Journals
  Publication Years
  Keywords
Search within results Open Search
Please wait a minute...
For Selected: Toggle Thumbnails
Precise visual navigation method for agricultural robot based on virtual navigation line
LIANG Zhen, FANG Tiyu, LI Jinping
Journal of Computer Applications    2021, 41 (1): 191-198.   DOI: 10.11772/j.issn.1001-9081.2020060927
Abstract406)      PDF (1980KB)(429)       Save
Aiming at the problem of navigation in the condition without artificial markers in farmland or wild environment, a precise visual navigation method for agricultural robot based on virtual navigation line was proposed. In this method, the robot can be guided to walk in a straight line without laying navigation lines or road signs. Firstly, the target area to be tracked was determined according to the requirements, and the robot was controlled to adjust the direction until the target moved to the center of vision field. Secondly, the reference target was determined according to the positions of the robot and the target, and the virtual navigation line was determined according to the positions of two targets. Thirdly, the navigation line was updated dynamically, and the offset angle and the offset distance were obtained by combining the virtual calibration line and the virtual navigation line. Finally, the fuzzy control table was constructed with the offset parameters, and the adjustment of rotation angle and walking speed of the robot was realized by the table. Experimental results show that the proposed algorithm can accurately recognize the navigation route and use the fuzzy control strategy to make the robot walk in a straight line to the target, and has the navigation accuracy within 10 cm.
Reference | Related Articles | Metrics
Application of gray cumulative projection histogram in detection of tire crown crack
Han Yanbin WANG Jie XIA Yingjie LI Jinping
Journal of Computer Applications    2014, 34 (8): 2221-2226.   DOI: 10.11772/j.issn.1001-9081.2014.08.2221
Abstract352)      PDF (950KB)(442)       Save

For automatic detection of tire crown cord overlap defect, a detection method based on the crown X ray image was presented. Firstly, the gray cumulative projection curves that X-ray image was projected along different angles were obtained. Secondly, the local peak energy distribution of curves were calculated and the energy feature vector was constructed by the n largest peak energy values. Thirdly, the tire crown crack image was recognized by the maximum projection curve which could be distinguished through the energy feature vector by Support Vector Machine (SVM). Lastly, using the position inverse calculation, the tire crown crack was located. The experimental results demonstrate that the proposed approach was effective to detect the defects of tire crown which caused by tire cord overlap. The highest rate of correct detection can reach 97.7% in the 1000 crown images collected by the process of production.

Reference | Related Articles | Metrics