Abstract: An agricultural spray implement includes a plurality of removable valve/filter/nozzle cartridges. Each removable cartridge has a housing that retains a high speed solenoid valve and a spray nozzle. When the solenoid valve is open, an agricultural liquid (for example, herbicide) flows through the solenoid valve, through a chamber in the housing, and through the nozzle. To monitor cartridge operation and/or to detect cartridge failures (for example, a solenoid valve that is stuck open or closed or a nozzle that is clogged), a pressure sensor is provided that detects a pressure in the chamber. A chamber pressure that does not change when the solenoid valve is controlled to open and/or close is indicative of cartridge failure. Operation of each of the many spray cartridges of the agricultural spray implement is monitored from a single display.

Abstract: An optical proximity sensor generates information indicative of a distance to an object in a field and in some embodiments also generates information indicative of a spectral reflectance characteristic of the object. The information indicative of the spectral reflectance characteristic can be used to determine whether the object in the field is a living plant or another object such as soil. Light emitted from the optical sensor for reflection off the object is modulated so that reflected light from the optical sensor can be discriminated from reflected ambient sunlight. The optical sensor is scanned over the field to map objects in the field and/or to determine the location of rows of crop plants. A sensor in accordance with the present invention has many uses in agriculture including spraying, cultivation and vehicle guidance.

Abstract: An agricultural spray implement includes a plurality of removable valve/filter/nozzle cartridges. Each removable cartridge has a single housing that retains a magnetized filter, a high speed solenoid valve, and a spray nozzle. In the event the system filter of the spray implement is removed, fine particles which otherwise might clog the solenoid valves are stopped from entering the solenoid valves by the magnetized filters of the valve/filter/nozzle cartridges. Each cartridge has a clean-out purge valve so that its magnetized filter can be unclogged without removal of the magnetized filter from the cartridge housing. A light emitting diode of the cartridge provides a visual indication that the cartridge is dispensing agricultural liquid. The light emitting diode is turned on when the solenoid valve is controlled to be open.

Abstract: An agricultural implement in accordance with the present invention includes a supporting member affixed to a farm vehicle, such as a tractor. The supporting member supports a plurality of sensors that each has a unique physical location along the supporting member such that the sensors traverse parallel paths as the vehicle moves across a field. Information gathered by the sensors can be combined with information as to the vehicle's position to create a map of the field. For example, information indicative of the presence or absence of weeds at specific locations in a field can be used to create a weed-map. To ensure that such maps accurately depict a field, the agricultural implement includes a control unit configured to automatically assign each sensor unit a unique address based upon the physical location of each sensor.

Abstract: Weeds growing around the bases of the stalks of cotton plants growing in a row in a cotton field are sprayed with herbicide without spraying the cotton stalks or wasting herbicide on bare ground. The cotton plants are adequately mature that their stalks exhibit a significantly different spectral reflectance characteristic than the weeds typically growing amid the cotton. The cotton plants are adequately tall that the majority of the leaves of the cotton plants are disposed outside the area which can be sprayed using an electronically-controlled valve and nozzle. Light is transmitted toward an object (a cotton stalk, a weed, or soil) in the row and the reflected light is analyzed. If the object has a spectral characteristic of a growing weed, then the valve is activated and the object is sprayed with herbicide.

Abstract: An agricultural implement (for example, a spray device) differentiates living plants growing in a field from background materials (such as soil) by detecting a change in slope of a reflectance characteristic of objects in a field of view. By using a change in slope of the reflectance characteristic, a small percentage of living plant material in the field of view can be detected and the agricultural implement need not be calibrated to a particular background material. In some embodiments, if the change in slope is determined to exceed a predetermined threshold amount, then it is determined that a weed likely exists in the field of view and a solenoid-operated spray valve is opened at the appropriate time to spray the entire area (including the weed) that was in the field of view with herbicide.

Abstract: An agricultural implement for spraying herbicide on weeds in a field without spraying herbicide on bare soil includes a photodetector circuit. The photodetector circuit includes a photodetector and an active filter. The photodetector is not AC coupled in parallel with an inductor/capacitor resonant circuit which tunes the active filter. As a result, changes in photodetector capacitance due to changes in ambient lighting conditions are not impressed across the resonant inductor/capacitor circuit and therefore do not adversely change the frequency and phase characteristics of the photodetector circuit.

Abstract: An optical proximity sensor generates information indicative of a distance to an object in a field and in some embodiments also generates information indicative of a spectral reflectance characteristic of the object. The information indicative of the spectral reflectance characteristic can be used to determine whether the object in the field is a living plant or another object such as soil. Light emitted from the optical sensor for reflection off the object is modulated so that reflected light from the optical sensor can be discriminated from reflected ambient sunlight. The optical sensor is scanned over the field to map objects in the field and/or to determine the location of rows of crop plants. A sensor in accordance with the present invention has many uses in agriculture including spraying, cultivation and vehicle guidance.