• Journal of rehabilitation welfare engineering & assistive technology
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• v.9 no.1
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• pp.1-9
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• 2015

This paper reviews trends of the rehabilitation welfare devices on the basis of products and markets. Latest assistive devices tend to have a fold function. Auxiliary power assist module has been added. The completion of products has been improved. The folding function has strong relationship with portability. Specifically, various mobility devices, including foldable devices, are associated with enhanced portability. Powered auxiliary wheels and upper extremity supporting modules have entered the market. The leading-edge technology like Segway's control technology applies to two-wheel wheelchairs. The brand- new technology, lower extremity robotic exoskeleton, applies to markets. Standing wheelchairs, ramps, stair climbing assistive devices becomes more common. In addition, a combination of a variety of smart devices is being promoted to the classical assistive devices' part. Rehabilitation welfare devices can be more valuable due to nice industrial design, improved materials, and processing technology.

• Smart Structures and Systems
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• v.13 no.6
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• pp.1041-1063
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• 2014

This work introduces a two-module robotic pipe inspection system with ultrasonic NDE device to evaluate the integrity of pipe structures. The proposed robotic platform has high mobility. The two module mobile robot platform overcomes pipe obstacle structures such as elbow, or T-branch joints by cooperative maneuvers. Also, it can climb up the straight pipeline at a fast speed due to the wheel driven mechanism. For inspection of pipe structure, SH-waves generated by EMAT are applied with additional signal processing methods. A wavelet transform is implemented to extract a meaningful and specific signal from the superposed SH-wave signals. Intensity ratio which is normalized the defect signals intensity by the maximum intensity of directly transmitted signals in the wavelet transforms spectrum is applied to evaluate defects quantitatively. It is experimentally verified that the robotic ultrasonic inspection system with EMAT is capable of non-destructive inspection and evaluation of defects in pipe structure successfully by applying signal processing method based on wavelet transform.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.20 no.10
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• pp.80-87
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• 2021

Our study introduces an improved modular agricultural platform to provide convenience to agricultural workers. We upgrade the platform design in three parts, namely, by adding a 458 pattern tire, electricity control, and four-wheel steering function, to improve the platform performance. Results showed that the upgrades enhanced the platform performance and reduced its overall weight as compared with the existing platform. To demonstrate the performance of our improved platform, we conducted five types of experiments with respect to the climbing angle, variable width, attitude control, speed, and obstacle passing.

• 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.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.38 no.1
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• pp.37-44
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• 2014

For testing a two-wheeled vehicle's per-charge range, this study conducted road and chassis dynamometer driving tests. Three typical road routes within Daejeon Metropolitan City were selected for the road-driving test. In the case of CVS-40 mode driving tests using a chassis dynamometer, various road-loading conditions were set. In this study, two-wheeled electric vehicles' per charge range on the road was confirmed through testing, and the range and energy consumption efficiency depending on various chassis dynamometer road load settings were measured. Then, the results of the actual road driving tests were compared with those of the chassis dynamometer driving tests, and road load settings that yielded per-charge range testing results similar to those under actual road driving conditions in the chassis dynamometer experiments were studied.

• Journal of Korean Society of Forest Science
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• v.104 no.1
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• pp.98-103
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• 2015

This study was conducted to analyze the running stability of a semi-crawler type mini-forwarder. The running stability analysis was performed by using a dynamic analysis program, RecurDyn. Physical properties of the semi-crawler type mini-forwarder was performed by using 3D CAD modeler, AutoCAD 3D. As a result from the computer simulation of stationary sideways overturning, it was found that the semi-crawler type mini-forwarder runs safely on a road with a slope not bigger than $20^{\circ}$ regardless whether it is empty or loaded, but in case of a road with a slope bigger than $20^{\circ}$, it is assumed that it is difficult for the car to run safely due to some dangers. In addition, it was found that the critical slope of its sideways overturning gets much smaller when empty since the location of its gravity center is elevated and much higher when it is loaded. As a result from the computer simulation of its hill-climbing ability, since the running speed is unstable in case of a road with a vertical slope not smaller than $28^{\circ}$, it is assumed that it is safe to drive it on a road with a slope not bigger than $28^{\circ}$. Taking a look at the result from an analysis of the running safety when it passes an obstacle, it was observed that a front tire comes off the ground when the running speed of the car is 5 and 4 km per hour respectively when it is empty and loaded while the gravity center of the front tire is watched. When taking a look at the changes in the location of the gravity center of the rear wheel crawler shaft, it was not found that the shaft comes off the ground at the test speeds both when it is empty and loaded.