• Journal of the Korean Institute of Intelligent Systems
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• v.24 no.1
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• pp.84-89
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• 2014

In this paper, an image-based visual servo control strategy for tracking a target object is applied to a camera-mounted omni-directional mobile robot. In order to get target angular velocity of each wheel from image coordinates of the target object, in general, a mathematical image Jacobian matrix is built using a camera model and a mobile robot kinematics. Unlike to the well-known mathematical image Jacobian, a simple rule-based control strategy is proposed to generate target angular velocities of the wheels in conjunction with size of the target object captured in a camera image. A camera image is divided into several regions, and a pre-defined rule corresponding to the target-located image region is applied to generate target angular velocities of wheels. The proposed algorithm is easily implementable in that no mathematical description for image Jacobian is required and a small number of rules are sufficient for target tracking. Experimental results are presented with descriptions about the overall experimental system.

• Journal of the Korean Society of Industry Convergence
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• v.23 no.2_2
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• pp.233-244
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• 2020

A double-parked car is the one that is parked in a crowded parking lot with its transmission gear in neutral position and its auxiliary brake released. A double-parked car can be moved by pushing it but doing so is very difficult and dangerous. In a previous study, we proposed an omni-directional mobile robot for moving a double parked car. In that study we adopted Mecanum wheels. Even though the proposed robot showed successful results, it has some drawbacks such as dependency on a load condition, complexity in control, inefficiency in power use, etc. To overcome those drawbacks, we propose a differential drive robot with ordinary two tire wheels. The proposed robot consists of two parts, one is a wheel part and the other is a body part. By selectively connecting or disconnecting those two parts with the aid of an electric brake, the proposed robot is able to have omni-directional mobility.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.25 no.2
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• pp.112-117
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• 2016

In the construction industry, concrete polishing is used to grind and rub the surface of concrete grounds with polishing machines to increase the strength of the concrete after deposition. Polishing is performed manually in spite of the generation of dust and the requirement of frequent replacements of the polishing pad. The concrete polishing robot developed in this research is a novel polishing automation system for preventing the workers from being exposed to poor working environments. This robot is able to change multiple polishing tools automatically; however, the workers can conveniently replace the worn-out polishing pads with new ones. The mobile platform of the polishing robot employs omnidirectional wheels to enable a flexible motion even in small and complicated workspaces. To evaluate the performance of the developed concrete polishing robot, extensive experiments including square trajectory tracking, automatic tool changing, actual polishing, and path generation simulation were performed.

• The Journal of the Korea institute of electronic communication sciences
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• v.19 no.1
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• pp.283-288
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• 2024

In this paper, a novel mechanism for overcoming obstacles is studied by designing an All-Directional RC car for obstacle traversal and creating test courses with various obstacles. We propose an algorithm for controlling the RDS3115 servo motor and utilize a gyro sensor to detect the incline of various obstacle terrains, adjusting the servo motor's angle to enable the RC car to navigate the terrain. Through terrain experiments in the test course, we determined the most suitable RC car turning angles for traversing all obstacle terrains created in the experimental terrain.

• Journal of the Institute of Convergence Signal Processing
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• v.23 no.1
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• pp.21-27
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• 2022

Traditional automobile or 2-wheeled robot have limitations on mobility because of their mechanical structure. As traditional automobile is being replaced by electric cars, robot technology is applied to the car industry. In robotics, many researchers worked on omnidirectional mobile robot and produced lots of noticeable results. However in many of the results, specialized wheels such as Mecanum wheels are required. That imposes restrictions on robot speed and outdoor driving. We proposed a 2-wheeled modular robot that has omnidirectional mobility without using specialized wheels. In this paper, we propose a 4-wheeled omnidirectional mobile robot that consists of those two modular robots. The proposed robot adopts electric brakes to combine wheel housings and the robot body or to separate wheel housings from the robot body. Two absolute-type encoders and four incremental encoders are used to control the position of the wheel housing and velocities of the wheels. The proposed robot has omnidirectional mobility and can move fast and outdoor with normal tire wheels. We implemented the proposed robot and the feasibility and stability of the robot is verified by two separate experiments.