Control system and method for operating a row crop cultivator tool

Abstract

The present invention relates to a control system and method for operating a row crop cultivator, which includes a main frame (308) operatively connected to a tractor vehicle; at least one wheel (304) operatively connected to the main frame (308) via an arm (310); a sensor (312) operatively connected to the arm (310) for measuring a depth wheel sensor value; a depth sensor controller (314) connected to the sensor (312) for receiving a measured depth wheel sensor value; a hydraulic cylinder depth control device (318) operatively connected to the main frame (308) for adjusting a working depth of the row crop cultivator tool (300); a main controller (316) operationally connected to the depth sensor controller (314) for controlling a working depth of the row crop cultivator tool (300) via the hydraulic cylinder depth control device (318).

Description

TITLE OF THE INVENTIONCONTROL SYSTEM AND METHOD FOR OPERATING A ROW CROP CULTIVATOR TOOLFIELD OF THE INVENTION

[0001] This invention relates in general to a row crop cultivator tool for unearthing weeds on cultivated row crops.BACKGROUND OF THE INVENTION

[0002] Row crop cultivators using circular steel discs have long been used to till soil and unearth weed from of row crops. For example, US Patent No. 5,785,129 (KELLER) discloses a row crop cultivator having a fixed depth of penetration.

[0003] During operation of known row crop cultivators, the weeding tools are positioned very close to the roots of the cultivated crops, and it becomes difficult to properly remove weeds without affecting the desired cultivated crops. This problem is further complicated by the soil type, humidity of the soil and speed of the row crop cultivator.

[0004] There exists therefore a need for a row crop cultivator tool that can remove weeds without significantly affecting the desired cultivated plants despite of soil type, humidity of the soil and moving speed of the row crop cultivator.SUMMARY OF THE INVENTION

[0005] In accordance with the present invention, there is provided a system and method for controlling a depth of a row crop cultivator.

[0006] In embodiments, the system and method for controlling a depth of the row crop cultivator is configured to perform substantial uniform depth control despite of soil type, humidity of the soil and moving speed of row crop cultivator.

[0007] In embodiments, a system and method solve the above problem by using a load cell to measure the normal force applied to the unit. A desired normal force is defined by the user. The system and method use the load cell in feedback as well as an electromechanical valve to adjust this normal force when it is no longer the desired value. The system and method can adjust the normal force by either reducing or increasing the force.

[0008] In embodiments, the system and method also make it possible to raise and lower each unit individually, greatly reducing the loss of plants in cultivation and non-weeded surfaces.

[0009] In embodiments, the system and method use a feedback loop to maintain the ideal working depth. This feedback is done through a load cell. It is efficient by its feedback speed.Calculations and adjustments can be done several times per second instead of having to stop the operation. Moreover, the invention controls the depth row by row instead of applying a parameter uniformly on all the units.

[0010] In embodiments, a system and method of the present invention raises one or more row crop cultivator units when arriving at the end of a row crop before turning the row crop cultivator in another direction. This embodiment solves the problem of the unnecessary uprooting of plants in cultivation when arriving at the end of a row crop. Indeed, when arriving at the end of the row and in crops sown in the opposite direction, units can uproot plants in cultivation which could have been saved if the unit were raised.

[0011] In embodiments, there is provided a row crop cultivator tool comprising: a main frame operatively connected to a tractor vehicle; at least one wheel operatively connected to the main frame via an arm; a sensor operatively connected to the arm for measuring a depth wheel sensor value; a depth sensor controller connected to the sensor for receiving a measured depth wheel sensor value; a depth control device operatively connected to the main frame for adjusting a working depth of the row crop cultivator tool; and a main controller operationally connected to the depth sensor controller for controlling a working depth of the row crop cultivator tool via the depth control device.

[0012] In embodiments, the depth control device comprises a hydraulic cylinder depth control device or an electric actuator depth control device or a pneumatic cylinder depth control device. In embodiments, the depth sensor controller is integrated in the main controller.

[0013] In embodiments, the depth control device is configured to raise the crop cultivator tool from a ground engaging position to a raised position.

[0014] In embodiments, there is provided a method for controlling a working depth of a row crop cultivator tool, the method comprising steps of: a) measuring a current depth wheel sensor value; b) comparing the current depth wheel sensor value to a set point and calculating a difference of the depth wheel sensor value with the set point; c) if the difference of the depth wheel sensor value is equal or below a deadband value, then maintaining a target pressure of the row crop cultivator tool at a previous set target pressure value; d) obtaining a current pressure of the row crop cultivator;e) if the current pressure obtained at step d) is not equal to a set target pressure value target pressure, then modifying the current pressure by a set slew rate and repeating steps d) and e); f) if the difference of the depth wheel sensor value is above the deadband value, then adding the current depth wheel sensor value to the difference of the depth wheel sensor value to obtain a summed value; and g) filtering the summed value with a proportional integral differential (PID) filter to obtain a filtered value and repeating steps d) and e).

[0015] In embodiments, there is provided a row crop cultivator tool comprising: a main frame operatively connectable to a tractor vehicle; at least one wheel operatively connected to the main frame via an arm; a sensor operatively connected to the arm for measuring a depth wheel sensor value; a depth control device operatively connected to the main frame for adjusting a working depth of the row crop cultivator tool; and at least one controller for controlling the working depth of the row crop cultivator tool via the depth control device.

[0016] In embodiments, the at least one controller is configured to: a) measure a current depth wheel sensor value; b) compare the current depth wheel sensor value to a set point and calculate a difference of the depth wheel sensor value with the set point; c) if the difference of the depth wheel sensor value is equal or below a deadband value, then maintain a target pressure of the row crop cultivator tool at a previous set target pressure value; d) obtain a current pressure of the row crop cultivator; e) if the current pressure obtained at step d) is not equal to a set target pressure value target pressure, then modify the current pressure by a set slew rate and repeating steps d) and e); f) if the difference of the depth wheel sensor value is above the deadband value, then add the current depth wheel sensor value to the difference of the depth wheel sensor value to obtain a summed value; and g) filter the summed value with a proportional integral differential (PID) filter to obtain a filtered value and repeating steps d) and e).In embodiments, there is provided a non-transitory computer-readable medium having computer-executable instructions stored thereon, which when executed by a controller of a row crop cultivator tool, cause the controller to perform the above steps.BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is a perspective view of a row crop cultivator tool, according to a preferred embodiment of the present invention.

[0018] Figure 2 is a perspective view of a row crop cultivator tool, according to another preferred embodiment of the present invention.

[0019] Figure 3 is a perspective view of a row crop cultivator tool, according to another preferred embodiment of the present invention.

[0020] Figure 4 is a flowchart diagram of control system and method for a row crop cultivator tool, according to a preferred embodiment of the present invention.

[0021] Figure 5 side view of the row crop cultivator tool shown in Figure 3, in a ground engaging position.

[0022] Figure 6 is a side view of the row crop cultivator tool shown in Figure 3, in a raised position.DETAILED DESCRIPTION OF THE ILLUSTRATIVE EMBODIMENTS

[0023] The present invention is illustrated in further details by the following non-limiting examples.

[0024] As will be appreciated by persons skilled in the art upon reading the following disclosure, various aspects described herein may be embodied as a system, a method or a computer program product (e.g., a non-transitory computer-readable medium having computer executable instruction for performing the noted operations or steps). Accordingly, those aspects may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects.

[0025] Furthermore, such aspects may take the form of a computer program product stored by one or more computer-readable storage media having computer-readable program code, or instructions, embodied in or on the storage media. Any suitable computer readable storage media may be utilized, including hard disks, CD-ROMs, optical storage devices, magnetic storage devices, solid-state storage devices, and / or any combination thereof.

[0026] Referring to Figure 1 , there is shown an embodiment of an over-the-row row crop cultivator tool 100, according to a preferred embodiment of the present invention. This preferred embodiment of the present invention is used for early season row crop cultivation. It allows for deep cultivation from a distance of 1 cm to 8cm from the row center. This preferredembodiment allows complete surface row crop cultivation on top of the cultivated row. The row crop cultivator tool 100 includes a pair of wheels 104 that are configured to support the row crop cultivator tool 100. The tool 100 includes a set of cutting and tilling instruments for cutting weed that include pair of tilling discs 124, a pair of tiling sweeps 126, and a pair of rotating star-shaped discs 128. The tool 100 also includes a combing tool 130 for racking the soil that has been uplifted by the tilling and weed cutting instruments.

[0027] Referring to Figure 2, there is shown an embodiment of a row crop cultivator tool 200, according to another preferred embodiment of the present invention. This preferred embodiment of the present invention is used for in season and late season row crop cultivation. It allows for deep cultivation of the inter-row region up to 3cm to the cultivated row center. The row crop cultivator tool 200 includes a at least one wheel 204 that are configured to support the row crop cultivator tool 200. The tool 200 includes a set of cutting and tilling instruments for cutting weed that include pair of tilling discs 224, a set of different tiling sweeps 226. The tool 200 also includes a combing tool 230 for racking the soil that has been uplifted by the tilling and weed cutting instruments.

[0028] Referring to Figure 3, in addition to Figure 1 , there is shown an embodiment of a row crop cultivator tool 300, similar to the one shown in Figure 1 , according to a preferred embodiment of the present invention. The row crop cultivator tool 300 is operatively connected to a row crop cultivator frame 302 that allows a tractor (not shown) to pull the row cultivator tool 300. The row crop cultivator tool 300 includes a pair of wheels 304 that are configured to support the row crop cultivator tool 300 at a configured working depth set by a working depth adjustment pin 334. In operation, the pair of wheels 304 roll on the soil surface 301. Each wheel 304 is mounted on a depth wheel arm 306. The depth wheel arm 306 is operationally mounted on a main frame 308 via a working depth adjustment mechanism 310. A depth sensor load cell 312 is mounted on the working depth adjustment mechanism 310 for measuring a depth of the tool 300. The depth sensor load cell 312 is mounted between the working depth adjustment mechanism 310 and a load sensing arm 332. The depth sensor load cell 312 is then able to measure the force applied to the wheels 304. The force is measured by deflection of the depth sensor load cell 312. The load sensing arm 332 is restricted by the working depth adjustment pin 334. The load sensing arm 332 is connected to the depth adjustment mechanism 310 by a single pivot point. The working depth adjustment pin 334 is used to set the maximum depth wheel position. The sensor load cell 312 is connected to a depth sensor load cell controller 314, which is in turn connected to a unit downforce, up force, depth and lift controller 316, which is in turn operatively connected viaconductor 317 to a controller of the tractor. The tool 300 also includes a hydraulic cylinder depth control device 318 that is operatively connected to the main frame 310 to adjust the working depth of the tool 300 with respect to the soil surface 301. The hydraulic cylinder control device 318 includes a hydraulic cylinder shown operationally mounted to the main frame 308. The hydraulic cylinder is a mechanical actuator that is used to provide unidirectional force through a unidirectional stroke. The hydraulic cylinder depth control device 318 can be substituted by an electric actuator depth control device or a pneumatic cylinder depth control device, as persons skilled in the art will understand. The hydraulic cylinder control device 318 is operatively connected to a hydraulic valve 320, which is in turn operatively connected to a hydraulic hose 322 that is operatively connected to the hydraulic system of the tractor (not shown). The hydraulic valve 320 contains a hydraulic pressure regulator and a hydraulic directional valve. The hydraulic pressure regulator allows for control of the hydraulic pressure reaching the hydraulic cylinder depth control device 318. The hydraulic directional valve allows for changing the direction of the pressure from the hydraulic valve 320 to the hydraulic cylinder depth control device 318. In case of substitution of the hydraulic cylinder depth control device 318 by an electric actuator depth control device, the hydraulic valve 320, and the hydraulic hose 322 are replaced by wiring connecting the electric actuator depth control device to the electric system of the tractor and by wiring to the unit downforce, upforce, depth and lift controller 316. In case of substitution of the hydraulic cylinder depth control device 318 by a pneumatic cylinder depth control device, the hydraulic valve 320 is replaced by a pneumatic valve, the hydraulic hose 322 is replaced by pneumatic hose.

[0029] The tool 300 includes a set of cutting and tilling instruments for cutting weed that include pair of tilling discs 324, a pair of tiling sweeps 326, and a pair of rotating star-shaped discs 328. The tool 300 also includes a combing tool 330 for racking the soil that has been uplifted by the tilling and weed cutting instruments. The tool 300 is configured to remove weeds that are located on each side of the cultivated grow crops 303 on the soil surface 301 .

[0030] Referring to Figure 4, there is shown a flowchart diagram 400 of a method for controlling operation of a row crop cultivator tool, such as the ones shown in Figures 1-3. In a preferred embodiment, the method includes steps of: a) at step 402, if the row crop cultivator tool 300 is required by the operator or an external control device to be raised, then setting the hydraulic pressure to a set pressure value, at step 404. In the preferred embodiments shown in Figures 1to 3, the set lift hydraulic pressure value is 100% of the tractor’s supplied hydraulic pressure in the lift direction; b) at step 406, measuring a current depth wheel sensor value at a set frequency. In the preferred embodiments shown in Figures 1 to 3, the set frequency is 24 Hz. The measured depth wheel sensor value can vary from 0 kg to 400 kg in the preferred embodiments shown in Figures 1-3; c) at step 408, comparing the current depth wheel sensor value to a set point and calculating a difference of the depth wheel sensor value with the set point; d) at step 410, if the difference of the depth wheel sensor value is equal or below a deadband value, then at step 412 maintaining a target hydraulic pressure of the row crop cultivator tool at a previous target pressure value; e) at step 414, obtaining a current hydraulic pressure of the row crop cultivator; f) if the current hydraulic pressure obtained at step e) is not equal to a set target pressure value target pressure, then at step 416 modifying the current hydraulic pressure by a set slew rate, i.e. 10% PWM per second, and repeating steps e) and f); The obtained current hydraulic pressure may be estimated or measured; g) at step 418, if the difference of the depth wheel sensor value is above the deadband value, then adding the current depth wheel sensor value to the difference of the depth wheel sensor value to obtain a summed value; and h) at step 420, filtering the summed value with a proportional integral differential (PID) filter to obtain a filtered value and repeating steps e) and f).

[0031] Referring now to Figure 5, there is illustrated the row crop cultivator tool 300 shown in Figure 3, in a ground engaging position. In this ground engaging position, the cultivator tool 300 is moved on the surface soil 301 along cultivated grow crops 301 and cuts down the undesired weeds 305. As is shown, the cultivated row crop 303 may be aligned in different directions and the row crop cultivator tool 300 needs to be raised when it reaches the end of a row so as not to damage the cultivated row crops 303 when changing directions.

[0032] Referring now to Figure 6, in addition to Figure 4, there is illustrated the row crop cultivator tool 300 shown in Figure 3, in a raised position. In this raised position, the cultivator tool 300 can be moved in another direction so as to not damage the cultivated row crops 303. Once, the row crop cultivator tool 300 is in another direction, it can be lowered back to the ground engaging position shown in Figure 5.

[0033] The scope of the claims should not be limited by the preferred embodiments set forth in the examples, but should be given the broadest interpretation consistent with the description as a whole.DEFINITIONS

[0034] The use of the terms "a" and "an" and "the" and similar referents in the context of describing the invention (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context.

[0035] The terms "comprising", "having", "including", and "containing" are to be construed as open-ended terms (i.e. , meaning "including, but not limited to") unless otherwise noted.

[0036] Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. All subsets of values within the ranges are also incorporated into the specification as if they were individually recited herein.

[0037] All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context.

[0038] The use of any and all examples, or exemplary language (e.g., "such as") provided herein, is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention unless otherwise claimed.

[0039] No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the invention.

[0040] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

[0041] Downforce is defined as additional force to the row crop cultivator tool’s mass in a downward direction.

[0042] Upforce is defined as force used to counter the row crop cultivator tool’s mass in an upward direction.

[0043] Depth is defined as the distance between the soil surface and the lowest point of the row crop cultivator tool.

[0044] Lift is defined as the action of completely lifting the row crop cultivator tool above the cultivated crop.

[0045] Deadband is defined as a range above and below a set value in which there is no movement commanded to the system.

[0046] Working depth is defined as the distance between the lowest point of the row crop cultivator tool and the soil surface.

Claims

CLAIMS1 . A method for controlling a working depth of a row crop cultivator tool, the method comprising steps of: a) measuring a current depth wheel sensor value; b) comparing the current depth wheel sensor value to a set point and calculating a difference of the depth wheel sensor value with the set point; c) if the difference of the depth wheel sensor value is equal or below a deadband value, then maintaining a target pressure of the row crop cultivator tool at a previous set target pressure value; d) obtaining a current pressure of the row crop cultivator; e) if the current pressure obtained at step d) is not equal to a set target pressure value target pressure, then modifying the current pressure by a set slew rate and repeating steps d) and e); f) if the difference of the depth wheel sensor value is above the deadband value, then adding the current depth wheel sensor value to the difference of the depth wheel sensor value to obtain a summed value; and g) filtering the summed value with a proportional integral differential (PID) filter to obtain a filtered value and repeating steps d) and e).

2. The method of claim 1 , further comprising verifying if the row crop cultivator tool has to be raised from a ground engaging position to a raised position.

3. A row crop cultivator tool (300) comprising: a main frame (308); at least one wheel (304) operatively connected to the main frame (308) via an arm (310); a sensor (312) operatively connected to the arm (310) for measuring a depth wheel sensor value; a depth sensor controller (314) connected to the sensor (312) for receiving a measured depth wheel sensor value; a depth control device (318) operatively connected to the main frame (308) for adjusting a working depth of the row crop cultivator tool (300); and a main controller (316) operationally connected to the depth sensor controller (314) for controlling the working depth of the row crop cultivator tool (300) via the depth control device (318).

4. The row crop cultivator tool (300) of claim 3, wherein the depth control device (318) comprises a hydraulic cylinder depth control device.

5. The row crop cultivator tool (300) of claim 3, wherein the depth control device (318) is an electric actuator depth control device or a pneumatic cylinder depth control device.

6. The row crop cultivator tool (300) of claim 3 or 4 or 5, wherein the depth sensor controller (314) is integrated in the main controller (316).

7. The row crop cultivator tool (300) of claims 3 or 4, wherein the working depth of the row crop cultivator tool (300) is operated by means of the method of claim 1 .

8. The row crop cultivator tool of any one of claims 1-7, wherein the depth control device (318) is configured to raise the crop cultivator tool (300) from a ground engaging position to a raised position.

9. A row crop cultivator tool (300) comprising: a main frame (308); at least one wheel (304) operatively connected to the main frame (308) via an arm (310); a sensor (312) operatively connected to the arm (310) for measuring a depth wheel sensor value; a depth control device (318) operatively connected to the main frame (308) for adjusting a working depth of the row crop cultivator tool (300); and at least one controller for controlling the working depth of the row crop cultivator tool (300) via the depth control device (318).

10. The row crop cultivator tool of claims 9, wherein the depth control device (318) is configured to raise the crop cultivator tool (300) from a ground engaging position to a raised position.11 . The row crop cultivator tool of claim 9 or 10, wherein the at least one controller is configured to: a) measure a current depth wheel sensor value; b) compare the current depth wheel sensor value to a set point and calculating a difference of the depth wheel sensor value with the set point;c) if the difference of the depth wheel sensor value is equal or below a deadband value, then maintain a target pressure of the row crop cultivator tool at a previous set target pressure value; d) obtain a current pressure of the row crop cultivator; e) if the current pressure obtained at step d) is not equal to a set target pressure value target pressure, then modify the current pressure by a set slew rate and repeating steps d) and e); f) if the difference of the depth wheel sensor value is above the deadband value, then add the current depth wheel sensor value to the difference of the depth wheel sensor value to obtain a summed value; and g) filter the summed value with a proportional integral differential (PID) filter to obtain a filtered value and repeating steps d) and e).

12. A non-transitory computer-readable medium having computer-executable instructions stored thereon, which when executed by a controller of a row crop cultivator tool, cause the controller to perform steps comprising: a) receiving a current depth wheel sensor value; b) comparing the current depth wheel sensor value to a set point and calculating a difference of the depth wheel sensor value with the set point; c) if the difference of the depth wheel sensor value is equal or below a deadband value, then maintaining a target pressure of the row crop cultivator tool at a previous set target pressure value; d) obtaining a current pressure of the row crop cultivator; e) if the current pressure obtained at step d) is not equal to a set target pressure value target pressure, then modifying the current pressure by a set slew rate and repeating steps d) and e); f) if the difference of the depth wheel sensor value is above the deadband value, then adding the current depth wheel sensor value to the difference of the depth wheel sensor value to obtain a summed value; and g) filtering the summed value with a proportional integral differential (PID) filter to obtain a filtered value and repeating steps d) and e).

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