Patent Publication Number: US-2021191408-A1

Title: Agricultural machine

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of priority to Japanese Patent Application No. 2019-230606 filed Dec. 20, 2019, Japanese Patent Application No. 2019-230607 filed on Dec. 20, 2019 and Japanese Patent Application No. 2019-229521 filed on Dec. 19, 2019. The entire contents of each of these applications are hereby incorporated herein by reference. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present disclosure relates to an agricultural machine provided with an automatic steering function. 
     2. Description of the Related Art 
     A baler work is performed by connecting a baler to a tractor and towing the baler by the tractor. Although uniformity is required for bales, the shape of a swath which is a collection of mowed grass and hay, does not necessarily correspond to the size of the baler. Therefore, even if the baler simply travels on a swath, it cannot always generate uniform bales. 
     Thus, U.S. Pat. No. 7,404,355 discloses a tractor and a baler which generate a cylindrical bale by providing a sensor and automatically steering the tractor while acquiring the position of a swath and a bale size. 
     Moreover, JP2019-054746A discloses a work vehicle, such as a tractor, which performs automatic steering (auto steering) based on a scheduled traveling route. The auto steering is to automatically control steering so that a work vehicle travels a scheduled traveling route which is set in advance. Therefore, a worker can focus on operations other than driving the vehicle to improve the work efficiency. 
     Even if the bales are generated by the automatic steering like the conventional technology, the bales are not always uniform. In order to generate the uniform bales, a worker needs to finely adjust a traveling path, while monitoring the bale size. 
     However, when the worker performs a manual operation to adjust the traveling path, the automatic steering function is canceled. 
     SUMMARY OF THE INVENTION 
     Preferred embodiments of the present invention provide agricultural machines that each increase the uniformity of bales, while continuing an automatic steering function. 
     Moreover, if the fine adjustment continues, the execution of the automatic steering function becomes meaningless. Thus, it is desirable that the fine adjustment of a traveling path of the automatic steering function is eliminated as much as possible. 
     The present disclosure is made in view of the foregoing problem, and another purpose thereof is to provide an automatic steering function which allows a vehicle to travel on a traveling path as intended by a worker as much as possible. 
     Moreover, as described above, when a worker operates a steering wheel while the auto steering is executed, the auto steering is generally canceled. 
     However, if the auto steering is always canceled when the manual steering operation occurs, it may not be as intended by the worker. Meanwhile, also during the auto steering, a manual steering operation may temporarily be needed. 
     In such a case, it is complicated and takes too much time to again set the auto steering. 
     The present disclosure is made in view of the foregoing problem, and still another purpose thereof is to provide a work vehicle which can continue an auto steering as intended by a worker. 
     An agricultural machine according to a first aspect of an example preferred embodiment of the present disclosure has an automatic steering function that causes the agricultural machine to automatically travel on a given path. The agricultural machine includes a swath information acquiring module configured to acquire a position of a swath, a first determining module configured to determine a traveling path of an automatic operation according to the automatic steering function based on the position of the swath, a setting module configured to set a work continuation width based on the traveling path, a second determining module configured to determine, when there is a manual operation by a worker during the automatic operation, whether a position of the agricultural machine during the manual operation is within the work continuation width, and an executing module configured to execute the automatic operation according to the automatic steering function. The executing module restores the traveling of the agricultural machine on the traveling path after a termination of the manual operation and continues the automatic operation according to the automatic steering function, when the second determining module determines that the agricultural machine is within the work continuation width, and cancels the automatic steering function at a time when the second determining module determines that the agricultural machine is not within the work continuation width. 
     According to this configuration, even when the manual operation is performed during the automatic operation according to the automatic steering function, the automatic steering function is not canceled as long as the agricultural machine is within the work continuation width. Thus, for example when fine adjustment of a traveling path of the agricultural machine is required in order to generate uniform bales, even if a worker performs the fine adjustment of the traveling path by the manual operation, the automatic steering function is not canceled. 
     Therefore, the uniformity of the bales can be improved while continuing the automatic steering function. 
     In the agricultural machine, the executing module may restore the traveling of the agricultural machine on the traveling path via a path determined based on at least any of a current position of the agricultural machine, a traveling direction of the agricultural machine, a distance between the agricultural machine and the traveling path, a resuming distance set in advance, and an angular velocity of a steering wheel during the manual operation. 
     According to this configuration, since the path of restoring the traveling of the agricultural machine on the traveling path is determined based on at least any of the current position of the agricultural machine, the traveling direction of the agricultural machine, the distance between the agricultural machine and the traveling path, the resuming distance set in advance, and the angular velocity of the steering wheel during the manual operation, the agricultural machine can be caused to go back to the traveling path through an optimal path. 
     In the agricultural machine, the executing module may cancel the automatic steering function when an angular velocity of a steering wheel during the manual operation is a given value or more. 
     According to this configuration, the automatic steering function is canceled when the steering operation of which the angular velocity is the given value or more is performed during the automatic operation according to the automatic steering function. Thus, for example when a so-called “rapid steering operation” takes place, the automatic steering function can be canceled. 
     In the agricultural machine, the agricultural machine may be communicable with an FMIS (Farm Management Information System) that is a system in which an external device performs a centralized control of information detected by various sensors, and the swath information acquiring module may acquire, from the FMIS, the position of the swath based on information on a formation process of a target swath. 
     According to this configuration, since the swath information is acquired from the FMIS, the traveling path is able to be determined based on the accurate position of the swath. Moreover, for example, even when a sensor for detecting the position of the swath is not provided, the position of the swath can be recognized. 
     In the agricultural machine, the first determining module may determine a subsequent traveling path based on a traveling footprint on which the agricultural machine traveled on the swath by the manual operation in a certain section. 
     According to this configuration, since the traveling path is determined based on the traveling footprint actually traveled on the swath by the manual operation, a traveling path close to that of the manual operation can be set. 
     An agricultural machine according to a second aspect of an example preferred embodiment of the present disclosure is an agricultural machine including an automatic steering function that causes the agricultural machine to automatically travel on a given path. The agricultural machine includes a swath information acquiring module configured to acquire a position of a swath, a first determining module configured to determine a traveling path of an automatic operation according to the automatic steering function based on the position of the swath, an executing module configured to cause the agricultural machine to travel on the traveling path by the automatic operation according to the automatic steering function, and a traveling-footprint acquiring module configured to acquire an actually-traveled footprint in a given first section up to a current time. The first determining module determines a subsequent traveling path based on the traveling footprint acquired by the traveling-footprint acquiring module for every given second section after the automatic operation is started. 
     According to this configuration, since the subsequent traveling path is determined based on the traveling footprint actually traveled for the every given second section, the traveling path based on the traveling footprint actually traveled on the swath is able to be determined. Thus, the traveling path is able to be determined for the every given second section according to the actual circumstances. 
     For example, when a baler work is performed by the agricultural machine, the path actually traveled is highly possibly a path which is adjusted by a worker so as to make bales uniform by taking the shape, etc., of the bale into consideration. By determining the traveling path according to the actual circumstances, such an effort of the worker to generate the uniform bales is able to be reduced. In other words, the fine adjustment by the worker is able to be reduced, that is, the traveling path as intended by the worker is able to be determined. 
     Note that, the given second section may be the same as or longer than the given first section. 
     In the agricultural machine, the first determining module may determine the traveling path by machine learning using a deep learning model. The deep learning model may output the traveling footprint by using the traveling footprint and a peripheral environment state in the first section as inputs. 
     According to this configuration, the traveling path considered to be optimal based on the traveling footprint and the peripheral environment, is able to be determined. 
     In the agricultural machine, the first determining module may approximate the traveling footprint by a sine wave and determine the approximated sine-wave path as the traveling path. 
     The traveling footprint of the agricultural machines has a shape close to the sine wave in many cases. According to this configuration, since the traveling path is determined as the approximated sine-wave path of the traveling footprint, the traveling path close to the traveling footprint is able to be determined. 
     The agricultural machine may further include a setting module configured to set a work continuation width based on the traveling path, and a second determining module configured to determine, when there is a manual operation by a worker during the automatic operation, whether a position of the agricultural machine during the manual operation is within the work continuation width. The executing module may restore the agricultural machine to the traveling path after a termination of the manual operation and continue the automatic operation according to the automatic steering function, when the second determining module determines that the agricultural machine is within the work continuation width, and may cancel the automatic steering function at a time when the second determining module determines that the agricultural machine is not within the work continuation width. 
     According to this configuration, even when the manual operation is performed during the automatic operation according to the automatic steering function, the automatic steering function is not canceled as long as the agricultural machine is within the work continuation width. Thus, for example when the fine adjustment of the traveling path of the agricultural machine is required in order to generate uniform bales, even if the worker performs the fine adjustment of the traveling path by the manual operation, the automatic steering function is not canceled. Therefore, the uniformity of the bales is able to be improved while continuing the automatic steering function. 
     In the agricultural machine, the first determining module may determine the traveling path based on information used to determine the traveling path before a startup of the agricultural machine, after the startup of the agricultural machine. 
     According to this configuration, for example, even when the work for one day is finished and an engine, etc., of the agricultural machine is stopped, from the beginning of the work on the next day, the traveling path is able to be determined using the information on the traveling footprint of the day before, etc. 
     A work vehicle according to a third aspect of an example preferred embodiment of the present disclosure is a work vehicle including an automatic steering function that causes the work vehicle to automatically travel on a given path. The work vehicle includes a setting module configured to set enable and disable of the automatic steering function, an executing module configured to execute the automatic steering function when the setting module enables the automatic steering function, a determining module configured to determine whether a steering operation of the work vehicle is performed by a worker, and an interruption button configured to interrupt the automatic steering function. The executing module cancels the automatic steering function, when the determining module determines that the steering operation is performed during the execution of the automatic steering function, without the interruption button being actuated. The executing module suspends the automatic steering function, when the determining module determines that the steering operation is performed with the interruption button being actuated, and resumes the automatic steering function after the interruption button is no longer actuated. 
     According to this configuration, even when the steering operation is performed during the execution of the automatic steering function, as long as the interruption button is actuated, the automatic steering function is simply suspended, and after the interruption button is no longer actuated, the function is resumed. Thus, it can suitably support a case when the worker wants to perform the steering operation without canceling the automatic steering function. That is, the automatic steering is able to be continued as intended or desired by the worker. 
     In the work vehicle, the executing module may derive an optimal path to restore the work vehicle to the given path based on a position of the work vehicle at a timing when resuming the automatic steering function, and the given path. The executing module may then cause the work vehicle to travel on the optimal path and to return to the given path. 
     According to this configuration, when the automatic steering function is resumed, the work vehicle can be returned to the given path through an optimal path. 
     In the work vehicle, the interruption button may be provided to a steering wheel. 
     According to this configuration, the worker can actuate interruption button while operating the steering wheel, and thus the actuation of the interruption button can be easier. 
     In the work vehicle, a steering wheel may be provided with a steering wheel spinner, and the interruption button may be provided to the steering wheel spinner. 
     According to this configuration, since the interruption button is provided to the steering wheel spinner, the interruption button is actuated while the rotation of the steering wheel is easily controlled, and thus the actuation of the interruption button can be easier. 
     In the work vehicle, the interruption button may be provided to an arm rest inside a cabin of the work vehicle. 
     According to this configuration, the worker can easily actuate interruption button. 
     The baler controllers according to various aspects of example preferred embodiments of the present disclosure described above, may be implemented by a computer, and in this case, a control program which operates the computer as the baler controller (software) to achieve the baler controller by the computer, and a computer readable recording medium which stores the program are encompassed in the scope of the present disclosure. 
     According to the first aspect of an example preferred embodiment of the present disclosure, even when the manual operation is performed during the automatic operation according to the automatic steering function, the automatic steering function is not canceled as long as the agricultural machine is within the work continuation width. Thus, for example when fine adjustment of a traveling path of the agricultural machine is required in order to generate uniform bales, even if a worker performs the fine adjustment of the traveling path by the manual operation, the automatic steering function is not canceled. Therefore, the uniformity of the bales is able to be improved while continuing the automatic steering function. 
     According to the second aspect of an example preferred embodiment of the present disclosure, since the subsequent traveling path is determined based on the traveling footprint actually traveled for the every given second section, the traveling path based on the traveling footprint actually traveled on the swath is able to be determined. Thus, the traveling path is able to be determined for every given second section according to the actual circumstances. Moreover, by determining the traveling path according to the actual circumstances, the effort of the worker to generate the uniform bales is able to be reduced. In other words, the fine adjustment by the worker is able to be reduced, that is, the traveling path as intended by the worker is able to be determined. 
     According to the third aspect of an example preferred embodiment of the present disclosure, even when the steering operation is performed during the execution of the automatic steering function, as long as the interruption button is actuated, the automatic steering function is simply suspended, and after the interruption button is no longer actuated, the function is resumed. Thus, it is able to suitably support a case when the worker wants to perform the steering operation without canceling the automatic steering function. That is, the automatic steering is able to be continued as intended by the worker. 
     The functions of the work vehicles according to various example preferred embodiments of the present disclosure may be implemented by a computer, and in this case, a control program which operates the computer as each module (software) provided to the work vehicle to achieve the function of the work vehicle by the computer, and a computer readable recording medium which stores the program are encompassed in the scope of the present disclosure. 
     The above and other elements, features, steps, characteristics and advantages of the present invention will become more apparent from the following detailed description of the preferred embodiments with reference to the attached drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a functional block diagram illustrating a structure of a tractor and a baler according to an example preferred embodiment of the present invention. 
         FIG. 2  is a view schematically illustrating the tractor and the baler. 
         FIG. 3  is a flowchart illustrating a flow of processing in the tractor. 
         FIG. 4  is a view illustrating a continuation of an automatic steering operation. 
         FIG. 5  is a view illustrating a continuation of the automatic steering operation. 
         FIG. 6  is a functional block diagram illustrating a structure of a tractor according to another preferred embodiment of the present invention. 
         FIG. 7  is a view illustrating one example of a method of determining a traveling path by a traveling controlling module. 
         FIG. 8  is a view illustrating one example of the method of determining the traveling path by the traveling controlling module when a nudge function is provided. 
         FIG. 9  is a functional block diagram of a tractor according to another example preferred embodiment of the present invention. 
         FIG. 10  is a flowchart illustrating a flow of processing in the tractor. 
         FIG. 11  is a view illustrating a driver&#39;s seat of the tractor when seen from rear. 
         FIG. 12  is a view illustrating one example of arrangement of an interruption button. 
         FIG. 13  is a view illustrating one example of arrangement of the interruption button. 
         FIG. 14  is a view illustrating one example of traveling of the tractor when the interruption button is actuated while executing an auto steering. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Hereinafter, example preferred embodiments of the present disclosure is described in detail. In an example preferred embodiment, a tractor  10  is connected to a baler  20  so that it is able to tow the baler  20 . The tractor  10  and the baler  20  are able to communicate with each other. A baler work is performed by the tractor  10  traveling while it tows the baler  20 . Here, the tractor  10  and the baler  20  are comprehensively referred to as an “agricultural machine  30 .” 
     In this preferred embodiment, the tractor  10  includes an automatic steering function. The tractor  10  is provided with a measuring sensor  16  to measure the position and shape of a swath, and determines a traveling path on which the automatic steering function causes the tractor  10  to travel automatically, and therefore, the tractor  10  travels on the traveling path. Further, a work continuation width or swath is set to the determined traveling path, and if the tractor  10  exists within the work continuation width, the tractor  10  does not cancel the automatic steering even if a manual operation is performed during the automatic steering, and continues the automatic steering after the manual operation. 
     Thus, the tractor  10  can travel by the automatic steering, and even if the manual operation is performed in order to finely adjust the traveling path of the tractor  10 , the automatic steering can be continued after the manual operation. Therefore, the troubles (the time and effort, processing, etc.) which are caused by canceling the automatic steering is able to be reduced. 
     Referring to  FIG. 2 , the tractor  10  which is a traveling vehicle is described.  FIG. 2  is a side view of the tractor  10  and the baler  20 . The tractor  10  includes a vehicle body  11 , a cabin  12  surrounded by the vehicle body  11 , front wheels  13  and rear wheels  14  which are propelled by power from an engine and/or a motor (not illustrated). The tractor  10  can slowdown and stop by using a brake (not illustrated). 
     The tractor  10  is provided with a GPS  15  and can acquire positional information from satellites. The tractor  10  can perform the automatic steering by using the positional information, and can also automatically travel on a swath  40 . The GPS  15  may be provided with an inertial measurement unit (IMU). The positioning accuracy of the GPS can be supplemented by the inertial measurement unit. Moreover, since the inertial measurement unit can measure the angles of three axes, it can measure a vehicle posture of the tractor on irregularities, a sloping ground, etc. of a field. The tractor  10  may also be provided with a measuring sensor  16 , such as a lidar and a camera. The tractor  10  may also detect the swath by the measuring sensor  16 , and automatically travel on the swath  40 . 
     Moreover, the baler  20  includes a frame  21 , a rear gate  22 , and traveling wheels  23 . The baler  20  is connected physically and electrically with the tractor  10  via a connector  31 . The baler  20  is towed by the tractor  10  and forms a bale  41 . 
     The baler  20  feeds hay, straw, etc. which are mowed grass, wheat, etc. in the swath  40  from an inlet port  24  into an internal space surrounded by the frame  21  and the rear gate  22 , and forms the bale  41 . A baler sensor  25  is located in the internal space surrounded by the frame  21  and the rear gate  22 , and detects the size of the bale  41 . When the bale  41  grows to a given size, the tractor  10  stops, and the bale  41  is packed and discharged from the baler  20 . 
     Next, functions of the tractor  10  and the baler  20  are described with reference to  FIG. 1 .  FIG. 1  is a functional block diagram of the tractor  10  and the baler  20 . 
     As illustrated in  FIG. 1 , the tractor  10  includes a tractor controller  100 , a tractor communication unit  110 , a sensor  120 , a user interface  130 , an actuator  140 , and a terminal  150 . These components are connected to each other according to the International Standard ISO11783 based on CAN (Control Area Network), which is referred to as ISOBUS. 
     The tractor controller  100  includes an ECU (Electronic Control Unit), and a CPU (Control Processing Unit), a memory, a control software, etc. The tractor controller  100  performs a control related to traveling of the tractor  10  (e.g., traveling and stop), PTO (Power Take-Off) which transmits the power from the engine to a work machine, such as the baler  20 , and a control of a hitch which attaches the work machine to the tractor. 
     The tractor controller  100  includes a swath information acquiring module  101 , a traveling controlling module (a first determining module, a second determining module, an executing module)  102 , and a work continuation width setting module (a setting module)  103 . The swath information acquiring module  101  acquires swath information measured by the measuring sensor  16  (the position, the shape, etc.), and notifies it to the traveling controlling module  102 . 
     The traveling controlling module  102  is to perform the automatic steering function, and determines a suitable traveling path based on the swath information notified from the swath information acquiring module  101 , and the shape of the bale  41  notified from the baler  20 , and controls the actuator  140  so that the tractor  10  travels on the determined traveling path. 
     The work continuation width setting module  103  sets the work continuation width during the execution of the automatic steering function. The work continuation width is a given width corresponding to a distance from the center line of the traveling path set in order to perform the automatic steering function. The given distance is determined based on the width of the swath  40 , the size of the bale generated by the baler  20 , the width of the tractor  10 , etc., and if the tractor  10  exists within the work continuation width, the automatic steering function will not be canceled. 
     The sensor  120  includes the GPS  15 , the measuring sensor  16 , and an odometer  122 , in addition to sensors to sense fundamental parameters of the tractor, such as a vehicle speed, a transmission status, an engine speed, a PTO rotational speed, a work machine attaching status, and a hydraulic pressure. The information acquired by the sensor  120  is sent to the tractor controller  100  and is used to control the tractor  10 . 
     The user interface  130  is a steering wheel and pedals of an accelerator and a brake, and allows an operator to perform an operation related to traveling of the tractor  10 . 
     The actuator  140  includes power sources, such as the engine and the motor, the transmission, a clutch axle, the brake, the front wheels  13 , the rear wheels  14 , and the PTO and the hitch which drive the work machine. Note that the brake may be an electronic brake. The actuator  140  is controlled by the tractor controller  100 . 
     The terminal  150  includes a display unit  151  and an operation accepting part  152 . The terminal  150  includes, for example, a touch panel, and it is able to display the information acquired from the sensors of the tractor  10  and the baler  20  and to be used to accept an operation related to the work of the baler  20 , and accept settings for the PTO and the hitch of the tractor  10 . 
     The tractor communication unit  110  performs two-way communications (intercommunications) with the baler  20 . Here, communications based on the International Standard ISO11783 is used. The tractor communication unit  110  also has a TIM (Tractor Implement Management) system so that it receives a control signal from the baler  20  and the tractor controller  100  performs controls of the speed of the tractor  10 , the rotational speed of the PTO, the height of the hitch, the hydraulic pressure, etc. Note that the terminal  150  may be connected to the baler  20  without through the tractor communication unit  110 . Moreover, the terminal  150  is also connected to the tractor controller  100 . 
     As illustrated in  FIG. 1 , the baler  20  includes a baler controller  200 , a baler communication unit  210 , the baler sensor  25 , and a work part  220 . These are connected with each other through the ISOBUS. 
     The baler controller  200  includes an ECU (Electronic Control Unit), and a CPU (Control Processing Unit), a memory, a control software, etc. The baler controller  200  performs a control to compress hay and straw and to form the bale having a given size and shape. 
     There are mainly two types of balers  20  which form a cylindrical bale  41  (referred to as a “round baler”) and which form a square bale  41  (referred to as a “square baler”). The shape of the bale  41  can be determined by [longitudinal dimension (length)]×[lateral dimension (width)]×[height], when a traveling direction of the baler  20  is the longitudinal direction (length direction), a direction perpendicular to the traveling direction of the baler  20  is the lateral or transverse direction (width direction), and a height direction of the baler  20  is the height direction. As one example, the square-shaped bale  41  has 200 cm (length)×80 cm (width)×90 cm (height), and the round bale  41  has 120 cm (width)×150 cm (diameter: length and height). For example, as for the round baler, hay and straw are uniformly distributed in the width direction, the bale  41  is grown without an eccentricity in the thickness in the width direction, and when the bale  41  reaches a target size (diameter), the work is stopped. 
     The baler controller  200  transmits necessary information, such as the current size and shape of the bale  41 , or a speed-control request, such as a slowdown (if needed) to the tractor  10  through the baler communication unit  210 . The information or request is displayed on the terminal  150  of the tractor  10 . Here, the width of the bale  41  is normally not in agreement with the width of the swath  40 , and even if it is in agreement, the density of the swath  40  is rarely constant in the width direction, and the swath  40  has a mountain shape. Therefore, if the bale is not uniform in the transverse direction (width direction), the baler controller  200  transmits the information to the tractor  10 , and the information is displayed on the terminal  150 . 
     Even during the automatic steering operation, the worker finely adjusts the traveling path of the tractor  10  based on the information, and, for example, steers so that the tractor  10  travels offset from the center of the swath  40  so as to make the bale  41  uniform. Moreover, the worker may also steer so that the tractor  10  travels in a zigzag manner with respect to the swath  40  to make the bale  41  uniform. 
     The baler sensor  25  measures, for example, the size, shape, weight, and the uniformity of the surface of the bale  41 . The information acquired by the baler sensor  25  is sent to the baler controller  200  and is used for the control. In this preferred embodiment, for example, a plurality of bale size sensors are lined up in the transverse direction and define and function as the baler sensor  25 , and measure the size of the bale  41  and the uniformity in the width direction. 
     The work part  220  creates the bale  41 . As described above, the work part  220  compresses hay, straw, etc. entered from the inlet port  24 , and shapes them to form the bale  41 . Moreover, after the bale is created, the work part  220  packs the bale  41  and discharges it from a bale discharging part  221 . Note that the discharge of the bale  41  is performed by opening the rear gate  22 . 
     The baler communication unit  210  performs the two-way communication with the tractor  10  by the communication based on the ISO11783, and sends the necessary information to the tractor  10 . The baler communication unit  210  also sends the request for the speed control as needed. 
     Next, a flow of processing in the tractor  10  is described with reference to  FIG. 3 .  FIG. 3  is a flowchart illustrating the flow of processing in the tractor  10 . 
     As illustrated in  FIG. 3 , when the operation of the tractor  10  is started (S 101 ) and a start setting of the automatic steering operation is performed, the measuring sensor  16  detects the swath  40  (S 102 ), and the work continuation width setting module  103  sets a work continuation width (S 103 ). Then, the automatic steering operation is started (S 104 ). 
     When a manual operation (steering operation) is performed during the automatic steering operation (YES at S 105 ), the traveling controlling module  102  determines whether the position of the tractor  10  is within in the work continuation width (S 106 ). The determination of whether the tractor  10  is located within the work continuation width is performed based on the position of the tractor  10  obtained by the GPS  15  described above. Then, if determined that the tractor  10  is within the work continuation width (YES at S 106 ), the automatic steering is suspended, and the tractor  10  travels based on the manual operation of the worker. Then, when the manual operation of the worker is finished (YES at S 107 ), the traveling controlling module  102  steers the tractor  10  so that the tractor  10  is restored to or returns to the preset traveling path, and continues the automatic steering operation (S 108 ). 
     The determination of the manual operation being finished can be made, for example, when the worker releases his/her hand(s) from the steering wheel, when there has not been steering operation for a given period of time, and when there is an input indicating that the manual operation is finished into a switch. Note that the determination of whether the worker released the hand from the steering wheel can be made by attaching a sensor to the steering wheel. 
     Moreover, a path for returning to the traveling path may be determined, for example, based on a relation between the traveling direction of the tractor  10  and the traveling path, a distance between the position of the tractor  10  and the traveling path when the manual operation is finished, a setting of a path length for returning to the traveling path, and an angular velocity (an angle and a time) of the steering operation in the manual operation. 
     Here, a case is considered where the manual operation is performed because there is an obstacle. In this case, if the worker could avoid the obstacle without significantly steering the steering wheel, the tractor  10  and the baler  20  are possible to return to the scheduled path by the shortest route. On the other hand, if the steering wheel is steered significantly and the tractor  10  and the baler  20  are returned by the shortest route, they may roll over. Especially, since the baler  20  becomes heavier when the size of the bale  41  increases, the steering needs to be performed carefully. Thus, in such a case, the tractor  10  and the baler  20  return at a steering angle at which they will not roll over to the path on which the tractor  10  and the baler  20  were originally scheduled to travel by the auto steer. The convergence sensibility of such a return may be set using the terminal  150 , or it may be changed according to the size of the bale  41 . 
     On the other hand, at Step S 105 , if there is no manual operation (NO at S 105 ), the automatic steering operation is continued as it is. Moreover, if the tractor  10  exits the work continuation width at Step S 106  (NO at S 106 ), the traveling controlling module  102  cancels the automatic steering operation (S 109 ). 
     Next, a continuation of the automatic steering operation is described with reference to  FIGS. 4 and 5 .  FIGS. 4 and 5  are views illustrating the continuation of the automatic steering operation. As described above, in this preferred embodiment, when the tractor  10  exists within the work continuation width, it does not cancel the automatic steering operation even if there is a manual operation. 
     For example, as illustrated in  FIG. 4 , considering a case where a traveling path  402  of the automatic steering operation is set with respect to the swath  40 , and the work continuation width  403  ( 403 L,  403 R) is set with a width Th. In this case, if the worker operates nothing, the tractor  10  travels along the traveling path  402 . Here, as illustrated in  FIG. 5 , assuming that the worker operates the steering wheel so that the tractor  10  deviates to the right from the traveling path  402  and travels on a traveling path  405 . Then, assuming that the worker finishes the steering operation (manual operation) at Point A. In this case, since the tractor  10  exists within the work continuation width  403  during a period from the start to the end (Point A) of the manual operation, the automatic steering operation is not canceled. Then, since the manual operation is canceled at Point A, the traveling controlling module  102  controls the tractor  10  to travel so that the tractor  10  returns to the traveling path  402  along an optimal path from Point A. Then, when the tractor  10  returns to the traveling path  402 , the traveling controlling module  102  continues the automatic steering operation. 
     Modification 1 
     In the above preferred embodiment, when the tractor  10  exists within the work continuation width  403 , the automatic steering operation is not canceled. However, for example, if a so-called “rapid steering operation” takes place, the automatic steering operation may be canceled even if the tractor  10  exists within the work continuation width  403 . 
     That is, if an amount of steering operation exceeds a threshold within a given period of time, the automatic steering operation is canceled because of the “rapid steering operation.” When there is a “rapid steering operation,” an unexpected situation may be occurring, such as an obstacle or a person being appeared. In this modification, since the automatic steering operation is canceled in such a situation, the safety measure is improved. 
     Modification 2 
     The swath information acquiring module  101  may acquire the swath position from an FMIS (Farm Management Information System). The FMIS is a system which performs a centralized management of information detected by various sensors. If information related to the swath formed by collecting the mowed hay, grass, etc. is managed by the FMIS before the bale work, the tractor  10  communicates with the FMIS to acquire the information and recognizes the swath position. 
     Modification 3 
     The traveling controlling module  102  may acquire a traveling footprint when the tractor  10  travels on a swath for a certain distance by the manual operation, and may set the subsequent traveling path based on the traveling footprint. By using the traveling footprint obtained by actually traveling on the swath, a traveling path close to that of the manual operation can be set. 
     Note that, when the shape of the bale  41  is adjusted by using such a manual operation, the baler sensor  25  may measure the shape of the bale  41 , and the baler controller  200  or the tractor controller  100  may perform a machine learning to utilize the measured shape for the future automatic steering. 
     Preferred Embodiment 2 
     In Preferred Embodiment 1 described above, the traveling controlling module  102  determines the traveling path based on the swath detected by the measuring sensor  16 . In this preferred embodiment, in addition to that, the traveling controlling module  102  determines the subsequent traveling path based on the traveling footprint of the past. Note that, here, an actually-traveled path is referred to as the “traveling footprint,” and a scheduled-traveling path is referred to as the “traveling path.” 
     First,  FIG. 6  illustrates a functional block diagram of a tractor  10 A in this preferred embodiment. As illustrated in  FIG. 6 , the tractor  10 A in this preferred embodiment includes a tilt sensor  123  in the sensor  120 , and a traveling-path determining module (traveling-footprint acquiring module)  1021  in the traveling controlling module  102 , as compared with the tractor  10  in Preferred Embodiment 1 described above. 
     The traveling-path determining module  1021  of the traveling controlling module  102  approximates, each time the tractor  10 A travels a given section (given second section), the traveling footprint of the tractor  10 A in a previous section (given first section) up to the current time by a sine wave when seen from the sky, and determines the sine-wave path when seen from the sky as the subsequent traveling path. 
     Referring to  FIG. 7 , this path is described concretely.  FIG. 7  is a view illustrating one example of a method of determining the traveling path by the traveling controlling module  102 . In  FIG. 7 , the tractor  10 A travels from the left to the right. When the tractor  10 A travels from Point X to Point Y, and when the traveling-path determining module  1021  determines at Point Y the traveling path after Point Y, it determines the subsequent traveling path based on the actually-traveled footprint in the given section X-Y (given first section). That is, in the given section X-Y, when the traveling path determined by the traveling-path determining module  1021  is a path  701 , and the traveling footprint on which the tractor  10 A actually traveled by a manual operation of the worker is a footprint  702 , the traveling-path determining module  1021  approximates, by a sine wave, the footprint  702  by using a difference (offset amount) between the footprint  702  and a swath center line, and determines the path indicated by the approximated sine wave as a future traveling path  703 . 
     Thus, since the future traveling path is able to be determined based on the latest actually-traveled footprint, the traveling path conforms more with the actual situation. Here, the swath center line is a line along the center of the swath in the traveling direction. 
     Note that the traveling footprint may be acquired based on the position of the tractor  10 A detected by the GPS  15 , or may be calculated based on the steered amount of the steering wheel of the user interface  130 , the traveling speed of the tractor  10 A, etc. 
     Alternatively, when the tractor  10 A travels, by a so-called “nudge function,” on a line offset to the left or the right from the swath center line (hereinafter, also referred to as the “nudge line”) as a guide line, the traveling-path determining module  1021  may use a path indicated by a sine wave with respect to the nudge line as the traveling path. For example, as illustrated in  FIG. 8 , when the nudge line exists on the left side of the swath center line in the traveling direction, and a traveling path  701 A and a traveling footprint  702 A exist on the basis of the nudge line, the traveling-path determining module  1021  may determine a path indicated by a sine wave using the nudge line as the center line (i.e., a sine wave offset to left side from the swath center line) as a traveling path  703 A. 
     Modification 4 
     The traveling-path determining module  1021  may determine the traveling path by performing machine learning using a deep learning model which is a kind of AI (Artificial Intelligence). That is, the traveling-path determining module  1021  may determine the traveling path by performing the machine learning by using information indicative of states of peripheral environment, such as various sensor values acquired by the sensor, the swath position, and the bale shape, and the actually-traveled path, as learning data. 
     Therefore, a more appropriate traveling path conforming with the actual situation is able to be determined. 
     Modification 5 
     The traveling-path determining module  1021  may determine the traveling path based on the sensor value detected by the tilt sensor  123 . In a sloping ground, a difference may occur in the traveling footprint between the tractor  10 A and the baler  20 . Thus, by determining the traveling path based on the detection value of the tilt sensor  123 , the traveling path is able to be determined in consideration of the difference in the traveling footprint between the tractor  10 A and the baler  20 . 
     Modification 6 
     The traveling path determined by the traveling-path determining module  1021  may be displayed on the display unit  151  of the terminal  150 . By displaying it on the display unit  151 , the worker can clearly recognize the traveling path. Moreover, the traveling path may be displayed along with the swath position etc. Therefore, the worker can recognize a relation between the traveling path and the swath position. 
     Modification 7 
     The information used to determine the traveling path may be stored in the tractor controller  100  even after a key of the tractor  10 A is turned off (e.g., after the engine is stopped). Therefore, when a work is again performed using the tractor  10 A, the traveling path is able to be determined using the previous information. 
     Moreover, in the method of determining the traveling path by using the machine learning, the machine-learned contents may be stored in the tractor controller  100  even after the key of the tractor  10 A is turned off. Therefore, when the work is again performed using the tractor  10 A, the traveling path is able to be determined based on the previously learned contents. 
     The control block of the tractors  10  and  10 A and the baler  20  (particularly, the tractor controller  100 , the baler controller  200 ) may be implemented, for example, by a logic circuit (hardware) embodied in an integrated circuit (IC chip) or may be implemented by software, for example. 
     In the latter case, the tractors  10  and  10 A and the baler are provided with a computer which executes a command of a program which is software which achieves the functions. For example, the computer is provided with at least one processor (control device) and at least one computer-readable recording medium which stores the program described above. By the processor of the computer reading and executing the program from the recording medium, the purpose of the present disclosure is achieved. For example, a CPU (Central Processing Unit) may be used as the processor. For example, as the recording medium, “non-transitory tangible medium” such as a ROM (Read Only Memory), a tape, a disc, a card, a semiconductor memory, and a programmable logic circuit, may be used. In addition, a RAM (Random Access Memory) which develops the program may also be provided. Moreover, the program may be supplied to the computer via an arbitrary transmission medium (a communication network, a broadcast wave, etc.) which can transmit the program. Note that one mode of the present disclosure may also be implemented as a form of data signal embedded in a carrier wave, where the program is implemented by an electronic transmission. 
     Preferred Embodiment 3 
     Below, another preferred embodiment of the present disclosure is described in detail. As illustrated in  FIG. 9 , the tractor  10  according to this preferred embodiment is a work vehicle provided with an auto steering function. In the auto steering function of the tractor  10 , auto steering is executed by turning ON an auto steering switch  132 , and the auto steering is canceled by performing a manual steering operation etc. However, in this preferred embodiment, even if the manual steering operation is performed during the auto steering, the auto steering is not completely canceled while an interruption button  133  is actuated, and the auto steering is again performed when the interruption button  133  is no longer actuated. Moreover, while the interruption button  133  is actuated, the tractor  10  can be steered by the manual steering operation. 
     Thus, even if the manual steering operation is performed during the execution of the auto steering, the auto steering is not always completely canceled, and therefore, the worker can cancel the auto steering as he/she intended. 
     Note that since the general functions of the tractor  10  as an agricultural machine are achievable by known arts, the description thereof is omitted herein. Moreover, although the tractor  10  is described as one example in this preferred embodiment, the present disclosure is applicable to various work vehicles, such as combines and rice transplanters. 
     Moreover, a coupling part including a three-point linkage etc. may be provided to a rear portion of the tractor  10 , and the working device, such as the baler, may be detachably and movably attached to the tractor  10  through the coupling part. Moreover, the working device is not limited to the baler and it may be a tilling machine, a fertilizer distributor, a spray machine, a harvester, a reaper, etc. 
       FIG. 9  is a functional block diagram of the tractor  10 . As illustrated in  FIG. 9 , the tractor  10  includes an auto steer user interface  131 , the actuator  140 , a tractor controller  160 , and the display unit  151 . The auto steer user interface  131  allows the worker to operate the tractor  10 , and includes a steering wheel  154 , pedals  155 , such as an accelerator pedal and a brake pedal, and various control switches (control lever  157 ), as illustrated in  FIG. 11 . Moreover, the auto steer user interface  131  includes the auto steering switch  132  and the interruption button  133 . 
     The auto steering switch  132  is a switch to execute the auto steering. After an engine startup, the auto steering can be executed by turning “ON” the auto steering switch  132 . Note that the auto steering switch  132  may be displayed on the display unit  151  (described later) as an icon. In this case, by operating (e.g., tapping) the icon, the auto steering can be executed (ON) and canceled (OFF). 
     When the interruption button  133  is actuated while executing the auto steering, the auto steering is not completely canceled during the actuation, even if the manual steering operation is performed by the worker. In more detail, when the interruption button  133  is actuated while executing the auto steering, the worker is able to steer the tractor  10  by the manual steering operation, and when the interruption button  133  is no longer actuated, the tractor  10  returns to the scheduled traveling route set by the auto steering and the auto steering is continued. 
     Moreover, the interruption button  133  is in an “ON” state while being actuated by the worker, and on the other hand, it will be in an “OFF” state when the worker releases his/her finger. 
     To the scheduled traveling route, the tractor  10  may return by the shortest-distance path from a position at the timing of the interruption button  133  not being actuated, or it may return by the optimal path in consideration of the traveling direction. 
     Note that the auto steering is canceled when the manual steering operation is performed during the auto steering, without the interruption button  133  being actuated. 
     The actuator  140  is to propel the tractor  10  and includes a prime mover (an engine such as a diesel engine and a gasoline engine, an electric motor, etc.) and a transmission. 
     The tractor controller  160  performs various controls, such as a travel system and a work system of the tractor  10 , and includes an auto steering controlling module  161  (a setting module, an executing module, a determining module). 
     The auto steering controlling module  161  performs setting and execution of the auto steering of the tractor  10 . The auto steering controlling module  161  performs the auto steering when the auto steering switch  132  is turned ON. Moreover, when the interruption button  133  is actuated while executing the auto steering, the execution of the auto steering is suspended while the interruption button  133  is actuated, and when the actuation of the interruption button  133  is finished, the auto steering is resumed. 
     The auto steering controlling module  161  automatically controls the steering of the tractor  10  based on the scheduled traveling route setting. For example, the auto steering controlling module  161  controls the traveling direction of the tractor  10  so that the traveling position of the tractor  10  matches with the scheduled traveling route. That is, the traveling position of the tractor  10  is compared with the position indicated by the scheduled traveling route, and when the traveling position matches with the scheduled traveling route, the steering direction is maintained. On the other hand, when the traveling position does not match with the scheduled traveling route, the auto steering controlling module  161  controls the steering direction to control the traveling direction of the tractor  10  so that an amount of deviation of the traveling position from the scheduled traveling route becomes zero. 
     The display unit  151  is a display device disposed near the driver&#39;s seat, which displays various meters, and allows the worker to perform setting of the auto steering, etc. More than one display unit  151  may be provided. For example, as illustrated in  FIG. 11 , the meters may be installed in a dashboard meter  151 A in front of the driver&#39;s seat, and the functions for setting the auto steering and controlling an implement may be separately installed in a terminal  151 B (same as the terminal  150  in the previous preferred embodiment) on the right or left side of the driver&#39;s seat. 
       FIG. 10  is a flowchart illustrating a flow of processing in the tractor  10  when executing the auto steering. 
     As illustrated in  FIG. 10 , when the engine of the tractor  10  is started (S 111 ) and the auto steering switch  132  is turned ON (YES at S 112 ), the auto steering controlling module  161  executes the auto steering (S 113 ). During the auto steering, before the steering wheel is manually operated (NO at S 114 ), when the interruption button  133  is actuated (YES at S 117 ), the auto steering controlling module  161  suspends the auto steering while the interruption button  133  is actuated (S 118 ). Then, when the actuation of the interruption button  133  is finished (YES at S 119 ), the auto steering controlling module  161  performs the control to bring the tractor  10  back to the scheduled traveling route (S 120 ), and resumes the auto steering (S 113 ). 
       FIG. 11  is a view illustrating the driver&#39;s seat of the tractor  10  seen from rear. As illustrated in  FIG. 11 , the driver&#39;s seat of the tractor  10  is provided with a seat  153  near the center, a steering wheel  154  forward of the seat  153 , the dashboard meter  151 A (display unit  151 ) which displays the meters, the pedals  155 , such as the accelerator pedal and the brake pedal, at the worker&#39;s feet, a console box on the left side of the seat  153 , an arm rest  159  on the right side of the seat  153 , and the control lever  157 . Moreover, the terminal  151 B (display unit  151 ) which allow the worker to perform the setting of the auto steer of the tractor and the control of the implement is disposed forward of the control lever  157 . Although the details will be described later, in this preferred embodiment, the interruption button  133  is provided to the steering wheel  154 , a steering wheel spinner  156  attached to the steering wheel  154 , or the arm rest  159 . Note that the interruption button  133  may be displayed as an icon on the terminal  151 B. 
       FIGS. 12 and 13  are views illustrating layouts of the interruption button  133 . In this preferred embodiment, as illustrated by  401  in  FIG. 12 , the interruption button  133  may be disposed at an inner portion of the steering wheel  154 . By disposing the interruption button  133  at the inner portion of the steering wheel  154 , it becomes easier to perform the steering operation, while actuating the interruption button  133 . Moreover, when the worker wants to resume the auto steering, it becomes easier to remove the finger from the interruption button  133  to end the actuating. Moreover, it becomes possible to perform the steering operation and the actuating of the interruption button  133  with a single hand, thus improving the work efficiency of the worker. 
     Moreover, as illustrated by  402  in  FIG. 12 , the interruption button  133  may be disposed at the steering wheel spinner  156  provided to the steering wheel  154 . By disposing the interruption button  133  at the steering wheel spinner  156 , the worker can continue actuating the interruption button  133 , while easily performing the steering operation with the single hand. 
     Alternatively, as illustrated in  FIG. 13 , the interruption button  133  may be disposed at a portion of the arm rest  159 . By disposing the interruption button  133  at the portion of arm rest  159 , the worker can securely actuate the interruption button  133  when the auto steering is suspended. 
     Further, as illustrated in  FIG. 11 , the interruption button  133  may be disposed at the worker&#39;s feet. Although the interruption button  133  is disposed at the worker&#39;s feet in  FIG. 11 , a pedal  155  for the interruption button  133  may be additionally provided. 
     Note that the disposed position of the interruption button  133  is not limited to the above position, and it may be disposed at other positions, as long as it is a position where the interruption button  133  is easily operated by the worker and the worker&#39;s steering operation is not impeded or affected. 
     Although in the above preferred embodiments the interruption button  133  is described as one example of interrupting or suspending the auto steering, it is not limited to the button and may be other elements, such as a switch, which can be turned “ON” and “OFF.” That is, it may be of an alternate type in which “ON” and “OFF” are interchanged each time it is operated, without being limited to the type which becomes “OFF” when the worker removes his/her finger. 
       FIG. 14  is a view illustrating a traveling path of the tractor  10  when the auto steering of the tractor  10  is executed, the interruption button  133  is actuated during the auto steering, and the actuation of the interruption button  133  is then ended. 
     As illustrated in  FIG. 14 , a scheduled traveling route  65  is set by using the auto steering, and the tractor  10  travels on the scheduled traveling route  65  according to the auto steering, from the left to the right in this figure. 
     Then, the worker discovers an obstacle  61  during traveling, and he/she then steers the tractor  10  to the right at Point A, while actuating the interruption button  133 . In this case, the tractor  10  changes the path to the right based on the worker&#39;s steering operation, and travels on the traveling route  63  while avoiding the obstacle  61 . Then, at Point B, when the actuation of an interruption button  133  is ended, the tractor  10  returns to the scheduled traveling route  65  through an optimal path, and resumes the auto steering. 
     The optimal path may be a path which connects the position of the tractor  10  and the scheduled traveling route  65  by the shortest distance, or may be derived from the traveling direction, the speed of the tractor  10 , and an angle between the scheduled traveling route  65  and the traveling direction of the tractor  10 . For example, when the obstacle  61  is not so large and the tractor  10  can avoid the obstacle  61  without being steered significantly, the tractor  10  can return to the scheduled path by the shortest route. On the other hand, when the obstacle  61  is large and a deviation from the scheduled traveling route  65  is large, the tractor  10  may roll over if the tractor  10  returns by the shortest route. In that case, the tractor  10  returns to the scheduled traveling route  65  at such an angle that the tractor  10  will not roll over. The returning condition to the scheduled traveling route  65  may be variously set by using the terminal  151 B. 
     Thus, even in the situation where conventionally the auto steering is canceled and it must be set again, this preferred embodiment can prevent the cancelation of the auto steering which is not intended by the worker only with the easy operation of actuation of the interruption button  133 . 
     This is effective when automatically creating the subsequently scheduled traveling path by referring to the previous path (i.e., currently traveling path). For example, when repeating a work for performing an agricultural work by a straight-line movement, and if there is the obstacle  61  at a certain location and a maneuver for avoiding the obstacle is taken, the tractor  10  may learn a portion parallel to the location as a curve and it may repeatedly perform a similar automatic traveling also for the subsequent route. On the other hand, in the present application, while the interruption button  133  is actuated, the tractor  10  can continue traveling straight for the subsequent path as the worker intended, if he/she sets the tractor  10  to ignore the obstacle  61  without learning. 
     The tractor controller  160  (auto steering controlling module  161 ) of the tractor  10  may be implemented, for example, by a logic circuit (hardware), such as an ECU (Electronic Control Unit) embodied in an integrated circuit (IC chip), or may be implemented by software. 
     In the latter case, the tractor controller  160  is provided with a computer which executes a command of a program which is software which achieves the functions. For example, this computer is provided with at least one processor (control device) and at least one computer-readable recording medium which stores the program described above. By the processor of the computer reading and executing the program from the recording medium, the purpose of the present disclosure is achieved. For example, a CPU (Central Processing Unit) may be used as the processor. For example, as the recording medium, “non-transitory tangible medium” such as a ROM (Read Only Memory), a tape, a disc, a card, a semiconductor memory, and a programmable logic circuit, may be used. In addition, a RAM (Random Access Memory) which develops the program may also be provided. Moreover, the program may be supplied to the computer via an arbitrary transmission medium (a communication network, a broadcast wave, etc.) which can transmit the program. Note that one mode of the present disclosure may also be implemented as a form of data signal embedded in a carrier wave, where the program is implemented by an electronic transmission. 
     While preferred embodiments of the present invention have been described above, it is to be understood that variations and modifications will be apparent to those skilled in the art without departing from the scope and spirit of the present invention. The scope of the present invention, therefore, is to be determined solely by the following claims.