Patent Description:
According to the invention there is provided a system for sensing characteristics of a trench in a soil surface during planting operations as defined by the appended claim.

Referring now to the drawings, wherein like reference numerals designate identical or corresponding parts throughout the several views, <FIG> illustrates an agricultural planter row unit <NUM>. The row unit <NUM> is comprised of a frame <NUM> pivotally connected to a toolbar <NUM> by a parallel linkage <NUM> enabling each row unit <NUM> to move vertically independently of the toolbar <NUM>. The frame <NUM> may operably support one or more hoppers <NUM>, a seed meter <NUM>, a seed delivery mechanism <NUM>, a downforce control system <NUM>, a seed trench opening assembly <NUM>, a trench closing assembly <NUM>, a packer wheel assembly <NUM>, and a row cleaner assembly <NUM>. It should be understood that the row unit <NUM> shown in <FIG> may be for a conventional planter or the row unit <NUM> may be for a central fill planter, in which case the hoppers <NUM> may be replaced with one or more mini-hoppers and the frame <NUM> modified accordingly as would be recognized by those of skill in the art.

The downforce control system <NUM> is configured to apply lift and/or downforce on the row unit <NUM> such as disclosed in U. Publication No. <CIT>.

The seed trench opening assembly <NUM> may include a pair of opening discs <NUM> rotatably supported by a downwardly extending shank member <NUM> of the frame <NUM>. The opening discs <NUM> may be arranged to diverge outwardly and rearwardly so as to open a v-shaped trench <NUM> in the soil <NUM> as the planter traverses the field. The seed delivery mechanism <NUM>, such as a seed tube or seed conveyor, may be positioned between the opening discs <NUM> to deliver seed from the seed meter <NUM> into the opened seed trench <NUM>. The depth of the seed trench <NUM> may be controlled by a pair of gauge wheels <NUM> positioned adjacent to the opening discs <NUM>. The gauge wheels <NUM> may be rotatably supported by gauge wheel arms <NUM> which are pivotally secured at one end to the frame <NUM> about pivot pin <NUM>. A rocker arm <NUM> may be pivotally supported on the frame <NUM> by a pivot pin <NUM>. It should be appreciated that rotation of the rocker arm <NUM> about the pivot pin <NUM> sets the depth of the trench <NUM> by limiting the upward travel of the gauge wheel arms <NUM> (and thus the gauge wheels) relative to the opening discs <NUM>. The rocker arm <NUM> may be adjustably positioned via a linear actuator <NUM> mounted to the row unit frame <NUM> and may be pivotally coupled to an upper end of the rocker arm <NUM>. The linear actuator <NUM> may be controlled remotely or automatically actuated as disclosed, for example, in International Publication No. <CIT>.

A downforce sensor <NUM> may be configured to generate a signal related to the amount of force imposed by the gauge wheels <NUM> on the soil. The pivot pin <NUM> for the rocker arm <NUM> may comprise the downforce sensor <NUM>, such as the instrumented pins disclosed in <CIT>.

The seed meter <NUM> may be any commercially available seed meter, such as a finger-type seed meter or vacuum-type seed meter as are well-known in the art. One example of a suitable vacuum-type seed meter is the VSet® meter, available from Precision Planting LLC, <NUM> Townline Rd, Tremont, IL <NUM>.

The trench closing assembly <NUM> may include a closing wheel arm <NUM> pivotally attached to the row unit frame <NUM>. A pair of offset closing wheels <NUM> may be rotatably attached to the closing wheel arm <NUM> and angularly disposed to "close" the seed trench <NUM> by pushing the walls of the open seed trench back together over the deposited seed <NUM>. An actuator <NUM> may be pivotally attached at one end to the closing wheel arm <NUM> and at its other end to the row unit frame <NUM> to vary the down pressure exerted by the closing wheels <NUM> depending on soil conditions. The closing wheel assembly <NUM> may be of the type disclosed in International Publication No. <CIT>.

The packer wheel assembly <NUM> may comprise an arm <NUM> pivotally attached to the row unit fame <NUM> and extending rearward of the closing wheel assembly <NUM> and in alignment therewith. The arm <NUM> may rotatably supports a packer wheel <NUM>. An actuator <NUM> may be pivotally attached at one end to the arm <NUM> and at its other end to the row unit frame <NUM> to vary the amount of downforce exerted by the packer wheel <NUM> to pack the soil over the seed trench <NUM>.

The row cleaner assembly <NUM> may be any commercially available row cleaner assembly. One example of a suitable row cleaner assembly is the CleanSweep® system available from Precision Planting LLC, <NUM> Townline Rd, Tremont, IL <NUM>. The row cleaner assembly <NUM> may include an arm <NUM> pivotally attached to the forward end of the row unit frame <NUM> and aligned with the trench opening assembly <NUM>. A pair of row cleaner wheels <NUM> may be rotatably attached to the forward end of the arm <NUM>. An actuator <NUM> may be pivotally attached at one end to the arm <NUM> and at its other end to the row unit frame <NUM> to adjust the downforce on the arm to vary the aggressiveness of the action of the row cleaning wheels <NUM> depending on the amount of crop residue and soil conditions.

Referring to <FIG> and <FIG>, a monitor <NUM> is visible to an operator within the cab of a tractor pulling the planter. The monitor <NUM> may be in signal communication with a GPS unit <NUM>, the trench closing assembly actuator <NUM> and the packer wheel assembly actuator <NUM> to enable operational control of the trench closing assembly <NUM> and the packer wheel assembly <NUM> based on the signals generated by the trench closing sensors <NUM> (as discussed later). Also, as discussed later, the monitor <NUM> may be programmed to display operational recommendations based on the signals generated by the trench closing sensors <NUM>. The monitor <NUM> may also be in signal communication with the row cleaner actuator <NUM>, the depth adjustment actuator <NUM>, the downforce control system <NUM> and the trench opening assembly <NUM>, respectively.

The various trench closing sensors and other sensors as described herein may be used to verify whether good seed-to-soil contact is being achieved during planting operations and may be used to enable automatic or remote adjustment of the planter while on-the-go.

<FIG> illustrates a trench closing sensor <NUM> to determine if the closing wheel assembly <NUM> is sufficiently closing the open seed trench <NUM> with soil and/or to determine the amount of compaction of the soil over the seed within the seed trench <NUM>. The trench closing sensor <NUM> comprises wire, string or other suitable elongate member (hereinafter referred to as the "drag wire" <NUM>) disposed to drag in the seed trench <NUM>. Generally, as the open seed trench <NUM> and drag wire <NUM> are covered with soil by the closing wheel assembly <NUM> during planting operations, the trench closing sensor <NUM> measures or detects whether the seed trench is being adequately closed with soil by measuring the amount of force required to pull the wire <NUM> through the soil or by measuring the amount of strain, pulling force or tension in the drag wire or by measuring the amount of soil pressure acting on the drag wire <NUM>.

To adequately measure or detect if the seed trench is being adequately closed with soil, the end of the drag wire <NUM> may terminate proximate to the vertical axis <NUM> extending through the center of the closing wheel <NUM> of the closing wheel assembly <NUM> of the row unit <NUM> or several inches rearward of the vertical axis <NUM>.

The drag wire <NUM> may be supported by any suitable structure that permits the rearward end of the drag wire <NUM> to drag within the seed trench <NUM>. For example, the drag wire <NUM> may be supported from the seed tube <NUM>, the seed tube guard <NUM>, the shank <NUM>, or from another appurtenance <NUM> aligned with the seed trench such as a seed firmer. An example of a commercially available seed firmer is a Keeton® seed firmer available from Precision Planting, LLC, <NUM> Townline Rd, Tremont, IL <NUM>. Another commercially available appurtenance <NUM> which aligns with the seed trench is a FurrowJet™, also available from Precision Planting, LLC.

<FIG> is an enlarged view of trench closing sensor <NUM> shown in <FIG>. A cavity <NUM> is formed in the plastic body <NUM> of the seed firmer appurtenance <NUM>. The rearward end of the drag wire <NUM> extends outwardly from the rear of the body <NUM> through an aperture <NUM>. The forwarded end of the drag wire <NUM> may be coupled to an instrument <NUM> (such strain gauge, a hall effect sensor or a potentiometer) disposed within the cavity <NUM>. The signals generated by the instrument <NUM>, are communicated to the monitor <NUM> by signal wires <NUM>.

In use, as the row unit <NUM> travels forwardly, the closing wheels <NUM> of the trench closing assembly <NUM> close the open seed trench <NUM> by pushing the walls of the seed trench <NUM> back together over the deposited seed <NUM> and the drag wire <NUM>. As the drag wire <NUM> is pulled through the soil of the closed seed trench, the instrument <NUM> measures the strain on the drag wire <NUM>, or the amount of pulling force or tension exerted on the drag wire <NUM>. It should be appreciated that if the seed trench <NUM> is optimally closed producing good seed-to-soil contact, the instrument <NUM> will measure a greater strain, tension or pulling force than if the seed trench is poorly closed. Likewise, the instrument <NUM> can detect if the trench closing assembly <NUM> is excessively compacting the soil or inadequately packing the soil depending on the strain, tension or pulling force required to pull the drag wire <NUM> through the closed trench.

<FIG> illustrates another trench closing sensor 1000A. Rather than measuring the pulling force or tension in the wire, a pressure transducer <NUM>, such as a piezoresistive or piezoelectric transducer, is coupled to the rearward end of the drag wire <NUM> to measure the pressure being exerted on the transducer <NUM> by the surrounding soil pushed into the seed trench <NUM> by the closing wheel assembly <NUM>. The pressure detected by the transducer <NUM> is communicated by signal wires <NUM> to the monitor <NUM>. It should be appreciated that the more soil pushed into the seed trench <NUM> by the closing wheel assembly <NUM>, the more soil covers the transducer <NUM> generating a higher pressure measurement. Conversely, if the closing wheel assembly is not pushing a sufficient amount of soil into the seed trench to adequately cover the seed, the transducer <NUM> will measure a lower pressure.

<FIG> illustrates another trench closing sensor 1000B in which multiple drag wires <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM> are stacked vertically, each coupled to a respective instrument <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM> (such strain gauge, a hall effect sensor or a potentiometer) disposed within the cavity <NUM> so as to provide a profile perspective of the trench closure. It should be appreciated that rather than three drag wires as illustrated in <FIG>, there may be only two stacked drag wires or more than three stacked drag wires. Additionally, it should be appreciated that each of the stacked the drag wires <NUM> may be instrumented with a pressure transducer as described above or one of more of the stacked wires may be instrumented with a pressure transducer while other wires are coupled to an instrument <NUM> disposed within the cavity <NUM>. Each drag wire <NUM> may have a different geometry, length or diameter as compared to other drag wires <NUM>. The different geometries or diameters may provide a different signal response for different areas within the trench. Alternatively, instead of vertical alignment, multiple drag wires <NUM>, <NUM>-<NUM>, <NUM>-<NUM> can be stacked horizontally (not shown), or a combination of horizontal and vertical stacks (not shown).

Instrument <NUM>-<NUM>, <NUM>-<NUM>, and <NUM>-<NUM> may send an electrical current to multiple drag wires <NUM>-<NUM>, <NUM>-<NUM>, and <NUM>-<NUM>, respectively. If any of drag wires <NUM>-<NUM>, <NUM>-<NUM>, or <NUM>-<NUM> make contact, an electrical circuit will be formed, and instruments <NUM>-<NUM>, <NUM>-<NUM>, and <NUM>-<NUM> may then determine which drag wires <NUM>-<NUM>, <NUM>-<NUM>, and <NUM>-<NUM> are in contact with one another. This information may be sent to monitor <NUM> by signal wire <NUM>. Knowing whether the multiple drag wires <NUM>-<NUM>, <NUM>-<NUM>, and <NUM>-<NUM> are touching provides information about whether multiple drag wires <NUM>-<NUM>, <NUM>-<NUM>, and <NUM>-<NUM> are sensing the same location or different locations. When contacted, multiple drag wires <NUM>-<NUM>, <NUM>-<NUM>, and <NUM>-<NUM> are measuring the same location and provides another measurement to determine whether the trench is open or closed. For example, if the furrow is open, multiple drag wires <NUM>-<NUM>, <NUM>-<NUM>, and <NUM>-<NUM> would fall under gravity and contact one another.

<FIG>, illustrates another a trench closing sensor 1000C in which multiple drag wires <NUM>-<NUM>, <NUM>-<NUM>, and <NUM>-<NUM> comprise non-conductive material with conductive tips <NUM>-<NUM>, <NUM>-<NUM>, and <NUM>-<NUM> at their rearward ends. The conductive tips <NUM>-<NUM>, <NUM>-<NUM>, and <NUM>-<NUM> are connected to respective instruments <NUM>-<NUM>, <NUM>-<NUM>, and <NUM>-<NUM> , and by respective electrically conductive wires <NUM>-<NUM>, <NUM>-<NUM>, and <NUM>-<NUM>.

<FIG> illustrates another trench closing sensor 1000D. Trench closing sensor <NUM> has a first body <NUM>-<NUM> and a second body <NUM>-<NUM>. The second body <NUM>-<NUM> may be detachable from the first body <NUM>-<NUM> by any suitable attachment, such as a fastener, nut and bolt, screw, and/or clip. The second body <NUM>-<NUM> includes a pivot member <NUM> attached at one end to a pivot <NUM>. The other end of the pivot member <NUM> extends downwardly from the pivot <NUM> to which is attached the drag wire <NUM>. The drag wire <NUM> extends rearward through second body <NUM>-<NUM>. A biasing element <NUM> (such as a spring) biases pivot member <NUM> forward towards the first body1004-<NUM>. A stop (not shown) may be provided to prevent movement of the pivot member <NUM> too far forward. In a neutral position, the pivot member <NUM> is perpendicular to the ground. A transmitter <NUM> (such as a magnet) is disposed on the pivot plate <NUM>. Transmitter <NUM> generates a signal (such as a magnetic field) that is detected by a receiver <NUM> (such as a Hall Effect sensor) disposed in the first body1004-<NUM>. The transmitter <NUM> may be disposed on the pivot plate <NUM> on the side facing the first body <NUM>-<NUM>. The receiver <NUM> is in communication with monitor <NUM> through signal wire <NUM>. The receiver <NUM> may be disposed on a circuit board and then connected to signal wire <NUM>, such as illustrated in <FIG> (discussed later).

In use, as drag wire <NUM> is pulled by contact with soil, pivot member <NUM> will pivot rearward, and the distance between transmitter <NUM> and receiver <NUM> will increase and change the signal (magnetic field) measured by receiver <NUM>. An advantage of this two-piece construction, permits easier replacement of the drag wire <NUM> when it becomes worn by simply removing second body <NUM>-<NUM> and replacing it with a new second body1004-<NUM>.

<FIG> illustrate another alternative trench closing sensor 1000E. The trench closing sensor 1000E is similar to the trench closing sensor 1000D except that a resilient plate <NUM> replaces pivot member <NUM> and pivot1022. The transmitter <NUM> is disposed on resilient plate <NUM>. In use, as drag wire <NUM> is pulled by contact with soil, the resilient plate <NUM> deflects, and returns to its original position when no force is applied. As illustrated in <FIG>, resilient plate <NUM> may have a T shape. It should be appreciated that the pivot member <NUM> and pivot <NUM> (referenced in the trench closing sensor 1000D) may be utilized in place of the resilient plate <NUM>.

<FIG> illustrates another trench closing sensor 1000F. The trench closing sensor 1000F is similar to the trench closing sensor 1000E except that the transmitter <NUM> attached to the resilient plate <NUM> in the second body <NUM>-<NUM> is replaced by a first magnet <NUM> and the receiver <NUM> is replaced by a second magnet <NUM> and Hall Effect sensor <NUM> in the first body <NUM>-<NUM>. The first and second magnets <NUM>, <NUM> are arranged so that the same poles (both N-N or S-S) are oriented towards each other. Hall Effect sensor <NUM> is disposed equidistant from first magnet <NUM> and second magnet <NUM> so that the field measured at this middle point is zero. The benefit of having this configuration is that the full voltage range for the Hall Effect sensor <NUM> is available to measure the magnetic field in the compressed space as compared to only having half of the voltage range available to read the magnetic field at a distance from to infinity. It should be appreciated that the pivot member <NUM> and pivot <NUM> (referenced in the trench closing sensor 1000D) may be utilized in place of the resilient plate <NUM>.

Depending on the strength of the Hall Effect sensor (<NUM>, <NUM>, or <NUM>), measuring a small amount of drag can be affected by the earth's magnetic field and the direction of travel. Orientation of the Hall Effect sensor (<NUM>, <NUM>, or <NUM>) in relation to the earth's magnetic field may cause the Hall Effect sensor (<NUM>, <NUM>, or <NUM>) to measure a larger or smaller force. To compensate, a reference sensor <NUM> to measure the earth's magnetic field without the force being measured by Hall Effect sensor (<NUM>, <NUM>, or <NUM>) may be disposed on the row unit <NUM> as shown in in <FIG>, or, alternatively, the reference sensor <NUM> may be disposed on the toolbar <NUM> or other component of the agricultural implement (not shown). The reference sensor <NUM> may be a Hall Effect sensor, a magnetometer, a compass, or any instrument that measures a magnetic field. The measurement from Hall Effect sensor (<NUM>, <NUM>, or <NUM>) may be compared to the reference sensor <NUM> to determine the actual force measured by Hall Effect sensor (<NUM>, <NUM>, or <NUM>). Alternatively, rather than actually measuring the earth's magnetic field, the reference sensor <NUM> may derive the earth's magnetic field from the position of the agricultural implement from the GPS location and direction of travel, such as with GPS <NUM>. The earth's magnetic field may be referenced from a database based on the position and direction of travel of the implement.

It should also be appreciated that any of the trench closing sensors <NUM>-1000F may be comprised of a single body <NUM> (as shown in <FIG>) or the two-piece bodies <NUM>-<NUM>, <NUM>-<NUM> as shown in <FIG>.

Additionally, as shown in <FIG>, any of the drag wires <NUM> described herein may be made in two parts, wherein a drag wire base section <NUM> and a replaceable drag wire <NUM>-<NUM> are connected at a detachable connection <NUM> which allows for easier replacement of the drag wire should it become worn.

Referring to <FIG> the drag wire <NUM> utilized in any of the trench closing sensors <NUM>-1000f may be provided with a wear protector <NUM> made from any material that increases wear resistance compared to the material of drag wire <NUM>. The wear protector <NUM> may be made from tungsten carbide. However, because tungsten carbide can be brittle, the wear protector is applied in a plurality of pieces along the length of the drag wire <NUM>. It should be appreciated however, that the wear protector <NUM> may be a single continuous piece instead of a plurality of individual wear protection pieces as shown in <FIG>. Whether as a single piece or as a plurality of pieces, wear protector <NUM> may cover from greater than <NUM> up to <NUM>% of the drag wire <NUM> or the percentage of coverage with the wear protector <NUM> of the drag wire <NUM> extending from body of the firmer may be <NUM> to <NUM>%, about <NUM>%, greater than <NUM>%, or <NUM>-<NUM>%.

As shown in <FIG>, which is applicable to all the trench closing sensors <NUM>-1000F previously described, rather than drag wire <NUM> being straight, the drag wire <NUM> may instead be bent or curved in a serpentine configuration extending from sidewall to sidewall of the trench <NUM>. The serpentine wire <NUM> may be instrumented with a bend sensor <NUM> such that as the trench is closed over the serpentine drag wire, causing the drag wire to straighten out as the wire is pulled through the soil, a more accurate measurement may be obtained than with a straight wire. Additionally, rather than a serpentine wire, the wire may be in the form of a coil (not shown) to detect forces acting in all three dimensions.

A reference sensor <NUM> (<FIG>, <FIG>) may be provided to "calibrate" the trench closing sensors <NUM>-1000F to account for conditions that may have an effect on the drag coefficient properties of the soil, including such factors as planter speed, trench depth, soil texture, soil moisture and soil density. As best illustrated in <FIG>, the reference sensor <NUM> includes a drag member <NUM> which is disposed to drag through the soil outside of the seed trench <NUM>. The reference sensor <NUM> may be disposed forward of the trench opening assembly <NUM> as shown in <FIG> or the drag member <NUM> may be mounted between the row units <NUM> (not shown). The drag member <NUM> is supported by an arm <NUM> which is adjustably positionable with respect to a gauge wheel <NUM> to vary the penetration depth of the drag member <NUM> with respect to the soil surface. The arm <NUM> is instrumented with a strain gauge <NUM> to detect the strain exerted on the arm <NUM> as the drag member <NUM> drags through the soil. Signal wires <NUM> transmit the electrical resistance change in the strain gauge <NUM> to the monitor <NUM>. The monitor <NUM> is programmed to correlate the electrical resistance change to detected strain in the arm <NUM> which can then be correlated with the signals generated by the drag wire sensor <NUM>-1000F to define the range of the force, tension or pressure that the trench closing sensors <NUM>-1000F should be detecting if the seed trench is being adequately closed by the trench closing assembly <NUM>.

The reference sensor <NUM> may be the penetration force of row unit <NUM>. The penetration force may be measured directly with force sensor <NUM>, such as a strain gauge, disposed at the opener disc spindle <NUM> as illustrated in <FIG>. The penetration force of row unit <NUM> may also be determined by subtracting the gauge wheel force measured by downforce sensor <NUM> from the applied force as applied by the downforce control system <NUM> and the mass of row unit <NUM>.

The reference sensor <NUM> may be the electrical conductivity or reflectance of the soil measured using the electrical conductivity sensors <NUM> and reflectance sensors <NUM> as described in connection with <FIG> discussed below.

The reference sensor <NUM> may be the geospatial soil type information based on GPS location, such as the USDA SSURGO data, which may be useful when changing zones in the field. The data for each zone in the field can be the reference.

An alternative reference sensor 1100A, illustrated in <FIG>, includes a coulter arm <NUM> attached to row unit <NUM> with a coulter <NUM> attached to coulter arm <NUM> with axle <NUM>. At axle <NUM>, a force sensor <NUM>, such as downforce sensor <NUM>, measures the force that coulter <NUM> transmits to axle <NUM>. Force sensor <NUM> is in data communication with monitor <NUM>.

An alternative reference sensor 1100B, illustrated in <FIG>, includes arm <NUM> mounted to row unit <NUM> (or alternatively to toolbar <NUM>), and at the opposite end of arm <NUM> is bracket <NUM>. A coulter arm <NUM> is pivotably mounted to bracket <NUM>, and a force device <NUM>, such as a spring, is disposed to connect coulter arm <NUM> to bracket <NUM> to apply a fixed force to coulter arm <NUM>. Alternatively, the force device may be a pneumatic device, hydraulic device, an electromechanical device, or an electro-hydraulic device. A coulter <NUM> is rollingly mounted to coulter arm <NUM>. A gauge wheel arm <NUM> is pivotably connected to coulter arm <NUM>, and a gauge wheel <NUM> is rollingly mounted to gauge wheel arm <NUM>. An angle sensor <NUM> is disposed at the pivoting connection between gauge wheel arm <NUM> and coulter arm <NUM>. Examples of angle sensor <NUM> include, but are not limited to, a rotary potentiometer or Hall-effect sensor. Angle sensor <NUM> is in data communication with monitor <NUM>. Force device <NUM> applies a known force to coulter <NUM>. As the hardness of the soil changes, gauge wheel arm <NUM> will rotate, and angle sensor <NUM> measures the amount of rotation.

Another reference sensor that may be used in conjunction with drag wire sensor <NUM>-1000F is the speed of row unit <NUM>. As the speed of travel changes, the force, tension or pressure measured will directly change with the change in speed. The speed of row unit <NUM> may be determined by any suitable device, such as a speedometer on the tractor (tractor wheel speed), GPS distance change over time, or ground speed radar. Any of these devices may be in data communication with monitor <NUM>.

In yet another alternative, any the trench closing sensors <NUM>-1000F may utilize a fluid tube drag wire instead of metal, string or other material. The fluid tube drag wire <NUM> may be filled with a fluid (gas or liquid) and connected to pressure sensor instrument <NUM>, but with all other features of the prior sensors <NUM>-1000F remaining the same. In use, as soil covers the fluid tube drag wire <NUM>, the fluid tube will compress causing an increase in the pressure in fluid tube which is measured by the pressure sensor instrument <NUM>. The fluid tube drag wire <NUM> may be not elongatable longitudinally (i.e., fore to aft in line with the direction of travel) so that any pressure change that would be caused by elongation is minimized or eliminated. The fluid tube may have a rigid side that does not elongate. At least <NUM>% or at least <NUM>% of the circumference/perimeter of fluid tube drag wire <NUM> may be rigid and the remainder is compressible. In cross-section, the fluid tube drag wire <NUM> may be circular or it may be square or polygonal in shape and may have one, two, or three rigid sides.

<FIG> illustrate an embodiment of a trench closing sensor <NUM> according to the invention, wherein the seed firmer appurtenance <NUM> includes a pressure sensing drum <NUM> secured within the body of the firmer which results in outwardly bulging drum heads <NUM> as best viewed from the front elevation view of <FIG>. The drum heads <NUM> may move together or independently. A pressure transducer (not shown) may be disposed within the drum <NUM> to measure the pressure exerted against the drum heads <NUM> by the soil as the soil is pushed into the trench <NUM> by the closing wheels <NUM> of the closing wheel assembly <NUM>. It should be appreciated that if the trench <NUM> is optimally closed producing good seed-to-soil contact, the pressure sensing drum <NUM> will measure a greater pressure than if the seed trench is poorly closed. Likewise, the pressure sensing drum <NUM> may detect if the trench closing assembly <NUM> is excessively compacting the soil or inadequately packing the soil depending on the measured pressure or the measured reactive force of the soil being pinned together by the closing wheels. Additionally, the pressure sensing drum <NUM> may sense the closing wheel penetration into the soil, from which the trench closure can be inferred. It should be appreciated that in such an embodiment, the firmer <NUM> may need to be elongated so the firmer body extends further rearwardly toward the closing wheels than a conventional Keeton® firmer (as referenced above) such that the drum <NUM> is positioned to measure the pressure exerted by the soil where the closing wheels <NUM> are closing the trench <NUM>. The pressure sensing drum <NUM> may be incorporated into any of the trench closing sensors <NUM>-1000F described above.

<FIG> illustrates an appurtenance <NUM> wherein any of the previously described trench closing sensors <NUM>-1000F incorporate other sensors disposed along the body <NUM> of the firmer. These other sensors may include reflectivity sensors 350a and 350b, a temperature sensor <NUM> and electrical conductivity sensors 370f and 370r such as disclosed in International Publication No. <CIT>. These other sensors <NUM>, <NUM>, <NUM> are shown as being in data communication with monitor <NUM> via a wireless transmitter <NUM>-<NUM>. A male and female coupler <NUM>, <NUM> may be provided which enables a detachable portion <NUM> of the firmer body containing the sensors and instrumentation to be detached from the main body <NUM> of the firmer appurtenance <NUM>. A camera <NUM> oriented within the firmer to be rearward facing may also be disposed in the firmer.

<FIG> illustrate another trench sensor <NUM> in which the seed firmer appurtenance <NUM> includes sensors <NUM> disposed in a vertical relationship on the body <NUM> of the firmer. The sensors <NUM> may be any of the above referenced sensors and the vertically oriented sensors <NUM> may be incorporated into any of the previously described drag wire trench closing sensors <NUM>-1000F.

The smoothness of the trench sidewall or the detecting of fractured sidewalls or knitting is predictive of the risk of the trench opening back up after it has been closed by the closing wheels. The following sensors can be used to detect the smoothness of the sidewalls: GPR disposed at an angle to a vertical cross-section of the sidewall; LIDAR; time of flight camera; a mini-penetrometer; or electrical conductivity sensors. Additionally the camera <NUM> may provide visual indication of sidewall fracturing or knitting.

The density of the soil within the trench can affect the depth of seed embedding. The soil density may be determined by electrical conductivity or inductance sensors <NUM> disposed in the firmer body <NUM> as shown in <FIG>. Alternatively, soil density may be determined using a GPR and common midpoint ("CMP") analysis.

The moisture of the soil may be detected with electrical conductive sensors <NUM> disposed in the firmer as shown in <FIG>. Alternatively, an instrument <NUM> may be coupled to the drag wire <NUM> adapted to function as an electrical conductivity sensor to detect the soil moisture at the seed level as the drag wire is dragged through the trench.

The ingress of dry dirt into the soil trench may be detected by electrical conductivity or inductance sensors in the drag wires <NUM> as previously described. Alternatively, dry dirt ingress may be detected visually by the camera <NUM> and the color of the soil.

<FIG> illustrates another trench sensor <NUM> adapted for sensing electrical conductivity in which the appurtenance <NUM> is shown as a FurrowJet™ as previously referenced and as disclosed in International Publication No. <CIT>. Although trench sensor <NUM> is shown as being embodied in a FurrowJet™, it should be appreciated that any appurtenance, including a Keeton® seed firmer as previously referenced, may be utilized for the trench sensor <NUM>. In <FIG>, the trench sensor <NUM> comprises an appurtenance <NUM> mounted to the row unit <NUM> via a bracket <NUM>, that may include a forward bracket <NUM> and a rearward bracket <NUM>. The appurtenance <NUM>, includes outwardly diverging wing members <NUM>-<NUM>, <NUM>-<NUM> each having an electrical conductor sensor <NUM>-<NUM>, <NUM>-<NUM>. The appurtenance <NUM> also includes an instrumented drag wire <NUM> with an electrical conductivity sensor <NUM>. The appurtenance <NUM> may include one or more liquid placement tubes <NUM>, <NUM> in communication with a liquid product source (not shown). Liquid injection needles <NUM>-<NUM>, <NUM>-<NUM> (<FIG>) may extend through respective wing members <NUM>-<NUM>, <NUM>-<NUM> for injecting liquid product communicated via the liquid tubes <NUM>, <NUM> into the respective sidewalls of the trench (see <FIG>). The electrical conductivity in the trench sidewall as measured by electrical conductivity sensor <NUM>-<NUM>, <NUM>-<NUM> is measured and compared to the electrical conductivity of the closed trench measured by electrical conductivity sensor <NUM> disposed on the drag wire <NUM>. By measuring at approximately the same depth and at approximately the same location, the closing of the trench may be more accurately measured. To further improve measurement, the left and right trench walls may be measured by electrical conductivity sensor <NUM>-<NUM>, <NUM>-<NUM> to provide a right and left reading that is used as a reference to the reading taken by the drag wire electrical conductivity sensor <NUM>. Electrical conductivity sensors <NUM>-<NUM> and <NUM>-<NUM> may be insulated from wing member <NUM>-<NUM>, <NUM>-<NUM>, respectively, by an insulator (not shown) disposed between the electrical conductivity sensors <NUM>-<NUM>, <NUM>-<NUM> and wing members <NUM>-<NUM>, <NUM>-<NUM>, respectively, allowing for a more direct reading of the trench sidewalls without having to account for electrical conductivity generated by fluids (such as salt solutions) flowing through injection needles <NUM>-<NUM>, <NUM>-<NUM>.

<FIG> is a trench sensor <NUM> with opposing electric probes <NUM> disposed on opposing sides of the firmer body which may be used for detecting alignment of the firmer within the trench. The electric probes may provide the operator with binary feedback (e.g., yes/no contact with the sidewall) or feedback indicating the load being applied by the sidewall against the electric probe, wherein a large load on one side of the firmer will indicate if the firmer is out of alignment with the center of the seed trench. The electrical probes <NUM> may be incorporated into any of the previously described drag wire trench closing sensors <NUM>-1000F.

Alternatively, the camera <NUM> providing a rearward-looking view of the seed trench, may provide the operator with a visual indication of the furrow geometry and alignment of the firmer <NUM> within the bottom of the trench. Additionally, if spiked wheels are being used for the closing wheels <NUM>, the camera may provide visual indication if the spike wheels are undesirably kicking the seeds from the bottom of the seed trench, requiring adjustment of the spike wheels.

Camera <NUM> can view the area behind trench closing sensors <NUM>-1000F to view the amount of closing behind trench closing sensors <NUM>-1000F and under trench closing assembly <NUM> in the trench. The image can be displayed on the monitor <NUM>.

As illustrated in <FIG>, an appurtenance <NUM> can include a trench closing sensor <NUM> disposed at end <NUM> of appurtenance <NUM> to sense the trench behind appurtenance <NUM> and under trench closing assembly <NUM> in the trench. Trench closing sensor <NUM> includes a transmitter <NUM> and a receiver <NUM>. While shown with the transmitter <NUM> disposed over receiver <NUM>, receiver <NUM> can be disposed over transmitter <NUM>. Alternatively, transmitter <NUM> and receiver <NUM> can be a single transceiver. Trench closing sensor <NUM> can be light/reflectivity, radar, sonar, ultrasonic, or LIDAR. For radar, sonar, ultrasonic, or LIDAR, a distance from appurtenance <NUM> to the closed portion of the trench is measured. Knowing the position of trench closing assembly <NUM> relative to appurtenance <NUM>, there is an expected distance that the trench should be closed. If the measured distance is different from the expected distance, an alarm can be displayed on monitor <NUM> and/or a deviation to the distance can be associated with the georeferenced coordinates obtained from GPS, and the deviation can be mapped. As an example, if the distance is as expected, the location can be displayed as green, and if the distance is not as expected, the location can be displayed as red.

Referring to <FIG>, work layer sensors <NUM>, such as disclosed in PCT Application No. <CIT> may be disposed on row unit <NUM> to generate a signal or image representative of the soil densities or other soil characteristics throughout a soil region of interest, hereinafter referred to as the "work layer" <NUM>. Work layer sensors <NUM> may determine the effectiveness of the closing of the trench to identify if there are any void spaces in the closed trench or changes in soil density. The work layer sensors may be used in conjunction with the trench closing sensor <NUM>-1000F.

<FIG>, <FIG> and <FIG> schematically illustrate alternative work layer sensors <NUM>. The representative image or signal generated by the work layer sensor <NUM> is hereinafter referred to as the "work layer image" <NUM>. In one particular application discussed later, the work layer sensors <NUM> may be mounted to a planter row unit <NUM> (<FIG>) for generating a work layer image <NUM> of the seed trench as the planter traverses the field. The work layer image <NUM> may be displayed on a monitor <NUM> visible to an operator within the cab of a tractor and the planter may be equipped with various actuators for controlling the planter based on the characteristics of the work layer <NUM> as determined from the work layer image <NUM>.

The work layer sensor <NUM> for generating the work layer image <NUM> may comprise a ground penetrating radar system, an ultrasound system, an audible range sound system, an electrical current system or any other suitable system for generating an electromagnetic field <NUM> through the work layer <NUM> to produce the work layer image <NUM>. It should be understood that the depth and width of the work layer <NUM> may vary depending on the agricultural implement and operation being performed.

<FIG> is a schematic illustration of a work layer sensor <NUM>-<NUM> disposed in relation to a seed trench <NUM> formed in the soil <NUM> by a planter, wherein the seed trench <NUM> comprises the soil region of interest or work layer <NUM>. The work layer sensor <NUM>-<NUM> comprises a transmitter (T1) disposed on one side of the seed trench <NUM> and a receiver (R1) disposed on the other side of the seed trench <NUM> to produce the electromagnetic field <NUM> through the seed trench to generate the work layer image <NUM>.

The work layer sensor <NUM> may comprise a ground-penetration radar subsurface inspection system such as any of the following commercially available systems: (<NUM>) the StructureScan™ Mini HR available from GSSI in Nashua, New Hampshire; (<NUM>) the 3d- Radar GeoScope™ Mk IV coupled to a 3d-Radar VX-Series and/or DX-Series multi-channel antenna, all available from 3d-Radar AS in Trondheim, Norway; or (<NUM>) the MALA Imaging Radar Array System, available from MALA Geoscience in Mala, Sweden. The commercially available system may be mounted to the planter or other implement, or may be mounted to a cart which moves with the implement; in either case the system is preferably disposed to capture an image of a work layer in the area of interest (e.g., the seed trench). The work layer image <NUM> may be generated from the signal outputs of the work layer sensor <NUM> using commercially available software such as GPR-SLICE (e.g., version <NUM>) available from GeoHiRes International Ltd. located in Borken, Germany. Any ground penetrating radar can be replaced with a radar that is focused on the surface and used in any of the described configurations.

<FIG> are intended to be representative examples of work layer images <NUM> generated by the work layer sensor <NUM>-<NUM> of <FIG> showing various characteristics of the seed trench <NUM>, including, for example, the trench depth, the trench shape, depth of seed <NUM>, the seed depth relative to the trench depth, crop residue <NUM> in the trench, and the void spaces <NUM> within the trench. As described in more detail later, the work layer images <NUM> may be used to determine other characteristics of the work layer <NUM>, including, for example, the seed-to-soil contact, percentage of trench closed, percentage of upper half of trench closed, percentage of lower half of trench closed, moisture of the soil, etc..

<FIG> schematically illustrates, in plan view, another work layer sensor <NUM>-<NUM> disposed with respect to a seed trench <NUM>. A transmitter (T1) is disposed on one side of the seed trench <NUM>, a first receiver (R1) is disposed on the other side of the seed trench <NUM>, and a second receiver (R2) is disposed adjacent and rearward of the transmitter (T1). <FIG> is a representative illustration of the work layer image <NUM> generated through the trench between the transmitter (T1) and the first receiver (R1)) and <FIG> is a representative illustration of the work layer image <NUM> generated between the transmitter (T1) and the second receiver (R2) providing an image of the undisturbed soil adjacent to the seed trench.

<FIG> is an elevation view schematically illustrating another work layer sensor <NUM>-<NUM> disposed with respect to a seed trench <NUM>. The work layer sensor <NUM>-<NUM> comprises a plurality of transmitter and receiver pairs disposed above and transverse to the seed trench <NUM>.

<FIG> is a representative illustration of the work layer image <NUM> generated by the work layer sensor <NUM>-<NUM> of <FIG> which provides a view not only of the seed trench but also a portion of the soil adjacent to each side of the seed trench.

For each of the work layer sensors <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM>, the frequency of operation of the work layer sensors <NUM> and the vertical position of the transmitters (T) and receivers (R) above the soil and the spacing between the transmitters (T) and receivers (R) are selected to minimize signal to noise ratio while also capturing the desired depth and width of the soil region of interest (the work layer <NUM>) for which the work layer image <NUM> is generated.

<FIG> illustrates one example of a particular application of the work layer sensors <NUM> disposed on a row unit <NUM> of an agricultural planter. The row unit <NUM> includes a work layer sensor 100A disposed on a forward end of the row unit <NUM> and a work layer sensor 100B disposed rearward end of the row unit <NUM>. The forward and rearward work layer sensors 100A, 100B may comprise any of the work layer sensors <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM> previously described.

The forward work layer sensor 100A is disposed to generate a reference work layer image (hereinafter a "reference layer image") 110A of the soil prior to the soil being disturbed by the planter, whereas the rearward work layer sensor 100B generates the work layer image 110B, which in this example, is the image of the closed seed trench <NUM> in which the seed has been deposited and covered with soil. For the reasons explained later, it is desirable to obtain both a reference image 110A and the work layer image 110B for analysis of the soil characteristics through the work layer <NUM>.

It should be appreciated that the forward and rearward work layer sensors 100A, 100B referenced in <FIG> may employ any of the work layer sensors <NUM>-<NUM>, <NUM>-<NUM> or <NUM>-<NUM> previously described. However, it should be appreciated that if the work layer sensors <NUM>-<NUM> or <NUM>-<NUM> are employed, the forward work layer sensor 100A may be eliminated because the work layer sensors <NUM>-<NUM> and <NUM>-<NUM> are configured to generate the work layer images <NUM> of undisturbed soil adjacent to the seed trench <NUM> which could serve as the reference layer image 110A.

It should be appreciated that rather than positioning the work layer sensors <NUM> as shown in <FIG>, the work layer sensors may be positioned after the row cleaner assembly <NUM> and before the trench opening assembly <NUM> or in one or more other locations between the trench opening discs <NUM> and the closing wheels <NUM> or the packing wheel <NUM> depending on the soil region or characteristics of interest.

<FIG> is a schematic illustration of a system <NUM> which employs work layer sensors <NUM> to provide operator feedback and to control the planter row unit <NUM>. Work layer sensors 100A, 100B are disposed to generate a reference layer image 110A of undisturbed soil and a work layer image 110B of the closed seed trench (i.e., after seed is deposited, covered with soil by the closing wheel assembly <NUM> and the soil packed with the packing wheel assembly <NUM>). As previously described, the work layer sensors 100A, 100B may be separate work layer sensors disposed forward and rearward of the row unit <NUM> as illustrated in <FIG>, or the work layer sensors 100A, 100B may comprise a single work layer sensor with transmitters (T) and receivers (R) disposed to generate both a reference layer image 110A and a work layer image 110B.

The work layer image 110B may be communicated and displayed to the operator on a monitor <NUM> comprising a display, a controller and user interface such as a graphical user interface (GUI), within the cab of the tractor.

The monitor <NUM> may be in signal communication with a GPS unit <NUM>, the row cleaner actuator <NUM>, the downforce control system <NUM>, the depth adjustment actuator <NUM>, the trench closing assembly actuator <NUM> and the packer wheel assembly actuator <NUM> to enable operational control of the planter based on the characteristics of the work layer image 110B.

For example, if the work layer image 110B indicates that residue in the seed trench <NUM> is above a predetermined threshold (as explained below), a signal is generated by the monitor <NUM> to actuate the row cleaner actuator <NUM> to increase row cleaner downforce. As another example, if the seed depth is less than a predetermined threshold (as explained below), a signal is generated by the monitor <NUM> to actuate the downforce control system <NUM> to increase the downforce and/or to actuate the depth adjustment actuator <NUM> to adjust the gauge wheels <NUM> relative to the opening discs <NUM> to increase the trench depth. Likewise if the seed depth is greater than a predetermined threshold, a signal is generated by the monitor <NUM> to actuate the downforce control system <NUM> to decrease the downforce and/or to actuate the depth adjustment actuator <NUM> to decrease the trench depth. As another example, if the upper portion of the trench has more than a threshold level of void space (as explained below), a signal is generated by the monitor <NUM> to actuate the trench closing wheel assembly actuator <NUM> to increase the downforce on the closing wheels <NUM>. As another example, if the lower portion of the trench has more than a threshold level of void space (as explained below), a signal is generated by the monitor <NUM> to actuate the packer wheel assembly actuator <NUM> to increase the downforce on the packer wheel <NUM>.

In still other examples, the work layer image 110B may identify and/or analyze (e.g., determine depth, area, volume, density or other qualities or quantities of) subterranean features of interest such as tile lines, large rocks, or compaction layers resulting from tillage and other field traffic. Such subterranean features may be displayed to the user on the monitor <NUM> and/or identified by the monitor <NUM> using an empirical correlation between image properties and a set of subterranean features expected to be encountered in the field. In one such example, the area traversed by the gauge wheels (or other wheels) of the planter (or tractor or other implement or vehicle) may be analyzed to determine a depth and/or soil density of a compaction layer beneath the wheels. In some such examples, the area of the work layer image may be divided into subregions for analysis based on anticipated subterranean features in such sub-regions (e.g., the area traversed by the gauge wheels may be analyzed for compaction).

In other examples, the monitor <NUM> may estimate a soil property (e.g., soil moisture, organic matter, or electrical conductivity, water table level) based on image properties of the work layer image 110B and display the soil property to the user as a numerical (e.g., average or current) value or a spatial map of the soil property at geo-referenced locations in the field associated with each soil property measurement (e.g., by correlating measurements with concurrent geo-referenced locations reported the GPS unit <NUM>).

Alternatively or additionally, the monitor <NUM> could be programmed to display operational recommendations based on the characteristics of the work layer image 110B. For example, if the work layer image 110B identifies that the seed <NUM> is irregularly spaced in the trench <NUM> or if the seed <NUM> is not being uniformly deposited in the base of the trench, or if the spacing of the seed <NUM> in the trench does not match the anticipated spacing of the seed based on the signals generated by the seed sensor or speed of the seed meter, such irregular spacing, nonuniform positioning or other inconsistencies with anticipated spacing may be due to excess speed causing seed bounce within the trench or excess vertical acceleration of the row unit. As such, the monitor <NUM> may be programmed to recommend decreasing the planting speed or to suggest increasing downforce (if not automatically controlled as previously described) to reduce vertical acceleration of the planter row units. Likewise to the extent the other actuators <NUM>, <NUM>, <NUM>, <NUM>, <NUM> are not integrated with the monitor controller, the monitor may be programmed to display recommendations to the operator to make manual or remote adjustments as previously described based on the characteristics of the work layer image 110B.

<FIG> illustrates the process steps for controlling the planter and providing operator feedback. At steps <NUM> and <NUM>, the reference image 110A and work layer image 110B is generated by the work image sensor(s) <NUM>. At step <NUM>, the work layer image 110B may be displayed to the operator on the monitor <NUM> in the cab of the tractor. At step <NUM>, the reference layer image 110A is compared with the work layer image 110B to characterize the work layer image. At step <NUM>, the characterized work layer image 110B is compared to predetermined thresholds. At step <NUM>, control decisions are made based on the comparison of the characterized work layer image 110B with the predetermined thresholds. At step <NUM>, the planter components may be controlled by the monitor <NUM> generating signals to actuate one or more of the corresponding actuators <NUM>, <NUM>, <NUM>, <NUM>, <NUM> and/or at step <NUM>, corresponding recommendations may be displayed to the operator on the monitor display.

To characterize the work layer image 110B at step <NUM>, the monitor <NUM> compares one or more characteristics (e.g., density) of the reference image 110A with the same characteristics of the work layer image 110B. A characterized image may be generated comprising only portions of the work layer image differing from the reference image by at least a threshold value. The characterized image may then be used to identify and define features of the work layer image 110B, such as the trench shape, the trench depth, residue in the trench, seeds and seed placement within the trench, void spaces within the trench, and density differences of the soil within the trench.

For example, to determine the seed depth, the seed is identified or identifiable from the work layer image 110B by determining regions within the work layer image having a size or shape corresponding to a seed and having a density range empirically corresponding to seed.

Once a region is identified as a seed, the vertical position of the seed with respect to the soil surface is readily measurable or determined.

As another example, the amount of residue in the trench can be determined by (a) defining the area of the trench cross-section (based on soil density differences between the reference image 110A and the work layer image 110B); (b) by identifying the regions within the trench having a density range empirically corresponding to residue; (c) totaling the area of the regions corresponding to residue; and (d) dividing the residue area by the trench cross-sectional area.

As shown in <FIG>, leveling sensor <NUM> may be provided to determine the levelness of the soil after the trench is closed by the closing wheels as well as levelness of the soil between rows. The leveling sensor <NUM> may be contact sensors comprising spring steel wires supported on one or more arms which measure displacement of the spring steel wires as the wires drag over the top of the soil behind the closing wheels or between rows. Alternatively, the contact leveling sensors may comprise a chain which drags over the top of the soil behind the closing wheels or between the rows with a sensor to determine drag force variations. Alternatively, the contact sensor may comprise a flap that drags over the top of the soil behind the closing wheels or between rows in which the shape or amount of bending of the flap is measured. Alternatively, an accelerometer may be disposed on the flap to measure levelness of the soil. Rather than contact sensors, the leveling sensor <NUM> may comprise a non-contact sensor, such as LIDAR, time of flight camera, GPR, or sonar may be disposed behind the closing wheels and between the rows.

<FIG> illustrates a thrown soil sensor <NUM> for measuring how well a trench is closed by measuring whether any soil is thrown away from the closed trench. Similar to a "rooster tail" thrown by a motor boat traveling through water, the amount of soil thrown by the closing system can be measured. In <FIG>, the thrown soil sensor8000 includes a plate <NUM> attached to the back of the trench closing assembly <NUM>. The plate <NUM> has a force sensor <NUM> for measuring the impact of soil thrown against the plate <NUM>. An example of a force sensor <NUM> that may be adapted for use in the thrown soil sensor <NUM> is the grain impact sensor disclosed in U. Patent Publication No. <CIT>.

<FIG> illustrates another thrown soil sensor 8000A. The thrown soil sensor 8000A has an arm <NUM> attached to the back of the trench closing assembly <NUM>. A pair of beam sensors <NUM>-<NUM> and <NUM>-<NUM> are disposed on arm <NUM>. A beam (e.g., light or ultrasonic) is transmitted and received between beam sensors <NUM>-<NUM> and <NUM>-<NUM>, with one being at least a transmitter and one being at least a receiver. Both beam sensors <NUM>-<NUM> and <NUM>-<NUM> could be both a transmitter and a receiver, and different frequencies could be used. The thrown soil sensors <NUM>, 8000A may be installed on other agricultural equipment, such as a tillage unit, to measure soil thrown by the agricultural equipment.

<FIG> shows a trench depth sensor system <NUM>. The trench depth sensor system <NUM> has one or both of a trench sensor <NUM> and ground sensor <NUM>. The trench sensors <NUM> and ground sensor <NUM> may be ultrasonic or radar sensors. Trench sensor <NUM> is disposed on closing system <NUM> after the opening assembly <NUM> in a direction of travel to sense the distance to the bottom of seed trench <NUM>. Ground sensor <NUM> is disposed on row unit <NUM> after trench sensor <NUM> in a direction of travel to sense the distance to soil surface <NUM>. Both trench sensor <NUM> and ground sensor <NUM> are at a fixed distance to the bottom of closing wheels <NUM>, and both are in communication with monitor <NUM>. The depth (HG) of closing wheels <NUM> in the soil can be determined by subtracting a distance measured by ground sensor <NUM> from the distance of ground sensor <NUM> to the bottom of closing wheels <NUM>. The distance (HF) of closing wheels <NUM> above the bottom of seed trench <NUM> can be determined by subtracting the distance of trench sensor <NUM> to the bottom of closing wheels <NUM> from a distance measured by trench sensor <NUM>. One or both of these measurements may also be used in combination with the measurements of the trench closing sensor <NUM>-1000F to determine closing effectiveness. Trench sensor <NUM> and ground sensor <NUM> may each independently be an ultrasonic sensor, radar, or a laser.

As illustrated in <FIG>, an angle sensor <NUM> can be disposed at the connection of closing wheel arm <NUM> and frame <NUM>, and angle sensor <NUM> is in communication with monitor <NUM>. The angle sensor <NUM> can be the same as the pivot arm angle sensor <NUM> in <CIT>. The angular output of angle sensor <NUM> can be combined with the measurements of the trench closing sensor <NUM>-1000F to determine closing effectiveness of the seed trench. Examples of angle sensor <NUM> include, but are not limited to, rotary potentiometer and Hall-effect sensor.

The signals generated by the in-trench sensors <NUM>-1000F, <NUM>, <NUM>, <NUM>, <NUM> or out-of-trench sensors <NUM>, <NUM>, <NUM>, <NUM>, <NUM> may be communicated by signal wires <NUM> or other wired or wireless communication to the monitor <NUM> as the actual measurement or the monitor <NUM> may be programmed to convert and display on the monitor screen the actual force, tension or pressure measured by the sensor <NUM>-1000F or the other trench characteristics measured by the sensors <NUM>, <NUM>, <NUM>, <NUM> or by the sensors <NUM>, <NUM>, <NUM>, <NUM>, <NUM>. If the desired displayed force or other trench characteristic is outside the desired range, the downforce on the closing wheel <NUM> may be adjusted. The adjustment of the closing wheel downforce may be adjusted manually by adjusting the position of a conventional coil spring corresponding to discrete preload settings. Alternatively, if the closing wheel assembly <NUM> is equipped with trench closing wheel assembly actuator <NUM> as previously described, the operator may manually actuate the trench closing wheel assembly actuator <NUM> as needed to increase or decrease the amount of downforce exerted by the closing wheels <NUM> to keep the force measured by the trench closing sensor <NUM>-1000F within the desired range or other characteristics within the desired range measured by the other sensors <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>. Alternatively, the monitor <NUM> may be programmed to automatically actuate the trench closing wheel assembly actuator <NUM> to increase or decrease the downforce on the closing wheels <NUM> depending on whether the trench closing sensor <NUM>-1000F detects that the force, tension or pressure on the drag wire(s) <NUM> falls below or exceeds a predefined minimum and maximum threshold force or if other characteristics not within the desired range measured by the other sensors <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>. Rather than adjusting the downforce on the closing wheel assembly <NUM> via a conventional coil spring or actuator, the angle of the closing wheels may be adjusted to increase or decrease the aggressiveness of the closing wheels. For example, as is known in the art, an actuator or mechanical adjustment (not shown) may be provided to decrease or increase the angle of the closing wheels with respect to the direction of travel or with respect to vertical thereby adjusting the amount of soil the closing wheels push into the seed trench. If a closing wheel angle actuator is provided to adjust the closing wheel angle, the operator may actuate the actuator manually or the monitor <NUM> may be programmed to automatically actuate the actuator to adjust the aggressiveness of the closing wheels depending on the force detected by the trench closing sensors <NUM>-1000F or other characteristics detected by the other in trench sensors <NUM>, <NUM>, <NUM> or other out of trench sensors <NUM>, <NUM>, <NUM>, <NUM>, <NUM>.

<FIG> illustrates how the camber angle of the closing wheels may be adjusted so that axis A-<NUM> and A-<NUM> through the closing wheels <NUM>-<NUM> and <NUM>-<NUM> intersect the seed <NUM> in the trench <NUM>. The work layer sensors described above may be used to locate the seed <NUM> in the trench <NUM>. The position of the closing system <NUM> with respect to any of the work layer sensors is known, and closing wheels <NUM>-<NUM> and <NUM>-<NUM> may be adjusted by actuator <NUM> to adjust the camber angle of closing wheels <NUM>-<NUM> and <NUM>-<NUM>. Alternatively, the camber angle may be adjusted to intersect the bottom of trench <NUM>. It may be assumed that seed <NUM> is at the bottom of trench <NUM>. The bottom of trench <NUM> may be determined by any instrument that determines the depth of trench <NUM>. Non-limiting examples of instruments that may determine the depth of trench <NUM> are disclosed in <CIT>, <CIT>, <CIT>, <CIT>, <CIT>, <CIT>, <CIT>, <CIT>, <CIT>, <CIT>, <CIT>, <CIT>, <CIT>, <CIT>, <CIT>, <CIT>, <CIT>, <CIT>, and International Application No. <CIT> with respect to the disclosed distance/depth determination subject matter. The angle may then be determined by assuming that the trench is centered between closing wheels <NUM>-<NUM> and <NUM>-<NUM>. In <FIG>, closing system <NUM> includes a closing frame member <NUM>. Closing wheels <NUM>-<NUM> and <NUM>-<NUM> are attached to axles <NUM>-<NUM> and <NUM>-<NUM>, respectively. Axles <NUM>-<NUM> and <NUM>-<NUM> are connected to axle arms <NUM>-<NUM> and <NUM>-<NUM>, respectively, which are pivotably connected to frame member <NUM> and actuator arms <NUM>-<NUM> and <NUM>-<NUM>, respectively, which are pivotably connected to the actuator <NUM>. The actuator <NUM> is in communication with monitor <NUM>, wherein the actuator <NUM> receives signals to rotate, which causes actuator arms <NUM>-<NUM> and <NUM>-<NUM> to move closer or farther from the center of closing frame <NUM> to cause the angle of axle arms <NUM>-<NUM> and <NUM>-<NUM> with respect to closing frame member <NUM> to change, which, in turn, changes the camber angles of closing wheels <NUM>-<NUM> and <NUM>-<NUM>. While shown with one actuator <NUM>, there can be two actuators <NUM>-<NUM> and <NUM>-<NUM> with axle arm <NUM>-<NUM> connected to actuator <NUM>-<NUM> and axle arm <NUM>-<NUM> connected to actuator <NUM>-<NUM> to allow for independent adjustment of the camber angles of closing wheels <NUM>-<NUM> and <NUM>-<NUM> (not shown).

Alternatively, or additionally, the packer wheel assembly <NUM> may be adjusted based on the tension, pulling force or pressure detected by the drag wire(s) <NUM>. The adjustment of the packer wheel downforce may be adjusted manually by adjusting the position of a conventional coil spring corresponding to discrete preload settings, or, if the packer wheel assembly <NUM> is equipped with an actuator <NUM> as previously described, the operator may manually actuate the actuator <NUM> or the monitor <NUM> may be programmed to automatically actuate the actuator <NUM> to increase or decrease the amount of downforce exerted on the packer wheel <NUM> to keep the force, tension or pressure measured by the trench closing sensor <NUM>-1000F within the desired range or other trench characteristics within the desired range.

<FIG> and <FIG> are schematic illustrations of a system <NUM> which employs the trench closing sensors <NUM>-1000F and reference sensors <NUM>-1100B to provide operator feedback and to control the closing wheel assembly <NUM> and packer wheel assembly <NUM> of the planter row unit <NUM>. At steps <NUM> and <NUM>, the reference sensor <NUM> detects the strain (via the strain gauge <NUM>) exerted on the arm <NUM>. At step <NUM>, the strain exerted on the arm <NUM> is correlated to define the range of force, tension or pressure that should be detecting if the seed trench is being adequately closed by the trench closing assembly <NUM>. At step <NUM> the trench closing sensor <NUM>-1000F detects the force, tension or pressure exerted by the soil on the drag wire(s) <NUM>. At step <NUM> the force, tension or pressure exerted by the soil on the drag wire(s) <NUM> of the trench closing sensor <NUM>-1000F may be displayed to the operator on the monitor <NUM> in the cab of the tractor in relation to the correlated range of the force, tension or pressure that the trench closing sensor <NUM>-1000F should be detecting if the seed trench is being adequately closed by the trench closing assembly <NUM>. At step <NUM>, control decisions are made based on the comparison of the characterized range with the force, tension or pressure detected by that the trench closing sensor <NUM>-1000F. At step <NUM>, the closing wheel assembly <NUM> or the packer wheel assembly <NUM> may be controlled by the monitor <NUM> generating signals to actuate one or more of the corresponding actuators <NUM>, <NUM> and/or at step <NUM>, corresponding recommendations may be displayed to the operator on the monitor display.

Claim 1:
A system for sensing characteristics of a trench in a soil surface during planting operations, the system comprising:
a trench opening assembly (<NUM>) configured to open a trench (<NUM>) in the soil surface as said trench opening assembly (<NUM>) moves in a forward direction of travel;
a trench closing assembly (<NUM>) disposed rearward of said trench opening assembly (<NUM>) to close said opened trench (<NUM>) with soil as said trench closing assembly (<NUM>) moves in said forward direction of travel;
an appurtenance (<NUM>) disposed in said open trench (<NUM>) rearward of said trench opening assembly (<NUM>) and forward of said trench closing assembly (<NUM>), said appurtenance (<NUM>) having a body (<NUM>) supporting at least one sensor (<NUM>) configured to provide characteristics of said trench,
characterized in that said at least one sensor (<NUM>) includes a pressure sensing drum (<NUM>) secured within said appurtenance body (<NUM>), said appurtenance body (<NUM>) being elongate so as to extend rearwardly toward the closing wheels (<NUM>) into an area of said trench (<NUM>) closed with soil by said trench closing assembly (<NUM>) such that the pressure sensing drum (<NUM>) is positioned to measure a pressure exerted by the soil where the closing wheels (<NUM>) are closing the trench, said pressure sensing drum (<NUM>) instrumented to measure an amount of pressure applied to said pressure sensing drum (<NUM>) in said closed area of said trench (<NUM>), said measured pressure indicative of closure of said closed area with soil.