In-ground seed spacing monitoring system for use in an agricultural seeder

A row crop unit for use in an agricultural seeder includes a furrow opener for opening a furrow in the soil, a seed metering system for metering seed to be placed in the furrow, and a seed placement system for placing seeds in the furrow. The seed placement system and the seed metering system are in communication with each other and at least in part define a seed travel path associated with the furrow. A furrow closer covers the seed in the furrow with soil. A seed temperature conditioner is associated with the seed travel path for varying a temperature of seed traveling through the seed travel path. A temperature sensitive sensor is positioned to sense seed which has been deposited in the furrow between the furrow opener and the furrow closer. An optional packaging tube holds a temperature sensor or sensor array. A lens is mounted with the same tube. A larger diameter tube may be positioned around the sensor packaging tube. A positive air pressure/air flow may be introduced between the two tubes. This positive air-flow forms a positive pressure and/or air flow barrier to push dust away from the sensor lens or sensor surface.

FIELD OF THE INVENTION

The present invention relates to agricultural seeders, and, more particularly, to seed spacing monitoring systems for use in such seeders.

BACKGROUND OF THE INVENTION

An agricultural seeder, such as a row crop planter, air seeder or grain drill, places the seed at a desired depth within a plurality of parallel seed trenches (or furrows) formed in soil. In the case of a row crop planter, a plurality of row crop units are typically ground driven using wheels, shafts, sprockets, transfer cases, chains and the like. Each row crop unit has a frame, which is movably coupled with a tool bar. The frame may carry a main seed hopper, herbicide hopper and insecticide hopper. If the granular herbicide and insecticide are used, the metering mechanisms associated therewith for the dispensing of the granular product into the seed trench are relatively simple. On the other hand, mechanisms necessary to properly meter seeds at a predetermined rate and to place the seeds at predetermined relative locations and depth within the seed trench are relatively complicated.

The mechanisms associated with metering and placing of the seeds generally can be divided into a seed metering system and a seed placement system, which are in communication with each other. The seed metering system receives the seeds in a bulk manner from a seed hopper carried by the frame. Different types of seed metering systems can be used such as seed plates, finger plates and seed disks. In the case of a seed disk metering system, a seed disk is formed with a plurality of seed cells spaced about the periphery thereof. Seeds are moved into the seed cells with one or more seeds in each seed cell depending upon the size and configuration of the seed cell. A vacuum or positive pressure airflow may be used in conjunction with the seed disk to assist in movement and retention of the seeds in the seed cells. The seeds are singulated and discharged at a predetermined rate to the seed placement system.

The seed placement system may be categorized as a gravity drop system or a power drop system. In the case of a gravity drop system, a seed tube has an inlet end, which is positioned below the seed metering system. The singulated seeds from the seed metering system merely drop into the seed tube and fall by way of gravitational force from a discharge end thereof into the seed trench. The seed tube may be curved in a rearward manner to assist in directing the seed into the seed trench.

A seed placement system of the power drop variety generally can be classified as a seed conveyor belt drop, rotary valve drop, chain drop or air drop. These types of seed placement systems provide somewhat consistent placement of the seeds along a predetermined path at a desired spacing.

It is well known in the agricultural industry to use an electronic planting monitor on seeders to monitor the seed which is placed in the furrow. When first employed, monitors were used to alert the operator of a plugged row unit or a unit without any seed to avoid continued operation of the planter without actually planting seed. More recently, studies have quantified the importance of accurate seed spacing in improving crop yields. As a result, monitor technology has advanced in efforts to determine seed spacing. Current monitors determine skips and multiples of seed. These monitors also predict seed spacing in the furrow based on the timing of seed passing a sensor (such as a photo-electric eye) in a seed tube but are not capable of determining actual seed spacing.

One example of a seed spacing monitor is disclosed in U.S. Pat. No. 6,386,128 B1 (Svoboda et al.). The '128 patent senses the seed and determines a geospatial location of the seed. From this information, seed spacing can be determined. However, the sensor is described as detecting the falling seed and transmitting a corresponding signal to the computer which then records the seed drop event. In this system, since the sensor detects “falling” seed, any bounce or roll of the seed in the furrow is not accounted for in determining the seed location.

U.S. Pat. No. 7,726,251 B1 (Peterson et al.), which is assigned to the assignee of the present invention, discloses that it is possible to sense seeds directly in a seed trench. Referring toFIGS. 7 and 8, a sensor may be used to sense seeds in the seed trench, and the pulses representing each sensed seed are used to uniformly stagger seeds relative to each other in a twin row seeding application.

What is needed in the art is a way of more accurately detecting seed spacing of seeds which are placed in a furrow in the soil.

SUMMARY OF THE INVENTION

The seed spacing monitoring system of the present invention uses a seed temperature conditioner such as a heater to vary a temperature of the seed prior to placement in the furrow, and a temperature sensitive sensor such as an infra-red (IR) sensor array to sense the seed in its final location in the seed furrow immediately before the furrow is closed, covering the seed with soil.

The invention in one form is directed to a row crop unit for use in an agricultural seeder for planting seeds in soil. The row crop unit includes a furrow opener for opening a furrow in the soil, a seed metering system for metering seed to be placed in the furrow, and a seed placement system for placing seeds in the furrow. The seed placement system and the seed metering system are in communication with each other and at least in part define a seed travel path associated with the furrow. A furrow closer covers the seed in the furrow with soil. A seed temperature conditioner is associated with the seed travel path for varying a temperature of seed traveling through the seed travel path. A temperature sensitive sensor is positioned to sense seed which has been deposited in the furrow between the furrow opener and the furrow closer.

The invention in another form is directed to a seed spacing detection method for detecting seed spacing of seeds placed in a furrow by a seeder. The method includes the steps of: opening a furrow in the soil; metering seed to be deposited in the furrow; varying a temperature of the seed prior to being deposited in the furrow; placing the metered seed in the furrow; and detecting seed in the furrow before the seed is covered with soil using a temperature sensitive sensor.

The invention in yet another form is directed to a row crop unit for use in an agricultural seeder for planting seeds in soil. The row crop unit includes a furrow opener for opening a furrow in the soil, a seed metering system for metering seed to be placed in the furrow, and a seed placement system for placing seeds in the furrow. The seed placement system and the seed metering system are in communication with each other and at least in part define a seed travel path associated with the furrow. A furrow closer covers the seed in the furrow with soil. A seed temperature conditioner is associated with the seed travel path for varying a temperature of seed traveling through the seed travel path. A temperature sensitive sensor or sensor array is positioned to sense seed which has been deposited in the furrow between the furrow opener and the furrow closer. The invention may further include a packaging tube for use with the IR sensor. The packaging tube for the IR sensor or sensor array may include a lens for reduced viewing angle and hence increased sensitivity. The sensor packaging tube may further be placed inside of another larger diameter tube, and positive air flow may be introduced between the 2 tubes. This positive air-flow forms an air flow barrier to push dust away from the sensor lens or sensor surface.

DETAILED DESCRIPTION OF THE INVENTION

Referring now to the drawings, and more particularly toFIG. 1, there is shown an embodiment of an agricultural seeder10of the present invention. In the embodiment shown, seeder10is in the form of a row crop planter but may also be in the form of a grain drill, etc. A prime mover in the form of a tractor12is coupled with and provides motive power to seeder10through a suitable coupling arrangement, such as a draw bar or 3-point hitch arrangement.

Seeder10includes a number of row crop units14, with each row crop unit14being substantially identically configured. A seed spacing monitoring system16, which may be located onboard each of seeder10and tractor12(as shown), is used to monitor the placement of seeds within respective furrows18formed by each row crop unit14. Seed spacing monitoring system16may include an electrical processor16A onboard seeder10, an electrical processor16B onboard tractor12, a ground speed sensor19and a number of temperature sensitive sensors (not visible inFIG. 1) for detecting seeds in respective furrows18.

Ground speed sensor19may be located on tractor12or seeder10and provides an output signal to electrical processor16A and/or16B representative of the speed of seeder12across the ground. For example, the ground speed signal may be determined based on the engine speed and selected gear of tractor12, a ground speed sensor19on seeder12, a ground driven speed sensor associated with a ground contacting wheel of seeder12, a Global Positioning System (GPS), a sonar system directed at the ground, a radar system directed at the ground, etc.

Referring now toFIG. 2, there is shown a single row crop unit20of a multi-row planter, with each row crop unit20being substantially identical and connected to a common tool bar22. Only a single row crop unit20is shown and described below for simplicity sake.

Row crop unit20includes a multi-part frame24which is attached to tool bar22by parallel linkage26. Tool bar22is coupled to a traction unit (not shown inFIG. 2), such as tractor12. For example, tool bar22may be coupled to tractor12using a draw bar or 3-point hitch assembly. Tool bar22may be coupled with transport wheel assemblies, marker arms, etc. which may be of conventional design and not shown for simplicity sake.

Frame24carries a double disc furrow opener28for forming a seed trench in soil. An optional fluted coulter wheel30, particularly for use in no till situations, may be placed ahead of double disc furrow opener28. A pair of gauge wheels32are respectively associated with the pair of discs of double disc furrow opener28. More particularly, each gauge wheel32is positioned generally in line with and immediately adjacent to the outside of each respective disc of double disc furrow opener28. Each gauge wheel32may be vertically adjusted to adjust the depth of the trench which is cut into the soil using double disc furrow opener28.

A furrow closer in the form of a pair of closing wheels34is also carried by frame24. Closing wheels34are positioned generally in line with double disc furrow opener28. Closing wheels34are preferably biased in a downward direction and have a peripheral edge with a shape which may vary, depending upon the application.

A seed metering system36and a seed placement system38are also carried by frame24(each shown partially in phantom lines). Seed metering system36receives seed from a main seed supply, such as seed from a distant main seed hopper which is supplied via air or the like, or a seed hopper40carried above frame24. Seed metering system36singulates the seed and transfers the seed to seed placement system38. Seed placement system38is in the form of a gravity drop seed tube, but could be configured differently, such as a power drop seed placement system with a powered wheel, etc.

According to an aspect of the present invention, a temperature sensitive sensor42forming part of the seed spacing monitoring system16is supported to sense seeds in the furrow prior to the seeds being covered by closing wheels34. Temperature sensitive sensor42is preferably located between furrow opener28and closing wheels34, and detects the presence of seeds within the furrow18. Temperature sensitive sensor42provides a plurality of seed presence signals to electrical processor16A (FIG. 1), with each seed presence signal being indicative of a respective seed present in the furrow.

In the embodiment illustrated inFIG. 2, temperature sensitive sensor42is configured as an IR sensor which detects the presence of individual seeds in the furrow by sensing a temperature difference between the individual seeds and the surrounding ground. This may be accomplished by using a seed temperature conditioner to either heat or cool the seeds prior to placement within the furrow. For example, a seed temperature conditioner in the form of a heater44can be used to blow hot air across the seeds at a suitable location within seed metering system36. Heating of the seed between 1 to 20° F., preferably between 1 to 5° F., and even as little as 1.8° F., more than the ground temperature will enable IR sensing. Also, cooling by that difference will enable IR sensing. With such an IR sensor, a narrow sensing window can be used to sense when a seed passes the sensor within the furrow, and the sensing event can be time stamped or geo-referenced.

Other types of heaters may also be used. For example, it is possible to heat the air used to move the seed from central tanks to the mini-hoppers on the row unit. Heaters which are powered by electric, gas or diesel, etc. can be used to heat the air surrounding the seed. It may also be possible to heat seeds with the exhaust air from the vacuum fan. Heated air can also be used through a nozzle to agitate the seeds in the mini-hopper and also heat the seeds. It may also be possible to divert some of the engine exhaust to heat the seeds directly or use an air-to-air heat exchanger.

Referring now toFIG. 3, there is shown another embodiment of a single row crop unit50of a multi-row planter, with each row crop unit50being substantially identical and connected to a common tool bar51. Only a single row crop unit50is shown and described below for simplicity sake.

Row crop unit50carries a double disc furrow opener52for forming a seed trench53in the soil. An optional coulter wheel54, particularly for use in no-till situations, may be placed ahead of double disc furrow opener52. A pair of gauge wheels56are respectively associated with the pair of discs of double disc furrow opener52. More particularly, each gauge wheel56is positioned generally in line with and immediately adjacent to the outside of each respective disc of double disc furrow opener52. Each gauge wheel56may be vertically adjusted to adjust the depth of the trench which is cut into the soil using double disc furrow opener52. A furrow closer in the form of a pair of closing wheels58is positioned generally in line with double disc furrow opener52. Closing wheels58are preferably biased in a downward direction and have a peripheral edge with a shape which may vary, depending upon the application.

A seed placement system60is shown in the form of a gravity drop seed tube62, but could be configured differently, such as a power drop seed placement system with a powered wheel, etc.

A seed metering system64receives seed from a main seed supply, such as seed from a distant main seed hopper which is supplied via air or the like, or a seed hopper carried by tool bar51. Within a housing66of seed metering system64there is a seed pool area. A seed disk within housing66(not visible) has a plurality of holes with seed cells on the seed side of the disk intermittently spaced about the periphery thereof. The vacuum airflow promotes entry of the seeds into the seed cells and maintains the seeds in place within the seed cells. Seeds are transported from the seed cells to seed tube62. Of course, seed meter26may be configured with a positive pressure to assist in seed movement rather than a vacuum pressure.

Similar to row crop unit20described above, row crop unit50has a heater44which heats the seed and a temperature sensitive sensor68which is located in an area between furrow opener52and closing wheels58(FIGS. 3 and 4). Heater44is located in association with the seed travel path, and specifically is shown located in association with seed metering system64. Alternatively, heater44may be located in association with the seed placement system60(as shown at44A) or along the seed travel path ahead of the seed metering system (as shown at44B). Temperature sensitive sensor68may be configured as described above with reference to temperature sensitive sensor42, such as a linear IR sensor array. Temperature sensitive sensor68is coupled with electrical processor16A, either wired or wirelessly, and provides a plurality of seed presence signals to electrical processor16A. Electrical processor16A receives the plurality of seed presence signals from temperature sensitive sensor68and a speed signal from speed sensor19, and determines a seed spacing which is dependent upon each of the seed presence signals and speed signal.

Temperature sensitive sensor68, also shown schematically inFIG. 4, may be configured as an IR camera or an IR scanner. In the embodiment shown inFIGS. 3 and 4, temperature sensitive sensor68is configured as an IR scanner with a 1×4 linear array of IR sensors (i.e., four IR sensors arranged in a single row) providing at least one seed presence signal to electrical processor16A and/or16B. The linear array of IR sensors68provide discrete output signals, with each output signal corresponding to one or more seed presence signals. Alternatively, the array of IR sensors68can provide a combined (composite) signal to electrical processor16A and/or16B. IR sensor68is positioned at a downward and rearward facing orientation relative to a travel direction of the row crop unit, allowing a longer portion of the furrow53to be sensed between the furrow opener52and closing wheels58. More particularly, IR sensor68is positioned at an angle of between approximately 15° to 60°, and preferably approximately 30°, relative to a horizontal. For other applications, it may be desirable to position IR sensor68with a front face which is generally horizontal. Moreover, IR sensor68may be positioned such that it is canted with a side-to-side orientation of between approximately 5° to 45° relative to a vertical (FIG. 5). When positioned with a canted orientation, it is possible for each sensor (e.g., of a linear 1×4 array) to provide discrete signals to electrical processors16A and/or16B. The center two sensors (2and3) may be used to detect seeds in the furrow18, and the outer two sensors (1and4) may be used to detect seeds on either side the furrow18in the event of seed bounce, etc.

In the embodiments of the seed spacing monitoring systems described above, temperature sensitive sensors42and68provide seed presence signals to electrical processors16A and/or16B, which in turn time stamp the seed presence signals and determine a seed spacing based on the time relationship between seeds. However, it may be desirable to geo-reference the seed presence signals using a geo-referencing system. One type of geo-referencing system is a Global Positioning System (GPS)74which may be used to geo-reference the location of each sensed seed within the furrow. More specifically, the assignee of the present invention markets a GPS known as a “GreenStar” GPS which is typically mounted on top of the cab of tractor12(not shown), and could be used with the present invention for geo-referencing of the seed presence signals. As another option, a stand-alone GPS could be mounted to seeder10for geo-referencing the seed presence signals. As yet another option, a geo-referencing system configured as a localized sensor system could be used to geo-reference the seed presence signals. For example, sensors could be positioned at predefined locations around the perimeter of a field which interact with a transceiver mounted on seeder10for geo-referencing the seed presence signals.

Referring now toFIG. 6, there is shown another exemplary placement location for an IR sensor100relative to a double disk furrow opener102and gauge wheels104. In this embodiment, IR sensor100is located between the double disk furrow opener102, and is attached to the bottom end of seed placement tube106. IR sensor100communicates a seed presence signal to an electrical processor16A and/or16B. An example of a seed presence signal is shown inFIG. 7. The seed presence signal may be in the form of an analog signal with spikes occurring at seed presence locations within the furrow or seed trench53. The seed presence locations may be time stamped as shown on the horizontal axis and converted to a seed spacing as described above, or alternatively may be geo-referenced to determine a seed spacing.

Referring now toFIG. 8, IR sensor68is shown within an optional sensor packaging assembly110, including an inner packaging tube112and an outer packaging tube114. Inner packaging tube112and outer packaging tube114are each constructed of a transparent or translucent material, such as a suitable plastic, that allows the individual sensors making up IR sensor68to sense the individual seeds within furrow18. IR sensor68may include a number of lenses116respectively associated with each individual sensor118of IR sensor68for providing a reduced viewing angle and hence increased sensitivity. Alternatively, inner packaging tube112may include an integral lens for providing a reduced viewing angle and increased sensitivity. Inner packaging tube112may be placed inside of the larger diameter outer packaging tube114, and a positive air flow may be introduced between the two tubes112and114. This positive air-flow forms an air flow barrier to repel dirt away from the sensor lenses116or sensor surface.

Referring now toFIG. 9, a method of operation80of the seed spacing monitoring system16will be described in greater detail. As described above, a furrow opener28,52,102is used to open a furrow in the soil (block82). A seed metering system36,64receives seed from a seed source, singulates the seed, and passes the singulated seed to a seed placement system (block84). The singulated seed is deposited in the furrow by seed placement system38,60at a predetermined seeding population (block86). A temperature sensitive sensor42,68,100detects a series of seeds and transmits seed presence signals corresponding to each sensed seed to electrical processor16A and/or16B (block88). Electrical processor16A (or16B) measures the time between the seeds and/or alternatively geo-references the seeds using a GPS74(block90). The time between seeds is combined with a ground speed and used to determine a seed spacing between seeds (blocks92and94). Alternatively, the geo-referenced seed locations may be used to directly determine the seed spacing between seeds. The monitoring method continues while the seeding operation is in effect, such as for a third seed, fourth seed, etc. (line96).

More particularly, in the event that a time based approach is used, the ground speed is typically measured in units of miles per hour (miles/hour) and the time between seeds is measured in units of seconds/seed. Using appropriate conversion factors, the seed spacing (inches per seed) can be converted in one embodiment as follows:

The ground speed and temperature sensitive sensor output signal can thus be combined in an appropriate manner to yield a measurement of seed spacing between seeds. The electrical processor16B onboard tractor12may include a visual display which provides information to the operator in the form of the percentage of skips, the percentage of double seeding, the actual or average spacing of the seed, etc.

Memory within electrical processor16A and/or16B can store the seed spacing information for a predetermined number of seeds and calculate an average seed spacing together with a measure of variability, such as the standard deviation in the seed spacing, and display that information to the operator, such as at a display of electrical processor16B. The operator can determine if the seed spacing is within the desired limits and also if the variability in seed spacing is within desired limits. If the average seed spacing and/or the variability are outside the desired limits, the operator can take corrective action.