Patent Description:
A harvester is an agricultural machine used to harvest and process crops. For instance, a combine harvester may be used to harvest grain crops, such as wheat, oats, rye, barley, corn, soybeans, and flax or linseed. In general, the objective is to complete several processes, which traditionally were distinct, in one pass of the machine over a portion of the field. In this respect, most harvesters are equipped with a detachable header or harvesting implement, which cuts and collects the crop from the field. The harvester also includes a crop processing system, which performs various processing operations (e.g., threshing, separating, etc.) on the harvested crop received from the header. Furthermore, the harvester includes a crop tank, which receives and stores the harvested crop after processing.

When performing a harvesting operation, the header is positioned at a predetermined height above the field surface. Such positioning, in turn, permits a cutter bar mounted on the header to sever the crops present within the field from the associated stubble at a desired cutting height. As the harvester travels across the field to perform the harvesting operation, the contour or topography of the field may vary. In this respect, many current combines use an automatic header height control system that attempts to maintain a generally constant cutting height above the field surface regardless of the field contour or field position relative to the base combine. While such systems work well, improvements are needed.

Harvesting implements are e.g. known from <CIT>, <CIT> and <CIT>.

Accordingly, an improved system and method for controlling harvesting implement height of an agricultural harvester would be welcomed in the technology.

Aspects and advantages of the technology will be set forth in part in the following description.

The invention is directed to a system for controlling harvesting implement height of an agricultural harvester. The system includes first and second actuators configured to adjust first and second operating parameters associated with a height or an orientation of the harvesting implement relative to a field surface, respectively. Furthermore, the system includes a sensor configured to capture data indicative of the height of the harvesting implement relative to the field surface and a computing system communicatively coupled to the sensor. In this respect, the computing system is configured to monitor the height of the harvesting implement relative to the field surface based on the data captured by the sensor. Additionally, the computing system is configured to determine an implement height error signal by comparing the monitored height of the harvesting implement to a predetermined target height. Moreover, the computing system is configured to divide the determined implement height error signal into a first frequency portion and a second frequency portion, with the second frequency portion having a higher frequency than the first frequency portion. In addition, the computing system is configured to control an operation of the first actuator based on the first frequency portion of the implement height error signal. Furthermore, the computing system is configured to control an operation of the second actuator based on the second frequency portion of the implement height error signal.

As an example, not according to the invention, the present subject matter is directed to a method for controlling harvesting implement height of an agricultural harvester. The agricultural harvester, in turn, includes first and second actuators configured to adjust first and second operating parameters associated with a height of the harvesting implement relative to a field surface, respectively. The method includes monitoring, with a computing system including one or more computing devices, the height of the harvesting implement relative to the field surface. Furthermore, the method includes determining, with the computing system, an implement height error signal by comparing the monitored height of the harvesting implement to a predetermined target height. Additionally, the method includes dividing, with the computing system, the implement height error signal into a first frequency portion and a second frequency portion, with the second frequency portion having a greater frequency than the first frequency portion. Moreover, the method includes controlling, with the computing system, an operation of the first actuator based on the first frequency portion of the implement height error signal. In addition, the method includes controlling, with the computing system, an operation of the second actuator based on the second frequency portion of the implement height error signal.

In fact, it will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope of the appended claims.

In general, the present subject matter is directed to systems and methods for controlling harvesting implement height of an agricultural harvester. As will be described below, the agricultural harvester may include a chassis, a feeder housing pivotably coupled the chassis, and a feeder face plate pivotably coupled to the feeder housing. The feeder face plate may, in turn, be coupled to a harvesting implement (e.g., a header) of the harvester. Moreover, the harvesting implement may include a cutter bar configured to sever the crops present within the field from the associated stubble.

Furthermore, the agricultural harvester may include first and second actuators configured to adjust first and second operating parameters associated with a height of the harvesting implement relative to the field surface, respectively. For example, in some embodiments, the first actuator(s) may correspond to a lift actuator(s) configured to pivot the feeder housing relative to the chassis such that the harvesting implement is raised and lowered relative to the field surface. Additionally, in such embodiments, the second actuator(s) may correspond to a tilt actuator(s) configured to pivot the feeder face plate relative to the feeder housing. Such pivoting, in turn, adjusts the fore/aft tilt angle or orientation of the harvesting implement relative to the field surface, which raises or lowers the cutter bar relative to the field surface.

In several embodiments, a computing system may be configured to control the operation of the lift and tilt actuators to maintain the cutter bar of the header at a desired height above the field surface. More specifically, the computing system may monitor the height of the header relative to the field surface (e.g., based on received sensor data). Moreover, the computing system may determine an implement height error signal by comparing the monitored height of the harvesting implement to a predetermined target height. In addition, the computing system may divide the implement height error signal into a first or low frequency portion and a second or high frequency portion. For example, in one embodiment, the computing system may pass the implement height error signal through a high pass filter to determine the high frequency portion and a low pass filter to determine the low frequency portion. Thereafter, the computing system may control the operation of the lift and tilt actuators based on the low and high frequency portions of the implement height error signal, respectively.

Controlling the operation of the lift and tilt actuators based on the low and high frequency portions of the implement height error signal, respectively, improves the operation of the agricultural harvester. More specifically, the harvesting implement generally has a much greater translational moment of inertia than rotational moment of inertia. As such, more force is required to lift the harvesting implement with the lift actuator(s) than to tilt the harvesting implement with the tilt actuator(s). Thus, the harvesting implement can be tilted with the tilt actuator(s) much quicker than it can be lifted with the lift actuator(s). However, the tilt actuator(s) generally have a much smaller range of motion than the lift actuator(s). The low frequency portions of the implement height error signal are generally associated with larger, but slower changes in field topography. Conversely, the high frequency portions of the implement height error signal are generally associated with small, but quicker changes in field topography. In this respect, using the low frequency portions to control the operation of the lift actuator(s) allows the system to make large adjustments to the cutter bar height that could not be made with the tilt actuator(s) (e.g., due to its/their smaller range of motion). Moreover, using the high frequency portions to control the operation of the tilt actuator(s) allows the system to make small and frequent to the cutter bar height that could not be made with the lift actuator(s) (e.g., due its/their slower response time(s)). Thus, controlling the operation of the lift and tilt actuators based on the low and high frequency portions allows a generally constant cutting height to be maintained regardless of the magnitude or frequency at which the field topography changes.

Referring now to the drawings, <FIG> illustrates a partial sectional side view of the agricultural harvester <NUM>. In general, the harvester <NUM> may be configured to travel across a field in a forward direction of travel (indicated by arrow <NUM>) to harvest a crop <NUM>. While traversing the field, the harvester <NUM> may be configured to process and store the harvested crop within a crop tank <NUM> of the harvester <NUM>. Furthermore, the harvested crop may be unloaded from the crop tank <NUM> for receipt by the crop receiving vehicle (not shown) via a crop discharge tube <NUM> of the harvester <NUM>. Moreover, in the illustrated embodiment, the harvester <NUM> is configured as an axial-flow type combine in which the harvested crop is threshed and separated while being advanced by and along a longitudinally arranged rotor <NUM>. However, in alternative embodiments, the harvester <NUM> may have any other suitable harvester configuration, such as a traverse-flow type configuration.

The harvester <NUM> may include a chassis or main frame <NUM> configured to support and/or couple to various components of the harvester <NUM>. For example, in several embodiments, the harvester <NUM> may include a pair of driven, front wheels <NUM> and a pair of steerable, rear wheels <NUM> coupled to the chassis <NUM>. As such, the wheels <NUM>, <NUM> may be configured to support the harvester <NUM> relative to the ground and move the harvester <NUM> in the forward direction of travel <NUM>. Furthermore, the harvester <NUM> may include an operator's platform <NUM> having an operator's cab <NUM>, a crop processing system <NUM>, the crop tank <NUM>, and the crop discharge tube <NUM> supported by the chassis <NUM>. As will be described below, the crop processing system <NUM> may be configured to perform various processing operations on the harvested crop as the crop processing system <NUM> transfers the harvested crop between a harvesting implement <NUM> (e.g., a header) of the harvester <NUM> and the crop tank <NUM>. Furthermore, the harvester <NUM> may include an engine <NUM> and a transmission <NUM> mounted on the chassis <NUM>. The transmission <NUM> may be operably coupled to the engine <NUM> and may provide variably adjusted gear ratios for transferring engine power to the wheels <NUM> via a drive axle assembly (or via axles if multiple drive axles are employed).

Furthermore, as shown in <FIG>, the harvester <NUM> includes a feeder <NUM> that couples to and supports the harvesting implement <NUM>. More specifically, the feeder <NUM> may include a feeder housing <NUM> extending from the forward end <NUM> to an aft end <NUM>. As will be described below, the forward end <NUM> of the feeder housing <NUM> may, in turn, be coupled to harvesting implement <NUM>. Moreover, the aft end <NUM> of the feeder housing <NUM> may be pivotably coupled to the chassis <NUM> adjacent to a threshing and separating assembly <NUM> of the crop processing system <NUM>. Such a pivotable coupling may permit movement of the harvesting implement <NUM> relative to a field surface <NUM> in a vertical direction (indicated by arrow <NUM>).

Additionally, the agricultural harvester <NUM> may include one or more lift actuators <NUM> coupled between the chassis <NUM> and the feeder housing <NUM>. In several embodiments, the lift actuator(s) <NUM> may correspond to a fluid-driven actuator(s), such as a hydraulic or pneumatic cylinder(s). In such embodiments, a rod(s) <NUM> of the lift actuator(s) <NUM> may be extended relative to an associated cylinder(s) <NUM> of the lift actuator(s) <NUM> to pivot the forward end <NUM> of the feeder housing <NUM> upward in the vertical direction <NUM>, thereby raising the harvesting implement <NUM> relative to the field surface <NUM>. Similarly, the rod(s) <NUM> of the lift actuator(s) <NUM> may be retracted relative to the associated cylinder(s) <NUM> of the lift actuator(s) <NUM> to pivot the forward end <NUM> of the feeder housing <NUM> downward in the vertical direction <NUM>, thereby lowering the harvesting implement <NUM> relative to the field surface <NUM>. In this respect, the operation of the lift actuator(s) <NUM> may be controlled to move the harvesting implement <NUM> upward and downward in the vertical direction <NUM> relative to a field surface <NUM> to adjust the cutting height or distance (e.g., as indicated by arrow <NUM> in <FIG>) between a cutter bar <NUM> (<FIG>) of the harvesting implement <NUM> and the field surface <NUM> as the topography of the field varies. However, in alternative embodiments, the lift actuator(s) <NUM> may correspond to any other suitable type of actuator(s), such as an electric linear actuator(s).

As the harvester <NUM> is propelled in the forward direction of travel <NUM> over the field with the crop <NUM>, the crop material is severed from the stubble by one or more knives (not shown) positioned on the cutter bar <NUM> at the front of the harvesting implement <NUM>. The crop material is delivered by a header auger <NUM> to the forward end <NUM> of the feeder housing <NUM>, which supplies the harvested crop to the threshing and separating assembly <NUM>. In general, the threshing and separating assembly <NUM> may include a cylindrical chamber <NUM> in which the rotor <NUM> is rotated to thresh and separate the harvested crop received therein. That is, the harvested crop is rubbed and beaten between the rotor <NUM> and the inner surfaces of the chamber <NUM> to loosen and separate the grain, seed, or the like from the straw.

The harvested crop separated by the threshing and separating assembly <NUM> may fall onto a crop cleaning assembly <NUM> of the crop processing system <NUM>. In general, the crop cleaning assembly <NUM> may include a series of pans <NUM> and associated sieves <NUM>. In general, the separated harvested crop may be spread out via the oscillation of pans <NUM> and/or sieves <NUM> and may eventually fall through apertures defined by the sieves <NUM>. Additionally, a cleaning fan <NUM> may be positioned adjacent to one or more of the sieves <NUM> to provide an air flow through the sieves <NUM> that removes chaff and other impurities from the harvested crop. For instance, the fan <NUM> may blow the impurities off the harvested crop for discharge from the harvester <NUM> through the outlet of a straw hood <NUM> positioned at the back end of the harvester <NUM>. The cleaned harvested crop passing through the sieves <NUM> may then fall into a trough of an auger <NUM>, which may be configured to transfer the harvested crop to an elevator <NUM> for delivery to the crop tank <NUM>.

Referring now to <FIG>, a side view of one embodiment of a feeder <NUM> of the agricultural harvester <NUM> is illustrated. As mentioned above, the feeder <NUM> may include a feeder housing <NUM> having its forward end <NUM> coupled to the harvesting implement <NUM>. In several embodiments, the harvesting implement <NUM> may be coupled to the feeder <NUM> to permit a fore/aft tilt angle (indicated by arrow <NUM>) of the harvesting implement <NUM> to be adjusted. The "fore/aft tilt angle" of the harvesting implement <NUM>, in turn, is the angle defined between a longitudinal axis <NUM> of the harvesting implement <NUM> and the field surface <NUM>, with the longitudinal axis <NUM> extending between a forward end <NUM> of the harvesting implement <NUM> and an aft end <NUM> of the harvesting implement <NUM>. Specifically, in one embodiment, the feeder <NUM> may include a feeder face plate <NUM> pivotably coupled to the forward end <NUM> of the feeder housing <NUM> via a pivot joint <NUM>. Moreover, the feeder face plate <NUM> may be coupled (e.g., bolted) to the harvesting implement <NUM>. However, in alternative embodiments, the harvesting implement <NUM> may be pivotably coupled to the feeder <NUM> in any other suitable manner.

Additionally, the agricultural harvester <NUM> may include one or more tilt actuators <NUM> configured to adjust the fore/aft tilt angle <NUM> of the harvesting implement <NUM>. For example, the tilt actuator(s) <NUM> may be coupled between the feeder face plate <NUM> and the forward end <NUM> of the feeder housing <NUM>. In several embodiments, the tilt actuator(s) <NUM> may correspond to a fluid-driven actuator(s), such as a hydraulic or pneumatic cylinder(s). In such embodiments, a rod(s) <NUM> of the tilt actuator(s) <NUM> may be extended relative to an associated cylinder(s) <NUM> of the tilt actuator(s) <NUM> to pivot the feeder face plate <NUM> relative to the forward end <NUM> of the feeder housing <NUM>. Such extension may, in turn, pivot the harvesting implement <NUM> in a manner that lowers the forward end <NUM> of the harvesting implement <NUM> relative to the field surface <NUM>, thereby increasing the fore/aft tilt angle <NUM> and decreasing the cutting height <NUM>. Similarly, the rod(s) <NUM> of the tilt actuator(s) <NUM> may be retracted relative to the associated cylinder(s) <NUM> of the tilt actuator(s) <NUM> to pivot the feeder face plate <NUM> relative to the forward end <NUM> of the feeder housing <NUM>. Such retraction may, in turn, pivot the harvesting implement <NUM> in a manner that raises the forward end <NUM> of the harvesting implement <NUM> relative to the field surface <NUM>, thereby decreasing or flattening the fore/aft tilt angle <NUM> and increasing the cutting height <NUM>. In this respect, the operation of the tilt actuator(s) <NUM> may be controlled to move the cutter bar <NUM> upward and downward in the vertical direction <NUM> relative to a field surface <NUM> to adjust the cutting height <NUM>. As will be described below, the operation of the tilt actuator(s) <NUM> may be controlled in addition to the lift actuator(s) <NUM> to maintain a generally constant cutting height <NUM> above the field surface <NUM> as field topography changes. However, in alternative embodiments, the tilt actuator(s) <NUM> may correspond to any other suitable type of actuator(s), such as an electric linear actuator(s).

It should be further appreciated that the configuration of the agricultural harvester <NUM> described above and shown in <FIG> and <FIG> is provided only to place the present subject matter in an exemplary field of use. Thus, it should be appreciated that the present subject matter may be readily adaptable to any manner of harvester configuration.

Referring now to <FIG>, a schematic view of one embodiment of a system <NUM> for controlling harvesting implement height of an agricultural harvester is illustrated in accordance with aspects of the present subject matter. In general, the system <NUM> will be described herein with reference to the agricultural harvester <NUM> described above with reference to <FIG> and <FIG>. However, it should be appreciated by those of ordinary skill in the art that the disclosed system <NUM> may generally be utilized with agricultural harvesters having any other suitable harvester configuration.

As shown in <FIG>, the system <NUM> may include one or more sensors <NUM> of the agricultural harvester <NUM>. In general, the sensor(s) <NUM> may be configured to capture data indicative of the distance between the harvesting implement <NUM> and the field surface <NUM>. In several embodiments, the sensor(s) <NUM> may be configured to capture data indicative of the cutting height or the distance between the cutter bar <NUM> and the field surface <NUM> (e.g., the distance <NUM> in <FIG>). As will be described below, the data captured by the sensor(s) <NUM> may be used to control the operation of the lift and tilt actuators <NUM>, <NUM> to maintain a generally constant cutting height at the topography or surface profile of the field varies.

The sensor(s) <NUM> may be configured in any suitable manner that allows the sensor(s) <NUM> to capture data indicative of the distance between the harvesting implement <NUM> and the field surface <NUM>. In several embodiments, the sensor(s) <NUM> may be non-contact-based sensor(s). For example, in one embodiment, the sensor(s) <NUM> may be ultrasonic sensor(s) positioned within the harvesting implement <NUM> that detect the distance between the sensor(s) <NUM> and the field surface <NUM> using emitted sounds waves. Alternatively, the sensor(s) <NUM> may be contact-based sensor(s). For example, in one embodiment, the sensor(s) <NUM> may include a biased or spring-loaded sensor arm(s) (not shown) that contacts the ground as the harvester <NUM> travels across the field.

In several embodiments, the system <NUM> may include a computing system <NUM> communicatively coupled to one or more components of the agricultural harvester <NUM> to allow the operation of such components to be electronically or automatically controlled by the computing system <NUM>. For instance, the computing system <NUM> may be communicatively coupled to the sensor(s) <NUM> via a communicative link <NUM>. As such, the computing system <NUM> may be configured to receive data from the sensor(s) <NUM> indicative of the distance between the harvesting implement <NUM> and the field surface <NUM> (e.g., the cutting height or the distance between the cutter bar <NUM> and the field surface <NUM>). Moreover, the computing system <NUM> may be communicatively coupled to the lift actuator(s) <NUM> of the harvester <NUM> via the communicative link <NUM>. In this respect, the computing system <NUM> may be configured to control the operation of the lift actuator(s) <NUM> such that the actuator(s) <NUM> raises and lowers the harvesting implement <NUM> relative to the field surface. Furthermore, the computing system <NUM> may be communicatively coupled to the tilt actuator(s) <NUM> of the harvester <NUM> via the communicative link <NUM>. In this respect, the computing system <NUM> may be configured to control the operation of the tilt actuator(s) <NUM> such that the actuator(s) <NUM> adjusts the fore/aft tilt angle of the harvesting implement <NUM> relative to the field surface. Additionally, the computing system <NUM> may be communicatively coupled to any other suitable components of the agricultural harvester <NUM> via the communicative link <NUM>, such as the engine <NUM>, the transmission <NUM>, and/or the like.

In general, the computing system <NUM> may comprise one or more processor-based devices, such as a given controller or computing device or any suitable combination of controllers or computing devices. Thus, in several embodiments, the computing system <NUM> may include one or more processor(s) <NUM> and associated memory device(s) <NUM> configured to perform a variety of computer-implemented functions. As used herein, the term "processor" refers not only to integrated circuits referred to in the art as being included in a computer, but also refers to a controller, a microcontroller, a microcomputer, a programmable logic circuit (PLC), an application specific integrated circuit, and other programmable circuits. Additionally, the memory device(s) <NUM> of the computing system <NUM> may generally comprise memory element(s) including, but not limited to, a computer readable medium (e.g., random access memory RAM)), a computer readable non-volatile medium (e.g., a flash memory), a floppy disk, a compact disk-read only memory (CD-ROM), a magneto-optical disk (MOD), a digital versatile disk (DVD) and/or other suitable memory elements. Such memory device(s) <NUM> may generally be configured to store suitable computer-readable instructions that, when implemented by the processor(s) <NUM>, configure the computing system <NUM> to perform various computer-implemented functions, such as one or more aspects of the methods and algorithms that will be described herein. In addition, the computing system <NUM> may also include various other suitable components, such as a communications circuit or module, one or more input/output channels, a data/control bus and/or the like.

The various functions of the computing system <NUM> may be performed by a single processor-based device or may be distributed across any number of processor-based devices, in which instance such devices may be considered to form part of the computing system <NUM>. For instance, the functions of the computing system <NUM> may be distributed across multiple application-specific controllers or computing devices, such as a harvesting implement controller (e.g., a header height controller and/or header tilt angle controller), a navigation controller, an engine controller, and/or the like.

Referring now to <FIG>, a flow diagram of one embodiment of example control logic <NUM> that may be executed by the computing system <NUM> (or any other suitable computing system) for controlling harvesting implement height of an agricultural harvester is illustrated in accordance with aspects of the present subject matter. Specifically, the control logic <NUM> shown in <FIG> is representative of steps of one embodiment of an algorithm that can be executed to control the harvesting implement height of an agricultural harvester in a manner that simultaneously controls the operation of the lift and tilt actuators of the harvester to maintain a generally constant cutting height as field topography changes. Thus, in several embodiments, the control logic <NUM> may be advantageously utilized in association with a system installed on or forming part of an agricultural harvester to allow for real-time control of harvesting implement height without requiring substantial computing resources and/or processing time. However, in other embodiments, the control logic <NUM> may be used in association with any other suitable system, application, and/or the like for controlling harvesting implement height of an agricultural harvester.

As shown in <FIG>, at (<NUM>), the control logic <NUM> includes receiving sensor data indicative of the height of a harvesting implement of an agricultural harvester relative to the field surface. In several embodiments, as mentioned above, the computing system <NUM> may be communicatively coupled to the sensor(s) <NUM> via the communicative link <NUM>. In this respect, during operation of the harvester <NUM>, the computing system <NUM> may receive data from the sensor(s) <NUM> that is indicative of the height of the harvesting implement <NUM> relative to the field surface <NUM>. For example, in one embodiment, the computing system <NUM> may receive data from the sensor(s) <NUM> that is indicative of the cutting height or the height of the cutter bar <NUM> relative to the field surface <NUM> (e.g., the distance <NUM> in <FIG>).

Furthermore, at (<NUM>), the control logic <NUM> includes monitoring the height of the harvesting implement relative to the field surface based on the received sensor data. For example, the computing system <NUM> may include a look-up table(s), suitable mathematical formula, and/or algorithms stored within its memory device(s) <NUM> that correlate the received sensor data to the height of the harvesting implement <NUM> (or, more specifically, the cutter bar <NUM>) relative to the field surface <NUM>.

Additionally, at (<NUM>), the control logic <NUM> includes determining an implement height error signal by comparing the monitored height of the harvesting implement to a predetermined target height. For example, the computing system <NUM> may compare the monitored height of the harvesting implement <NUM> (e.g., the height determined at (<NUM>)) to a predetermined target height. The predetermined target height may, in turn, be the desired cutting height or distance between the cutter bar <NUM> of the harvesting implement <NUM> and the field surface <NUM>. Thereafter, the computing system <NUM> may determine or generate an implement height error signal based on the difference between the monitored height of the harvesting implement <NUM> (or, more specifically, the cutter bar <NUM>) and the predetermined target height.

Moreover, at (<NUM>), the control logic <NUM> includes dividing the determined implement height error signal into a first frequency portion and a second frequency portion. Specifically, in several embodiments, the computing system <NUM> may be configured to divide the determined implement height error signal (e.g., the implement error signal determined at (<NUM>)) into a first or low frequency portion and a second or high frequency portion. The high frequency portion, in turn, has a greater frequency than the low frequency portion. In general, the low frequency portion of the implement error signal is indicative of larger and more gradual changes to the topography or profile of the field (e.g., hills, slopes, etc.). Conversely, the high frequency portion of the implement error signal is indicative of smaller and more frequent changes to the topography or profile of the field (e.g., small surface undulations, divots, etc.). In this respect, and as will be described below, the low frequency portion may be used to control the operation of the lift actuator(s) <NUM>, while the high frequency portion may be used to control the operation of the tilt actuator(s) <NUM>.

In some embodiments, at (<NUM>), the computing system <NUM> may use high and low pass filters to determine the high and low frequency portions of the implement height error signal. More specifically, in such embodiments, the computing system <NUM> may pass the implement height error signal through a low pass filter to determine the low frequency portion of the signal. Furthermore, in such embodiments, the computing system <NUM> may also pass the implement height error signal through a high pass filter to determine the determine frequency portion of the signal.

In other embodiments, at (<NUM>), the computing system <NUM> may use a single filter to determine the high and low frequency portions of the implement height error signal. More specifically, in such embodiments, the computing system <NUM> may pass the determined implement height error signal through a filter to determine one of the high or low frequency portions of the signal. Thereafter, the computing system <NUM> may determine of the other of the high or low frequency portions of the implement height error signal based on the determined high or low frequency portion and the original implement height error signal. For example, in one embodiment, the computing system <NUM> may pass the determined implement height error signal through a high pass filter to determine the high frequency portion of the signal. Thereafter, the computing system <NUM> may determine of the low frequency portion of the implement height error signal based on the determined high frequency portion and the original implement height error signal. However, in other embodiments, the computing system <NUM> may pass the determined implement height error signal through a low pass filter to determine the low frequency portion of the signal. Thereafter, the computing system <NUM> may determine of the high frequency portion of the implement height error signal based on the determined low frequency portion and the original implement height error signal.

However, in alternative embodiments, at (<NUM>), the computing system <NUM> may divide the determined implement height error signal into high and low frequency portions in any other suitable manner. For example, in some embodiments, the computing system <NUM> may use one or more band pass filters to divide the implement height error signal.

As shown in <FIG>, at (<NUM>), the control logic <NUM> includes determining an adjustment to be made by the lift actuator(s) of the agricultural harvester based on the determined low frequency component. More specifically, as mentioned above, the low frequency component of the implement height error signal is indicative of larger and more gradual changes to the topography or profile of the field. Such changes in field topography may generally be too large for the limited range of motion of the tilt actuator(s) <NUM>. However, in most instances, these changes in field topography are gradual enough that the lift actuator(s) <NUM> can adjust to height of the harvesting implement <NUM> relative to the field surface <NUM> quickly enough to maintain a generally constant cutting height. In this respect, the computing system <NUM> may analyze the low frequency portion of the implement heigh error signal to determine any adjustments to be made by the lift actuator(s) <NUM>. Such adjustments, in turn, move the harvesting implement <NUM> in the vertical direction <NUM> relative to the chassis <NUM> of the harvester <NUM>, thereby adjusting the cutting height of the cutter bar <NUM>.

In addition, at (<NUM>), the control logic <NUM> includes determining when the lift actuator(s) is able to make the determined adjustments. In certain instances, the low frequency portion of the implement height error signal may dictate adjustments that the lift actuator(s) <NUM> is unable to make. For example, in such instances, the lift actuator(s) <NUM> may be unable to move the harvesting implement <NUM> to the desired position quickly enough to maintain a generally uniform cutting height. As such, the computing system <NUM> may compare the duration across which the lift actuator(s) <NUM> is to make the adjustments as determined at (<NUM>) to the minimum time necessary for the lift actuator(s) <NUM> to make such adjustments. When the lift actuator(s) <NUM> is able to make the adjustments as determined at (<NUM>) quickly enough, the computing system <NUM> may, at (<NUM>), control the operation of the lift actuator(s) <NUM> to make such adjustments at the speed determined at (<NUM>). Conversely, when the lift actuator(s) <NUM> cannot make the adjustments as determined at (<NUM>) quickly enough, the computing system <NUM> may, at (<NUM>), control the operation of the lift actuator(s) <NUM> to make the adjustments at the maximum speed that such adjustments can be made.

Furthermore, at (<NUM>), the control logic <NUM> includes determining an adjustment to be made by the tilt actuator(s) of the agricultural harvester based on the determined high frequency component. More specifically, as mentioned above, the high frequency component of the implement height error signal is indicative of smaller and more frequent changes to the topography or profile of the field. The lift actuator(s) <NUM> may generally be unable to respond to such changes in the field topography. However, in most instances, these changes in field topography are small enough that the tilt actuator(s) <NUM> is able to adjust to height of the harvesting implement <NUM> relative to the field surface <NUM> to maintain a generally constant cutting height. In this respect, the computing system <NUM> may analyze the high frequency portion of the implement heigh error signal to determine any adjustments to be made by the tilt actuator(s) <NUM>. Such adjustments, in turn, adjust the fore/aft tilt angle <NUM> of the harvesting implement <NUM>, thereby adjusting the cutting height of the cutter bar <NUM>.

Additionally, at (<NUM>), the control logic <NUM> includes determining when the tilt actuator(s) can make the determined adjustments. In certain instances, the high frequency portion of the implement height error signal may dictate adjustments that the tilt actuator(s) <NUM> is unable to make. For example, in such instances, the range of motion of the tilt actuator(s) <NUM> may be too small to move the cutter bar <NUM> of the harvesting implement <NUM> to the desired height. As such, the computing system <NUM> may compare the magnitude of the adjustments as determined at (<NUM>) to the maximum adjustment that the tilt actuator(s) <NUM> can make. When the tilt actuator(s) <NUM> is able to make the adjustments as determined at (<NUM>), the computing system <NUM> may, at (<NUM>), control the operation of the tilt actuator(s) <NUM> to make the determined adjustments. Conversely, when the tilt actuator(s) <NUM> is not able to make the adjustments determined at (<NUM>), the computing system <NUM> may, at (<NUM>), control the operation of the tilt actuator(s) <NUM> to make the maximum adjustments to the fore/aft tilt angle that can be made. Thereafter, the computing system <NUM> may, at (<NUM>), control the operation of the lift actuator(s) <NUM> to make the remaining adjustments.

Referring now to <FIG>, a flow diagram of one embodiment of a method <NUM> for controlling harvesting implement height of an agricultural harvester is illustrated in accordance with aspects of the present subject matter. In general, the method <NUM> will be described herein with reference to the agricultural harvester <NUM> and the system <NUM> described above with reference to <FIG>. However, it should be appreciated by those of ordinary skill in the art that the disclosed method <NUM> may generally be implemented with any agricultural harvester having any suitable harvester configuration and/or within any system having any suitable system configuration. In addition, although <FIG> depicts steps performed in a particular order for purposes of illustration and discussion, the methods discussed herein are not limited to any particular order or arrangement. One skilled in the art, using the disclosures provided herein, will appreciate that various steps of the methods disclosed herein can be omitted, rearranged, combined, and/or adapted in various ways without deviating from the scope of the present disclosure.

As shown in <FIG>, at (<NUM>), the method <NUM> may include monitoring, with a computing system, the height of a harvesting implement of an agricultural harvester relative to a field surface. For example, as described above, the computing system <NUM> may monitor the height of the harvesting implement <NUM> of the agricultural harvester <NUM> relative to the field surface <NUM>.

Furthermore, at (<NUM>), the method <NUM> may include determining, with the computing system, an implement height error signal by comparing the monitored height of the harvesting implement to a predetermined target height. For example, as described above, the computing system <NUM> may determine an implement height error signal by comparing the monitored height of the harvesting implement <NUM> to a predetermined target height.

Additionally, as shown in <FIG>, at (<NUM>), the method <NUM> may include dividing, with the computing system, the implement height error signal into a first frequency portion and a second frequency portion. For example, as described above, the computing system <NUM> may divide the implement height error signal into a first or low frequency portion and a second or high frequency portion.

Moreover, at (<NUM>), the method <NUM> may include controlling, with the computing system, an operation of the first actuator based on the first frequency portion of the implement height error signal. For example, as described above, the computing system <NUM> may control the operation of the lift actuator(s) <NUM> based on the first or low frequency portion of the implement height error signal.

In addition, as shown in <FIG>, at (<NUM>), the method <NUM> may include controlling, with the computing system, an operation of the second actuator based on the second frequency portion of the implement height error signal. For example, as described above, the computing system <NUM> may control the operation of the tilt actuator(s) <NUM> based on the second or high frequency portion of the implement height error signal.

It is to be understood that the steps of the control logic <NUM> and the method <NUM> are performed by the computing system <NUM> upon loading and executing software code or instructions which are tangibly stored on a tangible computer readable medium, such as on a magnetic medium, e.g., a computer hard drive, an optical medium, e.g., an optical disc, solid-state memory, e.g., flash memory, or other storage media known in the art. Thus, any of the functionality performed by the computing system <NUM> described herein, such as the control logic <NUM> and the method <NUM>, is implemented in software code or instructions which are tangibly stored on a tangible computer readable medium. The computing system <NUM> loads the software code or instructions via a direct interface with the computer readable medium or via a wired and/or wireless network. Upon loading and executing such software code or instructions by the computing system <NUM>, the computing system <NUM> may perform any of the functionality of the computing system <NUM> described herein, including any steps of the control logic <NUM> and the method <NUM> described herein.

Claim 1:
A system (<NUM>) for controlling harvesting implement height of an agricultural harvester (<NUM>), the system (<NUM>) comprising:
a harvesting implement (<NUM>);
first and second actuators (<NUM>, <NUM>) configured to adjust first and second operating parameters respectively associated with a height or an orientation of the harvesting implement (<NUM>) relative to a field surface, respectively;
a sensor (<NUM>) configured to capture data indicative of the height of the harvesting implement (<NUM>) relative to the field surface; and
a computing system (<NUM>) communicatively coupled to the sensor (<NUM>), the computing system (<NUM>) configured to:
monitor the height of the harvesting implement (<NUM>) relative to the field surface based on the data captured by the sensor (<NUM>);
determine an implement height error signal by comparing the monitored height of the harvesting implement (<NUM>) to a predetermined target height;
characterized in that,
the computing system (<NUM>) is further configured to
divide the determined implement height error signal into a first frequency portion and a second frequency portion, the second frequency portion having a higher frequency than the first frequency portion;
control an operation of the first actuator (<NUM>) based on the first frequency portion of the implement height error signal; and
control an operation of the second actuator (<NUM>) based on the second frequency portion of the implement height error signal.