The present disclosure relates generally to systems and methods for nudging steering of agricultural vehicles.
Agricultural vehicles designed to harvest row crops pose unique issues with properly following rows in a field being harvested. In current technologies rows of the crops (e.g., stalks) may be detected, furrows in the field may detected and used as a basis for guiding steering of the harvesting vehicles. In other systems, more complex sensing technologies such as GPS location can be used to identify locations that may be compared to a map of the field for such purposes. In one current technology, for example, a row guidance system guides to a calibrated row sensor voltage based on a center resting position of the sensor or its associated detection members. Due to the mounting location on the vehicle, guiding to this centered voltage is not always ideal for row tracking, such as on curves and hillsides.
There is a need, therefore, for improved approaches to row guidance in such applications.
In certain embodiments, a system comprises a sensing arrangement that in operation senses alignment of an agricultural vehicle with two reference crop rows, the sensing arrangement outputting a reference alignment signal representative of relative closeness to the two reference crop rows. Processing circuitry receives and processes the reference alignment signal to regulate steering of the vehicle. For correction of alignment of the vehicle with the reference crop rows the processing circuitry implements a nudge by altering the reference alignment signal.
These and other features, aspects, and advantages of the present disclosure will become better understood when the following detailed description is read with reference to the accompanying drawings in which like characters represent like parts throughout the drawings, wherein:
One or more specific embodiments of the present disclosure will be described below. In an effort to provide a concise description of these embodiments, all features of an actual implementation may not be described in the specification. It should be appreciated that in the development of any such actual implementation, as in any engineering or design project, numerous implementation-specific decisions must be made to achieve the developers' specific goals, such as compliance with system-related and business-related constraints, which may vary from one implementation to another. Moreover, it should be appreciated that such a development effort might be complex and time consuming, but would nevertheless be a routine undertaking of design, fabrication, and manufacture for those of ordinary skill having the benefit of this disclosure.
When introducing elements of various embodiments of the present disclosure, the articles “a,” “an,” “the,” and “said” are intended to mean that there are one or more of the elements. The terms “comprising,” “including,” and “having” are intended to be inclusive and mean that there may be additional elements other than the listed elements. Any examples of operating parameters and/or environmental conditions are not exclusive of other parameters/conditions of the disclosed embodiments.
In general, the disclosure provides an improved and straightforward approach to adapting row crop steering guidance to accommodate changes required by actual field conditions. For example, the techniques implemented may utilize past row sensor data to apply an offset to the target voltage of the sensor improving row tracking during curve and hillside operation. This offset could be calculated based on sensor characterization data placed into a steering model. The disclosed techniques may be used in conjunction with existing technologies, such as the advanced farming system available under the commercial designation AFS from Case IH. Changes in steering, sometimes referred to herein as “nudges” may be implemented on the fly, and in control approaches that may be open loop (e.g., operator input or authorized) or closed loop (e.g., automatic without operator input).
Referring to the drawings,
As the harvester progresses in the field, it will cut and partially process the harvested product, such as by at least partial removal of grain from the cut crop. The separated grain may be transferred from the vehicle by a spout 22 which may contain an auger or other transport mechanisms. In operation, a grain cart or other collection vehicle will typically track beside the harvester to receive the harvested grain from the spout 22. Progress through the field, as indicated by arrow 24 will follow the direction of the rows such that the individual plants in each row will properly align with the header snouts to ensure proper cutting and processing.
In a currently contemplated embodiment, crops in the rows are detected and feedback from such detection may be used to help guide the steering of the vehicle to ensure alignment with the rows. However, in certain field conditions, particularly in curves, turns, and on hillsides steady state errors may occur and build that could result in deviation from the desired path aligned with the rows. The disclosed techniques provide for real or near-real time correction of the steering with or without prior knowledge of the field and crop topologies.
In particular,
In operation, and as discussed more fully below, the sensor feedback, in some cases in combination with other data, such as past steering data, position system data (e.g., GPS data) may be used to steer the vehicle to ensure proper alignment with the crop rows. When progressing in a straight segment of a field, as indicated by arrow 30, this control may satisfactorily control steering in a closed loop manner with little correction needed. In other segments of the field, such as in curves or turns, however, as shown in
But it has been found that such techniques may not produce sufficient correction of steering, particularly in curves, turns, and on hillsides. The disclosed approach allows for correction or adjustments of the desired setpoint of the row detection sensor to accommodate errors in guidance through the rows. An advantage of the technique is that it may be implemented as a supplement or complement to existing steering guidance approaches in enhance and improve their performance.
The sensor inputs may be applied to any suitable signal conditioning circuitry 54 that may that may perform signal conversion, scaling, and any other desired operations. The conditioned and/or processed signals are then applied to signal processing or control circuitry 56, which may comprise, for example, digital processors, on-board computers, and so forth. In some embodiments, the control circuitry is part of the vehicle control circuitry, or a subsystem of such circuitry. Memory circuitry 58 is provided which may store parameters such as settings, scaling factors, data related to vehicle steering dynamics, field maps, and so forth, but also any programming used for determining desired steering guidance based on the inputs mentioned above, as indicated generally by reference numeral 66.
It is contemplated that the system may allow for delivery of numerical, graphical, auditory, or some other indication to the vehicle operator related to the current steering conditions and settings, recommended nudges, automatically implemented nudges, and so forth. One or more interfaces 60 will be provided for this purpose. As will be appreciated by those skilled in the art, where desired simple numerical indications may be displayed that indicate steering settings and nudges current or recommended. In addition or instead, graphical displays may indicate the same type of information or even a more or less detailed depiction of the vehicle in the field, with past, present, and upcoming steering indicated graphically, along with any recommended or automatically implemented nudges. Where desired auditory or other alarms may provide the operator with indications of recommended changes in steering (e.g., nudges), for example.
It is also contemplated that the system may allow for open loop operation, where the vehicle operator is prompted or recommended to change or nudge the steering guidance. Where desired, semi or fully automated (e.g., closed loop) operation may be implemented wherein the control circuitry itself implements nudges based on detected signals, such as to more appropriately align the vehicle with upcoming crop rows, particularly in curves, turns and hillside scenarios. Such automated control may be notified to the operator on the interface. Moreover, the operator will have one or more input devices 64 that allow for changes in steering. These may include a steering wheel, but also devices (e.g., a touch screen) in which nudges (i.e., incremental changes or adjustments in sensor settings) may be selected. When recommendations are provided to the operator via the interface, such as for nudges that may be needed to more closely follow crop rows, these may be displayed on the display, and the operator may authorize them as desired (e.g., accept or reject). When operator inputs including the nudges are made, these are communicated to the control circuitry which then implements them for controlling one or more steering actuators 68, such as hydraulic cylinders or other mechanical controls that regulate positions of steered wheels.
While various approaches may be adopted to implement nudges in the steering control, in a currently contemplated embodiment offsets are made to the feedback signal from the row detection sensor or sensors. As noted above, an exemplary crop detection arrangement utilizes wands that physically contact the crops in the rows used to regulate steering. The sensed signal may be a voltage that indicates proper “centering” of the detection device or devices between reference rows. In such cases, this voltage may already be corrected to account for any calibration of the sensor or any other aspect of the detection apparatus. To implement nudges, then, this signal is augmented or reduced further by an amount based on the desired nudge, which may be in any relation to the desired change, such as proportional, linear, or non-linear. By way of example, in a case where the nominal output of the sensor is 2.5 volts, but a calibration has made the appropriate “centered” or correct alignment output 2.73 volts, a nudge may be input to move this value to 3.65 volts. That is, the nudge will effectively bias the “correct” or centered alignment to one side of the two reference rows. This straightforward nudge adjustment may then be used as the basis for upcoming steering control (within a desired control horizon, or until changed again). In open loop, or manual control, nudge “steps” (e.g., +/−a fraction of a volt in the example) may be employed where the operator may, for example, press a location on the display to increment (or reduce) the nudge in a desired direction. In closed loop operation, similar steps may be employed, or a stored look-up-table may serve to correlate the amount of correction or nudge of the sensor signal with detected variation desired in the steering. Such tables may also take into account other sensor inputs of the type mentioned above. Moreover, various steering algorithms may be used that allow for changes in the sensor feedback as a basis for the desired nudge. In some systems, the “aggressivity” of steering changes (e.g., corresponding to one or more gains in the system control) may be altered as well, particularly where the field conditions are changing more rapidly as compared to the vehicle speed. All such control changes may be made in ways and at rates to more closely follow the reference rows, to avoid understeer and understeer, as well as any instability in steering changes.
The closed loop process 82 of
While only certain features have been illustrated and described herein, many modifications and changes will occur to those skilled in the art. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the disclosure.
The techniques presented and claimed herein are referenced and applied to material objects and concrete examples of a practical nature that demonstrably improve the present technical field and, as such, are not abstract, intangible or purely theoretical. Further, if any claims appended to the end of this specification contain one or more elements designated as “means for (perform)ing (a function) . . . ” or “step for (perform)ing (a function) . . . ”, it is intended that such elements are to be interpreted under 35 U.S.C. 112(f). However, for any claims containing elements designated in any other manner, it is intended that such elements are not to be interpreted under 35 U.S.C. 112(f).