[1] Liu Haitao, Guan Shengxiao, Qin Liang, et al. Study on vision-based navigation system of intelligent-robot［J］. Computer Applications and Software, 2010, 27(12): 218-220.

[2] Hua Xijun, Liao Qian, Chen Meiyun, et al. Road recognition for vision navigation system of tractor in shadow environment［J］. Journal of Agricultural Mechanization Research, 2012, 34(4): 189-193.

[3] He Y H, Wang H, Zhang B. Color-based road detection in urban traffic scenes［J］. IEEE Transactions on Intelligent Transportation System, 2004, 5(4): 309-319.

[4] Tian Zheng, Xu Cheng, Mi Chao, et al. Road segmentation based on vanishing point and principal orientation estimation［J］. Journal of Computer Research and Development, 2014, 51(4): 762-772.

[5] Ding Weili, Li Yong, Wang Wenfeng, et al. Vanishing point detection algorithm for urban road image based on the envelope of perpendicular and parallel lines［J］. Acta Optica Sinica, 2014, 34(10): 1015002.

[6] Gao D Z, Li W, Duan J M. A practical method of road detection for intelligent vehicle［C］. 2009 IEEE International Conference on Automation and Logistics Shenyang, China August, 2009: 980-985.

[7] Wang Wenfeng, Ding Weili, Li Yong, et al. An efficient road detection algorithm based on parallel edges［J］. Acta Optica Sinica, 2015, 35(7): 0715001.

[8] Kong H, Audibert J Y, Ponce J. General road detection from a single image［J］. IEEE Transactions on Image Processing, 2010, 19(8): 2211-2220.

[9] Li Yong, Ding Weili. Navigationline of vision extraction algorithm based on dark channel［J］. Acta Optica Sinica, 2015, 35(2): 0215001.

[10] Torii T. Research in autonomous agriculture vehicles in Japan［J］. Computers and Electronics in Agriculture, 2000, 25(1-2): 133-153.

[11] Gao Guoqin, Li Ming. Navigating path recognition for greenhouse mobile robot based on K-means algorithm［J］. Transactions of the Chinese Society of Agricultural Engineering, 2014, 30(7): 25-33.

[12] Tian J, Sun J, Tang Y. Tricolor attenuation model for shadow detection［J］. IEEE Transactions on Image Processing, 2009, 39(2): 195-201.

[13] Qu L Q, Tian J D, Han Z, et al. Pixel-wise orthogonal decomposition for color illumination invariant and shadow-free image［J］. Optics Express, 2014, 23(3): 2220-2239.

[14] Duan Zhigang, Qu Liangqiong, Tian Jiandong, et al. Outdoor illumination shadow detection based on orthogonal decomposition［J］. Acta Optica Sinica, 2016. 36(8): 0815002.

[15] Otsu N. A threshold selection method from gray-level histograms［J］. IEEE Transactions on System, Man and Cybernetics, 1979, 9(1): 62-66.

[16] Mac Queen J. Some methods for classification and analysis of multivariate observations［C］. Proceedings of the Fifth Berkeley Symposium on Mathematical Statistics and Probability, 1967, 1(14): 281-297.

[17] lvarez J M, Lpez A M, Gevers T, et al. Combining priors, appearance, and context for road detection［J］. IEEE Transactions on Intelligent Transportation Systems, 2014, 15(3): 1168-1178.