Patent Publication Number: US-2021171133-A1

Title: Monitoring system, traveling machine system and monitoring method

Description:
TECHNICAL FIELD 
     The present disclosure relates to a monitoring system, a traveling machine system and a monitoring method. 
     This application is based upon and claiming the benefit of priority from Japanese Patent Application No. 2019-220319, filed in Japan on Dec. 5, 2019, the entire content of which is incorporated herein by reference. 
     BACKGROUND 
     Conventionally, there has been a traveling machine in which a rubber crawler containing a core is mounted to a machine body (for example, JP2011207317A (PTL 1). 
     CITATION LIST 
     Patent Literature 
     PTL 1: JP2011207317A 
     SUMMARY 
     In the traveling machine as described above, generally, at the time of traveling on an inclined surface, deviation (a rubber crawler is removed from an underbody of a machine body) may occur. However, conventionally, an operator who drives a traveling machine has to predict a prior warning of deviation sensuously from an attitude of the machine body, a traveling state or a sound etc., and grasping the prior warning of deviation has been difficult. 
     An object of the present disclosure is to provide a monitoring system, a traveling machine system and a monitoring method which ensures grasping of a prior warning of deviation more reliably. 
     According to the present disclosure, there is provided a monitoring system which is used for a traveling machine having a rubber crawler and a machine body, the monitoring system including: an angle sensor; a force sensor; and a processing section, wherein the rubber crawler includes a plurality of cores which are arranged along a crawler circumferential direction and is mounted to an underbody of the machine body, the angle sensor is configured to detect an inclination angle to a horizontal surface of the machine body, the force sensor is configured to detect a force applied from the rubber crawler to an idler of the underbody or a physical amount correlating with the force, and the processing section is configured to determine existence or non-existence of a prior warning of deviation based on outputs from the angle sensor and the force sensor. 
     In the traveling machine system according to the present disclosure, the above-described monitoring system and the traveling machine including the rubber crawler and the machine body are included. 
     In the monitoring method according to the present disclosure, there is provided a monitoring method which uses the above-described monitoring system, including: an angle detecting step in which the angle sensor detects an inclination angle to a horizontal surface of the machine body; a force detecting step in which the force sensor detects the force applied from the rubber crawler to the idler of the underbody or the physical amount correlating with the force; and a determining step in which the processing section determines existence or non-existence of the prior warning of deviation based on the output from the angle sensor in the angle detecting step and the output from the force sensor in the force detecting step. 
     According to the present disclosure, the monitoring system, the traveling machine system and the monitoring method which ensure grasping of the prior warning of deviation more reliably can be provided. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In the accompanying drawings: 
         FIG. 1  is a schematic drawing illustrating a monitoring system according to one embodiment of the present disclosure and a traveling machine system according to one embodiment of the present disclosure; 
         FIG. 2  is a side view illustrating an underbody apparatus of  FIG. 1  with a force sensor of  FIG. 1 ; 
         FIG. 3  is a perspective view illustrating a part of a rubber crawler of  FIG. 1  with a cross section in a width direction; 
         FIG. 4  is an explanation view for explaining a tension mechanism and the force sensor of  FIG. 2 ; 
         FIG. 5  is an explanation view illustrating an appearance of the traveling machine of  FIG. 1  seen from the rear side for explaining a state that there is a prior warning of deviation in the traveling machine of  FIG. 1 ; and 
         FIG. 6  is an explanation view illustrating an apparatus of a left underbody apparatus of  FIG. 5  seen from an inner side in a machine body right-left direction for explaining a state that there is a prior warning of deviation in the traveling machine of  FIG. 1 . 
     
    
    
     DETAILED DESCRIPTION 
     A monitoring system, a traveling machine system and a monitoring method according to the present disclosure is preferably applied to a traveling machine including a rubber crawler containing a core, and, for example, preferably applied to a construction machinery (including a mini-excavator) and agricultural machines (including a tractor and a combine). 
     Hereinafter, an embodiment of the monitoring system, the traveling machine system and the monitoring method according to the present disclosure will be explained with illustration with reference to the drawings. 
     In each drawing, common constituent elements are applied the same reference numerals. 
       FIGS. 1 to 6  are drawings for explaining a monitoring system  4  according to one embodiment of the present disclosure, a traveling machine system  5  according to one embodiment of the present disclosure and a monitoring system according to one embodiment of the present disclosure. 
     [Traveling Machine System  5 ] 
     First, a configuration of the traveling machine system  5  of this embodiment will be explained. 
     As illustrated in  FIG. 1 , the traveling machine system  5  of this embodiment includes a traveling machine  3  and the monitoring system  4  of this embodiment. The traveling machine  3  has a rubber crawler  1  and a machine body  2 . The monitoring system  4  is configured to be used for the traveling machine  3 , and more specifically, configured to monitor as to whether there is a prior warning of deviation in the traveling machine  3 . 
     (Traveling Machine  3 ) 
     Hereinafter, the traveling machine  3  will be explained. As described above, the traveling machine  3  has the rubber crawler  1  and the machine body  2 . The rubber crawler  1  is mounted to an underbody  21  of the machine body  2 . While the traveling machine  3  may be configured as a construction machinery (including a mini-excavator) and agricultural machines (including a tractor and a combine) for example, use may be arbitrary as long as it is configured to travel using a rubber crawler containing a core, and also, the configuration may be arbitrary not limited to one explained with illustration in the present specification. 
     The traveling machine  3  has an underbody apparatus  31  configured to drive on a road surface. The underbody apparatus  31  of the traveling machine  3  has the underbody  21  of the machine body  2  and the rubber crawler  1  mounted to the underbody  21 . The traveling machine  3  may include one or more underbody apparatuses  31 . In an example of  FIG. 1 , the traveling machine  3  includes two underbody apparatuses  31  (one on each of right and left sides), and thus, two units of the underbody  21  of the machine body  2  and the rubber crawler  1  (one on each of right and left sides). 
     &lt;Rubber Crawler  1 &gt; 
     Here, the rubber crawler  1  will be explained.  FIG. 3  illustrates the rubber crawler  1  alone. The rubber crawler  1  is configured as a rubber crawler containing a core. As illustrated in  FIG. 3 , the rubber crawler  1  includes a crawler body  12 , a plurality of lugs  14 , one or more cord layers  15 , a plurality of cores  13  and a plurality of holes  16 . 
     The crawler body  12  is configured as endless (annular). The crawler body  12  is configured as a belt. The crawler body  12  is constituted by rubber. 
     Additionally, in the present specification, “a crawler inner circumferential side,” “a crawler outer circumferential side,” “a crawler circumferential direction (CD),” “a crawler width direction (WD)” and “a crawler thickness direction (TD)” respectively refer to an inner circumferential side, an outer circumferential side, a circumferential direction, a width direction and a thickness direction in the crawler body  12 , and these are directions fixed to the crawler body  12 . In each drawing, for convenience, the crawler circumferential direction (CD) is illustrated by an arrow CD, the crawler width direction (WD) is illustrated by an arrow WD and the crawler thickness direction (TD) is illustrated by an arrow TD. 
     Each of the plurality of lugs  14  included by the rubber crawler  1  protrudes from an outer circumferential surface  122  of the crawler body  12  to the crawler outer circumferential side. The shape or arrangement of the lugs  14  are not limited to one illustrated in each drawing, and may be arbitrary. End surfaces at the crawler outer circumferential side of the lug  14  are configured to contact the road surface. The lugs  14  are constituted by rubber. 
     The cord layer  15  includes a plurality of cords  15   a  arranged along the crawler width direction WD. Each of these cords  15   a  extends over the entire circumference along the crawler circumferential direction CD. The cord layer  15  is embedded in an inner portion of the crawler body  12 . As in an example illustrated in  FIG. 3 , the rubber crawler  1  may include the cord layer  15  only at one portion in the crawler thickness direction TD (in this case, the number of layers of the cord layer  15  is one layer), or may include the cord layer  15  at plural portions in the crawler thickness direction TD (in this case, the number of layers of the cord layer  15  is plural layers). 
     The cord layer  15  has a function of inhibiting the crawler body  12  from extending in the crawler circumferential direction CD. 
     For example, the cord  15   a  is constituted by metal (such as steel). 
     The plurality of cores  13  included by the rubber crawler  1  are arranged along the crawler circumferential direction CD. These cores  13  are arranged with constant pitch intervals along the crawler circumferential direction CD. Here, “pitch interval” refers to a distance in the crawler circumferential direction CD between centers of a pair of cores  13  in the crawler circumferential direction CD, the pair of cores  13  being adjacent to each other in the crawler circumferential direction CD. 
     Each core  13  is constituted by metal (for example, iron or steel). 
     Each core  13  is partially embedded in the inner portion of the crawler body  12 . Each core  13  is arranged at the crawler inner circumferential side than the cord layer  15 . 
     Each core  13  includes a base portion  132  and a pair of projections  131 . The base portion  132  is configured as plate-like for example, and extends in the crawler width direction WD. In the example in  FIG. 3 , the base portion  132  is substantially rectangular as illustrated by a dashed line in  FIG. 3  in which the crawler width direction is a longitudinal direction in a planar view of the base portion  132 . Additionally, the shape of the base portion  132  in the planar view may be another shape. Each of the pair of projections  131  extends from the base portion  132  toward the crawler inner circumferential side. Each projection  131  partially or entirely projects toward the crawler inner circumferential side than an inner circumferential surface  121  of the crawler body  12 . The pair of projections  131  are separated from each other in the crawler width direction WD. The pair of projections  131  are respectively positioned at both sides about the center of the base portion  132  in the crawler width direction WD. Of the base portion  132 , a central portion  132   c  connects the pair of projections  131 . Of the base portion  132 , a pair of wing portions  132   w  are constituted by outer portions than the pair of projections  131  in the crawler width direction WD. The base portion  132  is embedded in the inner portion of the crawler body  12 . 
     Of the projections  131  of the core  13 , a portion projecting to the crawler inner circumferential side than the inner circumferential surface  121  of the crawler body  12  may be partially or entirely covered by a membranous rubber (a coating rubber which is not illustrated), or may be exposed to the outside, not covered by the membranous rubber (the coating rubber which is not illustrated). 
     Also, the base portion  132  of the core  13  may be entirely covered by the crawler body  12 , or a portion thereof (for example, the central portion  132   c ) may be exposed to the outside, not covered by the crawler body  12 . 
     The central portion  132   c  of the base portion  132  of the core  13  has a function of transmitting a driving force from a sprocket  212  to the rubber crawler  1  by engaging with a pin  212   p  of the sprocket  212  of the underbody  21  of the machine body  2  not through rubber or through rubber. The pair of projections  131  of the core  13  have a function as a guide which, not through rubber or through rubber, controls movement of each rotating body (the sprocket  212 , an idler  213 , a track roller  214 ) of the underbody  21  of the machine body  2  in the crawler width direction WD, thereby inhibiting deviation. 
     Additionally, in the present specification, “a top surface ( 131   a )” of the projection ( 131 ) of the core  13  refers to an end surface at the crawler inner circumferential side of the projection ( 131 ). “A root” of the projection ( 131 ) of the core  13  refers to a virtual end surface at the crawler outer circumferential side of the projection ( 131 ), corresponding to a cross section of the projection ( 131 ) at a position where the projection ( 131 ) and the base portion ( 132 ) are connected. “A side surface” of the projection ( 131 ) of the core  13  refers to, of surfaces of the projection ( 131 ), ones other than the top surface ( 131   a ) and the root. 
     Of the inner circumferential surface  121  of the crawler body  12 , portions which are adjacent to the pair of projections  131  of the core  13  at both outer sides in the crawler width direction WD constitute track roller passing surfaces  121   a . Each track roller passing surface  121   a  is configured such that the track roller  214  rolls thereon. 
     As in the example in  FIG. 3 , each track roller passing surface  121   a  is preferably configured as flat without unevenness over the entire circumference at least partially in the crawler width direction WD. 
     Each of the plurality of holes  16  included by the rubber crawler  1  is formed between the central portions  132   c  of the projections  131  in the crawler circumferential direction CD. Each hole  16  is concave toward the crawler outer circumferential side. Each hole  16  is configured such that the pin  212   p  of the sprocket  212  can be inserted. 
     Each hole  16  may be configured as a bottomed hole (a concave) not passing through the crawler body  12  in the crawler thickness direction TD, or may be configured as a bottomless hole (a through-hole) passing through the crawler body  12  in the crawler thickness direction TD. 
     Each hole  16  is concave to the crawler outer circumferential side than an end surface at the crawler inner circumferential side of the central portion  132   c  of the projection  131 . Due to this, the pin  212   p  of the sprocket  212  can engage with the central portion  132   c  of the core  13  in a state that it is inserted in the hole  16 , and thus transmit the driving force to the rubber crawler  1 . 
     In the example of  FIG. 3 , the hole  16  is formed on the crawler body  12  and is concave to the crawler outer circumferential side than the inner circumferential surface  121  of the crawler body  12 . Additionally, the hole  16  is not necessarily concave to the crawler outer circumferential side than the inner circumferential surface  121  of the crawler body  12  as long as the hole  16  is concave to the crawler outer circumferential side than the end surface at the crawler inner circumferential side of the central portion  132   c  of the projection  131 , and may be arranged only at the crawler inner circumferential side than the inner circumferential surface  121  of the crawler body  12 . 
     &lt;Machine Body  2 &gt; 
     Next, the machine body  2  will be explained. The machine body  2  is a portion other than the rubber crawler  1  of the traveling machine  3 . 
     Additionally, in the present specification, “a machine body up-down direction (UDD),” “a machine body front-rear direction (FRD)” and “the machine body right-left direction (LRD)” respectively refer to the up-down direction, the front-rear direction and the right-left direction seen from an operator who rides the machine body  2 , and these are directions fixed to the machine body  2 . In each drawing, for convenience, the machine body up-down direction (UDD) is illustrated by an arrow UDD, the machine body front-rear direction (FRD) is illustrated by an arrow FRD and the machine body right-left direction (LRD) is illustrated by an arrow LRD. 
     As illustrated in  FIG. 1 , the machine body  2  includes a drive section  24 , an operator room  22  and one or more (two in the example of  FIG. 1 ) underbodies  21 . 
     The drive section  24  is configured to drive and control the sprocket  212  of each underbody  21  of the machine body  2 . In this example, the drive section  24  is configured as a hydraulic type, and includes, for example, an engine, a hydraulic pump and a control valve. 
     Additionally, the drive section  24  may be configured to drive the sprocket  212  by types other than a hydraulic type. 
     Also, the drive section  24  may be configured to drive portions other than the sprocket  212  (an attachment etc.) in the machine body  2 . 
     The operator room  22  is configured such that the operator enters an inner portion of the operator room  22  to drive the traveling machine  3 . 
     The rubber crawler  1  is mounted around the underbody  21 . The underbody  21  of the machine body  2  and the rubber crawler  1  mounted to the underbody  21  constitute the underbody apparatus  31  of the traveling machine  3 . The underbody  21  of the machine body  2  is configured such that the underbody apparatus  31  of the traveling machine  3  travels on the road surface by transmitting the driving force to the rubber crawler  1  mounted around the underbody  21 . 
       FIG. 2  illustrates the underbody apparatus  31  of the traveling machine  3 . As illustrated in  FIG. 2 , the underbody  21  of the machine body  2  includes a plurality of rotating bodies  212  to  214 , a frame  211  and a tension mechanism  215 . The underbody  21  includes the sprocket  212 , one or more idlers  213  and one or more track rollers  214  as the rotating bodies  212  to  214 . 
     The sprocket  212  is a drive wheel. The sprocket  212  is configured to rotate in accordance with control by the drive section  24  ( FIG. 1 ). The sprocket  212  is attached to a shaft  212   s . The sprocket  212  has a plurality of pins  212   p  at its outer circumferential side. Each pin  212   p  is configured to enter the hole  16  of the rubber crawler  1  to engage with the central portion  132   c  of the core  13 , thereby transmitting the driving force to the rubber crawler  1 . 
     Additionally, the sprocket  212  is not limited to one illustrated, and may have an arbitrary configuration. 
     In an example of  FIG. 2 , the sprocket  212  is arranged at an upper side than the idler  213  and the track roller  214 . 
     The idler  213  is an idling wheel. The idler  213  has a function of maintain tension of the rubber crawler  1 . In the example of  FIG. 2 , one underbody  21  has two idlers  213 . These two idlers  213  are arranged to face to each other in the machine body front-rear direction FRD. Of these two idlers  213 , a front-side idler  213   f  is a front idler, and a rear-side idler  213   r  is a rear idler. Each idler  213  is supported by a support shaft  213   s  and configured to rotate due to friction with the rubber crawler  1 . The support shaft  213   s  is attached to the frame  211 . 
     As clear from  FIG. 2 , in this example, the idler  213  generally constitutes a rolling portion configured to pass through between the pair of projections  131  of the core  13  of the rubber crawler  1 . Additionally, the idler  213  is not limited to one illustrated, and may have an arbitrary configuration. For example, instead of or in addition to the rolling portion configured to pass through between the pair of projections  131  of the core  13 , the idler  213  may have two rolling portions configured to pass through both outer sides in the crawler width direction WD to the pair of projections  131  of the core  13 . 
     The track roller  214  has a function of supporting a load and guiding the rubber crawler  1  to inhibit deviation. In the example of  FIG. 2 , three track rollers  214  are arranged between the pair of idlers  213 . However, the number of track rollers  214  may be arbitrary. Each track roller  214  is supported by a support shaft  214   s , and configured to rotate due to friction with the rubber crawler  1 . The support shaft  214   s  is attached to the frame  211 . 
     As clear from  FIG. 2  and  FIG. 5  which will be described later, in this example, each track roller  214  has two rolling portions  214   f  configured to pass on the track roller passing surfaces  121   a  ( FIG. 3 ) at both outer sides in the crawler width direction WD to the pair of projections  131  of the core  13 . However, each track roller  214  is not limited to one illustrated, and may have an arbitrary configuration. For example, instead of or in addition to the rolling portions  214   f  configured to pass through both outer sides in the crawler width direction WD to the pair of projections  131  of the core  13 , each track roller  214  may include one rolling portion configured to pass through between the pair of projections  131  of the core  13 . 
     The tension mechanism  215  is connected to the idler  213 , and more specifically, connected to the support shaft  213   s  of the idler  213 . The tension mechanism  215  is configured to adjust the tension of the rubber crawler  1  by adjusting a force acting between the idler  213  and the rubber crawler  1 . 
     As illustrated in  FIGS. 2 and 4 , in this example, the tension mechanism  215  is connected to the front idler  213   f , and more specifically, connected to the support shaft  213   s  of the front idler  213   f . However, the tension mechanism  215  may be connected to the rear idler  213   r , and more specifically, may be connected to the support shaft  213   s  of the rear idler  213   r.    
     In this example, the tension mechanism  215  has a grease cylinder  215   a , a piston rod  215   d , a grease nipple  215   c  and grease  215   e . The grease cylinder  215   a  is connected to the idler  213  (more concretely, the support shaft  213   s  of the idler  213 ). The piston rod  215   d  is configured such that an inner portion of the grease cylinder  215   a  can be relatively displaced in an axial direction of the piston rod  215   d  to the grease cylinder  215   a . An accommodation space  215   b  is defined in an inner portion of the grease cylinder  215   a , and the grease  215   e  is housed in the accommodation space  215   b . The accommodation space  215   b  is also defined by one end portion (a left end portion in  FIG. 4 ) in the axial direction of the piston rod  215   d , and due to relative displacement in the axial direction of the piston rod  215   d , a volume of the accommodation space  215   b  can be changed. The other end portion (a right end portion in  FIG. 4 ) in the axial direction of the piston rod  215   d  may be connected to a not illustrated recoil spring for example, or may be fixed to the frame  211  and the like. The grease nipple  215   c  is configured to adjust the amount of the grease  215   e  in the accommodation space  215   b  of the grease cylinder  215   a  by injecting or ejecting the grease  215   e  manually etc. via the grease nipple  215   c . The tension mechanism  215  with the above configuration is configured such that the force acting between the idler  213  and the rubber crawler  1  can be adjusted, and thus the tension of the rubber crawler  1  can be adjusted by adjusting the amount of the grease  215   e  in the accommodation space  215   b  of the grease cylinder  215   a  via the grease nipple  215   c . The larger the amount of the grease  215   e  in the accommodation space  215   b  becomes, the larger the force acting between the idler  213  and the rubber crawler  1  (in the example in the drawing, a force in the machine body front-rear direction FRD) becomes, and thus the tension of the rubber crawler  1  increases. 
     Additionally, the underbody  21  of the machine body  2  is not limited to one illustrated, and may have an arbitrary configuration. For example, the underbody  21  may have only one idler  213 . In such a case, the idler  213  is preferably arranged to face the sprocket  212  in the machine body front-rear direction FRD, and the track roller  214  is preferably arranged between the sprocket  212  and the idler  213 . 
     In the traveling machine  3  thus configured, at the time of traveling on an inclined surface, deviation may occur. Here, deviation will be explained with reference to  FIGS. 5 and 6 . 
       FIG. 5  is a drawing illustrating an appearance of the traveling machine  3  of  FIG. 1  seen from the rear side for explaining a state that there is a prior warning of deviation in the traveling machine  3  of  FIG. 1 .  FIG. 6  illustrates an appearance of the left underbody apparatus  31  in  FIG. 5  seen from an inner side in the machine body right-left direction LRD (from the right side of  FIG. 5 ). 
     Additionally, in the present specification, “deviation” refers to removal of the rubber crawler  1  from the underbody  21  of the machine body  2 , and more specifically, refers to a state that the rolling portion  214   f  of the track roller  214  overrides the projection  131  of the core  13  and is positioned at an opposite side from a position at which it should be normally located about the projection  131 . Consequently, while a concrete aspect of deviation is different depending on a structure of the track roller  214 , in an example of  FIG. 5  for example, deviation of the track roller  214  refers to a state that any one of the pair of rolling portions  214   f  of the track roller  214  overrides the projection  131  of the core  13  and is positioned between the projections  131  of the core  13 . 
     At the time of traveling on the inclined surface of the traveling machine  3 , mainly as illustrated in  FIG. 5 , deviation tends to occur when the machine body right-left direction LRD of the machine body  2  is inclined to a horizontal surface, and moreover, the machine body right-left direction LRD of the machine body  2  and the crawler width direction WD of the rubber crawler  1  are different from each other (that is, mutually non-parallel), whereby the underbody  21  of the machine body  2  is floated from the rubber crawler  1 . Such difference between the machine body right-left direction LRD of the machine body  2  and the crawler width direction WD of the rubber crawler  1  tends to occur when, as in an example in  FIG. 5  for example, of the right and left pair of underbody apparatuses  31 , the rubber crawler  1  of one underbody apparatus  31  (the right side of  FIG. 5 ) contacts an inclined road surface IS which is inclined in a right-left direction to the horizontal surface, while the rubber crawler  1  of the other underbody apparatus  31  (the left side of  FIG. 5 ) contacts a horizontal road surface HS which is substantially parallel to the horizontal surface. In this case, in the underbody apparatus  31  which contacts the inclined road surface IS (the right side in  FIG. 5 ), the machine body right-left direction LRD of the underbody  21  of the machine body  2  and the crawler width direction WD of the rubber crawler  1  are substantially parallel to the inclined road surface IS and substantially parallel to each other, so that there is no risk of deviation. On the other hand, in the underbody apparatus  31  which contacts the horizontal road surface HS (the left side in  FIG. 5 ), the machine body right-left direction LRD of the underbody  21  of the machine body  2  is substantially parallel to the inclined road surface IS, while, as also illustrated in  FIG. 6 , the rubber crawler  1  is twisted to droop down mainly at a portion between the pair of idlers  213  in the machine body front-rear direction FRD to contact the horizontal road surface HS to be substantially parallel thereto, whereby the crawler width direction WD of the rubber crawler  1  is substantially parallel to the horizontal road surface HS (and thus the horizontal surface), and as a result, the track roller  214  of the underbody  21  of the machine body  2  is floated from the rubber crawler  1 . This may lead a state of existence of a prior warning of deviation, for example, the rolling portion  214   f  of the track roller  214  of the underbody  21  overrides the projection  131  of the core  13  of the rubber crawler  1 . Moreover, when an inclination angle θ of the machine body right-left direction LRD of the machine body  2  to the horizontal surface becomes larger, the rolling portion  214   f  of the track roller  214  is moved to the opposite side about the projection  131 , which may lead deviation. 
     Additionally, at the time of traveling on the inclined surface as described above, the deviation occurs more easily as the inclination angle θ of the machine body right-left direction LRD of the machine body  2  to the horizontal surface becomes larger. 
     (Monitoring System  4 ) 
     Next, the monitoring system  4  of this embodiment will be explained. As describe above, the monitoring system  4  is configured to monitor as to whether the prior warning of deviation exists in the traveling machine  3 . A user of the monitoring system  4  is, for example, the operator who drives the traveling machine  3 . 
     As illustrated in  FIG. 1 . the monitoring system  4  includes an angle sensor  45 , a force sensor  41 , a processing section  42 , a notification section  43  and a storing section  44 . 
     The angle sensor  45  is configured to detect the inclination angle θ ( FIG. 5 ) of the machine body  2  to the horizontal surface. The inclination angle θ of the machine body  2  to the horizontal surface concretely refers to the inclination angle in the machine body right-left direction LRD of the machine body  2  to the horizontal surface. A detected signal of the inclination angle θ detected by the angle sensor  45  is outputted to the processing section  42 . 
     The angle sensor  45  is, for example, constituted by a level. 
     The angle sensor  45  is attached to the machine body  2 . The angle sensor  45  may be attached to an arbitrary portion in the machine body  2 . 
     Preferably, the angle sensor  45  outputs the detected signal of the inclination angle θ to the processing section  42 , for example continuously or every predetermined time interval, during traveling of the traveling machine  3 . 
     As in the example in  FIG. 5  for example, in a case where, of the right and left pair of underbody apparatuses  31 , the rubber crawler  1  of one underbody apparatus  31  (the right side in  FIG. 5 ) contacts the inclined road surface IS which is inclined in the right-left direction to the horizontal surface, while the rubber crawler  1  of the other underbody apparatus  31  (the left side of  FIG. 5 ) contacts the horizontal road surface HS which is substantially parallel to the horizontal surface, the inclination angle θ detected by the angle sensor  45  substantially corresponds to an inclination angle α ( FIG. 5 ) of the inclined road surface IS to the horizontal surface, and substantially corresponds to an angle made by the machine body right-left direction LRD of the underbody  21  in the underbody apparatus  31  which contacts the horizontal road surface HS (the left side of  FIG. 5 ) and the crawler width direction WD of a portion of the rubber crawler  1  which contacts the horizontal road surface HS to be substantially parallel thereto. 
     The force sensor  41  is configured to detect a force applied from the rubber crawler  1  to the idler  213  of the underbody  21  (the front idler  213   f  or the rear idler  213   r ) or a physical amount correlating with the force. 
     A detected signal of the force detected by the force sensor  41  or the physical amount correlating with the force is outputted to the processing section  42 . 
     The force sensor  41  preferably outputs the detected signal of the force or the physical amount to the processing section  42 , for example, continuously or every predetermined time interval, during traveling of the traveling machine  3 . 
     The force sensor  41  is preferably attached to the underbody apparatus  31 , and more preferably, is attached to the underbody  21 . 
     Here, as the “physical amount correlating with the force,” any force can be applied as long as it is a physical amount which is changed substantially in proportion to the force. 
     In this example, the force sensor  41  is configured as a pressure sensor. As illustrated in  FIG. 4 , the force sensor  41  is configured to detect pressure in the accommodation space  215   b  of the grease cylinder  215   a  of the tension mechanism  215  connected to the idler  213  (more specifically, the front idler  213   f  in this example), thereby detecting a physical amount (a pressure in this example) correlating with a force applied from the rubber crawler  1  to the idler  213  (more specifically, the front idler  213   f  in this example) of the underbody  21 . The larger the force applied from the rubber crawler  1  to the idler  213  (more specifically, the front idler  213   f  in this example) of the underbody  21  becomes, the larger the pressure in the accommodation space  215   b  of the grease cylinder  215   a  becomes. 
     In the example of  FIG. 4 , the force sensor  41  is configured to detect the pressure in the accommodation space  215   b  of the grease cylinder  215   a  via the grease nipple  215   c . However, the force sensor  41  may be configured to detect the pressure in the accommodation space  215   b  of the grease cylinder  215   a  based on the configuration which is different from that in the example in  FIG. 4 . 
     In the example in  FIG. 4 , the tension mechanism  215  is connected to the front idler  213   f , and accordingly, the force sensor  41  is configured to detect a physical amount correlating with a force applied from the rubber crawler  1  to the front idler  213   f . However, in a case where the tension mechanism  215  is connected to the rear idler  213   r  for example, the force sensor  41  may be configured to detect a physical amount correlating with a force applied from the rubber crawler  1  to the rear idler  213   r.    
     Additionally, the force applied from the rubber crawler  1  to the front idler  213   f  is always substantially the same as the force applied from the rubber crawler  1  to the rear idler  213   r.    
     Also, the force sensor  41  may be configured to detect the force applied from the rubber crawler  1  to the idler  213  of the underbody  21  or the physical amount correlating with the force by methods other than a method of detecting the pressure in the accommodation space  215   b  of the grease cylinder  215   a.    
     For example, the force sensor  41  may be configured as a strain sensor, and configured to detect the force applied from the rubber crawler  1  to the idler  213  of the underbody  21  or the physical amount (for example, a strain or a voltage) correlating with the force. In such a case, for example, the force sensor  41  is preferably attached to the support shaft  213   s  of the idler  213  (the front idler  213   f  or the rear idler  213   r ) of the underbody  21  or a portion which is adjacent to the support shaft  213   s  of the frame  211 . 
     Also, in the example in  FIG. 4 , the force sensor  41  is configured to detect the force applied from the rubber crawler  1  to the idler  213  in the machine body front-rear direction FRD or the physical amount correlating with the force. However, the force sensor  41  may be configured to detect a force applied from the rubber crawler  1  to the idler  213  in an arbitrary direction or a physical amount correlating with the force. 
     Additionally, in a case where the machine body right-left direction LRD of the machine body  2  and the crawler width direction WD of the rubber crawler  1  are mutually different from each other (that is, mutually non-parallel) as in the left underbody apparatus  31  in the example of  FIG. 5 , the larger the inclination angle θ of the machine body  2  to the horizontal surface in the machine body right-left direction LRD becomes, the more the rubber crawler  1  is twisted severely, which increases the tension of the rubber crawler  1 , and thus the force applied from the rubber crawler  1  to the idler  213  increases. 
     The processing section  42  is configured to control the entire monitoring system  4  which includes the angle sensor  45 , the force sensor  41 , the storing section  44  and the notification section  43  by executing a program stored in the storing section  44 . 
     For example, the processing section  42  is configured to determine existence or non-existence of the prior warning of deviation based on outputs from the angle sensor  45  and the force sensor  41 . More specifically, in this example, the processing section  42  is configured to determine that there is the prior warning of deviation when the inclination angle θ detected by the angle sensor  45  is larger than a predetermined angle and the force or the physical amount outputted from the force sensor  41  is larger than a predetermined force or physical amount. Also, the processing section  42  is configured to cause the notification section  43  to notify a warning when it is determined that there is the prior warning of deviation. Moreover, the processing section  42  is configured to, instead of or in addition to notifying by the notification section  43 , cause the drive section  24  of the machine body  2  to reduce the driving force when it is determined that there is the prior warning of deviation. A concrete processing of the processing section  42  will be explained later. 
     The processing section  42  is configured to include at least one processor such as a CPU (Central Processing Unit). The processing section  42  may be achieved by one processor, or may be achieved by a plurality of processors. The processor may be achieved as a single integrated circuit. The integrated circuit is also referred to as IC (Integrated Circuit). The processor may be achieved as a plurality of integrated circuits connected to be capable of communication and a discrete circuit. The processor may be achieved based on other various known technologies. 
     The processing section  42  may store an output from the angle sensor  45  or the force sensor  41  and/or a result of processing by the processing section  42  in the storing section  44 . 
     The processing section  42  may be provided to the machine body  2 , or may be provided at a place which is remote from the machine body  2 . In a case where the processing section  42  is provided to the machine body  2 , communication among the processing section  42 , the angle sensor  45 , the force sensor  41 , the notification section  43  and the drive section  24  may be wire communication or wireless communication. In a case where the processing section  42  is provided at the place which is remote from the machine body  2 , communication among the processing section  42 , the angle sensor  45 , the force sensor  41 , the notification section  43  and the drive section  24  preferably may be at least partially wireless communication. 
     The storing section  44  stores the program to be executed by the processing section  42  or various information which is used for processing executed by the processing section  42  and the like. 
     The storing section  44  is constituted by one or more ROM or one or more RAM, for example. While the storing section  44  may be configured by a semiconductor memory or a magnetic disk, for example, not limited to this, may be configured as an arbitrary storage unit. Also, for example, the storing section  44  may be configured from an external storage unit such as a memory card (including a USB). Also, the storing section  44  may be an internal memory of the processor constituting the processing section  42 . 
     The storing section  44  may be provided to the machine body  2 , or may be provided at the place which is remote from the machine body  2 . 
     The notification section  43  is provided to the machine body  2 . The notification section  43  is configured to notify a warning to the operator who drives in the operator room  22  in accordance with control by the processing section  42 . The notification section  43  can have, for example, at least one of a display or a voice output section. For example, the display capable of constituting the notification section  43  can include a display or a monitor configured to display a letter, an image, a movie and the like and/or a lamp configured to emit a light. For example, the voice output section capable of constituting an output section  85  can include a speaker configured to output a voice. 
     [Motoring Method] 
     Next, a method of monitoring the traveling machine  3  (and thus the monitoring method according to one embodiment of the present disclosure) using the monitoring system  4  of the above-described embodiment (and thus the traveling machine system  5  of this embodiment) will be explained. The monitoring method of this embodiment is used to monitor as to whether there is the prior warning of deviation in the traveling machine  3 . 
     Additionally, the monitoring method which will be explained below is not limited to the monitoring system  4  of the above-described embodiment, and can be achieved in the same manner using the monitoring system  4  related to another example explained in the present specification. 
     The monitoring method of this embodiment includes an angle detecting step, a force detecting step, a determining step and a countermeasure step. 
     (Angle Detecting Step) 
     In the angle detecting step, the angle sensor  45  detects the inclination angle θ of the machine body  2  to the horizontal surface (that is, the inclination angle of the machine body  2  to the horizontal surface in the machine body right-left direction LRD). The angle detecting step is executed during traveling of the traveling machine  3 . The angle sensor  45  outputs a detected signal of the inclination angle θ to the processing section  42 . The output from the angle sensor  45  to the processing section  42  is preferably executed in real time. 
     The angle sensor  45  preferably outputs the detected signal of the inclination angle θ to the processing section  42 , for example continuously or every predetermined time interval, during traveling of the traveling machine  3 . 
     (Force Detecting Step) 
     In the force detecting step, the force sensor  41  detects the force applied from the rubber crawler  1  to the idler  213  of the underbody  21  or the physical amount correlating with the force. The force detecting step is executed during traveling of the traveling machine  3 . The force sensor  41  outputs a detected signal of the force or the physical amount to the processing section  42 . The output from the force sensor  41  to the processing section  42  is preferably executed in real time. 
     The force sensor  41  preferably outputs the detected signal of the force or the physical amount to the processing section  42 , for example continuously or every predetermined time interval, during traveling of the traveling machine  3 . 
     More specifically, in this example, in the force detecting step, the force sensor  41  detects the pressure in the accommodation space  215   b  of the grease cylinder  215   a  of the tension mechanism  215  connected to the idler  213  (more specifically, the front idler  213   f  in this example) as the physical amount correlating with the force applied from the rubber crawler  1  to the idler  213 , and outputs the detected signal of the detected pressure. 
     (Determining Step) 
     In the determining step, the processing section  42  determines existence or non-existence of the prior warning of deviation based on the output from the angle sensor  45  in the angle detecting step and the output from the force sensor  41  in the force detecting step. 
     The processing section  42  preferably executes the determining step, for example continuously or every predetermined time interval, during traveling of the traveling machine  3 . 
     More specifically, in this example, in the determining step, the processing section  42  compares the inclination angle θ detected by the angle sensor  45  in the angle detecting step (and thus the detected signal outputted from the angle sensor  45 . Hereinafter, it is referred to as “a detected angle DA”) with a predetermined angle (hereinafter, it is referred to as “a threshold angle TA”), and compares the force or the physical amount detected by the force sensor  41  in the force detecting step (and thus the detected signal outputted from the force sensor  41 . Hereinafter, it is referred to as “a detected force etc. DF”) with a predetermined force or physical amount (hereinafter, it is referred to as “a threshold force etc. TF”). Moreover, in the determining step, the processing section  42  determines that there is the prior warning of deviation when the detected angle DA is larger than the threshold value TA and the detected force etc. DF is larger than the threshold force etc. TF, while it determines that there is no prior warning of deviation in the other cases. 
     (Countermeasure Step) 
     In the countermeasure step, a countermeasure is taken to prevent deviation when the processing section  42  determines that there is the prior warning of deviation in the determining step. 
     As an example of a concrete countermeasure, the processing section  42  may cause the notification section  43  provided to the machine body  2  to notify a warning to the operator. In this case, the operator who received the warning from the notification section  43  can prevent deviation by stopping the traveling machine  3  or operating in a reverse direction. 
     As another example of the concrete countermeasure, the processing section  42  may control the drive section  24  of the machine body  2 . Due to this, deviation can be automatically prevented without the need of operation by the operator. In this case, for example, the processing section  42  may stop the machine body  2  or reduce its speed by causing the drive section  24  to reduce the driving force. Alternatively, the processing section  42  may control the drive section  24  of the machine body  2  to change a traveling direction of the machine body  2  (for example, executing travelling in a reverse direction). 
     The countermeasure step can inhibit occurrence of the deviation. 
     Additionally, in the countermeasure step, the processing section  42  may execute any one of the notification by the notification section  43  and the control of the drive section  24  or may execute both at the same time. 
     Here, a function effect of the monitoring system  4  of the above-described embodiment, the traveling machine system  5  of this embodiment and the monitoring method of this embodiment will be explained. 
     In this embodiment, as described above, the angle sensor  45  detects the inclination angle θ of the machine body  2  to the horizontal surface, and the force sensor  41  detects the force applied from the rubber crawler  1  to the idler  213  of the underbody  21  or the physical amount correlating with the force, and moreover, the processing section  42  determines existence or non-existence of the prior warning of deviation based on the outputs from the angle sensor  45  and the force sensor  41 . More specifically, in this example, as described above, the processing section  42  is configured to determine that there is the prior warning of deviation when the inclination angle outputted from the angle sensor  45  (the detected angle DA) is larger than a predetermined angle (the threshold value TA) and the force or the physical amount outputted from the force sensor  41  (the detected force etc. DF) is larger than a predetermined force or physical amount (the threshold force etc. TF). 
     Conventionally, the operator who drives the traveling machine has required to predict the prior warning of deviation sensuously from the attitude of the machine body, the traveling state or the sound etc., and grasping the prior warning of deviation has been difficult, and thus preventing the deviation has been difficult. Occurrence of deviation may lead downtime accompanied by recovery efforts or damage to the rubber crawler (for example, breakage of the rubber crawler due to an excessive tension, and cutting or removal of rubber of the rubber crawler caused by interference with the frame of the machine body). 
     Regarding this point, in this embodiment, the processing section  42  determines existence or non-existence of the prior warning of deviation based on the outputs from the angle sensor  45  and the force sensor  41 , which ensures grasping of the prior warning of deviation more reliably, and thus deviation is inhibited from occurring. By inhibiting the deviation from occurring, downtime can be reduced, and inhibiting construction period delay and inhibiting occurrence of the cost of recovery of the machine body etc. can be achieved. Also, by inhibiting the deviation from occurring, damage of the rubber crawler  1  is inhibited, and a service life of the rubber crawler  1  can be made longer. 
     Also, in this embodiment, the processing section  42  determines existence or non-existence of the prior warning of deviation based on the outputs from both the angle sensor  45  and the force sensor  41 , so that the prior warning of deviation can be grasped more correctly. In other words, unlike the example in  FIG. 5 , in a case where both the rubber crawlers  1  of the right and left pair of underbody apparatuses  31  of the traveling machine  3  contact the inclined road surface IS which is inclined in the right-left direction to the horizontal surface, in both the underbody apparatuses  31 , the machine body right-left direction LRD of the machine body  2  and the crawler width direction WD of the rubber crawler  1  are substantially parallel, so that deviation is difficult to occur. Accordingly, if the processing section  42  determines existence or non-existence of the prior warning of deviation only based on the output from the angle sensor  45 , a case where the rubber crawler  1  of one underbody apparatus  31  contacts the inclined surface IS, while the rubber crawler  1  of the other underbody apparatus  31  contacts to the horizontal road surface HS as in the example of  FIG. 5  (and thus deviation easily occurs) cannot be differentiated from a case where the rubber crawlers  1  of both the underbody apparatuses  31  contact the inclined road surface IS as described above (and thus deviation is difficult to occur). In a case where the machine body right-left direction LRD of the machine body  2  and the crawler width direction WD of the rubber crawler  1  are different from each other (that is, mutually non-parallel) as in the left underbody apparatus  31  of the example of  FIG. 5 , the larger the inclination angle θ of the machine body  2  to the horizontal surface in the machine body right-left direction LRD becomes, the more the rubber crawler  1  is twisted severely, which increases the tension of the rubber crawler  1 , and thus the force applied from the rubber crawler  1  to the idler  213  increases. In this embodiment, focusing this mechanism, the processing section  42  observes the output from the force sensor  41  in addition to the output from the angle sensor  45 , so that existence of the prior warning of deviation can be appropriately determined only when the rubber crawler  1  is twisted, and thus the prior warning of deviation can be grasped more correctly. 
     Also, in this example, as described above, when the processing section  42  determines that there is the prior warning of deviation, a countermeasure of causing the notification section  43  provided to the machine body  2  to notify a warning and/or controlling the drive section  24  of the machine body  2  (reducing the driving force of the drive section  24  etc.) is taken. Due to this, the deviation can be inhibited from occurring more reliably. Moreover, the operator can concentrate on driving since prediction of the prior warning of deviation is not required during traveling of the traveling machine  3 . 
     Additionally, preferably, the threshold angle TA, the threshold force etc. TF used in the determining step are set by a previous traveling test. 
     In each example explained in the present specification, the monitoring system  4  may set the threshold angle TA and/or the threshold force etc. TF used in the determining step at a plurality of stages depending on severity of the prior warning of deviation. Moreover, in the determining step, the processing section  42  may determine the severity of the prior warning of deviation in addition to existence or non-existence of the prior warning of deviation by comparing the output from the angle sensor  45  in the angle detecting step (the detected angle DA) and/or the output from the force sensor  41  in the force detecting step (the detected force etc. DF) with the plurality of threshold values (the threshold angle TA and/or the threshold force etc. TF). In addition, the processing section  42  may change the content of the countermeasure in the countermeasure step depending on the severity of the prior warning of deviation determined in the determining step. For example, the processing section  42  may cause the notification section  43  to execute notification in the countermeasure step when it is determined that the severity of the prior warning of deviation is low in the determining step, while may control the drive section  24  of the machine body  2  to stop the machine body  2  in the countermeasure step when it is determined that the severity of the prior warning of deviation is high in the determining step. 
     In each example explained in the present specification, the monitoring system  4  preferably includes the force sensor  41  in each underbody  21 . In this case, the processing section  42  determines existence or non-existence of the prior warning of deviation for each output from each force sensor  41  (that is, every underbody  21 ) in the determining step. Moreover, the processing section  42  preferably executes the countermeasure step when it is determined that there is the prior warning of deviation based on the output from at least any one force sensor  41 . 
     INDUSTRIAL APPLICABILITY 
     The monitoring system, the traveling machine system and the monitoring method according to the present disclosure is preferably applied to the traveling machine including the rubber crawler containing the core, and, for example, preferably applied to the construction machinery (including the mini-excavator) and the agricultural machines (including the tractor and the combine).