• Journal of the Korean Institute of Intelligent Systems
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• v.25 no.6
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• pp.578-584
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• 2015

In this study a moving platform for a mobile robot that can be traveling with a full automatic standing arm was developed. Conventional mobile robots generally may equip 4 wheels or 3 wheels with a caster wheel or independent driven wheels and have good statistic stability. When a mobile robot travels on a sharply perpendicular and narrow crossroad, it may need a special steering scheme such as going forward and backward repeatedly or it is sometimes physically impossible for the robot to go through the crossroad because of the size limit. The upright running mobile robot changes its posture to the upright posture which has a small planar area and is able to go through the crossroad. The upright control which was manually performed step by step before such as sequences of uprighting (returning), checking, and balancing, is now automated.

• Journal of Advanced Marine Engineering and Technology
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• v.23 no.6
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• pp.731-737
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• 1999

This paper describes the path tracking control for a mobile robot which has two casters at the front and rear to keep balance and two driving wheels on the left and right sides of its body. Power wheeled steering method is adapted to control heading of the robot. It is very difficult to find appropriate feedback gains when linear regulator control scheme is adapted to path tracking con-trol of this type of robot. Therefore in this paper we propose the path tracking control algorithm using the fuzzy logic control scheme for this type of root. Simulation to prove the validity of the proposed two algorithms is performed. The results are reported as last part in this paper.

• Journal of Advanced Navigation Technology
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• v.14 no.5
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• pp.697-709
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• 2010

The patrol robot is a typical extreme robot for the military use. It helps soldiers by detecting and informing a potential risk instead, and warning earlier. Also, these kinds of extreme robots need good ability to conquest rough road. In this paper, we studied new mechanism through which we can get high speed on the flat road with round shape wheels, and simultaneously can get good ability to overcome rough road with blade-shape wheels. The shape of the wheels is being self-adaptively changed automatically according to the condition of the road without using additional actuator.

• Journal of the Korean Institute of Intelligent Systems
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• v.22 no.5
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• pp.570-576
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• 2012

In this research a moving platform for a mobile robot which can run with upright posture is proposed. It is able to stand with standing arms and run uprightly based on an inverted pendulum mechanism. Conventional mobile robots generally may equip 4 wheels or 3 wheels including a caster and have good statistic stability. They need a steering mechanism to choose which way to go since they have a square or rectangular configuration with multiple wheels. When a mobile robot meets a sharply perpendicular and narrow crossroad, it may need a special steering scheme such as going forward and backward repeatedly or it sometimes cannot even pass through the crossroad because of its size. The proposed moving platform for a mobile robot changes to a upright posture which has a small planar area and is able to pass through the crossroad. We propose a moving platform for a mobile robot with a inverted pendulum mechanism and standing arms which can make the mobile robot upright.

• The Journal of the Korea institute of electronic communication sciences
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• v.7 no.1
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• pp.187-194
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• 2012

This paper compares two collision avoidance algorithms using a simulator. The collision avoidance is vital for autonomous navigation of a mobile robot. Artificial potential field method and elastic force method are major approaches for the collision avoidance. The two algorithms are compared in the respect of the time for motion completion and the length of the motion path. The simulator is developed based on IPC(Inter Process Communication) and a differential drive mobile robot is used for the comparison.

• The Journal of the Korea institute of electronic communication sciences
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• v.6 no.5
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• pp.765-773
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• 2011

This paper proposes a control method for a differential robot to track and follow a moving object based on ultrasonic sensor. To track a target object, the method uses a transmitter and two receivers to get distances from the object. The method derives translational and rotational error by the distances and then it uses the errors to calculate control values based on PID control method. The control values are used to control the robot to follow moving object. The authors do some experimentations to analyze some characteristics such as influence of PID gain, influence of translational and rotational gain. This method not only can be applied for following moving object problem but also can be done group unit control problems.

• Journal of the Korean Society for Precision Engineering
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• v.30 no.2
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• pp.171-176
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• 2013

In this research a Self-Standable mobile Robot with standing arms based on an Wheeled Inverted Pendulum is developed. Almost existing mobile robots have wide planar shape that is statistically stable and it is sometimes hard for them to run or steer on a narrow road. A Wheeled Inverted Pendulum based mobile robot has vertical shape that is upright-running and easily steering on a narrow road. It, however, requires actively balancing control and never restores the shape once it falls down. This research develops a Self-Standable mobile robot which equips standing arms and is able to change its chassis' posture freely from planar to vertical shape or vice versa.

• Journal of the Korean Society for Precision Engineering
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• v.31 no.4
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• pp.319-326
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• 2014

Accurate estimation of the robot's position has an important role in autonomous navigation. Odometry is one of the most widely used techniques for mobile robot positioning. However, odometry has a well-known drawback that the position errors are accumulated when the travel distance increases. The UMBmark method is the conventional odometry calibration scheme for two wheel differential mobile robots. In the UMBmark method, the approximations for small angles are used in order to simplify the calculations. In this paper, we propose the new calibration scheme by using experimental orientation errors. Kinematic parameters can be calculated accurately without approximations by using experimental orientation errors. The numerical simulation and experimental results show that the odometry accuracy can be improved by the proposed method.

• 제어로봇시스템학회:학술대회논문집
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• 1997.10a
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• pp.231-236
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• 1997

We propose the hybrid control for the path control of wheeled mobile robot system. To develop the hybrid control of mobile robot, the continuous dynamics of mobile robot are modeled by the switched systems. The abstract model and digital automata for the path control are developed. This hybrid control system has the 3-layered hierachical structure : digital automata as the higher process, mobile robot system as the lower process, and the interface as the interaction process between the continuous dynamics and the discrete dynamics. The control of following the desired-paths with edges are investigated as the applications by the computer simulation.

• The Journal of Korea Robotics Society
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• v.9 no.3
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• pp.160-169
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• 2014

Odometry using wheel encoder is a common relative positioning technique for wheeled mobile robots. The major drawback of odometry is that the kinematic modeling errors are accumulated when the travel distance increases. Therefore, accurate calibration of odometry is required. In several related works, various schemes for odometry calibration are proposed. However, design guidelines of test tracks for odometry calibration were not considered. More accurate odometry calibration results can be achieved by using appropriate test track because the position and orientation errors after the test are affected by the test track. In this paper, we propose the design guidelines of test tracks for odometry calibration schemes using experimental heading errors. Numerical simulations and experiments clearly demonstrate that the proposed design guidelines result in more accurate calibration results.