Search | Korea Science

Park, Kwang-Ho;Kim, Hyung-O;Baek, Moon-Yeol;Kee, Chang-Doo
- Journal of Mechanical Science and Technology
- /
- v.17 no.10
- /
- pp.1411-1422
- /
- 2003
The detection of free spaces between obstacles in a scene is a prerequisite for navigation of a mobile robot. Especially for stereo vision-based navigation, the problem of correspondence between two images is well known to be of crucial importance. This paper describes multi-range approach of area-based stereo matching for grid mapping and visual navigation in uncertain environment. Camera calibration parameters are optimized by evolutionary algorithm for successful stereo matching. To obtain reliable disparity information from both images, stereo images are to be decomposed into three pairs of images with different resolution based on measurement of disparities. The advantage of multi-range approach is that we can get more reliable disparity in each defined range because disparities from high resolution image are used for farther object a while disparities from low resolution images are used for close objects. The reliable disparity map is combined through post-processing for rejecting incorrect disparity information from each disparity map. The real distance from a disparity image is converted into an occupancy grid representation of a mobile robot. We have investigated the possibility of multi-range approach for the detection of obstacles and visual mapping through various experiments.
PDF KSCI

Lee, Seung-Hoon;Kim, Dong-Hyung;Kang, Min-Sung;Gil, Myung-Soo;Kim, Young-Soo;Back, Sung-Hoon;Han, Chang-Soo
- Journal of Institute of Control, Robotics and Systems
- /
- v.18 no.5
- /
- pp.445-452
- /
- 2012
With the increasing number of high-rise and large-scale buildings, modern buildings are becoming intelligent, and are incurring high construction costs and requiring careful maintenance. Maintenance works for high-rise buildings significantly depend on human labor, unlike other construction processes that are gradually being automated. The resulting accidents may produce very high social and economic losses. To address this problem, herein, this paper proposes robotic building maintenance system using multi-robot concept, in specific, cleaning a building facade which is directly subjected to minimize human labor; that improves the process efficiency and economic feasibility. The sensor for detecting contamination of building's outer-wall glass is proposed; Kalman filter was used for estimating robots' status with the contamination of the window glass. Task allocation of the sensor based multi-robots for an effective way of task execution is introduced and the feasibility was verified through the simulations.
https://doi.org/10.5302/J.ICROS.2012.18.5.445 인용 PDF KSCI

Cheong, Seon-Hwan;Choi, Seong-Dae;Kweon, Hyun-Kyu;Choi, Eun-Hwan
- Journal of the Korean Society of Manufacturing Process Engineers
- /
- v.2 no.4
- /
- pp.33-39
- /
- 2003
The stiffness of multi-articulated industrial robots is very weak, because their structure is an articulated type with some links and joints. Thus it is known that cutting processes for metals are not accepted in machine shop well, but they have a lot of merits for cutting processes, for example, drilling, tapping, and engraving etc, because of the characteristics of their high degree of freedom. The temptation of cutting aluminium was carried out to investigate the feasibility and the limitations or constraints for cutting metals on them. First the mode shapes of 6 degree of freedom welding robot were taken and analysed, and next the cutting processes were practically carried out on it. The results of study were found out to show the feasibility of cutting processes at drilling under 6mm of tool diameter, as well as to have some limitations and constraints, for examples, feed rate, depth of cut and cutting force etc.
PDF