Patent Publication Number: US-2021169002-A1

Title: Harvester, Surrounding Condition Detection System, Surrounding Condition Detection Program, Recording Medium Recording the Surrounding Condition Detection Program and Surrounding Condition Detection

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is the United States national phase of International Application No. PCT/JP2019/020075 filed May 21, 2019, and claims priority to Japanese Patent Application No. 2018-154142 filed Aug. 20, 2018, the disclosures of which are hereby incorporated by reference in their entirety. 
    
    
     BACKGROUND OF THE INVENTION 
     Technical Field 
     The present invention relates to a harvester harvesting crops while traveling in a field. The invention relates also to a surrounding condition detection system for detecting conditions of surrounding of such harvester, a surrounding condition detection program for detecting conditions of surrounding of such harvester, a recording medium recording such surrounding condition detection program and a surrounding condition detection method for detecting conditions of the surrounding of the harvester. 
     Description of Related Art 
     Conventionally, a harvester such as a combine has been employed for harvesting crops. As an example of such type of combine, there is one configured to carry out a harvesting work by automated (autonomous) traveling in order to improve the harvesting efficiency (for example, Patent Document 1). 
     Patent Document 1 discloses an autonomous traveling work vehicle including a position calculating means for determining a position of the machine body with utilizing a satellite positioning system and a controlling means for causing the vehicle to effect traveling and a utility work autonomously along a set traveling route. Further, this autonomous traveling work vehicle includes an obstacle detecting means for detecting an obstacle if any in the surrounding, and a sensitivity adjusting means for varying sensitivity of the obstacle detecting means. The sensitivity of the obstacle detecting means is set high within a field, whereas the sensitivity of the obstacle detecting means is set low outside the field. Moreover, the sensitivity is set such that a larger detection range may be provided at the center portion within the field whereas the detection range becomes progressively smaller as the vehicle approaches the outer circumference of the field. 
     PATENT DOCUMENT 
     Patent Document 1: Japanese Unexamined Patent Application Publication No. 2015-191592 
     SUMMARY OF THE INVENTION 
     A harvester may travel not only in an un-reaped (unworked) land in a field where harvesting work has not been done, but also in a reaped land (worked land) where harvesting work has been done. As a subject (a target) to be detected will differ between such un-reaped land and reaped land as above, it is not readily possible to appropriately detect the detection subject by merely varying the sensitivity between the inside of the field and the outside of the field, or further varying between the center portion of the field and the outer circumference portion of the field, as provided by the technique disclosed in Patent Document 1. 
     Thus, there is a need for a technique that allows an automated traveling with appropriate detection of a detection object within a field. 
     According to a characterizing feature of a harvester relating to the present invention, a harvester configured to harvest crops while traveling in a field, comprises: 
     a self-machine (self-vehicle) position detection module included in a machine body and operable to detect a self-machine position; 
     a detection unit included in the machine body and including a plurality of detection modules capable of detecting conditions of surrounding of the machine body; 
     a map creation section operable to create, based on the self-machine position, a map indicative of a position of a reaped land in the field where the crops have been reaped and a position of an un-reaped land in the field where the crops have not yet been reaped; and 
     an operational mode setting section for setting operational modes of the plurality of detection modules respectively, based on the map and the self-machine position. 
     With the above-described characterizing feature, the operational mode setting section can set operational modes of the detection modules provided in the circumference of the machine body in accordance with the position on the map of the field, so that the detection module can detect an object (a target) appropriately within the field. For this reason, according to the inventive characterizing feature, it is possible to realize a combine that can effect an automated traveling with using detection results obtained by the detection modules. 
     Further, preferably, the operational mode setting section is configured to stop a detection function of a particular detection module among the plurality of detection modules, based on the map and the self-machine position, the particular detection module being directed to detection of the condition of the un-reaped land. 
     With the above-described arrangement, an erroneous detection can be prevented by disabling a detection module which may detect the crops. 
     Further, preferably, the operational mode setting section is configured to set detection ranges of the plurality of detection modules, based on the map and the self-machine position. 
     With the above-described arrangement, it becomes possible e.g. to distribute the detection range among the respective plural of detection modules. In such case, since the loads of the detection modules can be divided, it is possible to prevent detection delay and/or an erroneous detection. 
     Further, preferably, machine body works effected by the machine body include a straight traveling harvesting work in which the crops are harvested while the machine body is caused to travel straight, a turning harvesting work in which the crops are harvested while the machine body is caused to turn, and a turning traveling in which harvesting of the crops is suspended and the machine body is caused to turn; and 
     at the time of the turning harvesting work and at the time of the turning traveling, the operational mode setting section sets higher detection sensitivity for the lateral sides of the machine body than those for the front side and the rear side with respect to an advancing direction of the machine body. 
     With the above-described arrangement, during turning of the machine body, fucus of object detection can be given to the lateral side. Therefore, it is possible to prevent erroneous entrapment of an object present on the inner side of the turning at the time of turning of the machine body as well as accidental contact with an object present at an outer terminal end of foregoing turn. 
     Further, preferably, 
     at the time of traveling in the un-reaped land in the field, the operational mode setting section sets higher sensitivity for the reaped land located laterally of the machine body than for the reaped land located rearwardly of the machine body; and 
     at the time of traveling in the reaped land in the field, the operational mode setting section sets higher sensitivity for the reaped land located forwardly of the machine body than for the reaped land located laterally of the machine body. 
     With the above-described arrangement, detection of an object present in the forwardly located reaped land within the field is made easy, thus effectively preventing erroneous detection due to detection of the un-reaped land. 
     And, according to a characterizing feature of a surrounding condition detection system relating to the present invention, a surrounding condition detection system for a harvester configured to harvest crops while traveling in a field, the system comprising: 
     a self-machine position detection module operable to detect a self-machine position of the harvester; 
     a detection unit including a plurality of detection modules capable of detecting conditions of surrounding of the harvester; 
     a map creation section operable to create, based on the self-machine position, a map indicative of a position of a reaped land in the field where the crops have been reaped and a position of an un-reaped land in the field where the crops have not yet been reaped; and 
     an operational mode setting section for setting operational modes of the plurality of detection modules respectively, based on the map and the self-machine position. 
     With the above-described surrounding condition detection system too, as there is no substantial difference from the above-described harvester, substantially same advantageous effect as the harvester can be achieved. 
     Further, preferably, the operational mode setting section is configured to stop a detection function of a particular detection module among the plurality of detection modules, based on the map and the self-machine position, the particular detection module being assigned for detection of the conditions of the un-reaped land. 
     With the above-described arrangement, an erroneous detection can be prevented by disabling a detection module which may detect the crops. 
     Further, preferably, the operational mode setting section is configured to set detection ranges of the plurality of detection modules, based on the map and the self-machine position. 
     With the above-described arrangement, it becomes possible e.g. to distribute the detection range among the respective plural of detection modules. In such case, since the loads of the detection modules can be divided, it is possible to prevent detection delay and/or an erroneous detection. 
     Further, preferably, machine body works effected by the machine body of the harvester include a straight traveling harvesting work in which the crops are harvested while the machine body is caused to travel straight, a turning harvesting work in which the crops are harvested while the machine body is caused to turn, and a turning traveling in which harvesting of the crops is suspended and the machine body is caused to turn; and 
     at the time of the turning harvesting work and at the time of the turning traveling, the operational mode setting section sets higher detection sensitivity for the lateral sides of the machine body than those for the front side and the rear side with respect to an advancing direction of the machine body. 
     With the above-described arrangement, during turning of the machine body, fucus of object detection can be given to the lateral side. Therefore, it is possible to prevent erroneous entrapment of an object present on the inner side of the turning at the time of turning of the machine body as well as accidental contact with an object present at an outer terminal end of foregoing turn. 
     Further, preferably, 
     at the time of traveling in the un-reaped land in the field, the operational mode setting section sets higher sensitivity for the reaped land located laterally of the machine body than for the reaped land located rearwardly of the machine body; and 
     at the time of traveling in the reaped land in the field, the operational mode setting section sets higher sensitivity for the reaped land located forwardly of the machine body than for the reaped land located laterally of the machine body. 
     With the above-described arrangement, detection of an object present in the forwardly located reaped land within the field is made easy, thus effectively preventing erroneous detection due to detection of the un-reaped land. 
     And, according to a characterizing feature of a surrounding condition detection program relating to the present invention, a surrounding condition detection program for a harvester configured to harvest crops while traveling in a field, the program causing a computer to execute: 
     a self-machine position detection function causing a self-machine position detection module to detect a self-machine position of the harvester; 
     a detection function causing a detection unit including a plurality of detection modules to detect conditions of surrounding of the harvester; 
     a map creation function creating, based on the self-machine position, a map indicative of a position of a reaped land in the field where the crops have been reaped and a position of an un-reaped land in the field where the crops have not yet been reaped; and 
     an operational mode setting function setting operational modes of the plurality of detection modules respectively, based on the map and the self-machine position. 
     By installing such surrounding condition detection program in a computer and causing the computer to execute the program, it is possible to detect conditions of surrounding of a harvester configured to harvest crops while traveling in a field. 
     Further, preferably, the operational mode setting function is configured to stop a detection function of a particular detection module among the plurality of detection modules, based on the map and the self-machine position, the particular detection module being assigned for detection of the conditions of the un-reaped land. 
     With the above-described arrangement, an erroneous detection can be prevented by disabling a detection module which may detect the crops. 
     Further, preferably, the operational mode setting function is configured to set detection ranges of the plurality of detection modules, based on the map and the self-machine position. 
     With the above-described arrangement, it becomes possible e.g. to distribute the detection range among the respective plural of detection modules. In such case, since the loads of the detection modules can be divided, it is possible to prevent detection delay and/or an erroneous detection. 
     Further, preferably, machine body works effected by the machine body of the harvester include a straight traveling harvesting work in which the crops are harvested while the machine body is caused to travel straight, a turning harvesting work in which the crops are harvested while the machine body is caused to turn, and a turning traveling in which harvesting of the crops is suspended and the machine body is caused to turn; and 
     at the time of the turning harvesting work and at the time of the turning traveling, the operational mode setting function sets higher detection sensitivity for the lateral sides of the machine body than those for the front side and the rear side with respect to an advancing direction of the machine body. 
     With the above-described arrangement, during turning of the machine body, fucus of object detection can be given to the lateral side. Therefore, it is possible to prevent erroneous entrapment of an object present on the inner side of the turning at the time of turning of the machine body as well as accidental contact with an object present at an outer terminal end of foregoing turn. 
     Further, preferably, 
     at the time of traveling in the un-reaped land in the field, the operational mode setting function sets higher sensitivity for the reaped land located laterally of the machine body than for the reaped land located rearwardly of the machine body; and 
     at the time of traveling in the reaped land in the field, the operational mode setting function sets higher sensitivity for the reaped land located forwardly of the machine body than for the reaped land located laterally of the machine body. 
     With the above-described arrangement, detection of an object present in the forwardly located reaped land within the field is made easy, thus effectively preventing erroneous detection due to detection of the un-reaped land. 
     And, according to a characterizing feature of a recording medium relating to the present invention, a recording medium recording therein a surrounding condition detection program for a harvester configured to harvest crops while traveling in a field, the program causing a computer to execute: 
     a self-machine position detection function causing a self-machine position detection module to detect a self-machine position of the harvester; 
     a detection function causing a detection unit including a plurality of detection modules to detect conditions of surrounding of the harvester; 
     a map creation function creating, based on the self-machine position, a map indicative of a position of a reaped land in the field where the crops have been reaped and a position of an un-reaped land in the field where the crops have not yet been reaped; and 
     an operational mode setting function setting operational modes of the plurality of detection modules respectively, based on the map and the self-machine position. 
     By installing a surrounding condition detection program in a computer via the above-described recording medium and causing the computer to execute the program, it is possible to cause the computer to detect the conditions of surrounding of a harvester which harvests crops while traveling in a field. 
     Further, preferably, the operational mode setting function is configured to stop a detection function of a particular detection module among the plurality of detection modules, based on the map and the self-machine position, the particular detection module being assigned for detection of the conditions of the un-reaped land. 
     With the above-described arrangement, an erroneous detection can be prevented by disabling a detection module which may detect the crops. 
     Further, preferably, the operational mode setting function is configured to set detection ranges of the plurality of detection modules, based on the map and the self-machine position. 
     With the above-described arrangement, it becomes possible e.g. to distribute the detection range among the respective plural of detection modules. In such case, since the loads of the detection modules can be divided, it is possible to prevent detection delay and/or an erroneous detection. 
     Further, preferably, machine body works effected by the machine body of the harvester include a straight traveling harvesting work in which the crops are harvested while the machine body is caused to travel straight, a turning harvesting work in which the crops are harvested while the machine body is caused to turn, and a turning traveling in which harvesting of the crops is suspended and the machine body is caused to turn; and 
     at the time of the turning harvesting work and at the time of the turning traveling, the operational mode setting function sets higher detection sensitivity for the lateral sides of the machine body than those for the front side and the rear side with respect to an advancing direction of the machine body. 
     With the above-described arrangement, during turning of the machine body, fucus of object detection can be given to the lateral side. Therefore, it is possible to prevent erroneous entrapment of an object present on the inner side of the turning at the time of turning of the machine body as well as accidental contact with an object present at an outer terminal end of foregoing turn. 
     Further, preferably, 
     at the time of traveling in the un-reaped land in the field, the operational mode setting function sets higher sensitivity for the reaped land located laterally of the machine body than for the reaped land located rearwardly of the machine body; and 
     at the time of traveling in the reaped land in the field, the operational mode setting function sets higher sensitivity for the reaped land located forwardly of the machine body than for the reaped land located laterally of the machine body. 
     With the above-described arrangement, detection of an object present in the forwardly located reaped land within the field is made easy, thus effectively preventing erroneous detection due to detection of the un-reaped land. 
     And, according to a characterizing feature of a surrounding condition detection method relating to the present invention, a surrounding condition detection method for a harvester configured to harvest crops while traveling in a field, the method comprising: 
     a self-machine position detection step causing a self-machine position detection module to detect a self-machine position of the harvester; 
     a detection step causing a detection unit including a plurality of detection modules to detect conditions of surrounding of the harvester; 
     a map creation step creating, based on the self-machine position, a map indicative of a position of a reaped land in the field where the crops have been reaped and a position of an un-reaped land in the field where the crops have not yet been reaped; and 
     an operational mode setting step setting operational modes of the plurality of detection modules respectively, based on the map and the self-machine position. 
     With the above-described surrounding condition detection method too, as there is no substantial difference from the above-described harvester, substantially same advantageous effect as the harvester can be achieved. 
     Further, preferably, the operational mode setting step is configured to stop a detection function of a particular detection module among the plurality of detection modules, based on the map and the self-machine position, the particular detection module being assigned for detection of the conditions of the un-reaped land. 
     With the above-described arrangement, an erroneous detection can be prevented by disabling a detection module which may detect the crops. 
     Further, preferably, the operational mode setting step is configured to set detection ranges of the plurality of detection modules, based on the map and the self-machine position. 
     With the above-described arrangement, it becomes possible e.g. to distribute the detection range among the respective plural of detection modules. In such case, since the loads of the detection modules can be divided, it is possible to prevent detection delay and/or an erroneous detection. 
     Further, preferably, machine body works effected by the machine body of the harvester include a straight traveling harvesting work in which the crops are harvested while the machine body is caused to travel straight, a turning harvesting work in which the crops are harvested while the machine body is caused to turn, and a turning traveling in which harvesting of the crops is suspended and the machine body is caused to turn; and 
     at the time of the turning harvesting work and at the time of the turning traveling, the operational mode setting step sets higher detection sensitivity for the lateral sides of the machine body than those for the front side and the rear side with respect to an advancing direction of the machine body. 
     With the above-described arrangement, during turning of the machine body, fucus of object detection can be given to the lateral side. Therefore, it is possible to prevent erroneous entrapment of an object present on the inner side of the turning at the time of turning of the machine body as well as accidental contact with an object present at an outer terminal end of foregoing turn. 
     Further, preferably, 
     at the time of traveling in the un-reaped land in the field, the operational mode setting step sets higher sensitivity for the reaped land located laterally of the machine body than for the reaped land located rearwardly of the machine body; and 
     at the time of traveling in the reaped land in the field, the operational mode setting step sets higher sensitivity for the reaped land located forwardly of the machine body than for the reaped land located laterally of the machine body. 
     With the above-described arrangement, detection of an object present in the forwardly located reaped land within the field is made easy, thus effectively preventing erroneous detection due to detection of the un-reaped land. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a side view of a combine, 
         FIG. 2  is a view showing generally an automated traveling of the combine, 
         FIG. 3  is a view showing a traveling route in the automated traveling, 
         FIG. 4  is a block diagram showing configuration of the combine, 
         FIG. 5  is a view showing an example setting of an operational mode, 
         FIG. 6  is a view showing an example setting of the operational mode, and 
         FIG. 7  is a view showing an example setting of the operational mode. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     A harvester relating to the present invention is configured to detect appropriately conditions of a surrounding (surrounding condition(s)) in the course of harvesting crops while traveling in a field. Next, a harvester  10  of this embodiment will be explained. Incidentally, in the following, a combine  10  will be explained as an example of such harvester  10 . 
       FIG. 1  is a side view of the combine  10  of this embodiment. In the following, the combine  10  of this embodiment will be explained with citing a so-called standard type combine as an example thereof. Needless to say, however, the combine  10  may be a self-threshing type combine also. 
     Here, for the sake of facilitating understanding, in the instant embodiment, unless explicitly indicated otherwise, the term “front” (the direction of arrow F shown in  FIG. 1 ) means the front or forward side with respect to the machine body front/rear direction (traveling direction), and the term “rear” (the direction of arrow B shown in  FIG. 1 ) means the rear or reverse side with respect to the machine body front/rear direction (traveling direction). Further, the left/right direction or the horizontal direction means the machine body transverse direction (machine body width direction) orthogonal to the machine body front/rear direction. Moreover, the term “upper” (the direction of arrow U shown in  FIG. 1 ) and the term “lower” (the direction of arrow D shown in  FIG. 1 ) represent the positional relations with respect to the perpendicular direction (vertical direction) of the machine body, indicative of relations with respect to the ground height or clearance. 
     As shown in  FIG. 1 , the combine  10  includes a traveling vehicle body  11 , a crawler type traveling device  12 , a driving section  13 , a threshing device  14 , a grain tank  15 , a harvesting section H, a conveyer device  16 , a grain discharging device  17  and a self-machine position detection module  18 . 
     The traveling device  12  is provided under the traveling vehicle body  11  (an example of “machine body”, to be referred to simply as a vehicle body  11  hereinafter). The combine  10  is configured to be capable of self-propelling by means of the traveling device  12 . The driving section  13 , the threshing device  14  and the grain tank  15  are provided upwardly of the traveling device  12  and together constitute an upper part of the vehicle body  11 . In the driving section  13 , a driver driving the combine  10  and a monitoring person monitoring a work by the combine  10  can ride. Normally, a driver will act also as a monitoring person. Incidentally, in case the driver and the monitoring person are different persons, the monitoring person may monitor a work of the combine  10  from outside the machine body of the combine  10 . 
     The grain discharging device  17  is coupled to a rear lower portion of the grain tank  15 . Further, the self-machine position detection module  18  is attached to a front upper portion of the driving section  13  and detects the self-machine (self-vehicle) position. The self-machine position detection module  18  may employ a global positioning module configured as a GNSS module. This self-machine position detection module  18  includes a satellite antenna for receiving GPS signals and/or GNSS signals (to be collectively referred to as “GPS signals” in this embodiment) from an artificial satellite GS (see  FIG. 2 ). Incidentally, the self-machine position detection module  18  may include an inertial navigation module incorporating a gyro acceleration sensor and a magnetic azimuth sensor for supplementing satellite navigation. Needless to say, the inertial navigation module may alternatively be provided at a site separate from the self-machine position detection module  18 . In operation, the self-machine position detection module  18  detects a self-machine (self-vehicle) position which is a position of the combine  10 , based on the above-described GPS signals and the detection result of the inertial navigation module. Such self-machine position detected by the self-machine position detection module  18  will be used for the automated traveling (autonomous traveling) of the combine  10  and the respective functional sections to be described later as “self-machine position information”. 
     The harvesting section H is provided at a front portion of the combine  10 . The conveyer device  16  is provided rearwardly of the harvesting section H. The harvesting section H includes a cutting mechanism  19  and a reel  20 . The cutting mechanism  19  cuts or reaps planted crop stalks in a field. The reel  20 , as being rotatably driven, rakes in the planted crop stalks as harvesting targets or objects. With this arrangement, the harvesting section H is capable of harvesting crops (a kind of agricultural produce) in a field. The combine  10  can carry out a work traveling in which the combine  10  travels by the traveling device  12  while harvesting the crops in the field by the harvesting section H. 
     Reaped crop stalks reaped by the cutting mechanism  19  will be conveyed by the conveying device  16  to the threshing device  14 . In this threshing device  14 , the reaped cop stalks will be subjected to a threshing treatment. Grains obtained by the threshing treatment will then be reserved in the grain tank  15 . The grains reserved in the grain tank  15  will be discharged, when needed, to the outside of the machine by the grain discharging device  17 . Incidentally, in this combine  10 , between the vehicle body  11  and the traveling device  12 , there is provided a hydraulic inclination mechanism  110 , which allows inclination of the vehicle body  11  in the left/right direction and the front/rear direction relative to the traveling surface (field surface). 
       FIG. 2  is a view schematically showing the automated traveling of the combine  10 . As shown in  FIG. 2 , the combine  10  effects an automated traveling (autonomous traveling) along a traveling route set in the field. For this automated traveling, the above-described self-machine position information obtained by the self-machine position detection module  18  is utilized. 
     The combine  10  of this embodiment carries out a harvesting work in a field in accordance with the following procedure. 
     Firstly, a driving/monitoring person will manually operate the combine  10  and carry out a harvesting work while effecting a circumference reaping work traveling along a borderline of a field in an outer circumferential portion inside the field as shown in  FIG. 2 . An area formed as a reaping-completed (reaped) area (“worked area”) by the circumference reaping traveling will be set as an outer circumference area SA. And, the inner area left as an un-reaped land (“unworked area”) on the inner side of the outer circumference area SA will be set as a work subject area CA. 
     In the above, in order to secure a certain amount of width for the outer circumference area SA, the driver will cause the combine  10  to travel for 2 to 3 laps. With completion of one lap traveling of the combine  10 , the width of the outer circumference area SA is increased by the working width of the combine  10 . After completion of first two or three laps of traveling, the width of the outer circumference area SA will become about 2 to 3 times the working width of the combine  10 . Incidentally, the circumference reaping work traveling is not limited to such 2 to 3 laps of traveling, but may be more (equal to or more than 4 laps) or just one lap as well. 
     The outer circumference area SA is used as a space allowing the combine  10  to make a turn during harvesting traveling in the work subject area CA. Further, the outer circumference area SA is used also as a space allowing certain movements, such as a movement to a location for discharging grains or a movement to a location of fuel replenishment, after temporary completion of harvesting traveling. 
       FIG. 2  further shows a transporter vehicle CV which can collect and transport the grains harvested by the combine  10 . At the time of grain discharging, the combine  10  will move to the vicinity of the transporter vehicle CV and then discharge the grains to the transporter vehicle CV by the grain discharging device  17 . 
     Upon setting of the outer circumference area SA and the work subject area CA by the above-described traveling by the manual traveling, traveling routes in the work subject area CA will be calculated, as shown in  FIG. 3 . The calculated traveling routes will be set one after another based on the pattern of the work traveling and the combine  10  will be controlled for its automated traveling so that it may travel along the set traveling routes. 
       FIG. 4  is a block diagram showing configuration of a detection system (an example of a “surrounding condition detection system”)  1  for detecting conditions of surrounding of the combine  10 . As shown in  FIG. 4 , the detection system  1  includes, in addition to the self-machine position detection module  18  described above, respective functional sections consisting of a map creation section  30 , a machine body work information acquiring section  31 , an operational mode setting section  32  and a detection unit  40 . 
     The self-machine position detection module  18 , as described hereinbefore, detects the self-machine position of the combine  10 . The self-machine position detected by the self-machine position detection module  18  is transmitted or communicated as “self-machine position information”, to the map creation section  30  and the operational mode setting section  32  which will be described later. 
     The map creation section  30  creates, based on the self-machine position, a map indicative of a position of a reaped land of the field in which crop have been reaped and a position of an un-reaped land of the field in which crops have not yet been reaped. The self-machine position is transmitted as the self-machine position information from the self-machine position detection module  18 . In the above, the reaped land of the field in which crops have been reaped means an area within the field where crops have been reaped, and this area corresponds to the outer circumference area SA in the example shown in  FIG. 2 . The un-reaped land means an area within the field where crops have not yet been reaped, and this area corresponds to the work subject area CA in the example shown in  FIG. 2 . 
     As described above, when the driver/operator has caused the combine  10  to travel by a manual operation, the self-machine position detection module  18  acquires the self-machine positions and the map creation section  30  sets an outer shape or contour of the field based on the acquired self-machine positions. This outer shape becomes the basis for the creation of the map of the field. Further, the self-machine position detection module  18  will detect the self-machine positions also while the combine  10  is harvesting the crops at the time of the manual operation. The self-machine positions acquired this time will be set for the reaped land on the map. Upon setting of the outer circumference area SA, the combine  10  will effect automated traveling in the work subject area CA. In the course of this, the map will be created with switching (updating) the area where crops have been reaped from the un-reaped land to the reaped land. It is possible to arrange such that the map created by the map creation section  30  is stored within this map creation section  30  or may be stored in a storage section provided separately. 
     The machine body work information acquiring section  31  acquires machine body work information indicative of machine works to be carried out by the machine body  11  (an example of the “machine body” or “vehicle body”). Here, the term “machine body work information means information indicative of whether the combine  10  is currently engaged in a harvesting work or not and information indicative of mode of traveling of the combine  10 . This latter information indicative of a traveling mode of the combine  10  means information indicative of whether the traveling mode is straight traveling or turning traveling. In the instant embodiment, the machine body works include a straight traveling harvesting work in which crops are harvested while the machine body  11  is caused to travel straight, a turning harvesting work in which crops are harvested while the machine body  11  is caused to turn, and a turning traveling in which the machine body  11  is turned while harvesting of crops is suspended. 
     The machine body work information acquiring section  31  acquires machine body work information indicative of such machine works by calculating them from operational states of the respective functional sections of the combine  10 . The machine body work information acquired by the machine body work information acquiring section  31  is transmitted to the operational mode setting section  32  which will be described later. 
     The detection unit  40  is provided in the machine body  11  and constituted of a plurality of detection modules capable of detecting conditions of the surrounding of the machine body  11 . In the instant embodiment, the detection unit  40  is constituted of four ultrasonic sensors. Specifically, the detection unit  40  includes a front side detection module  41  disposed at a front center portion of the machine body  11  and capable of detecting a condition of the front side of the machine body  11 , a rear side detection module  42  disposed at a rear center portion of the machine body  11  and capable of detecting a condition of the rear side of the machine body  11 , a left side detection module  43  disposed at a left side portion of the machine body  11  and capable of detecting a condition of the left side of the machine body  11  and a right side detection module  44  disposed at a right side portion of the machine body  11  and capable of detecting a condition of the right side of the machine body  11 . 
     The operational mode setting section  32  sets operational modes respectively of the plurality of detection modules  41 - 44 , based on the map and the self-machine position. The map is created by the map creation section  30 . The self-machine position is detected by the self-machine position detection module  18  and transmitted as self-machine position information. 
     In the above, the operational modes respectively of the plurality of detection modules  41 - 44  indicate operational states of the plurality of detection modules  41 - 44 , respectively. The operational states correspond to a detection state for effecting detection, a stopped state not effecting any detection, a wide range detection state for effecting detection of a detection range wider than a predetermined range, a narrow range detection state for effecting detection of a detection range narrower equal to or narrower than the predetermined range, a high sensitivity state in which the detection sensitivity is set higher than a predetermined value, a low sensitivity state in which the detection sensitivity is set equal to or lower than the predetermined value, and so on. In the instant embodiment, the operational mode setting section  32  is able to set such operational modes for the respective detection modules  41 - 44 . 
     The operational mode setting section  32  stops the detection function of a particular detection module among the plurality of detection modules  41 - 44 , which particular detection module is directed to detection of an un-reaped land of interest, based on the map and the self-machine position. As described above, in this embodiment, the front side detection module  41  can detect a condition of the front side of the machine body  11 , and the rear side detection module  42  can detect a condition of the rear side of the machine body  11 . Further, the left side detection module  43  can detect a condition of the left side of the machine body  11 , and the right side detection module  44  can detect a condition of the right side of the machine body  11 . 
     When a reaping work of the outer circumference area SA of the field has been completed and a reaping work for the work subject area CA located on the inner side thereof is now to be carried out, an un-reaped land and a reaped land may be present in a mixed state in the circumference of the combine  10 . Specifically, as shown in  FIG. 5  for instance, it may be that the front side and one of the left and right opposed sides (the left side in the example shown in  FIG. 5 ) of the combine  10  are un-reaped lands (un-worked lands) whereas the rear side and the other one of the left and right opposed sides (the right side in the example shown in  FIG. 5 ) are reaped (worked) lands. In such case, the operational mode setting section  32  stops (disables) the detection functions of the front side detection module  41  and the left aide detection module  43  which are directed to condition detection of un-reaped (un-worked) lands and allows (enables) the detection functions of the rear side detection module  42  and the right side detection module  44  which are directed to condition detection of reaped (worked) lands. Here, disabling a detection function means not using detection of the detection module. As a specific method to do this, for instance, an arrangement may be provided such that the detection function of the detection module of interest is not to be outputted or that the detection result of the detection module is not to be utilized by the respective functional section. 
     Further, it is also possible to configure the operational mode setting section  32  to set the detection sensitivity for a reaped land present on the lateral side of the machine body  11  higher than that for a reaped land present on the rear side of the machine body  11 , during traveling in an un-reaped land in the field. When the combine  10  is traveling in a field while carrying out a reaping work therein, a reaped land will be formed on the rear side of the combine  10 . In this, the combine  10  travels away from the rear area. On the other hand, on the lateral side of the combine  10 , in many cases, a reaped land where reaping work has been completed will be formed. Then, advantageously, the operational mode setting section  32  sets the detection sensitivity of the detection modules disposed on the lateral sides (the left side detection module  43  and the right side detection module  44 ) higher than the detection sensitivity of the rear side detection module  42 . 
     Further, it is also possible to configure the operational mode setting section  32  to set the detection sensitivity for a reaped land present on the front side of the machine body  11  higher than the detection sensitivity for a reaped land present on the lateral side of the machine body  11 , during traveling in a reaped land in a field. One conceivable case of such traveling of the combine  10  in a reaped land is a case when the combine  10  is traveling toward the transporter vehicle CV at the time of discharging of grains onto this transporter vehicle CV. Then, in such case, the traveling speed may be higher than during a harvesting work. Then, advantageously, the operational mode setting section  32  will set the detection sensitivity of the front side detection module  41  higher than the detection sensitivity of the lateral side detection module (the left side detection module  43  and the right side detection module  44 ). 
     Moreover, the operational mode setting section  32  may alternatively be configured to set the detection ranges of the plurality of detection modules  41 - 44 , based on the map and the self-machine position. For instance, in the exemplary case shown in  FIG. 5 , in an area located on the left front side of the combine  10 , this can be detected by both the front side detection module  41  and the right side detection module  44 . However, since a reaped land is present to extend on the right side of the combine  10 , if the detection range of the right side detection module  44  is wide, the load (calculation load relating to the detection) will be significant. Then, advantageously, as shown in  FIG. 6 , the operational mode setting section  32  may set the respective detection ranges such that the area located on the right front side of the combine  10  may be covered by the front side detection module  41  and the right side detection module  44  in distribution whereas the area located on the right rear side of the combine  10  may be covered by the rear side detection module  42  and the right side detection module  44  in distribution. With this arrangement, it becomes possible to prevent detection delay and detection error. 
     Moreover, the operational mode setting section  32  may be configured to set the detection range of the detection module(s) directed to detection of a condition of a reaped land, in accordance with e.g. a traveling distance (non-working traveling distance) after detection of an object by the detection module until subsequent stop of the combine  10 . 
     Further advantageously, the operational mode setting section  32  may be configured to set the detection sensitivity for the lateral sides of the machine body  11  higher than those for the front side and the rear side in the advancing direction of the machine body  11 , during the turning harvesting work and the turning traveling. The turning harvesting work means a work in which crops are harvested while the machine body  11  is caused to turn. The turning traveling means traveling in which the machine body  11  is caused to turn while harvesting of crops is suspended. During such turning harvesting work and the turning traveling (for instance, the situation illustrated in  FIG. 7 ), in order to prevent erroneous entrapment of an object present on the inner side of the turning of the combine  10  as well as accidental contact with an object present at an outer terminal end of foregoing turn in particular, advantageously, the detection sensitivities of the left side detection module  43  and the right side detection module  44  may be set higher than the detection sensitivities of the front side detection module  41  and the rear side detection module  42 . 
     Other Embodiments 
     In the foregoing embodiment, it was explained that based on the self-machine position and the map, the operational mode setting section  32  stops the detection function of the detection module directed to detection of a condition of an un-reaped (un-worked) land, selectively among the plurality of detection modules. However, at the time of forward traveling reaping, the detection may be switched to the front side detection module  41 ; at the time of reverse traveling, the detection may be switched to the rear detection module  42 ; at the time of left turning, the detection may be switched to the left side detection module  43 ; and at the time of right turning, the detection may be switched to the right side detection module  44 , respectively. Further alternatively, the four detection modules  41 - 44  may be switched over among them for detection of interest, cyclically, to carry out conditions monitoring (obstacle detection). 
     In the foregoing embodiment, it was explained that the detection modules were constituted with using ultrasonic sensors. However, the detection modules may be cameras. In this case, at the time of forward traveling harvesting, the detection may be switched to a front side camera; at the time of reverse traveling, the detection may be switched to a rear side camera; and at the time of turning, the detection may be switched to a turning direction side camera, respectively. With this, erroneous detection can be prevented and the calculation load for detection result can be reduced. Further alternatively, four cameras may be cyclically switched over for detection to effect surrounding monitoring (obstacle detection). Still further alternatively, a bird&#39;s eye view (a surround view) may be created with using four cameras, for facilitating the worker&#39;s viewing of the surrounding conditions. 
     Moreover, in the case of constituting the detection modules by cameras, instead of using the four cameras as described above, it is possible to employ an all-around view camera capable of capturing an image of the combine  10  for the entire circumference of the combine  10  or a so-called spherical camera (360 degree camera) capable of omnidirectional panoramic photographing in all of the upper, lower and left and right directions of the combine  10 . In case such cameras as above are employed, the above-described advantageous effect can be achieved by setting in image(s) captured by the camera(s) an area to be used and an area not to be used by the operational mode setting section  32 . 
     Furthermore, the detection modules may be laser sensors or distance (range) sensors. In either case, as the operational mode setting section  32  sets an operational mode in accordance with a work state of the combine  10 , detection suitable for a particular work state of the combine  10  will be made possible. 
     Also, it is possible to arrange such that the detection modules detect abnormality of the machine body  11  of the combine  10 . In this case, advantageously, the detection modules will be constituted of cameras to capture images of the machine body  11 . With this, detection of abnormality of the machine body  11  is made possible. Further, the detection modules may be constituted of using microphones also. In this case, by analyzing the sounds (e.g. frequency analysis, etc.) collected by the microphones, it is possible to detect abnormality in the engine or abnormality (clogging etc.) in the grain discharging device  17 , etc. Incidentally, such detection by way of sounds is possible by carrying out a machine learning in advance and then making comparison with the sound obtained by the machine learning. With this, there is no necessity of provide any special sensor separately and it is also possible to reduce the number of sensors to be employed, so that abnormality detection of the combine  10  can be provided economically. 
     In the foregoing embodiment, the explanation was made with citing the combine  10  as an example of “harvester”. However, the invention is applicable also to any other harvester than the combine  10 , such as a cone harvester, etc. 
     In the foregoing embodiment, there were explained a harvester configured to harvest crops while traveling in a field as well as a detection system configured to detect condition of the surrounding of the harvester configured to harvest crops while traveling in a field. In addition, it is also possible to configure a surrounding condition detection program causing a computer to execute the respective functional sections in the foregoing embodiment. In this case, the surrounding situation detection program may be configured to cause the computer to execute a self-machine position detection function causing a self-machine position detection module to detect a self-machine position of the harvester, a detection function causing a detection unit including a plurality of detection modules to detect conditions of surrounding of the harvester, a map creation function creating, based on the self-machine position, a map indicative of a position of a reaped land in the field where the crops have been reaped and a position of an un-reaped land in the field where the crops have not yet been reaped, and an operational mode setting function setting operational modes of the plurality of detection modules respectively, based on the map and the self-machine position. 
     Further, such surrounding condition detection program may be configured to be recorded in a recording medium. 
     Moreover, for the surrounding condition detection program and the surrounding condition detection program recorded in a recording medium, the operational mode setting function may be configured to stop a detection function of a particular detection module among the plurality of detection modules, based on the map and the self-machine position, the particular detection module being assigned for detection of the conditions of the un-reaped land. Further, the operational mode setting function may be configured to set detection ranges of the plurality of detection modules, based on the map and the self-machine position. Also, machine body works effected by the machine body of the harvester may include a straight traveling harvesting work in which the crops are harvested while the machine body is caused to travel straight, a turning harvesting work in which the crops are harvested while the machine body is caused to turn, and a turning traveling in which harvesting of the crops is suspended and the machine body is caused to turn. Further, the operational mode setting function may be configured to set higher detection sensitivity for the lateral sides of the machine body than for the front side and the rear side with respect to the advancing direction of the machine body, during the turning harvesting work and the turning traveling. Moreover, the operational mode setting function may be configured to set higher detection sensitivity for the reaped land present laterally of the machine body than for the reaped land present rearwardly of the machine body, during traveling in the un-reaped land in the field or set higher detection sensitivity for the reaped land located forwardly of the machine body than the reaped land located laterally of the machine body, during traveling in the reaped land in the field. 
     Further, the operations effected by the respective functional sections in the foregoing embodiment may be configured as a surrounding condition detection method for a harvester configured to harvest crops while traveling in a field. In this case, the surrounding condition detection method may comprise a self-machine position detection step causing a self-machine position detection module to detect a self-machine position of the harvester, a detection step causing a detection unit including a plurality of detection modules to detect conditions of surrounding of the harvester, a map creation step creating, based on the self-machine position, a map indicative of a position of a reaped land in the field where the crops have been reaped and a position of an un-reaped land in the field where the crops have not yet been reaped, and an operational mode setting step setting operational modes of the plurality of detection modules respectively, based on the map and the self-machine position. 
     In the above-described surrounding condition detection method too, the operational mode setting step may be configured to stop a detection function of a particular detection module among the plurality of detection modules, based on the map and the self-machine position, the particular detection module being assigned for detection of the conditions of the un-reaped land. Or, the operational mode setting step may be configured to set detection ranges of the plurality of detection modules, based on the map and the self-machine position. Further, the machine body works effected by the machine body of the harvester may include a straight traveling harvesting work in which the crops are harvested while the machine body is caused to travel straight, a turning harvesting work in which the crops are harvested while the machine body is caused to turn, and a turning traveling in which harvesting of the crops is suspended and the machine body is caused to turn. Further, the operational mode setting step may be configured to set higher detection sensitivity for the lateral sides of the machine body than for the front side and the rear side with respect to the advancing direction of the machine body, during the turning harvesting work and the turning traveling. Moreover, the operational mode setting step may be configured to set higher detection sensitivity for the reaped land present laterally of the machine body than for the reaped land present rearwardly of the machine body, during traveling in the un-reaped land in the field or set higher detection sensitivity for the reaped land located forwardly of the machine body than the reaped land located laterally of the machine body, during traveling in the reaped land in the field. 
     INDUSTRIAL APPLICABILITY 
     The present invention can be used for detection of condition of the surrounding of a harvester configured to harvest crops while traveling in a field. 
     DESCRIPTION OF REFERENCE SIGNS 
     
         
         
           
               1 : detection system (surrounding condition detection system) 
               10 : combine (harvester) 
               11 : vehicle body (machine body) 
               18 : self-machine position detection module 
               30 : map creation section 
               32 : operational mode setting section 
               40 : detection unit 
               41 - 44 : detection modules