Patent Publication Number: US-2022225557-A1

Title: Bale retriever that generates driveable path for efficiency and to reduce compaction

Description:
FIELD OF THE INVENTION 
     The present invention pertains to agricultural vehicles and, more specifically, to bale retrievers and systems for producing and transporting crop material bales. 
     BACKGROUND OF THE INVENTION 
     Agricultural machines, such as balers, are well-known for collecting cut crop material and packing the cut crop material into bales for easier transport. A typical baler has a crop collector, which also may be referred to as a “pickup”, that utilizes tines or other elements to direct the cut crop material to a bale chamber that packs the crop material into a bale. After the crop material is packed into a bale with the desired size, the bale is ejected out the back of the baler. 
     Once the bale is formed, it needs to be transported from the field to a different location, such as a staging area, where the bale is stored. A bale retriever that includes a bale fork or similar pick up mechanism may be used to pick up multiple bales and move the bales to the staging area. While known bale retrievers are effective to pick up and transport bales, fuel use by the bale retriever remains an area where improvements can realize large economic gains. Further, known bale retrievers are not well-suited for use in picking up and transporting bales while one or more balers are actively producing bales in a field. 
     What is needed in the art is a bale retriever that can address some of the previously described issues of known bale retrievers. 
     SUMMARY OF THE INVENTION 
     Exemplary embodiments disclosed herein provide a bale retriever with a controller that defines an expected location of a bale based on a baler travel path and/or a baler planned path to generate a steering control signal for controlling a steering assembly of the bale retriever. 
     Exemplary embodiments disclosed herein also provide a bale retriever with a controller that generates a steering control signal that differs based on whether the controller is in an efficiency mode or a compaction mode and outputs the steering control signal to a steering assembly. 
     In some exemplary embodiments provided according to the present disclosure, a bale retriever includes: a chassis; a steering assembly carried by the chassis and configured to steer the bale retriever; a bale pick up carried by the chassis; and a controller operatively coupled to the steering assembly. The controller is configured to: receive a field signal corresponding to a field map; receive a baler travel signal corresponding to at least one of a baler planned path or a baler travel path of at least one baler; define an expected location of at least one bale on the field map based at least partially on the baler travel signal; generate a steering control signal based at least partially on the expected location of the at least one bale; and output the steering control signal to the steering assembly. 
     In some exemplary embodiments provided according to the present disclosure, a system for producing and transporting crop material bales includes: at least one baler including a crop collector configured to collect crop material from a field and a bale chamber configured to bale crop material collected by the crop collector; and at least one bale retriever including: a chassis; a steering assembly carried by the chassis and configured to steer the bale retriever; a bale pick up carried by the chassis; and a controller operatively coupled to the steering assembly. The controller is configured to: receive a field signal corresponding to a field map; receive a baler travel signal corresponding to at least one of a baler planned path or a baler travel path of at least one baler; define an expected location of at least one bale on the field map based at least partially on the baler travel signal; generate a steering control signal based at least partially on the expected location of the at least one bale; and output the steering control signal to the steering assembly. 
     In some embodiments, a method of controlling a bale retriever comprising a controller to retrieve bales in a field is provided. The method is performed by the controller and includes: receiving a field signal corresponding to a field map; receiving a baler travel signal corresponding to at least one of a baler planned path or a baler travel path of at least one baler; defining an expected location of at least one bale on the field map based at least partially on the baler travel signal; generating a steering control signal based at least partially on the expected location of the at least one bale; and outputting the steering control signal to a steering assembly of the bale retriever so the bale retriever is steered towards the expected location of the at least one bale. 
     In some exemplary embodiments provided according to the present disclosure, a bale retriever includes: a chassis; a steering assembly carried by the chassis and configured to steer the bale retriever; a bale pick up carried by the chassis; and a controller operatively coupled to the steering assembly. The controller is configured to: receive a field signal corresponding to a field map; define at least one windrow on the field map; receive a baler travel signal corresponding to a baler travel path of at least one baler; define a baler traveled path on the field map from the received baler travel signal; define an expected location of at least one bale on the field map; switch between an efficiency mode and a compaction mode; generate a steering control signal that is at least one of a shortest distance control signal or a compaction avoidance control signal; and output the steering control signal to the steering assembly. The controller is configured to generate the shortest distance control signal when in the efficiency mode and the compaction avoidance control signal when in the compaction mode, the shortest distance control signal corresponding to a straight-line path from the bale retriever to the expected location of the at least one bale that does not cross the at least one windrow and the compaction avoidance control signal corresponding to a path from the bale retriever to the expected location of the at least one bale that overlaps the baler traveled path. 
     In some exemplary embodiments provided according to the present disclosure, a system for producing and transporting crop material bales includes: at least one baler including a crop collector configured to collect crop material from a field and a bale chamber configured to bale crop material collected by the crop collector; and at least one bale retriever including: a chassis; a steering assembly carried by the chassis and configured to steer the bale retriever; a bale pick up carried by the chassis; and a controller operatively coupled to the steering assembly. The controller is configured to: receive a field signal corresponding to a field map; define at least one windrow on the field map; receive a baler travel signal corresponding to a baler travel path of the at least one baler; define a baler traveled path on the field map from the received baler travel signal; define an expected location of at least one bale on the field map; switch between an efficiency mode and a compaction mode; generate a steering control signal that is at least one of a shortest distance control signal or a compaction avoidance control signal; and output the steering control signal to the steering assembly. The controller is configured to generate the shortest distance control signal when in the efficiency mode and the compaction avoidance control signal when in the compaction mode, the shortest distance control signal corresponding to a straight-line path from the bale retriever to the expected location of the at least one bale that does not cross the at least one windrow and the compaction avoidance control signal corresponding to a path from the bale retriever to the expected location of the at least one bale that overlaps the baler traveled path. 
     In some embodiments, a method of controlling a bale retriever including a controller to retrieve bales in a field is provided. The method is performed by the controller and includes: receiving a field signal corresponding to a field map; defining at least one windrow on the field map; receiving a baler travel signal corresponding to a baler travel path of at least one baler; defining a baler traveled path on the field map from the received baler travel signal; defining an expected location of at least one bale on the field map; switching between an efficiency mode and a compaction mode; generating a steering control signal that is at least one of a shortest distance control signal or a compaction avoidance control signal; and outputting the steering control signal to a steering assembly of the bale retriever so the bale retriever is steered toward the expected location of the at least one bale. The controller is configured to generate the shortest distance control signal when in the efficiency mode and the compaction avoidance control signal when in the compaction mode, the shortest distance control signal corresponding to a straight-line path from the bale retriever to the expected location of the at least one bale that does not cross the at least one windrow and the compaction avoidance control signal corresponding to a path from the bale retriever to the expected location of the at least one bale that overlaps the baler traveled path. 
     One possible advantage that may be realized by exemplary embodiments disclosed herein is that the controller can define the expected location of a bale based on a prediction of where a baler will drop the bale, so the bale retriever can operate simultaneously with the baler in a field. 
     Another possible advantage that may be realized by exemplary embodiments disclosed herein is that multiple bale retrievers and balers can operate simultaneously in a field to expedite production and transportation of bales. 
     Another possible advantage that may be realized by exemplary embodiments disclosed herein is that the controller generating two possibly different control signals allows a user to control whether the bale retriever operates to maximize fuel efficiency and/or minimize ground compaction. 
     Another possible advantage that may be realized by exemplary embodiments disclosed herein is that real-time communication between the bale retriever and the baler can reduce the amount of time that a bale stays in the field outside the staging area with a low risk of the bale retriever driving into the baler, or vice versa. 
     Yet another possible advantage that may be realized by exemplary embodiments disclosed herein is that the controller of the bale retriever can be configured to define the expected bale location based on the baler travel path and one or more operating parameters of the baler, allowing the bale retriever to move toward the expected location before the baler has finished forming the bale. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       For the purpose of illustration, there are shown in the drawings certain embodiments of the present invention. It should be understood, however, that the invention is not limited to the precise arrangements, dimensions, and instruments shown. Like numerals indicate like elements throughout the drawings. In the drawings: 
         FIG. 1  illustrates a side view of an exemplary embodiment of a tractor and a baler that may be part of a system for producing and transporting crop material bales, provided in accordance with the present disclosure; 
         FIG. 2  illustrates a schematic diagram of an exemplary embodiment of a bale retriever that may be used as part of the system for producing and transporting crop material bales, provided in accordance with the present disclosure; 
         FIG. 3  illustrates a schematic view of an exemplary embodiment of a field map that may be defined by a controller of the bale retriever of  FIG. 2 , in accordance with the present disclosure; 
         FIG. 4  illustrates the field map of  FIG. 3  with both a straight-line path and a path from the bale retriever of  FIG. 2  to an expected location of a bale, in accordance with the present disclosure; 
         FIG. 5  illustrates the field map of  FIG. 3  when the bale retriever defines an imminent travel path of the baler, in accordance with the present disclosure; 
         FIG. 6  illustrates the field map of  FIG. 3  when the bale retriever defines the expected location of a bale based on a baler travel path and at least one operating parameter of the baler; 
         FIG. 7  illustrates a flow chart of an exemplary embodiment of a method for controlling a bale retriever, provided in accordance with the present disclosure; and 
         FIG. 8  illustrates a flow chart of another exemplary embodiment of a method for controlling a bale retriever, provided in accordance with the present disclosure. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring now to the drawings,  FIG. 1  illustrates a side view of an exemplary embodiment of a work vehicle  110  towing a baler  112  in accordance with the present disclosure to perform a baling operation within a field. As will be described further herein, the baler  112  may be part of a system  200  for producing and transporting crop material bales that includes the baler  112  and a bale retriever  202  (illustrated in  FIG. 2 ). As shown, the work vehicle  110  is configured as an agricultural tractor, such as an operator-driven tractor or an autonomous tractor. However, in some embodiments, the work vehicle  110  may correspond to any other suitable vehicle configured to tow a baler across a field or that is otherwise configured to facilitate the performance of a baling operation, including an autonomous baling vehicle. Additionally, as shown, the baler  112  is configured as a round baler configured to generate round bales. However, in some embodiments, the baler  112  may have any other suitable configuration, including being configured to generate square or rectangular bales. It should be further appreciated that the baler  112 , while shown as being towed by a tractor  110 , may also be a self-propelled baler that does not rely on a separate vehicle for propulsion and/or power to function. 
     As shown in  FIG. 1 , the work vehicle  110  includes a pair of front wheels  114 , a pair of rear wheels  116 , and a chassis  118  coupled to and supported by the wheels  114 ,  116 . An operator&#39;s cab  120  may be supported by a portion of the chassis  118  and may house various input devices for permitting an operator to control the operation of the work vehicle  110  and/or the baler  112 . Additionally, the work vehicle  110  may include an engine and a transmission mounted on the chassis  118 . The transmission may be operably coupled to the engine and may provide variably adjusted gear ratios for transferring engine power to the wheels  116  via a drive axle assembly. 
     As shown in  FIG. 1 , the work vehicle  110  may be coupled to the baler  112  via a tongue  122  mounted on a hitch  124  of the work vehicle  110  to allow the vehicle  110  to tow the baler  112  across the field. As such, the work vehicle  110  may, for example, guide the baler  112  toward crop material deposited in windrows on the field. As is generally understood, to collect the crop material, the baler  112  includes a crop collector  126  (shown schematically in  FIG. 1 ) mounted on the front end of the baler  112 . The crop collector  126  may, for example, have a rotating wheel with tines that collects crop material from the ground and directs the crop material toward a bale chamber  128  of the baler  112 . Inside the bale chamber  128 , rollers, belts, and/or other devices compact the crop material to form a generally cylindrically shaped bale  130 . The bale  130  is contained within the baler  112  until ejection of the bale  130  is instructed (e.g., by the operator and/or a baler controller  131 ). In some embodiments, the bale  130  may be automatically ejected from the baler  112  once the bale  130  is formed by the baler controller  131  detecting that the bale  130  is fully formed and outputting an appropriate ejection signal. 
     As shown in  FIG. 1 , the baler  112  may also include a tailgate  132  movable between a closed position (as shown in the illustrated embodiment) and an opened position via a suitable actuator assembly. The tailgate  132  and/or actuator assembly may be controlled to open and close by the baler controller  131 . In the closed position, the tailgate  132  may confine or retain the bale  130  within the baler  112 . In the open position, the tailgate  132  may rotate out of the way to allow the bale  130  to be ejected from the bale chamber  128 . Additionally, as shown in  FIG. 1 , the baler  112  may include a ramp  134  extending from its aft end that is configured to receive and direct the bale  130  away from the baler  112  as it is being ejected from the bale chamber  128 . In some embodiments, the ramp  134  may be spring loaded, such that the ramp  134  is urged into a raised position, as illustrated. In such embodiments, the weight of the bale  130  on the ramp  134  may drive the ramp  134  to a lowered position in which the ramp  134  directs the bale  130  to the soil surface. Once the bale  130  is ejected, the bale  130  may roll down the ramp  134  and be deposited onto the field. As such, the ramp  134  may enable the bale  130  to maintain its shape and desired density by gently guiding the bale  130  onto the field. 
     It should be appreciated that the configuration of the work vehicle  110  described above and shown in  FIG. 1  is provided only as one example. Thus, it should be appreciated that the present disclosure may be readily adaptable to any manner of work vehicle configuration. For example, in an alternative embodiment, a separate frame or chassis may be provided to which the engine, transmission, and drive axle assembly are coupled, a configuration common in smaller tractors. Still other configurations may use an articulated chassis to steer the work vehicle  110 , or rely on tracks in lieu of the wheels  114 ,  116 . Additionally, as indicated previously, the work vehicle  110  may, in some embodiments, be configured as an autonomous vehicle. In such embodiments, the work vehicle  110  may include suitable components for providing autonomous vehicle operation and, depending on the vehicle configuration, need not include the operator&#39;s cab  120 . 
     Additionally, it should be appreciated that the configuration of the baler  112  described above and shown in  FIG. 1  is provided only as one example. Thus, it should be appreciated that the present disclosure may be readily adaptable to any manner of baler configuration. For example, as indicated previously, the baler  112  may, in some embodiments, correspond to a square baler configured to generate square or rectangular bales. 
     Referring now to  FIG. 2 , a schematic view of an exemplary embodiment of a system  200  for producing and collecting crop material bales is illustrated in accordance with the present disclosure. In general, the system  200  will be described herein with reference to the work vehicle  110  and the baler  112  described previously with reference to  FIG. 1 . However, it should be appreciated that the system  200  may generally be utilized with work vehicles having any suitable vehicle configuration and/or balers having any suitable baler configuration. Additionally, for purposes of providing an example of a bale production and collection operation, the system  200  will generally be described herein with reference to performance of the bale production and collection operation following the example baling operation described herein. However, it should be appreciated that the system  200  may generally be utilized to perform a bale collection and transportation operation following the performance of any suitable baling operation within any suitable field. 
     The system  200  includes at least one baler  112  and at least one bale retriever  202  configured to collect bales previously deposited within a field. In some embodiments, the bale retriever  202  may be towed by the tractor  110  described previously with reference to  FIG. 1 . For example, upon completion of the baling operation, the baler  112  may be unhitched from the tractor  110  and a suitable bale pick up or other implement (e.g., a bale spear) may be installed on the tractor  110  to allow for the collection of bales from the field. In some embodiments, the bale retriever  202  may correspond to another suitable vehicle that can be used to collect bales standing within the field, including any suitable autonomous vehicle and/or any suitable operator-driven vehicle (e.g., a skid-steer loader). It should be appreciated that, in some embodiments, the baler(s)  112  and the bale retriever(s)  202  are separate vehicles in the system  200  that can operate simultaneously within a field to produce and collect crop material bales. 
     As shown in  FIG. 2 , the bale retriever  202  may include various components for allowing the bale retriever  202  to be moved across the field during the bale collection operation. For example, the bale retriever  202  may include an engine  204  and a transmission  206  coupled to the engine  204  for propelling the vehicle  202  through the field. In addition, the bale retriever  202  may include a steering assembly  208  for steering the bale retriever  202 . In some embodiments, the steering assembly  208  may be configured to be manually operated via the operator to steer the vehicle  202 . The steering assembly  208  may also be configured to be automatically and/or autonomously controlled to allow the bale retriever  202  to be directed along a predetermined path(s) across the field, either additionally or alternatively to manual control of the steering assembly  208 . For example, in some embodiments, the steering assembly  208  may include or form part of an auto-guidance system for automatically steering the bale retriever  202 . In such an embodiment, the bale retriever  202  may correspond to a fully autonomous vehicle, a semi-autonomous vehicle, or an otherwise manually operated vehicle having one or more autonomous functions (e.g., automated steering or auto-guidance functions). The bale retriever  202  also includes a bale pick up  209 , which may be a fork or other component that is configured to pick up crop material bales from a field and, for example, place the picked up bale on a holding platform (which may include a conveyor) of the bale retriever  202 . 
     Additionally, the bale retriever  202  may also include a positioning device  210  configured to monitor or track the position of the vehicle  202  as it is traversed across a field. For example, in some embodiments, the positioning device  210  may be configured to determine the exact location of the bale retriever  202  using a satellite navigation position system (e.g. a GPS system, a Galileo positioning system, the Global Navigation satellite system (GLONASS), the BeiDou Satellite Navigation and Positioning system, and/or the like). 
     As shown in  FIG. 2 , the bale retriever  202  may also include a controller  212 . The controller  212  is operatively coupled to the steering assembly  208  and, in some embodiments, one or more other components of the bale retriever  202  (e.g., the engine  204  and/or the transmission  206 ) for electronically controlling the operation of such component(s) (e.g. electronic control based on inputs received from the operator and/or automatic electronic control for executing one or more autonomous control functions). As will be described in greater detail herein, the controller  212  is configured to generate one or more paths for the bale collection operation while being capable of taking into account any negative impacts to the field (e.g., compaction and/or yield losses). For example, the controller  212  may be configured to generate guidance lines for collecting the various bales deposited within the field and for transporting such bales to a selected location defined relative to the field (e.g., a staging area). The controller  212  may then utilize the guidance lines for guiding the bale retriever  202  across the field as each bale is collected and subsequently delivered to the selected staging area. For example, in some embodiments, the controller  212  may be configured to automatically control the operation of the bale retriever  202  via control of the steering assembly  208  such that the bale retriever  202  is moved across the field along the determined guidance lines without any operator input (e.g., for autonomous vehicle operation and/or when otherwise operating in an autonomous mode). Alternatively, the controller  212  may be configured to display the determined guidance lines on an associated display device  214  of the bale retriever  202  to allow the operator to navigate the vehicle  202  across the field based on the displayed guidance lines. 
     In general, the controller  212  may correspond to any suitable processor-based device(s), such as a computing device or any combination of computing devices. Thus, as shown in  FIG. 2 , the controller  212  may generally include one or more processor(s)  216  and associated memory devices  218  configured to perform a variety of computer-implemented functions (e.g., performing the methods, steps, algorithms, calculations and the like disclosed herein). As used herein, the term “processor” refers not only to integrated circuits referred to in the art as being included in a computer, but also refers to a controller, a microcontroller, a microcomputer, a programmable logic controller (PLC), an application specific integrated circuit, and other programmable circuits. Additionally, the memory  218  may generally comprise memory element(s) including, but not limited to, computer readable medium (e.g., random access memory (RAM)), computer readable non-volatile medium (e.g., a flash memory), a floppy disk, a compact disc-read only memory (CD-ROM), a magneto-optical disk (MOD), a digital versatile disc (DVD) and/or other suitable memory elements. Such memory  218  may generally be configured to store information accessible to the processor(s)  216 , including data  220  that can be retrieved, manipulated, created and/or stored by the processor(s)  216  and instructions  222  that can be executed by the processor(s)  216 . 
     In some embodiments, the data  220  may be stored in one or more databases. For example, the memory  218  may include a bale collection database  224  for storing data associated with the bales to be collected from the field during the performance of the bale collection operation. Such data may, for instance, include any data collected during the performance of the prior baling operation, such as the position data associated with the location of the baling paths relative to the field, the heading data associated with the heading of the vehicle/baler along each baling path, and/or the position data associated with the specific location of each bale within the field. In addition, various other types of data may be stored within the bale collection database  224 . For example, in some embodiments, data may be stored within the bale collection database  224  that is associated with one or more operator inputs, one or more user-defined system preferences, and/or other system inputs relevant to one or more aspects of the present disclosure, such as data associated with the specific type of bales being collected (e.g., round bales vs. square/rectangular bales), data associated with the specific size of bales being collected (e.g., 4×5, 5×5, or 6×5), data associated with a desired or selected location for the staging area at which the bales will be aggregated, data associated with a desired spacing or arrangement of the collected bales within the staging area, and/or any other relevant data. 
     Additionally, as shown in  FIG. 2 , the memory  218  may also include a guidance database  226  for storing data associated with guiding the bale retriever  202  during the performance of the bale collection operation. For example, as indicated previously, the controller  212  may be configured to generate guidance lines along which the bale retriever  202  is to be traversed when collecting the bales and subsequently aggregating the bales at the desired staging area. As such, the guidance database  226  may, for example, include data associated with the computer-generated guidance lines, such as GPS data or map data that maps each guidance line across the field. 
     Referring still to  FIG. 2 , in some embodiments, the instructions  222  stored within the memory  218  of the controller  212  may be executed by the processor(s)  216  to implement a staging area module  228 . In general, the staging area module  228  may be configured to determine a location(s) relative to the field that will serve as a “staging area” for aggregating the various bales being collected from the field. Specifically, in some embodiments, the staging area module  228  may be configured to automatically select the location for the staging area based on one or more factors, including, but not limited to, the locations of the various bales within the field, the size and/or shape of the field, and/or any user-defined or predetermined system preferences associated with the desired location of the staging area relative to the field. The instructions  222  stored within the memory  218  of the controller  212  may also be executed by the processor(s)  216  to implement a path planning module  230 , which may be configured to plan a travel path of the bale retriever  202 , and a vehicle guidance module  232 , which may be configured to guide the bale retriever  202 . 
     In known bale retrievers, the bale retriever generally follows a pre-determined path and follows the baler in a field. While this is effective, there are a few shortcomings with such a strategy. For example, the bale retriever is not controlled based on the real-time data and thus is not being controlled to follow optimized paths for the current status of the field. Similarly, the bale retriever is not generally able to operate simultaneously with the baler. Further, following a single baler in the field limits the ability of the bale retriever to collect bales from multiple balers. 
     To address some of the previously described issues with known bale retrievers and systems that incorporate such bale retrievers, and referring now to  FIGS. 3-6 , the system  200  is illustrated in graphical form on a field map  300 . The controller  212  of the bale retriever  202  is configured to receive a field signal corresponding to the field map  300 , which may be stored in the memory  220  of the controller  212 . In some embodiments, the field map  300  is constructed and updated solely within the controller  212 ; in other embodiments, the field map  300  is presented as a graphic on the display device  214  in a manner that is similar to the graphical illustration of the field map  300  of  FIGS. 3-6 . It should thus be appreciated that the field map  300  may be constructed solely for use by the controller  212  or, alternatively, may also be presented graphically on a display device  214  or elsewhere so an operator may see the state of the field via the field map  300 . Field signals corresponding to the field map  300  may be received from a variety of sources. 
     In some embodiments, the field signal comes from the baler  112  as it operates and is continuously output to a communication interface  234  of the bale retriever  202 , which is operatively coupled to the controller  212 , so the controller  212  is configured to receive real-time signals corresponding to various aspects of the baler  112  and the field, as will be described further herein. For example, the communication interface  234  of the bale retriever  202  may interface with a corresponding communication interface  133  of the baler  112  (illustrated in  FIG. 1 ) using radio signals or other types of communication signals to receive the field signal. Alternatively, field signals corresponding to the field map  300  may be received from a communication network  310  that is established with the system  200  using one or more communication protocols and a network hub  311  that interfaces with the respective communication interfaces  133 ,  234  but is not carried by either the baler  112  or the bale retriever  202 . The network hub  311  may be, for example, a device commonly known as a “router” or similar device. It should be appreciated that the controller  212  of the bale retriever  202  may receive field signals from other sources, such as a vehicle other than the baler  112 , e.g., a mower-conditioner and/or an unmanned aerial vehicle. Further, while the field signal is described previously as being transmitted to the controller  212  wirelessly, in some embodiments the field signal corresponding to the field map  300  is received by the controller  212  from a physical connection, i.e., a wired connection, and/or a physical data source, e.g., a memory module. It should thus be appreciated that the field signal corresponding to the field map  300  may be received by the controller  212  in a variety of ways. 
     The controller  212  is configured to receive a baler travel signal corresponding to a baler planned path and/or a baler travel path of at least one baler, such as the baler  112 . The baler planned path may be a path that the baler  112  is expected to follow in the field map  300 , such as swath lines, and the baler travel path may be a path the baler  112  has traveled in the field map  300 . The baler travel signal corresponding to the baler planned path and/or the baler travel path may be communicated to the bale retriever  202  directly from the baler  112  via the respective communication interfaces  234 ,  133 , or, alternatively, communicated to the bale retriever  202  via the communication network  310 . In some embodiments, the controller  212  is configured to receive real-time signals corresponding to the baler planned path and/or the baler travel path via the communication interface  234  so the controller  212  may control various aspects of the bale retriever  202  based on current, rather than historical, information. For example, the baler controller  131  may be configured to output a baler location signal that corresponds to a set of GPS coordinates that the baler  112  has traveled across during a given time interval, such as 5 seconds, and a current heading of the baler  112 , which corresponds to a direction that the baler  112  is facing and thus the direction in which the baler  112  is expected to move forward. In some embodiments, the baler controller  131  is configured to output the baler travel signal whenever the current heading of the baler  112  changes, which indicates that the baler planned path and the baler travel path are changing. 
     The controller  212  is also configured to define an expected location of at least one bale  302  on the field map  300  based at least partially on the baler travel signal. In some embodiments, the controller  212  receives a previous bale drop location signal corresponding to a location of a previously dropped bale from the baler  112  and/or the communication network  310  and defines the expected location of the bale(s)  302  based at least partially on the received previous bale drop location signal. The baler controller  131  may, for example, record the current GPS coordinates of the baler  112  each time the baler  112  ejects a bale  302  and output such GPS coordinates as the previous bale drop location signal via the communication interface  133 . Based on the location of a previously dropped bale, the controller  212  may be configured to define the expected location of a bale that has not yet been dropped by predicting the location where the baler  112  will next drop a bale. In this respect, the controller  212  may be configured to define the expected location of the bale also based at least partially on one or more operating parameters of the baler  112 , including but not limited to the travel speed of the baler  112 , the current heading of the baler  112 , and/or a defined bale size (volume and/or mass) of each bale that is formed by the baler  112 . It should be appreciated that the controller  212  may also be configured to define the expected location of the bale based simply on the baler travel signal by predicting at what locations the baler  112  is expected to drop bales and/or based on the previous bale drop location signal that corresponds to one or more locations in the field map  300  where the baler  112  has dropped a bale. 
     In some embodiments, the controller  212  is configured to define the expected location of a bale  302  based at least partially on the baler planned path and/or the baler travel path and one or more operating parameters of the baler  112 , such as a travel speed of the baler  112 , a current heading of the baler  112 , and/or a defined size of the bales  302  produced by the bale chamber  128 . The controller  212  may, for example, define the expected location of a bale  302  by calculating a volume of crop material collected (or expected to be collected) by the baler  112  as the baler  112  travels along the baler travel path (or is expected to travel along the baler planned path), collects crop material, and packs the crop material into forming bales; based on this calculation, the controller  212  may define the expected location of a bale  302  to be a location where the baler  112  is expected to have collected a defined volume of crop material to form the bale  302  and ejected the bale  302  onto the field. Alternatively, or in addition, the controller  212  may receive one or more signals from the baler  112  to determine when the mass of crop material in the bale chamber  128  is equal to a defined mass of crop material to form a bale  302 , with the controller  212  then defining the expected location of the formed bale leaving the bale chamber  128  to be around the location of the baler  112  where the mass of crop material in the bale chamber  128  is equal to the defined mass. The controller  212  may take other parameters into account to define the expected location of a bale  302 , such as a volume of crop material per unit length of windrows in the field, that are provided by components other than the baler  112 , such as a mower-conditioner vehicle. Additional other parameters that the controller  212  may take into account to define the expected location of a bale  302  include, but are not limited to: a defined (or target) bale diameter; a defined (target) bale mass; a current diameter of a forming bale; a current weight of a forming bale; a swath volume from a previous raking and/or mowing operation; a historical distance traveled by the baler  112  to make bales in neighboring windrows; a slope of areas in the field map  300 ; and/or a planned driving path of the baler  112 , which can take into account, e.g., headlands and/or the next swath taken. Thus, it should be appreciated that the controller  212  can be configured to define the expected location of a bale  302  based on a variety of parameters. 
     In some embodiments, the controller  212  is configured to define at least one windrow, illustrated as a plurality of windrows  301  in  FIG. 3 , on the field map  300  that correspond to windrows in the field. The windrow(s)  301  can be defined in a variety of ways. In some embodiments, the windrow(s)  301  are defined based on swath lines that the baler  112  follows to travel through the field, with the swath lines being generally aligned with the windrows  301  so the baler  112  follows the windrows  301  to collect and pack crop material into bales  302 , as illustrated. In some embodiments, the swath lines define the baler planned path of the baler  112 . In some embodiments, the controller  212  is configured to define collected windrows  303 , illustrated in dashed lines, on the field map  300 . By defining the collected windrows  303  on the field map  300 , the controller  212  can keep track of space on the field that is free of crop material, the significance of which will be defined further herein. 
     Referring particularly now to  FIGS. 3-4 , it is illustrated how the controller  212  may define a baler traveled path  304  on the field map  300  from the received baler travel signal and switch between an efficiency mode and a compaction mode to generate a steering control signal that is a shortest distance control signal and/or a compaction avoidance control signal. The generated steering control signal is output to the steering assembly  208  to steer the bale retriever  202  toward the expected location of the bale to collect the bale. The controller  212  may be configured to switch between the efficiency mode and the compaction mode based on, for example, operator input to directly make the switch. In some embodiments, the controller  212  may be configured to automatically switch between the efficiency mode and the compaction mode based on a location within a field, e.g., switch to the efficiency mode in a portion of a field that is already heavily compacted and/or has a soil type that is less prone to compaction, and/or when the bale retriever  202  reaches certain fuel levels, e.g., switch to the compaction mode when the bale retriever  202  has a high level of fuel and/or the bale to be retrieved is in a portion of the field with soil that is prone to compaction. It should be appreciated that the foregoing ways of switching between the efficiency mode and the compaction mode are exemplary only, and other ways and/or rationales for the controller  212  switching between the modes are contemplated according to the present disclosure. 
     The controller  212  is configured to generate the shortest distance control signal when in the efficiency mode and to generate the compaction avoidance control signal when in the compaction mode. The shortest distance control signal corresponds to a straight-line path  401 , illustrated in dashed-line in  FIG. 4 , from the bale retriever  202  to the expected location of the bale  302  that does not cross a windrow  301 . The compaction avoidance control signal corresponds to a path  402 , illustrated in solid-lines in  FIG. 4 , from the bale retriever  202  to the expected location of the bale  302  that overlaps the bale traveled path. As illustrated in  FIG. 4 , it can be seen that the straight-line path  401  represents a minimal distance that the bale retriever  202  must travel to get to the expected location of the bale  302 , which minimizes the fuel consumption of the bale retriever  202  while also avoiding the bale retriever  202  driving over any windrows  301  and potentially damaging or dispersing crop material. On the other hand, the path  402  that overlaps the baler traveled path has the bale retriever  202  go over ground where the baler  112  has already traveled to reduce the risk of the bale retriever  202  compacting additional parts of the field, which can reduce yield. It should be appreciated that while the straight-line path  401  and the path  402  are illustrated as being different paths in  FIG. 4 , in some instances the straight-line path  401  and the path  402  will overlap. For example, if the expected locations of two bales  301  lie on a swath line and the bale retriever  202  is substantially on the swath line, the straight-line path  401  and the path  402  may overlap due to the bale retriever  202  following the swath line to the expected location of both bales  301 . Further, the generated steering control signal may be generated to avoid the bale retriever  202  driving into a bale drop zone Z until the bale retriever  202  is ready to drop its collected bale(s) at the bale drop zone Z. 
     To generate the shortest distance control signal, the controller  212  may be configured to determine a current location of the bale retriever  202 , such as a GPS-based location, and define the expected location of the bale  302  as a GPS-based location. The controller  212  may define the straight-line path  401  using trigonometric functions and/or the Pythagorean theorem and the GPS-based current location of the bale retriever  202  and the expected location of the bale  302  to define a hypotenuse, which represents the straight-line path  401  from the current location of the bale retriever  202  to the expected location of the bale  302 . It should be appreciated that the controller  212  may be configured to generate the shortest distance control signal in a variety of other ways, and the previously described way is just one exemplary way. 
     After defining the straight-line path  401 , the controller  212  also determines if the straight-line path  401  crosses a windrow  301  on the field map  300 . For example, as illustrated in  FIG. 4 , the bale retriever  202  could not travel to a bale  403  with a straight-line path and not cross one of the windrows  301 . In such a case, the controller  212  may be configured to determine when the traveled path of the baler  112  has gone over the windrows  301 , indicating that the windrows  301  have been collected, before generating the shortest distance control signal corresponding to the straight-line path toward the bale  403 . In some embodiments, the controller  212  is also configured to define one or more obstacle zones in the field map  300  and determine if the straight-line path  401  crosses an obstacle zone. In the given example, the windrows  301  may be considered obstacle zones. Other possible obstacle zones may include, but are not limited to, an area where there is a tree or significant mud. The obstacle zones may be defined by an operator manually; alternatively, or in addition, the obstacle zones may be defined based on a path traveled by another vehicle, such as a mower-conditioner, which presumably avoids obstacles in the field. 
     To generate the compaction avoidance control signal, the controller  212  may be configured to compare the expected location of the bale  302  with the baler traveled path, which may both represent areas, and determine a shortest path between the location of the bale retriever  202  and the expected location of the bale  302  that is bound within the baler traveled path and the expected location of the bale  302 . Generating the compaction avoidance control signal may also take other parameters into account, such as a location of headlands  406  in the field map  300 , to determine the shortest path bound within the baler traveled path. As illustrated in  FIG. 4 , the shortest path  402  corresponds to the bale retriever  202  traveling perpendicular and parallel to the windrows  301 , similarly to the movement pattern utilized by the baler  112  as it collects and packs crop material into the bales  302 . 
     While the previous description focuses on the interaction between one baler  112  and one bale retriever  202  of the system  200 , it should be appreciated that the system  200  can include multiple balers and bale retrievers. As illustrated in  FIG. 4 , a second baler  412 , which may be similar to the baler  112 , may be simultaneously collecting and packing crop material into bales  302  on the field. Similarly, a second bale retriever  404 , which may be similar to the bale retriever  202 , may be simultaneously collecting and transporting the formed bales  302 . The second baler  412  and the second bale retriever  404  may both be communicating with the communication network  310  using respective interfaces and functioning similarly to the baler  112  and bale retriever  202 . The controller  212  of the bale retriever  202  and the controller of the second bale retriever  404  may both be configured to receive a second baler travel signal corresponding to a travel path of the second baler  412  and define a second baler traveled path on the field map  300  from the received second baler travel signal from the second baler  412 . 
     In some embodiments, the bale retrievers  202 ,  404  are configured to communicate with one another so their respective controllers may determine which of the bale retrievers  202 ,  404  is in a better position to collect a certain bale. For example, the second bale retriever  404  may be more suited to collect the bale  403  because its straight-line path  405  to the bale  403  both is shorter than the corresponding straight-line path of the bale retriever  202  to the bale  403  and also does not cross any windrows  301  in the field. In this respect, the controller of the second bale retriever  404  may determine that it has an acceptable straight-line path to the bale  403 , whereas the bale retriever  202  does not, and generate a shortest distance control signal corresponding to the straight-line path  405  from the second bale retriever  404  to the expected location of the bale  403 . The controller of the second bale retriever  404  may also be configured to output a bale retrieval signal to the controller  212  of the bale retriever  202  that causes the controller  212  of the bale retriever  202  to remove the expected location of the bale  403  from the field map  300 , so the controller  212  does not output a steering control signal to the steering assembly  208  to steer the bale retriever  202  toward the bale  403 . Similarly, the controller  212  of the bale retriever  202  may output a bale retrieval signal to the controller of the second bale retriever  404  for bales  302 , which are further from the second bale retriever  404  and cannot be reached by a straight-line path without crossing windrows  301 , so the second bale retriever  404  does not steer toward the bales  302 . It should thus be appreciated that the system  200  can be adapted to include a plurality of balers  112 ,  412  and/or bale retrievers  202 ,  404  to expedite production and transportation of crop material bales in a field. 
     In some embodiments, and referring now to  FIG. 5 , the controller  212  is configured to predict an imminent travel path  501  of the baler  112  and generate the steering control signal so the bale retriever  202  does not cross the imminent travel path  501 . As used herein, the “imminent travel path” of the baler  112  is the travel path of the baler  112  that is expected to occur around the same time that the bale retriever  202  would be crossing the travel path  501 . As illustrated in  FIG. 5 , the imminent travel path  501  of the baler  112  follows one of the windrows  301  and is in a straight-line path  502  from the bale retriever  202  to a bale  503 . The controller  212  may be configured to predict the imminent travel path  501  based on the baler planned path, the baler travel path, the location of the baler  112 , a current heading of the baler  112 , and/or a travel speed of the baler  112 . Since the imminent travel path  501 , and a windrow  301 , are both in the straight-line path  502  from the bale retriever  202  to the bale  503 , the controller  212  may be further configured to compare a first time interval that it will take for the baler  112  to clear the area of the imminent travel path  501  and collect the windrow  301 , allowing the bale retriever  202  to follow the straight-line path  502  without crossing the imminent travel path  501  or the windrow  301 , to a second time interval that it will take for the bale retriever  202  to follow a different path. Based on the comparison and other considerations, which may be selected by an operator, the controller  212  may decide to wait for the baler  112  to collect the windrow  301  and then signal for the bale retriever  202  to follow the straight-line path  502  and collect the bale  503 . By having the controller  212  decide to wait for the baler  112  to collect the windrow  301 , a significant amount of fuel, and possibly time, may be saved compared to the bale retriever  202  driving around the windrow  301  to collect the bale  503 . 
     In some embodiments, and referring now to  FIG. 6 , the controller  131  of the baler  112  is configured to output an estimated bale drop location signal corresponding to an estimated bale drop location of a bale  603 , which is received by the controller  212  of the bale retriever  202 . The controller  212  may use the estimated bale drop location to define an expected location of the bale  603  and generate an appropriate steering control signal to direct the bale retriever  202  toward the bale  603 . As illustrated in  FIG. 6 , the bale retriever  202  may then steer and travel toward the bale  603  while staying outside an area encompassed by an imminent travel path of the baler  112  and the windrow  301 . After the baler  112  passes, and drops the bale  603  in the expected location, the bale retriever  202  may travel to the bale  603  and collect the bale  603 . By heading toward the expected location of the bale  603  based on the estimated bale drop location from the baler  112 , the bale retriever  202  does not need to follow the baler  112  around the field and can, for example, collect bales ejected by other balers and/or collect other bales previously ejected by the baler  112 . 
     From the foregoing, it should be appreciated that the system  200  including the bale retriever  202 ,  404  provided according to the present disclosure allows intelligent, automatic control of a bale retriever in a field. The bale retriever  202 ,  404  can operate based on expected locations of one or more bales in the field, allowing the bale retriever(s)  202 ,  404  to operate simultaneously with one or more balers  112 , 412 . The bale retriever  202 ,  404  can be in real-time communication with one or more balers  112 ,  412  operating in a same general area to coordinate movement of the bale retriever(s)  202 ,  404  and the baler(s)  112 ,  412  so bales are produced and transported at roughly the same time. By having the bale retriever  202 ,  404  able to switch between the efficiency mode and the compaction mode, the bale retriever  202 ,  404  can follows paths that maximize fuel efficiency and/or follow paths that minimize ground compaction. Thus, the system  200  provided according to the present invention can produce and transport crop materials bales in a manner that can maximize fuel efficiency and/or minimize ground compaction while also reducing the time that the bales sit in the field adjacent to where the baler ejects them. 
     Referring now to  FIG. 7 , an exemplary embodiment of a method  700  of controlling a bale retriever including a controller, such as the bale retriever  202  and/or the second bale retriever  404 , to retrieve bales in a field is illustrated. The method  700  is performed by the controller  212  and includes receiving  701  a field signal corresponding to a field map  300 ; receiving  702  a baler travel signal corresponding to at least one of a baler planned path or a baler travel path of at least one baler; defining  703  an expected location of at least one bale  302 ,  403  on the field map  300  based at least partially on the baler travel signal; generating  704  a steering control signal based at least partially on the expected location of the at least one bale  302 ,  403 ; and outputting  705  the steering control signal to a steering assembly  208  of the bale retriever  202  so the bale retriever  202  is steered towards the expected location of the bale(s)  302 ,  403 . The expected location of the bale(s)  302 ,  403  may be defined  703  in a variety of ways, as previously described. The method  700  may include, for example, receiving  706  a previous bale drop location signal corresponding to a location of a previously dropped bale, with defining  703  the expected location of the bale(s) being based at least partially on the received previous bale drop location signal. The method  700  may also include predicting  707  an imminent travel path  501  of the baler(s)  112 ,  412 , with the steering control signal being generated  704  so the bale retriever  202 ,  402  does not cross the imminent travel path  501 . It should be appreciated that the method  700  may also include any one or more of the previously described functions of the controller  212 . 
     Referring now to  FIG. 8 , another exemplary embodiment of a method  800  of controlling a bale retriever including a controller, such as the bale retriever  202  and/or the second bale retriever  404 , to retrieve bales in a field is illustrated. The method  800  is performed by the controller  212  and includes receiving  801  a field signal corresponding to a field map  300 ; defining  802  at least one windrow  301  on the field map  300 ; receiving  803  a baler travel signal corresponding to a baler travel path of at least one baler, such as the baler  112  and/or the second baler  412 ; defining  804  a baler traveled path  304  on the field map  300  from the received baler travel signal; defining  805  an expected location of at least one bale  302 ,  403  on the field map  300 ; switching  806  between an efficiency mode and a compaction mode; generating  807  a steering control signal that is at least one of a shortest distance control signal or a compaction avoidance control signal; and outputting  808  the steering control signal to a steering assembly  208  of the bale retriever  202 ,  404  so the bale retriever  202 ,  404  is steered toward the expected location of the at least one bale  302 ,  403 . The controller  212  is configured to generate  807  the shortest distance control signal when in the efficiency mode and the compaction avoidance control signal when in the compaction mode. The shortest distance control signal corresponds to a straight-line path  401 ,  405  from the bale retriever  202 ,  404  to the expected location of the at least one bale that does not cross the windrow(s)  301  and the compaction avoidance control signal corresponds to a path  402  from the bale retriever  202  to the expected location of the at the least one bale  302  that overlaps the baler traveled path  304 . In some embodiments, the method  800  further includes receiving  809  a bale drop location signal, which may be from the baler(s)  212 ,  412  and/or the communication network  310 , and the defined expected location of the at least one bale  302 ,  403  is based at least partially on the received bale drop location signal. In some embodiments, the method  800  further includes predicting  810  an imminent travel path  501  of the at least one baler  212 ,  412  and the steering control signal is generated  807  so the bale retriever  202 ,  404  does not cross the imminent travel path  501  when the bale retriever  202 ,  404  moves toward the expected location of the bale(s)  302 ,  403 . The method  800  may also include any of the previously described functions of the controller  212 , with further description being omitted for brevity. 
     It is to be understood that the steps of the method  700 ,  800  are performed by the controller  212  upon loading and executing software code or instructions which are tangibly stored on a tangible computer readable medium, such as on a magnetic medium, e.g., a computer hard drive, an optical medium, e.g., an optical disc, solid-state memory, e.g., flash memory, or other storage media known in the art. Thus, any of the functionality performed by the controller  212  described herein, such as the method  700 ,  800 , is implemented in software code or instructions which are tangibly stored on a tangible computer readable medium. The controller  212  loads the software code or instructions via a direct interface with the computer readable medium or via a wired and/or wireless network. Upon loading and executing such software code or instructions by the controller  212 , the controller  212  may perform any of the functionality of the controller  212  described herein, including any steps of the method  700 ,  800  described herein. 
     The term “software code” or “code” used herein refers to any instructions or set of instructions that influence the operation of a computer or controller. They may exist in a computer-executable form, such as machine code, which is the set of instructions and data directly executed by a computer&#39;s central processing unit or by a controller, a human-understandable form, such as source code, which may be compiled in order to be executed by a computer&#39;s central processing unit or by a controller, or an intermediate form, such as object code, which is produced by a compiler. As used herein, the term “software code” or “code” also includes any human-understandable computer instructions or set of instructions, e.g., a script, that may be executed on the fly with the aid of an interpreter executed by a computer&#39;s central processing unit or by a controller. 
     These and other advantages of the present invention will be apparent to those skilled in the art from the foregoing specification. Accordingly, it is to be recognized by those skilled in the art that changes or modifications may be made to the above-described embodiments without departing from the broad inventive concepts of the invention. It is to be understood that this invention is not limited to the particular embodiments described herein, but is intended to include all changes and modifications that are within the scope and spirit of the invention.