• International Journal of Control, Automation, and Systems
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• v.6 no.2
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• pp.234-242
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• 2008

The purpose of this paper is to verify the practical effectiveness of an interphalangeal coordination-based joint motion planning method for humanoid finger operations. For the purpose, several experiments have been performed and comparative experimental results are shown. Through the experimental works, it is confirmed that according to the employed joint motion planning method, the joint configurations for a finger's trajectory can be planned stably or not, and consequently the actual joint torque command for controlling the finger can be made moderately or not. Finally, this paper analyzes that the interphalangeal coordination-based joint motion planning method is practically useful for implementing a stable finger manipulation. It is remarkably noted that the torque pattern by the method is well-balanced. Therefore, it is expected that the control performance of humanoid or prosthetic fingers can be enhanced by the method.

• Korean Journal of Applied Biomechanics
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• v.28 no.2
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• pp.109-117
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• 2018

Objective: To compare head and hand movement patterns during squash forehand motions between experts and less-skilled squash players. Method: Four experts and four less-skilled squash players participated in this study. They performed squash forehand swings and a VICON motion analysis system was used to obtain displacement and velocity data of the head and right hand during the movement. Mann-Whitney U-tests were performed to compare head and hand range of motion and peak velocity, and cross-correlation was performed to analyze the head-hand coordination pattern between groups in three movement directions. Results: In terms of head and hand kinematic data, experts had greater head range of motion during down swings than less-skilled squash players. Experts seemed to reach peak hand velocity at impact by reaching peak head velocity followed by hand peak velocity within a given temporal sequence. In terms of head-hand coordination patterns, both groups revealed high positive correlations in the medial-lateral direction, indicating a dominant allocentric coordination pattern. However, experts had uncoupled coordination patterns in the vertical direction and less-skilled squash players had high positive correlations. These results indicate that the head-hand movement pattern likely an important factor squash forehand movement. Conclusion: Analysis of head and hand movement patterns could be a key variable in squash training to reach expert-level performance.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.1093-1098
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• 2003

In this paper, a practical methodology of hand-manipulator motion coordination for indoor service robot is introduced. This paper describes the procedures of opening door performed by service robot as a noticeable example of motion coordination. This paper presents well-structured framework for hand-manipulator motion coordination, which includes intelligent sensor data interpretation, object shape estimation, optimal grasping, on-line motion planning and behavior-based task execution. This proposed approach is focused on how to integrate the respective functions in harmony and enable the robot to complete its operation under the limitation of usable resources. As a practical example of implementation, the successful experimental results in opening door whose geometric parameters are unknown beforehand are provided.

• International Journal of Control, Automation, and Systems
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• v.4 no.2
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• pp.217-226
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• 2006

Grasping and manipulation by hands can be considered as one of inevitable functions to achieve the performances desired in humanoid operations. When a humanoid robot manipulates an object by his hands, each finger should be well-controlled to accomplish a precise manipulation of the object grasped. So, the trajectory of each joint required for a precise finger motion is fundamentally necessary to be planned stably. In this sense, this paper proposes an effective joint motion planning method for humanoid fingers. The proposed method newly employs a bio-mimetic concept for joint motion planning. A suitable model that describes an interphalangeal coordination in a human finger is suggested and incorporated into the proposed joint motion planning method. The feature of the proposed method is illustrated by simulation results. As a result, the proposed method is useful for a facilitative finger motion. It can be applied to improve the control performance of humanoid fingers or prosthetic fingers.

• Journal of Mechanical Science and Technology
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• v.17 no.2
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• pp.221-229
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• 2003

In the virtual environment, reality can be enhanced by offering the motion based on a motion simulator in harmony with visual and auditory modalities. In this research the Stewart-Gough-platform-based motion simulator has been developed. Implementation of vehicle dynamics is necessary in the motion simulator for realistic sense of motion, so bicycle dynamics is adopted in this research. In order to compensate for the limited range of the motion simulator compared with the real vehicle motion, washout algorithm composed of high-pass filter, low-pass filter and tilt coordination is usually employed. Generally, the washout algorithm is used with fixed parameters. In this research a new approach is proposed to tune the filter parameters based on fuzzy logic in real-time. The cutoff frequencies of the filters are adjusted according to the workspace margins and driving conditions. It is shown that the washout filter with the fuzzy-based parameters presents better performance than that with the fixed ones.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.1609-1614
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• 2003

This paper presents a new method driving multiple robots to their goal position without collision. To consider the movement of the robots in a work area, we adopt the concept of avoidability measure. To implement the concept in collision avoidance of multiple robots, relative distance between the robots is proposed. The relative distance is a virtual distance between robots indicating the threat of collision between the robots. Based on the relative distance, the method calculates repulsive force against a robot from the other robots. Also, attractive force toward the goal position is calculated in terms of the relative distance. The proposed method is simulated for several cases. The results show that the proposed method steers robots to open space anticipating the approach of other robots. The proposed method works as a local collision-free motion coordination method in conjunction with higher level of task planning and path planning method for multiple robots to do a collaborative job.

• Transactions on Control, Automation and Systems Engineering
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• v.4 no.1
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• pp.56-61
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• 2002

In this paper we describe an approach to coordinating the motion of a human with a mobile robot moving in a populated, continuously changing. natural environment. Our test application is a wheelchair accompanying a person through the concourse of a railway station moving side by side with the person. Our approach is based on a method for motion planning amongst moving obstacles known as Velocity Obstacle approach. We extend this method by a method for tracking a virtual target which allows us to vary the robot's heading and velocity with the locomotion of the accompanied person and the state of the surrounding environment.

• Convergence Security Journal
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• v.15 no.4
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• pp.149-154
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• 2015

The aim of this study is to suggest the change of behavior and motor skill of children with intellectual disabilities participating functional games using virtual reality. For this purpose, 5 children with intellectual disabilities completed a 16-week functional game program twice a week. The result was as following; the application of functional games using virtual reality has positive effect on behavior and motor skill -static coordination, hand motion coordination, normal motion coordination, motor speed, simultaneous spontaneous motion, single motion competency. The application and utilization of functional games using virtual reality systematically of children with intellectual disabilities can bring an improvement on their overall development.

• Korean Journal of Applied Biomechanics
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• v.18 no.4
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• pp.179-189
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• 2008

The purpose of this study was to investigate interjoint and intersegmental coordination of lower segments in skill process. For the investigation, we examined the difference of resultant linear velocity of segments and angle vs angle graph. Novice subjects were 9 male middle school students who have never been experienced a taekwondo. We analyzed kinematic variables of Side Kick motion through videographical analysis. The conclusions were as follows. 1. Examining the graph of novice subjects' maximal resultant linear velocity of the thigh, shank, and foot segment, as it gets closer to the end of the training, the maximal resultant linear velocity in each segment increases which can be assumed to be a result of the effective momentum transfer between adjacent segments. 2 This research showed a sequential transfer from trunk, to thigh, and then to shank as it gets closer to the end of learning at intersegment angular velocity, and it also showed pattern of throwlike motion and pushlike motion. 3. In three dimension of flexion-extension, adduction-abduction and internal-external rotation of the thigh and shank segment, the angle-angle diagram of knee joint and of hip joint showed that dynamic change was indicated at the beginning of learning but stable coordination pattern was indicated like skilled subject as novice subjects became skilled.

• Journal of Institute of Control, Robotics and Systems
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• v.5 no.8
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• pp.961-968
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• 1999

In this paper we handle a system that transform sensor data to sensor information. Sensor informations from redundant accelerometers are manipulated to represent the configuration of objects carrying sensors. Basic sensor unit of the proposed systme is composed of 3 accelerometers that are aligned along x-y-z coordination axes of motion. To refine the sensor information, at first the sensor data are fused by geometrical optimization to reduce the variance of sensor information. To overcome the error caused from inexact alignment of each sensor to the coordination system, we propose a calibration technique that identifies the transformation between the coordinate axes and real sensor axes. The calibration technique make the sensor information approach real value. Also, we propose a technique that decomposes the accelerometer data into motion acceleration component and gravity acceleration component so that we can get more exact configuration of objects than in the case of raw sensor data. A set of experimental results are given to show the usefulness of the proposed method as well as the experiments in which the proposed techniques are applied to human body motion capture.