Autonomous guidance system for small orchard sprayer with ultrasonic sensors

摘要

For a self-guiding track-type orchard sprayer, a low-cost steering controller was developed using two ultrasonic sensors, two electrically-operated cylinders and 80196kc microprocessor. The operating principle of controller was to travel the sprayerbetween artificial targets placed every 1.5m along both sides of the desired path. The ultrasonic sensors mounted on the front end of sprayer measure the distances to targets on both sides, and the difference between these two distances was used to determine the deviation from the desired path. Electrically-operated cylinders actuate the steering clutches to guide the sprayer. The field tests showed that the orchard sprayer could travel within RMS error of 5cm from the straight path. The different ground speeds did not affect the performance of the autonomous guidance system.