• The Journal of Korean Physical Therapy
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• v.23 no.3
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• pp.21-27
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• 2011

Purpose: The purpose of the present study was to examine, in stroke patients, differences between backward walking training applied on a treadmill and the same training applied on the ground. Methods: Twenty seven stroke patients were divided into a treadmill backward walking group of 14 patients and a ground backward walking group of 13 subjects. Each group performed their respective training method for 8 weeks (15 min per day, 4 days a week). Walking ability was measured using a 10 m MWS (Maximal Walking Speed) test and the GAITRite system to examine changes in walking. Cadence, stridelength, step time, step length and symmetry index of the less affected side were measured to examine changes in stance phase of the lower extremity of the more affected side. Results: 10 m MWS, cadence, stride length, step time and step length of the less affected side significantly increased and symmetry index significantly decreased after training in both groups. The treadmill backward walking group experienced a significantly greater increase in step time and step length and a significantly greater decrease in symmetry index than the ground backward walking group. Conclusion: The two walking training methods were effective for improving stability in stance phase of the lower extremity of the more affected side, but the treadmill method was more effective. The present study is meaningful in that it analyzed the effects of backward walking training methods on walking and the differences of the training methods to provide information necessary for effective treatment of stroke patients.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.15 no.2
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• pp.125-130
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• 2016

In this paper, we deal with the dynamic walking of a humanoid robot. In our method, the inverted pendulum model is used as a dynamic model for a humanoid robot in which the Zero Moment Point (ZMP) and COG constraints of the robot are analyzed by considering the motion of the robot as that of an inverted pendulum. The motion of a humanoid robot should be generated by considering the dynamics of the robot, which commonly requires a large amount of computation. If a robot walks from one position to another while keeping the ZMP in the stable region, then the robot remains dynamically stable. The linear inverted pendulum model regards the whole robot as a point mass. It is simple, and relatively less computation is needed; however, it cannot model the whole dynamics of a humanoid robot. We propose a method for modeling a humanoid robot as an inverted pendulum system having 14 point masses. We also show that the dynamic stability of a humanoid robot can be determined more precisely by our method.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.64 no.8
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• pp.1231-1239
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• 2015

We developed a robot that has four limbs, each of which has the same kinematic structure and has 6 degrees of freedom. The robot is 600mm high and weighs 4.3kg. The robot can perform walking and manipulating task by using the four limbs selectively. The robot has three walking patterns. The first one is biped walking, which uses two rear limbs as legs and two front limbs as arms. The second one is biped walking with supporting arms, which is basically biped walking but uses two arms as supporting legs for increasing stability of the robot. The last one is quadruped walking, which uses all the four limbs as legs. When a task for the robot is given, the robot approaches the task point by selecting an appropriate walking pattern among three walking patterns and performs the task. The robot has many degrees of freedom and is a redundant system for a three dimensional task. We propose a redundancy resolution method, in which the robot’s translational move to the task point is modeled as a prismatic joint and optimal solutions are obtained by optimizing some performance criteria. Several simulations are performed for the validity of the proposed method.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.54 no.6
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• pp.376-382
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• 2005

In this paper, practical biped humanoid robot is presented, designed, and modeled by fuzzy system. The humanoid robot is a popular research area in robotics because of the high adaptability of a walking robot in an unstructured environment. But owing to the lots of circumstances which have to be taken into account it is difficult to generate stable and natural walking motion in various environments. As a significant criterion for the stability of the walk, ZMP (zero moment point) has been used. If the ZMP during walking can be measured, it is possible for a biped humanoid robot to realize stable walking by a control method that makes use of the measured ZMP. In this study, measuring the ZMP trajectories in real time situations throughout the whole walking phase on the flat floor and slope are conducted. And the obtained ZMP data are modeled by fuzzy system to explain empirical laws of the humanoid robot. By the simulation results, the fuzzy system can be effectively used to model practical humanoid robot and the acquired trajectories will be applied to the humanoid robot for the human-like walking motions.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.4
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• pp.536-543
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• 2013

In this paper, we propose a new type of hexapod robot that can walk fast. Most of the conventional hexapod robots are either rectangular type of hexagonal type. Those robots have drawbacks in the speed and stability of walking. The proposed robot has six legs, one fore leg, one hind leg, two left legs and two right legs. The proposed robot forms relatively wide supporting polygons along the walking direction, so it can walk very fast stably. We implemented the proposed hexapod robot and showed the feasibility of the robot by 3+3 walking experiment and 2+4 walking experiment.

• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.1530-1534
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• 2004

This paper presents a novel bio-mimetic quadruped walking robot with a waist joint, which connects the front and the rear parts of the body. The new robot, called ELIRO-1(Eating LIzard RObot version 1), can bend its body while the legs is transferred, thereby increasing the stride and speed of the robot. The waist-jointed walking robot can move easily from side to side, which is an important feature to guarantee a larger gait stability margin than that of a conventional single rigid-body walking robot. We design the mechanical structure of the robot, which is small and light to have high movability and high degree of human friendship. In this paper, we describe characteristics of the waist joint and leg mechanism as well as the analysis using ADAMS to select appropriate actuators. In addition, a hardware and software of the controller of ELIRO-1 are described.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.2529-2534
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• 2003

A quadruped walking robot has a superior adaptablility as well as highly adaptable mobility in various environments. These special advantages are outstanding in the mobile robot group. In this work, we introduce the method for omni-directional gait and rotational gait which is the generalized control algorithm to perform any direction commands. In addition, to improve the stability of quadruped walking robot, we performed the optimization between walking angle and sequence of feet. The proposed ideas are applied to the actual design of MRWALLSPECT III(Multifunctional Robot for Wall inSpection version 3) that is designed to inspect of the large surface of industrial utilities. By implementing the proposed idea on the robot, it’s effectiveness is experimentally confirmed.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.67 no.5
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• pp.663-668
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• 2018

A combined CPG (Central Pattern Generator) based foot trajectory and GA (Genetic Algorithm) based joint compensation method is presented for adaptive humanoid walking. In order to increase an adaptability of humanoid walking for rough terrains, the experiment for rolling terrains are introduced. The CPG based foot trajectory method has been successfully applied to basic slops and variable slops, but has a limitation for the rolling terrains. The experiments are conducted in an ODE based Webots simulation environment using humanoid robot Nao to verify a stability of walking for various rolling terrains. The proposed method is compared to the previous CPG foot trajectory technique and shows better performance especially for the cascade rolling terrains.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.134.2-134
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• 2001

This paper treats the implementation of a statically stable control system for a biped walking robot with 10 degrees-of-freedom. Statically stable walking of a biped robot can be realized by keeping the center of mass (COM) inside the sole of the supporting foot (or feet) during single-support or double-support phases. We predetermined five static positions for walking based on the COM method. The positions can be represented by the length of the gait, the width between the feet, the height of the foot and two parameters in the hip movement. With the five parameters, we calculated the position trajectory. And we got the angular trajectories of 10 joints from the posit ion trajectory using the position tracking control and neural network. By tracking the angular trajectories, the robot can walk maintaining stability. We implemented walking of a biped robot throught the above ...

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2008.04a
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• pp.585-592
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• 2008

The aging society comes, the number of the old people expended. Technical aids allow elderly and handicapped people to live independently in their private homes as long as they wish. As a contribution to these required technological solutions, a demonstrator platform for a walking assistance robot. robot which has the capability to perform fetch and carry and various other supporting tasks. In this study, we addresses the development of a walking assistance robot system. We execute static analysis, vibration analysis and flexible dynamics to reserve stability at the design. Each motion of the robot uses a linear actuator and gears. Motion can be distinguished into 3 parts depending on the up & down, rotation, and cushion trans. In each motion, we compare the displacement of the case to be rigid with the case to be flexible. As a result, manufactured and feasibility of the walking assistance robot is validated through preliminary experiments.