Abstract:
A non-transitory computer-readable medium may store computer executable code. The computer executable code may include instructions to identify a turn to be taken by an agricultural vehicle and to receive a first set of data from at least one of a spatial locating system, one or more speed sensors, and one or more measurement devices. The computer executable code may also include instructions to calculate a second set of data based upon the first set of data. Further, the computer executable code may include instructions to select a vehicle action in anticipation of the turn, based on the first and second sets of data and to control a plurality of actuators to perform the vehicle action.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims priority from and the benefit of U.S. Provisional Patent Application No. 61/914,701, entitled “Automatic Guidance System with Stability Control for an Agricultural Vehicle,” filed Dec. 11, 2013, which is hereby incorporated by reference in its entirety. 
     
    
     BACKGROUND 
       [0002]    The subject matter described herein relates generally to agricultural vehicles such as tractors. Specifically, the present embodiments described below relate to automatic guidance systems with stability control that may be employed in agricultural vehicles. 
         [0003]    Many types of agricultural vehicles (e.g., tractors, combines, sprayers, etc.) may benefit from an automatic guidance system that navigates the vehicle through a preselected area. The automatic guidance system typically has an array of sensors, accelerometers, and other measurement devices to monitor the state of the vehicle (e.g., current speed, road slope, vehicle orientation, etc.). Other computer systems within the agricultural vehicle may also provide data to the automatic guidance system. An operator may upload or select information regarding the preselected area, and start the automatic guidance system, which uses the information regarding the state of the vehicle and the preselected area to navigate the vehicle. 
         [0004]    During operation, an agricultural vehicle may approach a swath line or a sharp turn; in such a situation, the automatic guidance system may arbitrarily limit the steering angle of the vehicle. The arbitrary limit for the steering angle may lead to poor turns by the agricultural vehicle, which may result in the vehicle being unable to follow the swath line, transition to a new swath line, or curve properly. Instances in which the agricultural vehicle veers off-course may result in loss of crop, or premature disengagement of the automatic guidance system. 
       BRIEF DESCRIPTION 
       [0005]    Certain embodiments commensurate in scope with the originally claimed invention are summarized below. These embodiments are not intended to limit the scope of the claimed invention, but rather these embodiments are intended only to provide a brief summary of possible forms of the invention. Indeed, the invention may encompass a variety of forms that may be similar to or different from the embodiments set forth below. 
         [0006]    In a first embodiment, an agricultural vehicle may include a plurality of actuators configured to control at least one system for turning the agricultural vehicle, a spatial locating system, one or more speed sensors, and one or more measurement devices. The agricultural vehicle may also include an automatic guidance system configured to navigate the agricultural vehicle. The automatic guidance system includes a receiver component configured to receive a first set of data from at least one of the spatial locating system, the one or more speed sensors, or the one or more measurement devices; a calculation component configured to calculate a second set of data based on the first set of data; a decision component configured to select a vehicle action based on the first and second sets of data; and an actuation component configured to control the plurality of actuators to perform the vehicle action. 
         [0007]    In a second embodiment, a non-transitory computer-readable medium may store computer executable code. The computer executable code may include instructions to identify a turn to be taken by an agricultural vehicle and to receive a first set of data from at least one of a spatial locating system, one or more speed sensors, and one or more measurement devices. The computer executable code may also include instructions to calculate a second set of data based upon the first set of data. Further, the computer executable code may include instructions to select a vehicle action in anticipation of the turn, based on the first and second sets of data and to control a plurality of actuators to perform the vehicle action. 
         [0008]    In a third embodiment, a method may include identifying a turn to be taken by an agricultural vehicle and receiving a first set of data from at least one of a spatial locating system, one or more speed sensors, and one or more measurement devices. The method may also include calculating a second set of data based upon the first set of data. Further, the method may include selecting a vehicle action in anticipation of the turn, based on the first and second sets of data, and controlling a plurality of actuators to perform the vehicle action. 
     
    
     
       DRAWINGS 
         [0009]    These and other features, aspects, and advantages of the present invention will become better understood when the following detailed description is read with reference to the accompanying drawings in which like characters represent like parts throughout the drawings, wherein: 
           [0010]      FIG. 1  is a perspective view of an embodiment of an agricultural vehicle that may employ an automatic guidance system with stability control; 
           [0011]      FIG. 2  is a block diagram of an embodiment of a computer system that may be employed in the agricultural vehicle of  FIG. 1 ; 
           [0012]      FIG. 3  is a block diagram of an embodiment of the agricultural vehicle that includes an automatic guidance system that may be employed in the agricultural vehicle of  FIG. 1 ; 
           [0013]      FIG. 4  is a block diagram of an embodiment of the automatic guidance system of  FIG. 3 ; 
           [0014]      FIG. 5  is a flow chart of an embodiment of a decision process that may be executed by the automatic guidance system of  FIG. 3 ; and 
           [0015]      FIG. 6  is a flow chart of an embodiment of a turn control process that may be executed as part of the decision process of  FIG. 5   
       
    
    
     DETAILED DESCRIPTION 
       [0016]    One or more specific embodiments of the present subject matter will be described below. In an effort to provide a concise description of these embodiments, all features of an actual implementation may not be described in the specification. It should be appreciated that in the development of any such actual implementation, as in any engineering or design project, numerous implementation-specific decisions must be made to achieve the developers&#39; specific goals, such as compliance with system-related and business-related constraints, which may vary from one implementation to another. Moreover, it should be appreciated that such a development effort might be complex and time consuming, but would nevertheless be a routine undertaking of design, fabrication, and manufacture for those of ordinary skill having the benefit of this disclosure. 
         [0017]    When introducing elements of various embodiments of the present subject matter, the articles “a,” “an,” “the,” and “said” are intended to mean that there are one or more of the elements. The terms “comprising,” “including,” and “having” are intended to be inclusive and mean that there may be additional elements other than the listed elements. The term “component” refers to a computer-related entity, either hardware, software, firmware, software in execution, or a combination of hardware and software. 
         [0018]    Present embodiments relate to automatic guidance systems for agricultural vehicles. Specifically, the embodiments described below relate to automatic guidance systems with stability control. The automatic guidance system may generally navigate an agricultural vehicle through a preselected area. In particular, the automatic guidance system may determine an appropriate vehicle action based on the data collected by measurement devices or parameters derived from measured data regarding the state of the agricultural vehicle. This may enable the automatic guidance system to make informed decisions that increase the overall stability of the agricultural vehicle during operation. The increased stability may reduce the likelihood that the agricultural vehicle veers off-course or makes poor turns during operation. Further, the informed decisions by the automatic guidance system may also improve the ability of the automatic guidance system to navigate the agricultural vehicle from one swath line to another swath line while reducing the likelihood that the agricultural vehicle veers off-course or makes a poor turn. 
         [0019]    With the foregoing in mind,  FIG. 1  illustrates an exemplary agricultural vehicle, in this case a tractor  10 . As will be appreciated, the tractor  10  is merely an example, and the present embodiments may used in be any type of agricultural vehicle (e.g., combines, sprayers, etc.) which may benefit from an automatic guidance system. The tractor  10  includes a body  12  that may house an engine, transmission, and power train (not separately shown). Further, the tractor  10  includes a cabin  14  where an operator may sit or stand to operate the tractor  10 . 
         [0020]    The tractor  10  has a front left wheel  16 , a front right wheel  18 , a rear left wheel  20 , and a rear right wheel  22  (not visible) that rotate to move the tractor  10 . The tractor  10  also includes a steering wheel  24  that causes the wheels  16  and  18  to turn (i.e., front-wheel drive). The steering wheel  24  may be mechanically coupled to the wheels  16 ,  18 ,  20 , and  22 , or may be communicatively coupled to a computer system that controls the wheels via actuators. As illustrated, the wheels  16  and  18  may be coupled together by an axle  26  so that both wheels  16  and  18  may be rotated together. In some embodiments, the steering wheel  24  may cause the wheels  20  and  22  to turn (i.e., rear-wheel or four-wheel drive). In certain embodiments, the tractor  10  may use a continuous track system or a combination of tracks and tire drives to move. 
         [0021]      FIG. 2  depicts a block diagram of an embodiment of a computer system  28  that may be employed in the tractor  10 . The computer systems  28  may monitor and control various parameters regarding the operation of the tractor  10  (e.g., climate control, emissions monitoring, security functions, etc.). The computer system  28  includes a processor  30  and memory  32 , as illustrated. The processor  30  may execute instructions stored on the memory  32  to perform various computer processes. The processor  30  may include, for example, general-purpose single- or multi-chip microprocessors. In addition, the processor  30  may be any conventional special purpose processor, such as an application-specific processor or circuitry. The memory  32  may be a mass storage device, a FLASH memory device, removable memory, etc. The computer system  28  may also include a display  34  and a user input device  36 . 
         [0022]    Further, the computer system  28  may include a hardware interface  38  suitable for interacting with measurement devices  40  and actuators  42 . Accordingly, the processor  30  may be communicatively coupled to measurement devices  40  such that the processor may receive data from the measurement devices  40 . In response to the measurement devices  40  data, the processor  30  may then execute instructions stored on the memory  32  to control components of the tractor  10  (e.g., wheels  16  and  18 ) via the actuators  42 . The actuators  42  may include valves, pumps, switches, and so on, useful in performing control actions such as turning the wheels  16  and  18 . In some embodiments, the computer system  28  may use the actuators  42  to navigate the tractor  10 , as described further below. 
         [0023]      FIG. 3  illustrates a block diagram of an embodiment of the tractor  10  that includes an automatic guidance system  44  that may be employed in the tractor  10 . The automatic guidance system  44  may include a particular type of computer system  28  that autonomously navigates the tractor  10  through a designated area. As may be appreciated, the automatic guidance system  44  may include a computer system that operates in real-time. The automatic guidance system  44  may receive data from measurement devices  40  regarding the current state of the tractor  10 . This data may include the speed of the tractor  10 , a yaw rate of the tractor  10 , and the spatial locating system information (e.g., from a global positioning system (GPS)) of the tractor  10 , among other things. The automatic guidance system  44  may derive other types of data based on the measurement devices  40  data, as discussed in further detail below. In certain embodiments, the automatic guidance system  44  may receive information from other computer systems  28  on board the tractor  10 . 
         [0024]    The automatic guidance system  44  may also receive navigation information  46  regarding the designated area. For example, the navigation information  46  may include a map (e.g., a swath map) detailing the area and planned trajectory for the tractor  10 . Furthermore, the navigation information  46  may also include other types of data such as a suggested maximum speed for traversing the designated area, such that the agricultural task (e.g., spraying pesticides) may be properly performed. In some embodiments, the navigation information  46  may be supplied directly to the automatic guidance system  44  by an operator (e.g., via a universal serial bus (USB) device, via the display  34  and the user input device  36 , etc.). In other embodiments, the automatic guidance system  44  may receive navigation information  46  without an operator, such as by downloading navigation information  46  from a remote computer system via a communications link (e.g., local area network (LAN)). In certain embodiments, the navigation information  46  may also be provided by the measurement devices  40  or other computer systems  28  on board the tractor  10 . 
         [0025]    Based on the data regarding the current state of the tractor  10  and the navigation information  46 , the automatic guidance system  44  navigates the tractor  10  through the preselected area As such, the automatic guidance system  44  may make informed decisions that increase the stability of the tractor  10 , particularly during turns. The increased stability of the tractor  10  may reduce the likelihood that the tractor  10  veers off-course, and may reduce the likelihood of loss of crop. Additionally, the informed decisions by the automatic guidance system  44  may increase the efficiency of transitions between swath lines by the tractor  10 . 
         [0026]      FIG. 4  depicts a block diagram illustrating a more detailed view of an embodiment of the automatic guidance system  44 . The automatic guidance system  44  includes a receiver component  48 , an evaluation component  50 , a calculation component  52 , a decision component  54 , and an actuation component  56 , as shown. The automatic guidance system  44  may also interact with the measurement devices  40  and the actuators  42  via the hardware interface  38 , and may receive data from other computer systems  28 , as well as navigation information  46 , as described above. 
         [0027]    The receiver component  48  may receive incoming data from the measurement devices  40  and other computer systems  28 . In certain embodiments, the receiver component  48  may also receive the navigation information  46 . For example, an operator may select a swath map via the display  34  and a user input device  36 ; in this situation, the swath map may be received through the receiver component  48 . Because the receiver component  48  may receive various types of information from a variety of sources, the receiver component  48  may include a sorting component  58 . The sorting component  58  may sort the information received based on the particular component that will next receive the information. 
         [0028]    The evaluation component  50  may determine whether or not the current trajectory of the tractor  10  should be maintained. That is, the evaluation component may receive trajectory data (e.g., spatial location) from the measurement devices  40  or from other computer systems  28  via the receiver component  48 . The evaluation component  50  may also have access to navigation information  46 , which may be stored on the memory  32 . In certain embodiments, the evaluation component  50  may receive navigation information  46  via the receiver component  48 , as described above. The evaluation component  50  may use the trajectory data as well as the navigation information  46  to determine if the tractor  10  should continue in a straight line or if the tractor  10  should turn in a particular direction. As will be appreciated, the evaluation component  50  may consider a motion at any angle other than 0° to be a “turn.” For example, moving the tractor  10  5° to the right to realign with the swath line and a full 90° turn to move from one swath line to another may both be considered to be a “turn” by the evaluation component  50 . Furthermore, the evaluation component  50  may consider any motion that requires a change in the steering angle of the tractor  10  to be a “turn.” 
         [0029]    In some embodiments, the evaluation component  50  may be integrated with the decision component  54 , such that one component performs both sets of tasks. The decision component  54 , as described in further detail below, may generally determine the next vehicle action for the tractor  10 . However, as noted above, the automatic guidance system  44  may operate in real-time. As such, in certain embodiments it may be beneficial to have one component that identifies whether the tractor  10  should continue in a straight line or turn, and other component that, based on that identification, determines the actual action the tractor  10  should take. Such a configuration, by increasing the number of components, may reduce the amount of work done by the decision component  54 , thereby reducing its latency as well as that of the automatic guidance system  44 . 
         [0030]    The calculation component  52  uses data from the receiver component  48  to derive other types of information useful to the automatic guidance system  44 . For example, the receiver component  48  may pass along data relating to the yaw rate of the tractor  10  and the calculation component  52  may use the yaw rate data to determine the slip angle of the tractor  10 . 
         [0031]    The decision component  54  may receive data from the receiver component  48 , the evaluation component  50 , and the calculation component  52  as inputs. Based on this data, the decision component  54  may determine the next appropriate action that the tractor  10  should take. For example, the decision component  54  may determine the next appropriate action based at least on current speed, current road slope, vehicle orientation, and a projected turn radius based on the current speed. In some embodiments, the decision component  54  may also use data relating to the center of gravity of the tractor  10 , the current yaw rate, the width of a wheelbase of the tractor  10 , the actual or predicted lateral acceleration, and the slip angle, among other things. In some embodiments, vehicle constants such as the center of gravity of the tractor and the width of the wheelbase may be stored in the memory  32 . 
         [0032]    A vehicle action may be any specific action that can be performed by the actuators  42  when selected by the decision component  54 . In some embodiments, vehicle actions may be limited to actions that can be performed by just one system in the tractor  10 . For example, vehicle actions may include, but are not limited to, moving the tractor  10  at the current speed and with the current steering angle (i.e., moving the tractor in a straight line); decreasing the speed of the tractor  10  without adjusting the steering angle; increasing the speed of the tractor  10  without adjusting the steering angle; and adjusting the steering angle of the tractor  10  without adjusting the speed. In other embodiments, a vehicle action may be sequence of actions performed by one or more systems in the tractor  10  that change the operational state of the tractor  10  (i.e., turning the tractor or continuing in a straight line). For instance, a vehicle action relating to turning the tractor  10  may be adjusting the steering angle of the tractor  10  and adjusting the speed of the tractor  10 . 
         [0033]      FIG. 5  illustrates a flow chart of an embodiment of a decision process that may be executed by the decision component  54 . In some embodiments, the decision component  54  may repeatedly execute the decision process  60  (i.e., real-time operation), as mentioned above. For example, the decision component  54  may be configured to execute the decision process  60  every 1 ms. In other embodiments, the decision component  54  may execute the decision process  60  at certain intervals (e.g., at certain locations on the swath line, every 5 minutes, etc.) or in certain situations (e.g. throughout the entirety of a turn larger than or equal to 45°. 
         [0034]    At block  62 , the decision component  54  determines whether the tractor  10  needs to turn. This information may be provided by the evaluation component  50 . If the decision component  54  determines that the tractor  10  does not need to turn, then at block  64  it evaluates whether the tractor  10  should maintain its current speed, which may be provided by the measurement devices  40  via the receiver component  48 . If the speed of the tractor  10  needs to change, then the decision component  54  determines whether the speed should be increased or decreased at block  68 . Based on the results of block  68 , the decision component  54  may select vehicle action  72  or  76 , which correspond to increasing or decreasing speed, respectively. If, at block  64 , the decision component  54  determines that the current speed of the tractor  10  should be maintained, it will then select a neutral vehicle action  74 , in which the speed and steering angle of the tractor  10  remain unchanged. 
         [0035]    If, at block  62 , the decision component  54  determines that the tractor  10  should make a turn, it will proceed to block  66 . During block  66 , the decision component  54  will then evaluate whether the turn can be made at the current speed and steering angle. To make this decision, the decision component  54  may take into account the current speed of the tractor  10 , the road slope, the vehicle orientation, the projected turn radius, and other inputs regarding the state of the tractor  10 , as noted above. If the decision component  54  determines, based on the inputs, that the turn can be made at the current speed and steering angle, then it may select the neutral action  74 . If not, then the decision component  54  may proceed to turn control process  70 . By evaluating a variety of data regarding the state of the tractor  10  at block  66 , the automatic guidance system  44  may navigate the tractor  10  more accurately, particularly during turns. This, in turn, may reduce the likelihood of loss of crop and premature disengagement of the automatic guidance system  44 , as mentioned above. This may also increase the efficiency of transitions between swath lines, also mentioned above. 
         [0036]      FIG. 6  illustrates a flow chart depicting the turn control process  70  that may be executed as part of the decision process  60 . At block  80 , the decision component  54  determines whether both the speed and the steering angle should be changed, based on factors such as current speed, road slope, vehicle orientation, center of gravity, and the projected turn radius. If both the speed and the steering angle do not need to be changed, the decision component proceeds to block  82 , which determines whether one of a new speed or a new steering angle is determines If the current speed of the tractor  10  should be changed (i.e., decreased), then the decision component  54  proceeds to block  68  and the appropriate vehicle action  72  or  76 , as described above. If the steering angle of the tractor  10  should be adjusted, then the decision component  54  selects vehicle action  78 , which corresponds to adjusting the steering angle. 
         [0037]    If, at block  80 , the decision component  54  determines that both the speed and the steering angle of the tractor  10  should be changed, then the decision component  54  evaluates at block  84  whether it is more feasible to change the speed or the steering angle. For example, the decision component  54  may decide, given the current speed of the tractor  10 , that it may be more realistic to adjust the steering angle by 10° than to decrease the speed by 5 miles per hour. Based on the results of block  84 , the decision component  54  may proceed to block  68  and select vehicle action  72  or  76 , or may select vehicle action  78 , as described above. In other embodiments, if the decision component  54  determines that both the speed and the steering angle of the tractor  10  should be changed at block  80 , the decision component  54  may select vehicle action  78  and one of vehicle actions  72  or  76 , as described above. 
         [0038]    After the decision component  54  selects a vehicle action  72 ,  74 ,  76 , or  78 , the actuation component  56  then controls the respective actuators  42  via the hardware interface  38  to perform the action. For example, vehicle action  78  corresponds to adjusting the steering angle of the tractor  10 , while the neutral vehicle action  74  corresponds to maintaining the current state of the actuator  42 . 
         [0039]    One or more of the disclosed embodiments, alone or in combination, may provide one or more technical effects useful for automatic guidance systems employed in agricultural vehicles. Certain embodiments may increase the stability of agricultural vehicles that rely on automatic guidance systems for general operation. For example, the present embodiments may determine vehicle actions such as adjusting a speed of the vehicle or adjusting a steering angle of the vehicle based on the area to be traversed and information related to the state of the agricultural vehicle. As such, the present embodiments may reduce the likelihood that the agricultural vehicle makes a poor turn or otherwise veers off-course, which may subsequently reduce the likelihood of damages, loss of crop, and premature disengagement of the automatic guidance system, which prompts manual emergency maneuvers. The present embodiments may also increase the accuracy and efficiency of transitions between swath lines performed by the agricultural vehicle. The technical effects and technical problems in the specification are exemplary and not limiting. It should be noted that the embodiments described in the specification may have other technical effects and may solve other technical problems. 
         [0040]    While only certain features of the invention have been illustrated and described herein, many modifications and changes will occur to those skilled in the art. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the invention.