Abstract:
A spout control system controls and aims a spout and a spout cap of a crop harvesting vehicle with respect to a separate crop hauling vehicle moving with the harvesting vehicle. The control system includes a video camera which is mounted on the cap and which views a field of view which includes a portion of the hauling vehicle. An image signal generated by the camera is received by an image processing unit. The image processing unit processes a digitized form of the image signal and automatically generates spout and cap control signals as a function thereof. Actuators automatically aim the spout and the cap in response to the control signal.

Description:
BACKGROUND OF THE INVENTION 
   The invention relates to a spout control system for controlling and aiming the crop discharge spout and cap of a material collecting vehicle with respect to a separate material hauling vehicle moving with the collecting vehicle. 
   It is difficult for the operator/driver of a material collecting vehicle, such as a forage harvester crop harvesting vehicle, to control the positioning of the crop discharge spout to achieve desired and/or even filling of a separate material hauling vehicle or crop hauling vehicle which moves along with the collecting or harvesting vehicle. This is because the operator must view spout and the hauling vehicle, thus diverting the operator&#39;s attention from other tasks which require the operator&#39;s attention. 
   A system for monitoring loading of products from the spout of a harvester to a separate material hauling vehicle is described in German patent No. DE 44 26 059, published Jan. 2, 1996. This system includes a camera mounted on the spout and a video monitor in the cab of the harvester which displays an image to the harvester operator. However, this system does not process any image signals and generate an automatic spout control signal as a function of a processed image. This system also requires that the harvester operator frequently view the monitor and manually adjust the aim of the spout. 
   Another system for monitoring loading of products from the spout of a working machine, such as a harvester or combine, to a separate material hauling vehicle is described in U.S. Pat. No. 6,097,425, issued Aug. 1, 2000. This system also includes a video camera mounted on the spout and a video display in the combine which displays an image to the combine operator. However, this system also does not process any image signals and does not generate automatic spout control signals as a function of a processed image, and this system also requires that the harvester operator frequently view the video display and manually adjust the aim of the spout. 
   U.S. Pat. No. 5,575,316, issued in 1996, describes a system for controlling the sweeping of a spout and the pivoting of discharge pipe on the end of the spout as a function of a distance signal generated by a range finder to achieve even filling of hauling vehicle moving along with a combine. This system does not use video cameras or image processing. 
   U.S. Pat. No. 5,749,783, issued in 1998, describes a system for automatically filling a hauling vehicle moving along with a harvesting vehicle as a function of signals generated by a pair of distance sensors. This system also does not use video cameras or image processing. 
   Spout control systems for self-propelled forage harvesters pulling drawbar-attached material receiving wagons are described in U.S. Pat. No. 4,401,403 issued in 1983, U.S. Pat. No. 4,441,846 issued in 1984 and U.S. Pat. No. 4,529,348 issued in 1985, all assigned to Deere &amp; Company. However, these systems all require an angle sensor to sense an angular position of the wagon relative to the pulling vehicle, and therefore are not suited for use when the hauling vehicle is separate from and not towed by the harvesting vehicle. These systems also does not use video cameras or image processing. 
   SUMMARY OF THE INVENTION 
   Accordingly, an object of this invention is to provide a system for automatically controlling the spout and cap of a harvesting vehicle with respect to a separate crop receiving vehicle as a function of processed images. 
   A further object of the invention is to provide such a system which permits, but does not require an operator to view a display. 
   These and other objects are achieved by the present invention, wherein a spout control system controls and aims a spout and cap of a crop harvesting vehicle with respect to a separate crop hauling vehicle moving with the harvesting vehicle. The control system includes at least one video camera which is mounted on or near the end of a pivotal cap on an end of the spout and which views a field of view which includes a portion of the hauling vehicle. An image signal generated by the camera is received by an image processing unit. The image processing unit processes a digital form of the image signal and automatically generates spout and cap control signals as a function thereof. Spout and cap actuators automatically move the spout and the cap in response to the control signal. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a schematic view of a crop gathering vehicle with a pivoting crop discharge spout and cap delivering crop to a crop receiving and hauling vehicle; 
       FIG. 2  is a simplified side view of a crop receiving and hauling vehicle; and 
       FIG. 3  is a simplified schematic diagram of the control system of the present invention. 
       FIGS. 4A and 4B  form a logic flow diagram illustrating a basic or executive routine performed by the control unit of FIG.  3 . 
       FIG. 5  is a logic flow diagram of a pre-operation calibration routine. 
       FIG. 6  is a table representing values used by the calibration routine. 
       FIG. 7  is a logic flow diagram of an image capture routine. 
       FIG. 8  is a logic flow diagram of an automatic tracking routine. 
       FIG. 9  is a logic flow diagram of an auto-calibration routine. 
       FIG. 10  is a logic flow diagram illustrating how the two controllers of  FIG. 3  cooperate. 
   

   DETAILED DESCRIPTION 
   Referring to  FIG. 1 , a material collecting vehicle or crop gathering vehicle  10 , such as a commercially available John Deere  50  Series self-propelled forage harvester, includes a pivotal crop discharge spout  12  which is pivoted by a conventional bi-directional electrohydraulic spout rotating motor  14 . The spout  12  has a conventional cap  16  pivoted by a conventional cap motor  18 . 
   According to the present invention, a video camera  24  is mounted on or attached to the cap  16  at the end of the spout  12 , so as to obtain an image of the field of view in the direction in which material is discharged from the spout  12  and of the crop receiving or hauling vehicle  26 , which is shown from the side in FIG.  2 . Optionally, as shown in  FIG. 3 , a second video camera  25  may also be mounted on the cap  16 . Two cameras may be used to obtain a useable image in case the crop stream would occlude the view of a single camera. In this case, one camera would be mounted on each side of the crop stream. The images from the two cameras can be electronically “stitched” together, or used alternatively. The spout  12  discharges material to a material hauling vehicle  26 , such as a crop hauling vehicle  26 . The camera  24  preferably moves with the cap  16  and is aimed by it. 
   As best seen in  FIG. 2 , the hauling vehicle  26  may have a cover  30  covering a crop carrying container  32 . The cover  30  preferably has a side opening  34  which receives crop from the spout  12  as the vehicles  10  and  26  move over terrain. 
   The system automatically selects a trackable feature within the field of view of the camera or cameras  24 ,  25  by any of several known techniques. The trackable feature may be a wear pattern, a portion of lettering, a structural element, or other feature. The trackable feature can also be a target  33  placed on a relatively featureless surface of the vehicle  26  in a location so that the target  33  is viewable by the camera  24 . Additional targets (not shown) could be placed on various locations on the hauling vehicle  26 . The camera image is analyzed to identify and track the trackable feature. 
   Referring now to  FIG. 3 , the control system includes an electronic signal processing and control unit  40  which controls the timing of image taking and the shutter speeds of the camera  24  and which processes image signals from the camera  24  and in response generates a spout command or control signal which is communicated to electronic control module  21  via bus  46 . Aiming and pivoting of the spout  12  and the cap  16  may be manually controlled by conventional operator control switches  20  and  22 , respectively, which may be mounted on a joystick (not shown) in a cab (not shown) of the harvester  10  or on a control panel (not shown). Switches  20  and  22  are connected to the electronic control module  21  which is also connected to the bus  46 . The control module  21  receives the automatic control signals from ECU  40  (via bus  46 ) and receives the manual control signals from switches  20  and  22 . Control module  21  then supplies spout and cap control signals to the spout motor  14  and cap motor  18  via the bus  46 . Preferably, control module  21  overrides the automatic control signals from the ECU  40  whenever the switches  20 ,  22  are manually operated. Alternatively, the functions of the ECU  40  and the control module  21  could be integrated into a single control unit. Preferably, the video data is compressed and then decompressed as it is transmitted from one component to another to allow more rapid transmission, analysis and display. 
   Optionally, the camera images may be displayed on a monitor  50  mounted in the cab (not shown) of the vehicle  10 . The signal delivered to the in-cab monitor  50  may be in either analog or digital format. The monitor  50  may be provided as a convenience for the harvest machine operator in initially positioning the discharge spout, but is not necessary for the automatic image capture, analysis, tracking and spout control functions. Because the monitor  50  can be any of a variety of commercially available displays, this feature can be implemented on existing machines with a variety of different display monitors of different types and sizes, and it possible to transmit the captured video image in either digital or analog format as necessary. In either format, the display of the image from camera  24  can be made to occupy either all, or only some part of the display portion of monitor  50  using known techniques. 
   The video camera  24  may be a commercially available analog or digital video camera. If a digital camera is used, then the control unit  40  need not digitize the images from the camera. If the captured image is analog, the image information will first be converted by the unit  40  to digital format by standard analog to digital image conversion means. The result is a digital map or image representing the field of view of the camera  24 . Preferably, data is transmitted between components in a PCI bus format in order to avoid the limitations of other formats. 
   If an additional camera  25  is used, the images from both cameras  24  and  25  can be electronically combined, by, for example, “stitching” the images together using known image processing techniques, so that the control unit  40  provides a single, integrated image covering the overlapping field of view of the cameras  24  and  25 , thereby providing a greater image coverage that is possible with the single camera  24 . In this case, the camera control unit  40  also perform a camera selection function. By electronically combining the images from both cameras  24  and  25 , it is possible to minimize or eliminate a blind spot created by the presence of the stream of crop material within a single camera&#39;s field of view during harvesting. Electronically combining images also enhances the capacity of the system to track the stream of crop material in real time to provide for exact placement of crop material regardless of wind drift or changes in trajectory caused by varying crop densities or field conditions. Image combining may be accomplished by known techniques such as digitally stitching images together. 
   In operation, the hauling vehicle  26  and the harvester  10  are initially positioned relative to each other so that the vehicle  26  can receive crop from the harvester  10 , and the ECU  40  executes an algorithm or routine as shown in  FIGS. 4-8 . 
     FIGS. 4A and 4B  show a simplified overview of the basic or executive signal processing and control algorithm  100  executed by the ECU  40 . Step  102  executes an initialization routine wherein a stored initialization file is retrieved or created based on operator inputs and system devices are initialized. Step  104  reads the inputs to the control system. Step  106 , in response to a shutdown command, directs the algorithm to step  108  which performs a system shutdown. Step  110 , in response to a calibration command, directs the algorithm to step  111 , which, if a flag is set to ready, directs the algorithm to step  112 , else to step  104 . 
   Step  112  calls a calibration subroutine  200  shown in more detail in FIG.  5 . Step  114 , in response to an autotrack command, directs the algorithm to step  115 , which, if a ready flag is set to ready, directs the algorithm to step  116 , else to step  104 . Step  116  calls an autotracking loop or subroutine  400  shown in more detail in FIG.  8 . Otherwise, the algorithm proceeds to step  118 . 
   Step  118  calls an image capture routine  300  shown in more detail in FIG.  7 . If the raw captured image is usable, step  120  directs the algorithm to step  122 , else to step  128 . Step  122  performs various known image processing functions, such as low pass filtering, edge enhancement, thresholding, stripe detection, etc. Step  124  evaluates the processed image to determine if the image includes features which can be used for tracking the movement of the spout  12  relative to the vehicle  26 . If in step  126 , the processed image is not usable, step  128  generates a not usable message for display or communication to the operator, sets the ready flag to not ready and returns the algorithm to step  104 . If the processed image is usable, step  126  directs the algorithm to step  130  which sets the ready flag to ready and returns the algorithm to step  104 . 
   Referring now to  FIG. 5 , if the ready flag indicates that the image is usable, a pre-operation calibration routine  200  begins at step  202  which initializes or creates in temporary memory, preferably from factory programmed non-volatile memory (not shown), a stored default data table or “jog” table of asset of spout displacement values and a set of spout actuator energizing time values, each spout displacement value representing an amount of spout displacement which would result from energizing the actuator for the corresponding actuator energizing time value. 
   Step  204  sets the order of a plurality of spout/cap movement modes to X (spout rotating), X fast (fast spout rotating), Y up (spout cap pivoting upward) and Y down (spout cap pivoting downward), so that these different spout/cap movement modes are calibrated in a certain order, one after the other. These modes can be performed in any order, and the order in which theses modes are performed can be pre-set or can be varied by an operator, if desired. Step  206  obtains the next jog table time and direction value. Step  207  output a spout and cap motion request to the control module  21  which energizes the spout motor  14  and/or the cap motor  18  as shown in FIG.  10 . 
   Step  208  calls the image capture routine  300  of FIG.  7 . Step  210  analyzes the captured image, determines the actual spout or cap movement and stores the result. 
   Step  212  tests for various error conditions, including camera failure, insufficient light, failed communications or end of travel. If an error condition exists, then step  218  generates an operator error message and performs error handling functions, such as operation retry, system shutdown. If no error condition exists, then step  212  directs the algorithm to step  214  which will return the algorithm to step  206  if the algorithm is not finished with the current movement mode. If all movement modes are not finished, step  216  returns the algorithm to step  204  for calibration with respect to the next movement mode. If all modes are finished, step  220  updates the jog table as a result of repeated operation of step  210 . After steps  218  or  220 , the algorithm returns to the main algorithm. 
   Referring now to  FIG. 7 , the image capture routine  300  begins at step  302  which, if multiple cameras are in use, identifies which camera is active. Step  304  issues camera commands to the active camera to obtain an image or images, to adjust the exposure or to otherwise optimize the captured image. Step  305  captures and digitizes one or more images. Step  306  manages image buffering or storing, such as, for example, frame averaging of multiple images, or deleting images no longer needed. 
   If a display  50  is present, and the operator requests that an image be displayed, then step  308  directs the algorithm to step  310 , else to step  316 . Step  310  processes the image, such as optimizing contrast and brightness levels for display purposes. Step  312  add desired overlay data, such as pointers or text messages. Step  314  outputs to the display  50  the processed image resulting from steps  310 - 312 . 
   Step  316  performs “intra” image processing functions, such as subsampling (using only some of the pixels in an image to speed up processing when maximum resolution is not needed), rotation, brightness and contrast adjustment. If a lower resolution image is acceptable, the system may capture only the odd or even image lines and then adjust for a proper vertical/horizontal ratio, or it may convert the image to gray scale. 
   Step  318  performs “inter” image processing functions (over multiple captured images), such as averaging to reduce effects of chaff. These functions are performed on an original image from steps  305  and  306 , but not on images processed for display on monitor  50 . Step  320  returns the algorithm to the main routine. 
   Referring now to  FIG. 8 , the automatic tracking routine  400  begins at step  402  which calls the image capture routine  300  of FIG.  7 . If, in step  404 , the captured image is not usable (the image status or “ready” flag=not ready), the algorithm proceeds to step  424 , else to step  406 . Step  406  performs known image preprocessing functions, such as low pass filtering, edge enhancement, thresholding, stripe detection, etc. Step  408  analyzes the captured image and searches the image for a previously selected trackable feature, such as the target  33 . The search may involve various known image searching techniques, such as center weighted, last track or brute force techniques. If a target was not found, step  410  directs the algorithm to step  424 , else to step  412 . 
   Step  412  calculates the displacement of the target  33  from its previous position and determines the movements required to move the spout  12  to a desired position. Step  414  determines whether or not the required spout movements are within certain limits, such as whether the spout can be moved quickly enough or whether the spout  12  would be driven into engagement with mechanical travel stops (not show). If not, step  414  directs the algorithm to step  428 , else to step  416 . 
   If the required spout motion is not finished step  416  directs the algorithm to step  418 . Step  418  uses a stored jog table, as exemplified by the table of  FIG. 6 , to obtain the motion commands which would produce the desired spout motion. Referring to  FIG. 6 , for each motion mode, there is stored a set of displacement values corresponding to a set of motor energization time values. 
   Referring again to  FIG. 8 , step  420  then outputs the motion command to the control module  21  which energizes the spout motor  14  and/or the cap motor  18  as shown in FIG.  10 . 
   If, in step  416 , the required spout motion is finished step  416  directs the algorithm to step  422  which calls an auto-calibration routine  500  shown in FIG.  9 . After step  422 , routine  400  returns at step  430 . 
   Step  424  increments a desired number of dead-reckoning passes, where a “dead reckoning pass” means an execution of the algorithm during which no spout or cap movement is commanded. Preferably, a limit number of dead-reckoning passes is stored upon startup of the system, and this limit number can be adjusted by an operator. If the limit number of dead reckoning passes is exceeded, step  426  directs the algorithm to step  428 , else to step  430 . Step  428  disables automatic spout control and sends a warning message to the operator. After step  428 , routine  400  returns at step  430 . 
   Thus, routine  400  processes the image from the camera  24  to determine if it contains an image of the previously selected trackable feature, such as target  33 . If the image contains an image of the trackable feature, routine  400  determines whether or not the spout  12  (or cap  16 ) must be moved in response to movement of the trackable feature within the image. If so, a spout movement command is obtained from the stored jog table routine (step  418 ) and this spout movement command is sent to control unit  21  (step  420 ), which then moves the spout, or cap or both accordingly. When the spout or cap or both have finished moving in response to this motion command, step  422  calls the autocalibration routine  500  which determines whether or not the jog table should be updated as a result of this most recent movement of the spout and/or cap. In this manner the stored jog table is continually updated during operation of the system in order to adjust for changes which can occur over time. 
   Referring now to  FIG. 9 , the auto-calibration routine  500  begins at step  502 . Step  504  adds the most recent motion command and spout/cap movement results data to a history file which is stored in the ECU  40 . Step  506  analyzes the information in the history file, such as performing a trend analysis on the information. Step  508  determines whether or not the resulting spout or cap movement deviates significantly from the desired spout or cap movement. If not, step  508  directs the algorithm to step  514 . If yes, step  508  directs the algorithm to step  510  which updates the jog table according to the results of the analysis performed in step  506 . Step  512  updates the jog table stored in the non-volatile memory (not shown). Then, the routine  500  returns at  514 . 
   Referring now to  FIG. 10 , the control module  21  executes an algorithm  600 , and in step  602  receives a motion request from the ECU  40 , as in steps  207  of FIG.  5  and step  420  of FIG.  8 . Step  604  decodes the received motion request. If there is a conflict between the decoded motion request and a manual motion command via switches  20  or  22 , then step  606  directs the algorithm to step  608 . Step  608  sets the ready flag equal to not ready, step  610  formulates an operator motion command, and step  614  outputs this operator motion command to the spout and cap motors  14  and  18 . 
   If there is no conflict between the decoded motion request and a manual motion command via switches  20  or  22 , then step  606  directs the algorithm to step  612 . Step  612  formulates an automatic motion command, and step  614  outputs this automatic motion command to the spout and cap motors  14  and  18 . The algorithm returns or continues at step  616 . 
   As a result, the system described herein obtains and processes an image of the trackable feature on the hauling vehicle  26 , and in response, generates spout steering and cap pivoting control signals which are communicated to the electrohydraulic spout motor  14  and to cap motor  18  to pivot the spout  12  in response to a change in the position of the selected target elements, if there is a movement of those elements relative to the camera&#39;s field of view during the automatic tracking mode. 
   Preferably, when the control unit  40  is operating in its automatic tracking mode, control unit  21  causes control unit  40  to operate in a subservient fashion with respect to manual control of the spout  12  via the spout control switches  20 ,  22 , and will drop out of its automatic tracking mode and revert to the automatic image capture mode and target selection mode whenever the operator exercises manual control over the spout  12 . If desired, the control unit  40  could also automatically returns to the automatic tracking mode upon the release of the switches  20 ,  22  by the operator following any manual interruption of the automatic tracking mode. Thus, the operator may interrupt automatic control by using the switches  20 ,  22  (during which the auto target select function continues to operate). Also, if desired, upon release of the switches  20 ,  22 , the control unit  40  reverts back to its auto track function and tracks the most recently selected “best target” in the last obtained image. 
   Thus, this spout control system is capable of operating in a stand-alone fashion such that there is no need for input from the driver of the hauling vehicle  26 , and the driver of the hauling vehicle  26  need only maintain an approximate position relative to the harvester  10 . 
   Optionally, the control unit  40  may be programmed to track multiple target elements in the field(s) of view of either or both cameras  24  and  25  in order to provide a control system which has an enhanced, image fault tolerance capacity, wherein the system can track one or more images concurrently and continue in its automatic tracking mode as long as at least one target image remains unobscured by dust, chaff or other environmental conditions. 
   The conversion of the above flow chart into a standard language for implementing the algorithm described by the flow chart in a digital computer or microprocessor, will be evident to one with ordinary skill in the art. 
   A portion of the disclosure of this patent document contains material which is subject to a claim of copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure, as it appears in the Patent and Trademark Office patent file or records, but otherwise reserves all other rights whatsoever. 
   While the present invention has been described in conjunction with a specific embodiment, it is understood that many alternatives, modifications and variations will be apparent to those skilled in the art in light of the foregoing description. For example, the invention can be applied to any system where a steerable spout is used to deliver material to relatively movable material receiving unit. Also, the invention can be applied to a crop delivery spout which delivers crop to a top loading crop hauling vehicle with the addition of edge tracking capability to use an edge of the hauling vehicle as the trackable feature. Accordingly, this invention is intended to embrace all such alternatives, modifications and variations which fall within the spirit and scope of the appended claims.