• The Transactions of the Korean Institute of Electrical Engineers D
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• v.49 no.5
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• pp.257-263
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• 2000

One of the basic assumptions in the static gait design for a walking robot is that the weight of leg should be negligible compared to that of body, so that the total gravity center is not affected by swing of a leg. Based on the ideal assumption of zero leg-weight, conventional static gait has been simply designed for the gravity center of body to be inside the support polygon, consisting of each support leg's tip position. In case that the weight of leg is relatively heavy, however, while the gravity center of body is kept inside the support polygon, the total gravity center of walking robot can be out of the polygon due to weight of a swinging leg, which causes instability in walking. Thus, it is necessary in the static gait design of a real robot a compensation scheme for the fluctuation in the gravity center. In this paper, a body impedance control is proposed to obtain the total gravity center based on foot forces measured from load cells of a real walking robot and to adjust its position to track the pre-designed trajectory of the corresponding ideal robot's body center. Therefore, the walking stability is secured even in case that the weight of leg has serious influence on the total gravity center of robot.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.7 no.2
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• pp.1-5
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• 2013

In this paper, we proposed how to estimate the walking state in the knee disarticulation prosthesis's knee angle control. In control of the knee disarticulation prosthesis, we can estimate walking state that measurement of knee angle using absolute encoder and measurement of load on the soles using strain gage. We suggested a method of estimating the current walking states which can be divided into four cases and showed the effectiveness of the method via a series of experiments.

• 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.

• 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 ...

• Journal of the Korean Institute of Telematics and Electronics B
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• v.33B no.9
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• pp.1-12
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• 1996

In this paper, we propose an adaptive gait by which a quadruped walking robot can walk against external disturbances. This adaptive gait mechanism makes it possible for a quadruped walking robot to change its gait and accommodate external disturbances form various external environmental factors. Under the assumption that external disturbances can be converted to an external force acting on the body of a quadruped walking robot, we propose a new criterion for the stability margin of a waling robot by using an effective mass center based on the zero moment point under unknown external force. And for a solution of an adaptive gait against external disturbances, an method of altitude control and reflexive direction control is suggested. An algorithmic search method for an optimal stride of the quadruped mehtod, the gait stability margin of a quadruped walking robot is optimized in changing its direction at any instance for and after the reflexive direction control. To verify the efficiency of the proposed approach, some simulaton results are provided.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.85.4-85
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• 2001

A learning controller is presented for repetitive walking motion of biped robot. The learning control scheme learns the approximate inverse dynamics input of biped walking robot and uses the learned input pattern to generate an input profile of different walking motion from that learnt. In the learning controller, the PID feedback controller takes part in stabilizing the transient response of robot dynamics while the feedforward learning controller plays a role in computing the desired actuator torques for feedforward nonlinear dynamics compensation in steady state. It is shown that all the error signals in the learning control system are bounded and the robot motion trajectory converges to the desired one asymptotically. The proposed learning control scheme is ...

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.05a
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• pp.238-243
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• 2002

This paper presents a design and a control of a biped walking AGO-robot and dynamic walking simulation for this system. The biped walking RGO-robot is distinguished from other one by which has a very light-weight and a new RGO type with servo motors. The gait of a biped walking AGO-robot depends on the constrains of mechanical kinematics and initial posture. The stability of dynamic walking is investigated by ZMP(Zero Moment Point) of the biped walking AGO-robot. It is designed according to a human wear type and is able to accomodate itself to human environments. The joints of each leg are adopted with a good kinematic characteristics. To test of the analysis of joint kinematic properties, we did the strain stress analysis of dynamic PLS and the study of FEM with a dynamic PLS. It will be expect that the spinal cord injury patients are able to train effectively with a biped walking RGO-robot.

• The Journal of Korean Physical Therapy
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• v.28 no.4
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• pp.227-231
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• 2016

Purpose: This study was conducted to explore the effects of aerobic exercise on the severity of disease and walking ability in patients with Parkinson's disease. Methods: Twelve patients with Parkinson's disease participated in the study. Participants were randomly assigned to either an aerobic exercise group (n=6) or a self-exercise group (n=6). All participants underwent treadmill training for 30 minutes. In addition, the experimental group (aerobic exercise group) and control group (self-exercise group) participated in a 30 minutes exercise program. In both groups, exercise was performed five times a week for four weeks. Outcome including disease severity (Unified Parkinson's Disease Rating Scale) and walking ability (10 m walking speed test, 6 minutes walking test, timed up-and-go test) were measured at baseline and after 4-weeks. Results: Significant differences in disease severity and walking ability were observed between the pre- and post-exercise groups (p<0.05). The improvement of disease severity and walking endurance was significantly higher in the experimental group than in the control group (p<0.05). Conclusion: These findings demonstrate that aerobic exercise is effective at improving disease severity and walking endurance in patients with Parkinson's disease.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.05a
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• pp.752-759
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• 2002

This paper presented a design and a control of a biped walking RGO and walking simulation by this system. The biped walking RGO was distinguished from the other one by which had a very light-weight and a new RGO type with 12-servo motors. The vibration evaluation of the dynamic PLS on the biped walking RGO was used to access by the 3-axis accelerometer with a low frequency vibration for the spinal cord injuries. The gait of a biped walking RGO depended on the constrains of mechanical kinematics and the initial posture. The stability of dynamic walking was investigated by a ZMP (Zero Moment Point) of the biped walking RGO. It was designed according to a human wear type and was able to accomodate itself to a human environments. The joints of each leg were adopted with a good kinematic characteristics. To test of the analysis of joint kinematic properties, we did the strain stress analysis of the dynamic PLS and the analysis study of FEM with a dynamic PLS. It will be expect that the spinal cord injury patients are able to recover effectively with a biped walking RGO.

• International Journal of Control, Automation, and Systems
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• v.6 no.2
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• pp.243-252
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• 2008

It has been reported that long-term exercise on a treadmill (running machine) may cause injury to the joints in a human's lower extremities. Previous works related to analysis of human walking motion are, however, mostly based on clinical statistics and experimental methodology. This paper proposes an analytical methodology. Specifically, this work deals with a comparison of normal walking on the ground and walking on a treadmill in regard to the external and internal impulses exerted on the joints of a human's lower extremities. First, a modeling procedure of impulses, impulse geometry, and impulse measure for the human lower extremity model will be briefly introduced and a new impulse measure for analysis of internal impulse is developed. Based on these analytical tools, we analyze the external and internal impulses through a planar 7-linked human lower extremity model. It is shown through simulation that the human walking on a treadmill exhibits greater internal impulses on the knee and ankle joints of the supporting leg when compared to that on the ground. In order to corroborate the effectiveness of the proposed methodology, a force platform was developed to measure the external impulses exerted on the ground for the cases of the normal walking and walking on the treadmill. It is shown that the experimental results correspond well to the simulation results.