Graduate Studies


First Advisor

Joe Luck

Second Advisor

Santosh Pitla

Third Advisor

Yufeng Ge

Date of this Version


Document Type



Monroe, Thomas. (2023). Evaluation of an Automated Nozzle Droplet Size and Flow Rate Control System Integration for Real-Time Weather Compensation on Agricultural Sprayers [Master's thesis, University of Nebraska - Lincoln]. DigitalCommons@University of Nebraska - Lincoln.


A THESIS Presented to the Faculty of The Graduate College at the University of Nebraska In Partial Fulfillment of Requirements For the Degree of Master of Science, Major: Agricultural and Biological Systems Engineering, Under the Supervision of Professor Joe D. Luck. Lincoln, Nebraska: May, 2023

Copyright © 2023 Thomas Monroe


A novel spray application control system was recently developed that can simultaneously control droplet size and flow rates from a variable orifice nozzle. The objectives of this project were to integrate automated pressure control with a novel algorithm for real-time compensation for environmental conditions (i.e., wind speed and relative humidity) to enable in-field droplet and flow control during spraying operations. A PID-based pump control system was developed to maintain system pressure by accessing the desired pressure from the previous algorithm developed. Additionally, a previously developed weather-compensation logic was digitized and incorporated into the software to generate a desired spray droplet size for the control system. With the new control components integrated into the existing system, the fully developed system was evaluated in a laboratory environment. Tests represented typical application rates using both steady and changing environmental values in a range of 0-10 mph of wind, 20-60% humidity range, and 17-23 L min-1 flow rate. Laboratory tests confirmed the ability of the system to automatically increase and decrease spray droplet sizes (while maintaining desired flow rates) for the test scenarios developed. The results of the testing will be compared with a standard nozzle that is unable to change droplet sizes using the same application conditions to confirm the efficiency of the newer corrective nozzles.

Advisors: Joe Luck and Santosh Pitla