• Journal of Institute of Control, Robotics and Systems
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• v.5 no.8
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• pp.990-994
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• 1999

This paper proposes a new fuzzy-neural algorithm for navigation of a mobile robot with stationary and moving obstacles environment. The proposed algorithm uses fuzzy algorithm for its speed control and neuralnetwork for effective collision avoidance. Some computer simulation results for a mobile robot equipped with ultrasonic range sensors show that the suggested navigation algorithm is very effective to escape in stationary and moving obstacles environment.

• 제어로봇시스템학회:학술대회논문집
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• 1991.10a
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• pp.1040-1045
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• 1991

An approach to time-varying obstacle avoidance problem is pursued. The mathematical formulation of the problem is given in Cartesian space and in joint space. To deal with the time-varying obstacles, view-time is introduced. A view-time is the time interval viewing the time-varying obstacles to model equivalent stationary obstacles. For the analysis of the properties of the view-time, avoidability measure is defined as a measure of easiness for a robot to avoid obstacles. Based on the properties, a motion planning strategy to avoid time-varying obstacles is derived. An application of the strategy to the collision-free motion planning of two SCARA robots and the simulation on the application are given.

• Journal of Biosystems Engineering
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• v.23 no.2
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• pp.179-186
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• 1998

This study was conducted to sense posture of an autonomous tractor using a DGPS, a gyro compass, and a potentiometer. Posture sensing system was constructed and its accuracy was evaluated. The accuracy of DGPS was evaluated under stationary and moving conditions, and the performance of the gyro compass and the potentiometer was investigated by measuring bearing and steering angles, respectively. Also, the effect of DGPS interference by obstacles was evaluated experimentally. The position accuracy was about 6.6cm(95%) under the stationary condition and 10 cm at sharp turning condition. Steering angle of the tractor could be related linearly to the output of the potentiometer that was installed on the rotating center of a knuckle arm. The positioning accuracy of the DGPS varied significantly according to the number of visible GPS satellites, but was good with more than 7 satellites. The DGPS gave bad solutions for sensing the posture of tractor when signals from satellites or the correction data from the base were interfered by obstacles.

• Proceedings of the KIEE Conference
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• 2000.07d
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• pp.2895-2897
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• 2000

This paper proposes a new fuzzy-neural algorithm for navigation of a mobile robot with stationary and moving obstacles environment. The proposed algorithm has two-layered hierarchical structure such as a lower layer for collision avoidance and goal approach. and upper layer for adaptive combination of these two algorithms. Some computer simulation results for a mobile robot equipped with ultrasonic range sensors show that the suggested navigation algorithm is very effective in stationary and moving obstacles environment.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.41 no.7
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• pp.809-822
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• 1992

A mathematical approach to solving the time-varying obstacle avoidance problem is pursued. The mathematical formulation of the problem is given in robot joint space(JS). View-time concept is used to deal with time-varying obstacles. The view-time is the period in which a time-varying obstacles. The view-time is the period in which a time-varying obstacle is viewed and approximated by an equivalent stationary obstacle. The equivalent stationary obstacle is the volume swept by the time-varying obstacle for the view-time. The swept volume is transformed into the JS obstacle that is the set of JS robot configurations causing the collision between the robot and the swept volume. In JS, the path avoiding the JS obstacle is planned, and a trajectory satisfying the constraints on robot motion planning is planned along the path. This method is applied to the collision-free motion planning of two SCARA robots, and the simulation results are given.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1995.04a
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• pp.880-885
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• 1995

This paper deals with the efficient planning of robot motions in the Cartesian space while avoiding the collision with obstacles. The motion planning problem is to find a path from the specified starting robot configuration that avoids collision with a known set of stationary obstacles. A simple and efficient algorithm was developed using "Backward" approach to solve this problem. The computational result was satisfactory enough to real problems. problems.

• Proceedings of the IEEK Conference
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• 2006.06a
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• pp.943-944
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• 2006

In this paper, we implemented the autonomous mobile robot which can recognize and avoid obstacles, then move to its destination using a camera and ultrasonic sensors. The mobile robot can avoid both stationary obstacles with a camera and moving obstacles with ultrasonic sensors. It can find the self-location with the map-based system, that is, it attempts to localize by collecting sensor data, then updating some belief about its position with respect to a map of the environment.

• Korean Journal of Applied Biomechanics
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• v.29 no.2
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• pp.97-104
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• 2019

Objective: The aim of this study was to investigate the strategies for avoiding moving and stationary walker using body segments during walking. Method: Ten healthy young adults (10 males, age: $24.40{\pm}0.49yrs$, height: $175.80{\pm}5.22cm$, body mass: $70.30{\pm}5.22kg$) participated in this study. Each participant was asked to perform a task to avoid collisions with another walker who was moving or stationary during walking on the 10 m walkway. Both walkers were performed at natural self-selected walking speed. Results: Medio-lateral avoidance displacement of the trunk and the pelvis were significantly increased when avoiding a stationary walker (p<.05). There were no significant differences in medio-lateral center of mass trajectory. Rotation angle of trunk, pelvis and foot on the vertical axis were significantly increased when avoiding a stationary walker (p<.05). Conclusion: Based on our results, when another walker moves continuously, the walker recognizes another walker as the object of social interaction and performs the avoidance strategies while expecting the cooperative distance. On the other hand, when another walker is stopped, it is determined that the walker has an obligation to avoid, and the walker performs a relatively safer avoidance strategy.

• Journal of ILASS-Korea
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• v.17 no.1
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• pp.27-34
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• 2012

In this paper an experimental study is presented to investigate the effect of a step edge and a stationary droplet on the dynamic behavior of impacting droplet on a wall. The main parameters are the distance from the edge and the center-to-center distance between two droplets. Photographic images are presented to show coalescence dynamics, shape evolution and contact line movement. The emphasis is on presenting the spreading length of droplet for the step edge and two coalescing droplets along their original centers. It is clarified that the droplet exhibits much different dynamic behavior depending on the location of the step edge. The momentum of impacting droplet was better transferred to the stationary droplet as the center- to-center distance between two droplets was reduced, which results in more spreading of coalescing droplet.

• Proceedings of the KIEE Conference
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• 2003.07d
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• pp.2381-2383
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• 2003

This paper presents an effective approach to dynamic obstacle avoidance for mobile robot. The main concept of this approach includes modified polar mapping for recognition of the moving obstacle in vision-based robot systems. To simplify the segmentation of the moving obstacle from the background and to obtain its relative position data the modified polar mapping is proposed. Dynamic moving obstacles are avoided with a vision sensor and stationary obstacles are avoided with a sonar sensor.