Automatic Guidance System Development Using LowCost Ranging Devices

Autonomous guidance of agricultural vehicles for various field operations serves to increase productivity. Low cost infra-red ranging devices were used in this study to estimate the guidance directrix (offset distance (d) and heading error angle (Ø)). Two kinds of tracks were used for evaluating the performance of the infra-red sensors, one track was made of a cardboard in the laboratory and the other track was made of wheat crop in the field. The cardboard track consisted of straight parallel and non parallel edges whereas the wheat crop track had a series of different edges including few curves. From the results it was concluded that the sensor consistently detected the profile of the tracks with good repeatability .Errors of 6% were observed in detecting the straight edges and errors 6.6% and 13% were obtained in detecting two different angled surfaces. The reasons for the errors were detected and explained briefly in the paper.