design, development and evaluation of a guidance-assistant system to replaces markers in sowing operations

this research presents a guidance-assistance system for agricultural swing machines. the new automatic steering system controls the vehicle based upon the position of the traces of the previous operation carried out on the field. for each image the trace of the tilled soil by seed drill is placed either on the center line, or on either side of the line. for traces coinciding with images' center line no correction would be needed and the guidance-assistant system can continue the command of sowing operation on the new path, otherwise the relative position of the trace is an indication of the need for steering wheel adjustment, as a result of which the tractor is guided either to the right or left so that the implement would be guided to work at the desired row spacing. the new system is a potential replacement for markers installed on the implement toolbar. the proposed system was evaluated at various conditions including different illumination intensities in laboratory, and on the filed. filed tests were completed with three forward speeds and three steering angles for each output response of the electronic circuit. distance error (de) and response time (rt) were found out for each forward speed and steering angle. results indicated that various illuminations had not distorted the outcome of the proposed algorithm. rt decreased with increase in forward speed and steering angle. effects of forward speed on de were significant at 0.01p whereas the effect of steering angle on de was not found out as non-significant. this suggests that it would be possible to assist the manual guidance of a planting unit carrying tractor through an automatic system equipped with a trace detecting camera.