Injection and fluid handling system for machine-vision controlled spraying

摘要

A fluid handling system was developed to allow on-demand chemical injection for a machine-vision controlled sprayer. Critical design parameters were to maintain a desired concentration of chemical within the solution and to maintain a constant spraypressure at the nozzles. Unlike conventional agricultural spray injection systems which are designed to respond to relatively slow vehicle speed changes within a relatively narrow range, the system reported in this paper was designed to respond quicklyover a wide dynamic range of flowrates. The design was evaluated with two injection rate control methods for accuracy of maintaining a desired concentration and response speed over a prescribed range of flowrate changes, simulating a "real world" weed map. A salt tracer was used to determine concentration changes in real time and spray pressure was recorded using an electronic transducer. The applied concentration was maintained within about 10 percent of the desired rate and pressure varied 5 percent over a dynamic flow range of 12:1.