Ultrasonic sensors are often used to adjust spray volume by allowing thecalculation of the crown volume of tree crops. The special conditions of the olive tree requirethe use of long-range sensors, which are less accurate and faster than the most commonlyused sensors. The main objectives of the study were to determine the suitability of the sensorin terms of sound cone determination, angle errors, crosstalk errors and field measurements.Different laboratory tests were performed to check the suitability of a commercial long-rangeultrasonic sensor, as were the experimental determination of the sound cone diameter atseveral distances for several target materials, the determination of the influence of the angleof incidence of the sound wave on the target and distance on the accuracy of measurementsfor several materials and the determination of the importance of the errors due to interferencebetween sensors for different sensor spacings and distances for two different materials.Furthermore, sensor accuracy was tested under real field conditions. The results show thatthe studied sensor is appropriate for olive trees because the sound cone is narrower for anolive tree than for the other studied materials, the olive tree canopy does not have a largeinfluence on the sensor accuracy with respect to distance and angle, the interference errorsare insignificant for high sensor spacings and the sensor’s field distance measurements weredeemed sufficiently accurate.
展开▼
