Real-time operation of mobile robots using linear image arrays

Abstract

A vision system using a pair of Linear Image Arrays is proposed for use with mobile robots for factory environments. This vision system was developed to perform the function of guidance, navigation, and obstacle detection. Using a standard 16-bit microprocessor for all of the computing tasks, low cost, small size, and low power consumption can be obtained. Real-time operation is achieved by using line images, which provide less data than two-dimensional images. However, this results in the need for special image processing techniques. Guidance and navigation are achieved using a new technique called the difference of medians, a robust method of detecting and locating known features in line images. Obstacle detection is performed by locating feature points in thresholded images and determining the distances to these feature points by template matching. A distance map is then generated, from which obstacles can be located. the algorithms used are chosen for their efficiency, with the result that a pair of images can be analyzed in less than 0.5 s.