Abstract:
A seeding machine having at least one tool bar, a plurality of row units and a processing circuit. Each of the plurality of row units are connected to the toolbar. Each of the row units have a seed metering device, a seed placement device and a seed sensor. The seed metering device includes a seed disk providing a metering action to a plurality of seeds. The seed placement device receives the seeds from the seed metering device. The seed sensor is positioned to detect the passage of seeds through either the metering device or the seed placement device. The seed sensor producing a signal indicative of the passage of the seeds. The processing circuit is receptive of the signal from each of the seed sensors of each of the plurality of row units. The processing circuit determines a seed placement parameter dependent upon the signal, the processing circuit alters the metering action of the seeds dependent on the seed placement parameter.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention relates to agricultural seeding machines, and, more particularly, to the monitoring of the placement of seed in a trench by a seeding machine. 
       BACKGROUND OF THE INVENTION 
       [0002]    An agricultural seeding machine, such as a row crop planter or grain drill, places the seed at a desired depth within a plurality of parallel seed trenches 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 a predetermined relative locations and depth within the seed trench are relatively complicated. 
         [0003]    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 disk. 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. 
         [0004]    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 
         [0005]    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. 
         [0006]    Certain seed types, such as flat corn seed with insecticide or other treatments thereon are difficult for vacuum meters to singulate. Poor singulation of difficult seed types is characterized by doubles, skips and bunches of seed carried by the disk. Doubles and skips refer to multiple seeds and no seed, respectively, in each seed cell. Bunches are multiple seeds carried by the seed pool accelerators, which protrude from the surface of the seed disk. These seed types generally are best planted with a flat seed disk in combination with a doubles eliminator. 
         [0007]    What is needed in the art is an agricultural seeding machine having an accurate positive seed spacing monitor and an efficient adjustment of a seed metering system. 
       SUMMARY OF THE INVENTION 
       [0008]    The invention includes a seeding machine having at least one tool bar, a plurality of row units and a processing circuit. Each of the plurality of row units are connected to the toolbar. Each of the row units have a seed metering device, a seed placement device and at least one seed sensor. The seed metering device includes a seed disk providing a metering action to a plurality of seeds. The seed placement device receives the seeds from the seed metering device. The seed sensor is positioned to detect the passage of seeds through either the metering device or the seed placement device. The seed sensor producing a signal indicative of the passage of the seeds. The processing circuit is receptive of the signal from each of the seed sensors of each of the plurality of row units. The processing circuit determines a seed placement parameter dependent upon the signal, and the processing circuit alters the metering action of the seeds dependent on the seed placement parameter. 
         [0009]    In another form, the invention includes a method of altering seed output of a seeding machine, the method including the steps of detecting a seed placement parameter of seeds being processed through either a seed metering device or a seed placement device and altering the seed placement parameter of the seeds dependent upon a target seed spacing criteria. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]      FIG. 1  is a perspective view of an agricultural seeding machine incorporating an embodiment of a monitoring and control unit of the present invention; 
           [0011]      FIG. 2  is an end view of the seeding machine having the monitoring and control unit as shown in  FIG. 1 ; 
           [0012]      FIG. 3  is a perspective view of a row unit having a metering and placement system that can be used in an embodiment of the seeding machine of  FIGS. 1 and 2 ; 
           [0013]      FIG. 4  is a perspective view of a metering system used by the row unit of  FIG. 3 ; 
           [0014]      FIG. 5  is a perspective partially exploded view of the metering system shown in  FIG. 4 ; and 
           [0015]      FIG. 6  is a partially sectioned view of the metering system of  FIGS. 4 and 5 . 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0016]    Referring now to the drawings, and more particularly to  FIG. 1 , there is shown an agricultural system  10  including a tractor  12  and seeding machine  14 . Seeding machine  14  is in the form of a row crop planter  14 , but could be a grain drill. Tractor  12  provides the motive power for planter  14  and the mechanisms therein. A seed spacing monitoring/control system  16  is incorporated and used by the operator of tractor  12  to monitor the placing of seeds, from planter  14 . An adjusting system  18  allows monitoring/control system  16  to alter the retention of seeds in a metering system in planter  14 . 
         [0017]    Now, additionally referring to  FIGS. 2-6 , there is shown details of planter  14  that includes tool bar  20 , seed supply  22 , row units  24  each including a metering device  26  having a seed disk  28  with holes  30  therein and a doubles eliminator  32 . Doubles eliminator  32  is also known as a singulator  32  which is positioned in an adjustable manner so as to prevent two seeds from being associated with each hole  30  in seed disk  28 . Metering devices  26  are either directly or indirectly connected to tool bar  20  that is in turn coupled with tractor  12 . Seed is supplied to metering devices  26  by way of seed supply  22  and the seed is pooled over a portion of seed disk  28 . Seed disk  28  is fluidly coupled to an airflow generator that supplies airflow to a cavity  46  and/or a cavity  48 . The airflow generator may have an adjustable airflow that is under the control of adjusting system  18 . The airflow generator may produce a positive or negative pressure depending on the configuration of planter  14 , for ease of explanation the airflow will be understood to be a vacuum system. Airflow caused by the vacuum system is supplied to cavities  46  and/or  48  and thereby to one side of seed disk  28  causing air to flow through holes  30 . The air flowing through holes  30  attracts seeds thereto as seed disk  28  is rotated through the pooled seeds in metering device  26 . Seeds are connected with holes  30  and rotate from the pooled seeds to a point of discharge, as illustrated as a dashed line in  FIG. 6 , from metering device  26  so that it may travel, by way of a seed placement system  50 , to the prepared trench in the soil. 
         [0018]    Row unit  24  additionally carries a double disc furrow opener  52  for forming a seed trench in the soil. An optional coulter wheel  54 , particularly for use in no-till situations, may be placed ahead of double disc furrow opener  52 . A pair of gauge wheels  56  are respectively associated with the pair of discs of double disc furrow opener  52 . More particularly, each gauge wheel  56  is positioned generally in line with and immediately adjacent to the outside of each respective disc of double disc furrow opener  52 . Each gauge wheel  56  may be vertically adjusted to adjust the depth of the trench which is cut into the soil using double disc furrow opener  52 . 
         [0019]    A pair of closing wheels  58  is also part of row unit  24 . Closing wheels  58  are positioned generally in line with double disc furrow opener  52 . Closing wheels  58  are preferably biased in a downward direction and have a peripheral edge with a shape which may vary, depending upon the application. 
         [0020]    Seed placement system  50  is shown in the form of a gravity drop seed tube  42 , but could be configured differently, such as a power drop seed placement system with a powered wheel, etc. 
         [0021]    Seed metering system  26  receives 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 bar  20  or a frame of row unit  24 . Within the housing of metering system  26  there is a seed pool area. Seed disk  28  has a plurality of holes  30  having seed cells on the seed side of disk  28  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 placement system  50 . Of course, seed meter  26  may be configured with a positive pressure to assist in seed movement rather than a vacuum pressure. 
         [0022]    Doubles eliminator  32  is adjustable in the manual sense as shown in  FIG. 4  where manual adjustor  44  can be seen. Manual adjustor  44  is adjusted to move doubles eliminator  32  relative to seed disk  28  so that seed that is passing thereby may be reduced so that each hole  30  carries only one seed. The adjustment of doubles eliminator  32  is desirable so that seeding occurs at the proper rate and optimal seed placement. Manual adjustment is often ignored by the operator since it is time consuming and not convenient to leave the tractor cab and adjust the several manual adjustors  44 . 
         [0023]    Row crops require accurate population levels or seeding rates to achieve maximum yields. Some crops, such as corn and cotton, yield best with even, precise plant spacing or plant-to-plant distances within a given row. The present invention evaluates the spacing of the seeds to achieve a consistent control of the plant-to-plant spacing of the seeds thereby optimizing yield over a field having the same seeding population but not having precise plant spacing. 
         [0024]    As the seed departs from metering device  26 , flows through seed tube  42  and is sensed by seed sensor  34 , as illustrated in  FIG. 6 . a signal is generated by seed sensor  34  that is sent to an electronic processing circuit that may be in monitoring system  16 . A display  36  on monitoring system  16  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. The processing circuit receives a signal from seed sensor  34  to thereby convey a seed placement parameter, which in the embodiment shown is in the form of the timing between the passage of each seed. The processing circuit additionally receives a speed signal that relates to a speed of tractor  12  and/or planter  14  upon the ground from a speed sensor  58 . Speed sensor  58  may be on tractor  12  or planter  14  and the signal is representative of the speed of planter  14  across the ground. The speed signal may be conveyed to the processing circuit by way of a communication of the signal from tractor  12 , or the speed can be determined by the placement of speed sensor  58  on planter  14  with speed sensor  58  being associated with a ground contacting wheel, a global positioning system, a sonar system directed at the ground or a radar system directed at the ground. 
         [0025]    In another embodiment of the present invention the speed signal used by the processing system is the rotational speed of seed disk  28 . Rotational sensor  60  is associated with seed disk  28  and produces a signal that is representative of the rotational speed of seed disk  28 . The signal of rotational sensor  60  that relates to the rotational speed of seed disk  28  is used by the processing circuit along with the signal from seed sensor  34  to produce a seed placement parameter that is used by the processing circuit as an evaluation of the performance of seed disk  28  and if the seed placement parameter is not within a target range, then adjusting system  18  is used to alter the performance of metering device  26  to bring the seed placement parameter within the target range. The seed placement parameter can among other things be considered to be a spacing between the seeds. Additionally, the processing circuit can utilize a predetermined timing as a criteria for the spacing of the seeds, such that a certain predetermined window of time is used and one or more seeds are expected to pass seed sensor  34  within this predetermined time. If a predetermined number of seeds does pass seed sensor  34  in the window of time then the spacing is considered on target, such as may occur with the doubles or skips. Conversely if the seed fails to pass or passes outside of the window then the spacing is considered to not be on target. Alternatively, a predetermined movement of seed disk  28  can be compared to the number of seeds that are placed as a determination of seed placement. For example, one revolution of seed disk  28  can include the placement of a specific number of seeds, such as  24  seeds. A variation from this number of seeds per revolution indicates that an adjustment is needed. If the predetermined movement is equivalent to one seed cell then the detection of each seed is correlated on a one-to-one basis to the movement of seed disk  28 . 
         [0026]    Adjusting system  18  includes an actuator  38  associated with each metering device  26  and controls  40  associated with a display  36  so that doubles eliminator  32  and/or airflow from airflow generator  22  can be adjusted, thereby altering the performance of seed disk  28  and the placement of seed in the seeding trench. 
         [0027]    Seed sensor  34  may be in the form of an optical sensor with a light source located on one side of seed tube  42  and a light sensor on an opposite side of seed tube  42 . Seed sensor  34  provides input to determine the time between the seeds as they travel by sensor  34 . Seeds that are too close based upon a target population, row spacing and speed indicates that more than one seed for the time period has been supplied by metering device  26 . Seeds that are too far apart in time indicates a skip situation. This information can be displayed on display  36  and controls  40  allow the operator to adjust doubles eliminator  32  by activating actuator  38  to either become more aggressive against doubles or less aggressive. Additionally the airflow supplied to seed disk  28  can be adjusted by either altering the speed of the fan causing the vacuum or adjusting the airflow supplied to cavities  46  and/or  48  of each metering device  26 . Further, adjusting system  18  can include the adjusting of the speed of an electric, hydraulic or other drive that may be connected to seed disk  28 , to thereby alter the seed spacing. If doubles eliminator  32  is positioned too aggressively it may knock the seeds off the disk causing skips in the planting sequence. Display  36  as well as control  40  may form an integral unit and may be positioned on the back of planter  14  so that the operator can monitor each metering device  26  while actually watching seed being delivered thereby. Additionally, display  36  and controls  40  may be located in an operating position such as a cab of tractor  12  so that operation of metering devices  26  can be adjusted while planter  14  is in operation. The seed to seed distance is information not available in the prior art and is utilized to drive the feedback mechanism of actuator  38  or the vacuum level supplied by the vacuum system to optimize the seed spacing supplied by seed disk  28 . This is used to great advantage if corn is being planted with different varieties of seeds in row units  24 . For example, when a hybrid seed corn is to be produced in which certain row units  24  may have one specific corn variety and other row units  24  will have a different corn variety, the individual sensing of seed spacing by each row unit  24  is utilized to individually adjust the retention of seeds by seed disk  28 , as planter  14  operates across the field. While the adjustment of a double eliminator has been manually available for some time, the feedback from a seed sensor and the ability of the operator to select an automatic adjustment mode or a selected adjustment mode of the double eliminator, seed disk rotational speed and/or airflow is a particularly useful aspect of the present invention. 
         [0028]    As sensor  34  detects a seed a signal is produced that is sent to monitoring system  16 . Monitoring system  16  detects the spacing between the seeds when the seeds leave metering device  26  or when they pass through placement system  50 . Monitoring system  16  conveys information to the control system and adjusting system  18  all of the processing functions being carried out by the processing circuit, which may be located in monitoring system  16 . The retention of the seeds to seed disk  28  is altered dependent on the spacing of the seeds. The criteria for the acceptable percentage of skips and doubles can be input into monitoring/control system  16  and doubles eliminator  32  and/or the airflow to a specific metering device  26  is adjusted by adjusting system  18  based on violations of the criteria. If the number of skips is too high the airflow may be increased and/or doubles eliminator  32  will be adjusted to be less aggressive. If the percentage of doubles is too high then the airflow to the metering device  26  is decreased and/or doubles eliminator  32  is adjusted to be more aggressive. 
         [0029]    The processing circuit in monitoring system  16  carries out the functions of receiving the signal from seed sensor  34 . The signal being representative of seed passing through seed tube  42 . The processing circuit determines by calculation or from a look-up table, compliance with a target seed spacing criteria and sends commands to actuator  38  to alter the seed spacing and/or the retention of seeds to disk  28 . The percentage of skips, percentage of doubles, current spacing of the seeds and average spacing of the seeds is determined by the processing circuit. This information is displayed on display  36  and can be used to alter the spacing of the seeds by the processing circuit sending a signal or a command to actuator  38 . The target seeding criteria can be as simple as a number representative of the desired spacing between the seeds, can include the allowable percentage of skips, percentage of doubles, current spacing of the seeds and average spacing of the seeds, or even vary by locations in the field and vary from row unit to row unit. 
         [0030]    Having described the preferred embodiment, it will become apparent that various modifications can be made without departing from the scope of the invention as defined in the accompanying claims.