GROUND SPEED IMPLEMENT HEIGHT CONTROL ADJUSTMENT RATE ON AGRICULTURAL VEHICLES

Abstract

An adjustable height implement system for an agricultural vehicle. The system includes a harvesting implement having an adjustable height, a control system operably connected to the harvesting implement to adjust the height of the harvesting implement with respect to the ground and a sensor configured to determine a ground speed. The control system alters the rate of the height adjustment in response to the ground speed. A method and agricultural vehicle are also disclosed.

Description

FIELD OF THE INVENTION

The present invention relates to the height control operation of an implement on an agricultural vehicle. In particular, the invention relates to a system and method for adjusting the rate of height adjustment of an implement on an agricultural vehicle.

BACKGROUND OF THE INVENTION

The operation of most agricultural vehicles requires substantial operational involvement and control by the operator. For example, in a cotton harvester the operator is required to control the direction and speed of the vehicle while also controlling the height of the harvesting drum, the amount of harvested crop stored on the vehicle and a variety of other operation conditions. Accordingly, to reduce the effort required by the operator, it is useful to automate as many tasks performed by the operator as possible.

Conventional cotton harvesters include two or more harvesting implements commonly supported for vertical movement on a fore-and-aft wheeled frame of the harvester. Each harvesting implement includes a harvesting assembly defining a plant passage and a harvesting mechanism arranged within the housing. As the cotton harvester is driven across the cotton field, a row of cotton plants passes through the passage, and the harvesting mechanism removes the cotton therefrom. Cotton grows along the entire height of the cotton plant. At the lower end, the cotton grows barely off the ground and sometimes on the ground. The harvesting implements, therefore, follow as close to the ground as possible so as to pick all of the cotton from the plants.

The ground over which the harvester is driven is usually uneven. Accordingly, if the harvesting implement is set for a lowermost point of depression on the ground, stalk lifters extending from a forward end of the harvesting implement will tend to “dig into” high points of ground contour. As the harvester is driven across the field, the wheels on the harvester frame ride between adjacent rows of cotton plants. In softer muddy conditions, the wheels of the harvester furthermore deform the field into slight recesses and valleys or raised ridges. As will be appreciated, proper positioning of the harvesting implement relative to the ground contour is further complicated in such undulating field conditions.

To optimize efficiency during the harvesting operation, cotton harvesters are known to include a harvesting implement height control system for automatically controlling the height of the harvesting implement relative to the ground contour. The elevation of the harvesting implement is primarily controlled by a lift mechanism actuated in accordance with ground contours. Variations of the ground contour are sensed by a ground engaging element, such as a shoe, mounted on the harvesting implement in a manner to press on the ground and be positionally displaced in response to variations of the ground contour profile.

During the harvesting process for cotton, it is generally necessary to have the harvesting implements very close to the ground (0.5-3.0 inches) to ensure optimal harvesting. To do this, the height control system must react to changes in terrain in a timely manner. Current height control systems use a fixed or manually adjustable reaction rate to control the response time. Since the average implement or drum is approximately 4 feet long and the entire length is needed to ensure optimal harvesting (as opposed to combine headers that only need the front of the header to be optimized), the optimal height control system for cotton harvesters must ensure that proper height is maintained for the entire length of the implement. Height changes of the implement that are too slow or too fast may result in inefficient harvesting. For example, a dip in terrain at a height rate of ground speed may result in crop that is not harvested during the period of time in which the height adjustment is taking place. In addition, faster changes of height at higher ground speed provide additional safety for the implement and the vehicle by adjusting to changes in the ground clearance at a greater rate of height adjustment.

Accordingly, it would be desirable to provide an automated implement height adjustment arrangement and method that provides a rate of height adjustment that is related and/or dependent upon the ground speed of the vehicle.

SUMMARY OF THE INVENTION

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate the preferred embodiment of the invention, and together with the description, serve to explain the principles of the invention.

One embodiment of the present invention includes an adjustable height implement system for an agricultural vehicle. The system includes a harvesting implement having an adjustable height, a control system operably connected to the harvesting implement to adjust the height of the harvesting implement with respect to the ground and a sensor configured to determine a ground speed. The control system alters the rate of the height adjustment in response to the ground speed.

Another embodiment of the present invention includes a method including providing an agricultural vehicle having an adjustable height implement system. The adjustable height implement system includes a harvesting implement having an adjustable height, a control system operably connected to the harvesting implement to adjust the height of the harvesting implement with respect to the ground and a sensor configured to determine a ground speed. The method further includes determining a ground speed with the sensor and altering the rate of height adjustment in response to the ground speed determined.

Still another aspect of the present invention includes an agricultural vehicle. The vehicle includes an adjustable height implement system for an agricultural vehicle. The adjustable height implement system includes a harvesting implement having an adjustable height, a control system operably connected to the harvesting implement to adjust the height of the harvesting implement with respect to the ground and a sensor configured to determine a ground speed. The control system alters the rate of the height adjustment in response to the ground speed.

An advantage of embodiments of the present invention includes efficient harvesting, including cotton harvesting, wherein the height at the point of harvest is adjusted to provide a maximum or near maximum harvesting efficiency.

Another advantage of embodiments of the present invention is a reduction in unnecessary power and strain on the equipment, particularly at low ground speeds.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates an agricultural vehicle including a harvesting implement having an automatically adjustable height.

FIG. 2 is a schematic representation of an embodiment of an implement position control system.

FIG. 3 is a flow chart illustrating a method according to an embodiment of the invention.

FIG. 4 illustrates an exemplary relationship between rate of height adjustment and ground speed.

FIG. 5 illustrates another exemplary relationship between rate of height adjustment and ground speed.

FIG. 6 shows a known exemplary control scheme for an implement head adjustment.

FIG. 7 shows a control scheme according to an embodiment of the invention for an implement adjustment.

DETAILED DESCRIPTION OF THE INVENTION

Reference will now be made in detail to the present preferred embodiment of the control circuit of the invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference characters will be used throughout the drawings to refer to the same or like parts.

Height control systems on cotton harvesters or other agricultural harvesters maintain a desired ground clearance and should operate in a manner that minimizes or eliminates potential damage to the implements or drums. The system of the present invention includes an automated height adjustment in response to the ground distance sensors. The arrangement of automated height adjustment may be any arrangement or system known for providing height control in response to the distance to the ground. “Height”, as used herein is meant to be a unit of distance corresponding to the distance between a component, such as a harvesting implement, and the ground. Height is not limited to an absolute number and may be relative to other components or calculated based on a plurality of measurements. The control system may include sensors providing measurements of ground control using physical measurements or digital signals from optical or other sensors. The control system is not limited to a fully automated system, but may also include a system that includes manual or override adjustments remotely or by the operator. The automated height control according to the present disclosure includes a control system that is capable of having altering rates of adjustment. That is, the height control system according to the present disclosure includes a rate of raising or lowering the implement, for example to a height set point, that may be adjusted to be a greater or lesser rate of speed.

The system according to the present disclosure includes known height sensor arrangements to detect changes in the terrain over which the implement is moving and calculates the distance between the implement and the ground. The system utilizes the measured or calculated distance from the ground to determine the desired height of the implement. The system then obtains the vehicle ground speed. The ground speed may be determined using any suitable technique for determining ground speed. The ground speed is determined in order to calculate the rate at which the implement should be moved to the desired height. Once the height is determined and the rate at which the height adjustment is to be made, then the system adjusts the height of the implement at the determined rate.

One embodiment includes a cotton harvester. A representative cotton harvesting vehicle 10 is shown in FIG. 1, including a cotton compacting structure and bin 11 for receiving and holding cotton harvested by a plurality of picker implements 14 arrayed across a forward end of vehicle 10. The cotton is conveyed from harvesting implements 14 through a plurality of parallel ducts 16 by air flows through the ducts. The cotton harvester travels along ground 12 and monitors a height of the implement 14 above the ground 12. Automatic controls provide height adjustment of implement 14 above ground 12.

FIG. 2 is a schematic representation of the preferred embodiment of the implement position control system 24. Control system 24 includes a microprocessor based control unit 26, a man-controller interface 28, a vehicle direction and speed control lever 30, a hydraulic control valve 32, and an implement lift mechanism 39 (e.g., hydraulic lift cylinders, cable lift arrangements, hydraulic motor and gear arrangements, or electric motor and gear arrangements).

One or more harvesting implements 14 may be supported at a forward end of frame 13. Each harvesting implement 14 is a conventional structure including a fore-and-aft extending housing assembly 18 which rotatably supports a harvesting mechanism (not shown) and other associated mechanisms for stripping or picking cotton from the plants as the harvester is driven across the field. A pair of stalk lifters 20 extend forwardly from a housing assembly 18 for guiding the cotton plants through a plant passage defined by the housing assembly 18.

In addition to man-controller interface 28, system 24 also includes a raise and lower switch 58 which may be mounted in lever 30. By way of example, raise and lower switch 58 is a centrally biased momentary contact switch. As shown in FIG. 2, man-controller interface 28 is coupled to unit 26 by a signal bus 60 and switch 58 may be coupled to unit 26 by a signal bus 70.

The control system for providing height control includes a control unit 26, man-controller interface 28, control lever 30, and valve 32 as well as the associated components that cooperatively provide height control to the implement 14. Control unit 26 is also coupled to ground speed sensor 72 by a signal bus 74. The ground speed sensor 72 may include any sensor or device capable of determining ground speed of the vehicle 10. For example, the ground speed sensor 72 may include a global positioning system (GPS) device, a shaft or motor speed indicator or any other device suitable for measuring a parameter suitable for determining or estimating ground speed. The ground speed can be directly measured, calculated or indirectly measured. In addition, the control unit is coupled to signal receiving assembly 48 by signal bus 73. The signal receiving assembly 48 provides a ground height measurement that is usable by the control unit 26 to determine the desired height of implement 14. The ground height measurement is not limited to the arrangement shown and may include any known arrangement for measuring or determining the height of the implement from ground 12.

Control unit 26 is in communication with control valve 32 which includes a raising solenoid 80 and a lowering solenoid 82 to which signal bus 78 is connected. Control unit 26 may apply pulse width modulated signals to solenoids 80 and 82 which allow valve 32 to control the flow of fluid between a pressurized hydraulic fluid source 84 and lift device 38. In the present embodiment, source 84 is a hydraulic pump connected in series with a hydraulic fluid storage tank and appropriate filters. The specific hydraulic arrangement is not limited. In addition, the invention is not limited to hydraulic lift mechanisms and may include electrical motor lift mechanism, pneumatic systems or any other arrangement that is suitable for lifting harvesting implements.

A lift mechanism 39, as shown in FIG. 2, is provided for supporting the harvesting implement 14 for vertical movement between lowered and raised elevational positions. The mounting and supporting system preferably includes a lift assembly 27 and an elongated tension arm 29 connected to the lift assembly.

The lift assembly operates essentially as a parallelogram type linkage which is pivotally connected to and extends forwardly from frame 13 of the vehicle 10. As illustrated in FIG. 2, the lift assembly 27 includes a pair of laterally spaced upper tension arms 29 extending generally parallel to a pair of laterally spaced lower lift arms 31, 34. The tension arms 29 have an effective length which is approximately equal to that of the lift arms 31 and 34, respectively, and, therefore, the harvesting implements 14 connected thereto are maintained in a generally level attitude during field operation as they are moved between lower and raised elevational positions. The harvesting implements 14 are preferably individually connected to the tension arm 29 which, as illustrated, is suitably connected to the lift assembly 27.

A pressurized hydraulic system 36 is preferably provided for adjusting the elevation of the harvesting implement 14. As shown in FIG. 2, the hydraulic system 36 includes hydraulic lift device 38 preferably in the form of linearly distendable hydraulic cylinders connected between the frame 13 and the implement 14. Conduits 40, 42 connect the valve 32 to the lift device 38.

During a harvesting operation, operation of the lift device 38 and thereby the harvesting elevation of the harvesting implement 14 is automatically controlled by a harvesting implement height sensing system generally indicated by reference numeral 46. As shown in FIG. 2, the height sensing system 46 includes a signal receiving assembly 48, a signal transmitting mechanism 50, and a linkage assembly 52 interconnecting the signal receiving assembly 48 and the signal transmitting mechanism 50.

In one embodiment, the signal transmitting mechanism 50 includes a ground contour sensing shoe or element 56 pivotally connected to the harvesting implement. The ground engaging element 56 is responsive to the ground contour and is operable to position control valve 32 within its range of movement to effect harvester implement elevation correlated with the vertical movement of the ground engaging element relative to the harvesting implement.

FIG. 3 shows a method according to an embodiment of the present invention. The method begins when the system for height adjustment rate is activated or as the system is called upon by the control unit 26 (step 310). The method first determines whether the automated height control system is activated (step 312). If the automated height control system is not activated (i.e., “NO” in FIG. 3), the method returns to step 310. Step 312 may be omitted in certain embodiments. For example, if manual adjustment is being provided, the height adjustment method according to the present invention may still be utilized. If the automated control system is activated (i.e., “YES” in FIG. 3), the method then determines whether height adjustment is required (step 314). The determination of whether height adjustment is required can be accomplished using any suitable method, including any method utilized by the automated height control system. For example, if the ground height value is determined to be larger than the desired number, the system will determine that height adjustment is required. If height adjustment is not required (i.e., “NO” in FIG. 3), the method returns to step 310. However, if height adjustment is required (i.e., “YES” in FIG. 3), the method then determines the ground speed (step 316). The ground speed can be determined using ground speed sensor 72 (see FIG. 2), which may include a global positioning system (GPS) device, a shaft or motor speed indicator or any other device suitable for measuring a parameter suitable for determining or estimating ground speed. The ground speed can be directly measured, calculated or indirectly measured. Once the ground speed is determined, a rate of height adjustment is determined (step 318). The rate of height adjustment is dependent upon the ground speed determined in step 316. After the rate of height adjustment is determined, the height of the implement is adjusted to the desired height from the ground at the rate of height adjustment (step 320).

The relationship between the rate of height adjustment and ground speed can vary with respect to the system on which it is utilized. The relationship is preferably such that the greater the ground speed, the greater the rate of height adjustment. As shown in FIG. 4, the rate of height adjustment can vary linearly with respect to the ground speed. However, the relationship between height adjustment rate and ground speed need not be linear and may be a non-linear or a discontinuous relationship. Another embodiment is shown in FIG. 5 wherein the relationship between height adjustment rate and ground speed may be altered at different rates at different areas of ground speed. The rate of height adjustment may be a direct input to the control unit, as a particular speed at which the implement 14 is raised or lowered. Alternately, the rate of height adjustment may be a factor or a variable input into a control algorithm. The rate of height adjustment may be a multiplier for a control gain or error rate. The resultant control function would result in a height adjustment that is raised or lowered at a rate corresponding to the control algorithm adjusted by the multiplier or factor corresponding to the rate of height adjustment determined for the particular ground speed. For example, the control unit 26 may include a product/integral/differential (PID) control loop into which an error signal is passed. In this embodiment, the PID control loop includes associated gains for each of the components of the control loop. The output for the PID control loop may be used to determine an output to valve 32. The height adjustment rate may be altered by multiplying the error and/or control loop gains by a factor corresponding to ground speed.

FIG. 6 shows a known exemplary control scheme for an implement head adjustment to a set point height 600. In this example, the control unit provides a set point corresponding to a desired height for the implement from the ground. As shown in FIG. 6, the position of the implement is adjusted over time until the height of the implement reaches set point height 600.

FIG. 7 shows a control scheme according to an embodiment of the invention for an implement adjustment to a set point height 600. As in FIG. 6, the control scheme includes a set point height 600 corresponding to a desired height determined by the control unit for the implement from the ground. Unlike the control scheme in FIG. 6, the rate at which the implement is adjusted is altered with ground speed. As shown in FIG. 7, a higher ground speed (i.e., the curves farther to the left on the graph) results in obtaining set point height 600 in a shorter period of time. A lower ground speed (i.e., the curves farther to the right on the graph) results in obtaining set point height 600 in a longer period of time. As a result, when the vehicle 10 is moving at a greater velocity (i.e., ground speed), the height of the implement 14 is adjusted more quickly to match the desired height so less crop is missed during harvesting and/or the implement 14 is more quickly pulled up to avoid terrain that may damage the implement. Likewise, the slower adjustment at lower speeds permits efficient harvesting, while reducing wear on the components.

While the invention has been described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the appended claims.

Claims

1. An adjustable height implement system for an agricultural vehicle comprising: a harvesting implement having an adjustable height;a control system operably connected to the harvesting implement to adjust the height of the harvesting implement with respect to the ground;a sensor configured to determine a ground speed;wherein the control system alters the rate of the height adjustment in response to the ground speed.

2. The adjustable height implement system of claim 1, wherein the agricultural vehicle is a cotton harvester.

3. The adjustable height implement system of claim 1, wherein the controller is capable of adjusting the harvesting implement height to a height corresponding to a desired height of the harvesting implement in response to the height measurement from the harvesting implement to the ground.

4. The adjustable height implement system of claim 1, wherein the rate of height adjustment in response to ground speed is a multiplier communicated to the control system.

5. The adjustable height implement system of claim 1, wherein the rate of height adjustment in response to ground speed is a multiplier to an error rate measurement of the control system.

6. The adjustable height implement system of claim 1, wherein the rate of height adjustment is altered linearly with respect to ground speed.

7. The adjustable height implement system of claim 1, wherein the rate of height adjustment is altered nonlinearly with respect to ground speed.

8. A method comprising: providing an agricultural vehicle having an adjustable height implement system comprising: a harvesting implement having an adjustable height;a control system operably connected to the harvesting implement to adjust the height of the harvesting implement with respect to the ground;a sensor configured to determine a ground speed;determining a ground speed with the sensor;altering the rate of height adjustment in response to the ground speed determined.

9. The method of claim 8, wherein the agricultural vehicle is a cotton harvester.

10. The method of claim 8, further comprising adjusting the harvesting implement height with the control system to a height corresponding to a desired height of the harvesting implement in response to the height measurement from the harvesting implement to the ground.

11. The method of claim 8, wherein the agricultural vehicle is a cotton harvester.

12. The method of claim 8, further comprising communicating the rate of height adjustment in response to ground speed to the control system as a multiplier.

13. The method of claim 8, wherein the altering includes adjusting the error rate to provide a higher or lower rate of height adjustment for the implement.

14. An agricultural vehicle comprising: an adjustable height implement system for an agricultural vehicle comprising:a harvesting implement having an adjustable height;a control system operably connected to the harvesting implement to adjust the height of the harvesting implement with respect to the ground;a sensor configured to determine a ground speed;wherein the rate of the height adjustment is altered by the control system in response to the ground speed.

15. The agricultural vehicle of claim 14, wherein the controller is capable of adjusting the harvesting implement height to a height corresponding to a desired height of the harvesting implement in response to the height measurement from the harvesting implement to the ground.

16. The agricultural vehicle of claim 14, wherein the rate of height adjustment in response to ground speed is a multiplier communicated to the control system.

17. The agricultural vehicle of claim 14, wherein the rate of height adjustment in response to ground speed is a multiplier to an error rate measurement of the control system.

18. The agricultural vehicle of claim 14, wherein the rate of height adjustment is altered linearly with respect to ground speed.

19. The agricultural vehicle of claim 14, wherein the rate of height adjustment is altered nonlinearly with respect to ground speed.