Variable Rate Application Equipment and Mechanisms

IntroductionIntroduction n Mapping or on-board sensors n Requirement for rapid changes in rate n Requirement for accurate and precise rate acquisition n Requirement for accurate and precise distribution and deposition

Principles of Chemical Application n Perfect uniformity not possible n Physical laws dictate rate and distribution n Metering and distribution device designs control performance

Liquid Metering ‘Controlling the rate of flow’

Orifice Flow

AgChem Variable Rate Applicator

Case-Tyler-Capstan Air command System

How do we change rates and treat small areas? n Valves must operate at high speeds n Valves must enable stepping of rates – e.g. 1x, 2x, 4x combinations for 1x, 2x, 3x, 4x, 5x, 6x, 7x, and off rates Variable Rate Spray Nozzles Sensed Area Sensor Assy.

Patchen Cartridge Valve n Designed as part of the Weedseeker sense/spot- spray system n Poppet-type cartridge valve

Patchen Schematic n Discharge Coefficient: 0.07 gpm/(psi^0.5) n Steady State Current Requirement: 0.32 Amps

Why Minimum Treatment Distance? n Need application resolution to match sensed resolution n Treatment Distance is a function of a minimum treatment time and ground speed. Variable Rate Spray Nozzles Sensed Area Sensor Assy.

Tri-valve Set for Varying Rate n Stepped rates - 1x, 2x, 3x, 4x, 5x, 6x, 7x and off n Can treat 0.6 by 0.6 m area applying the target rate on 85% of that area

Stepped Application Using a 3 Valve Set

OSU/GreenSeeker Unit 1 N-Fertilizer Applicator

GreenSeeker RT500 GreenSeeker RT200

GreenSeeker RT500 GreenSeeker RT200

RT200 and RT 500 Specifications n Estimated Price $15,000 for 60 ft applicator n Senses and treats boom width by 20 to 30 feet n Utilizes existing variable rate sprayer controllers and valves n Combination Sense and Treat, and Sense, Predict, and Treat strategies n Reaction time limited by existing controller and valves n Estimated Price $60,000 for 60 ft applicator No Longer Manufactured n Senses and treats each 2 ft by 2 ft area n Uses NTech high speed and high resolution controller and valves n Sense and Treat strategy n Reaction time < 0.1 s RT200 RT500

RT200 and RT 500 Specifications n Reaction time limited by existing controller and valves –Capstan Pulse Width Modulation 3 to 10Hz, 0 to 8 x –Raven type flow control valve 1 to 5 s, 1 to 2.5 x Reaction time < 0.1 s RT200 RT500

Sensing and Treatment Scale and Strategy 2 ft by 2 ft 30 ft by 60 ft Sensed Area Treated Area Sense, Predict, and Treat Strategy High Resolution Sense and Treat Strategy RT200 RT500

Sensing and Treatment Scale

GreenSeeker RT200 Equipped with Capstan PWM Sharpshooter

RT200 and RT500 Specifications n 6 sensors on 60 + ft boom n Can readily be mated with existing dry fertilizer and anhydrous ammonia applicators n Fast installation with minimal modifications n System intended for fertilizer and possibly and possibly products such as growth regulators and defoliants n 30 sensor on 60 ft boom n Existing dry fertilizer applicators cannot be used with this system n System custom installed on each manufacturer’s sprayer /boom n Can detect and spray weeds in fallow/no-till as well as apply fertilizer n System can be used for other crops and materials RT200 RT500

Ag Chem Variable Rate Granular Materials Applicator