A structured sign for guiding movable robots.

摘要

For the purpose of guiding a movable robot on a wide and flat floor like a usual factory, a gymnasium etc., we propose a specially designed guiding sign. It consists of a cylinder on whose surface four slits are cut in, and a fluorescent light which is placed just on the axis of the cylinder. Two of the slits are parallel to each other, and the other two are angled. A robot takes an image of the sign with a TV camera. After the thresholding operation, we have four bright sets of pixels which correspond to the four slits of the cylinder. By measuring the relative distances between those four points, we can compute the distance and the angle to the direction of the sign using simple geometrical equations. We have built an actual sign. Using a personal computer with an image processing capability, we have investigated accuracy of the proposed position identification method, and compared the experimental results against the theoretical analysis of measurement error. The data shows good coincidence between the analysis and the experiments. Finally, we have built a movable robot, which has three microprocessors and a TV camera, and done several trajectory following control experiments.