO are generated by PC simulation and implemented in real environment successfully.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.8 no.7
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• pp.1418-1423
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• 2004

A legged robot is friendly to human because it is resemble to human. And the robot can obtain support points freely because it has high degree of freedom for several joint as compared with a wheeled robot. Also the robot can create the relative position at desired position between support position and robot. The joint of robot cu used as manipulator. On the contrary the mechanism of robot is complicated to have many joint and moving speed is lower than wheeled robot. Also the legged robot is needed a special control not to fall on the ground because the robot is easy to vibrate when it is moving. The 4 leg structure is the minimum leg numbers not to fall and to realize safety gait continuously. A trot gait is investigated through experiments using a quadruped walking robot named TITAN-VIII.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2009.06a
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• pp.593-594
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• 2009

• Proceedings of the KIEE Conference
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• 2004.11c
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• pp.499-501
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• 2004

This paper deals with the implementation of a quadruped working robot using wireless sensor network with TinyOS. It is often required to install real time OS and wireless network in the mobile robot field since robots work alone without human intervention and also exchanging their information between robot systems. The suggested controller utilizes a built-in wireless network OS and makes the variance action related with human-kindly motions for a quadruped walking robot. In addition, a kinematics analysis of its structure and control architecture of robot system is suggested and verified the usefulness through the real experiment.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1996.11a
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• pp.815-819
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• 1996

In this work, regular rotational gaits of the quadruped crawling robot required to change its moving direction without affecting be its orientation and its static stability margin are studied. The regular rotational gaits provide the quadruped crawling robot with omnidirectional characteristics. However, the ideal foothold region for each of legs of the quadruped crawling robot is assumed for simplicity. Nonetheless, it is expected that the results of this paper will provide the insight for both design of legs of the crawling robot with omnidirectional characteristics as well as its operation of the crawling robot system with specified stability margin.

• 제어로봇시스템학회:학술대회논문집
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• 1988.10a
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• pp.113-118
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• 1988

The problem of controlling static gaits of a Quadruped Walking Robot is investigated. A theoretical approach to the gait study is proposed in which the static stability margins for periodic gaits are expressed in terms of the kinematic gait formula. The effects of the stride length to the static stability are analyzed, and the relations between the static stability and the initial body configurations are examined. Extensive computer simulations are performed to verify the analysis results.