Patent Publication Number: US-11643795-B2

Title: Work machine information processing device, information management system, and work machine information processing program

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a bypass continuation application of International PCT Application No. PCT/JP2020/014029, filed on Mar. 27, 2020, which is incorporated by reference herein in its entirety. 
    
    
     BACKGROUND 
     Technical Field 
     Certain embodiments of the present invention relate to a work machine information processing device, an information management system, and a work machine information processing program. 
     Description of Related Art 
     In the related art, for example, in a work machine such as an excavator, a technique is known in which a risk such as an entry of a person to a periphery of the work machine is detected to warn an operator of occurrence of the risk (for example, refer to the related art). 
     However, there exists no technique for improving safety of a work site by evaluating a behavior of an operator who recognized the risk. 
     SUMMARY 
     According to an aspect of the present invention, there is provided a work machine information processing device including a risk detector configured to detect a risk relating to a state or a surrounding environment of a work machine, notifier configured to notify an operator of the work machine of the risk detected by the risk detector, behavior detector configured to detect a behavior of the operator after the notification of the notifier, and calculator configured to calculate a safety behavior evaluation value obtained by quantitatively evaluating the behavior of the operator in terms of a degree of contribution to the safety, based on contents of the risk detected by the risk detector and the behavior of the operator detected by the behavior detector. 
     According to another aspect of the present invention, there is provided an information management system including a plurality of work machines on which the work machine information processing device in the above-described aspect is mounted, and an information management device configured to transmit and receive information to and from the plurality of work machines. The information management device includes storage unit for accumulating the safety behavior evaluation value received from the plurality of work machines. 
     According to still another aspect of the present invention, there is provided a computer readable medium storing a work machine information processing program that causes a computer of a work machine information processing device including risk detector to execute a process for detecting a risk relating to a state or a surrounding environment of a work machine. The process includes notifying an operator of the work machine of the risk detected by the risk detector, detecting a behavior of the operator after the notification of the notifier, and calculating a safety behavior evaluation value obtained by quantitatively evaluating the behavior of the operator in terms of a degree of contribution to the safety, based on contents of the risk detected by the risk detector and the behavior of the operator detected by the behavior detector. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a side view of an excavator to an embodiment of the present invention. 
         FIG.  2    is a block diagram illustrating a system configuration of the excavator in  FIG.  1   . 
         FIG.  3    is a view illustrating a detection range of an object detection unit. 
         FIG.  4    is a view illustrating a display example of safety behavior evaluation information. 
         FIG.  5    is a flowchart illustrating a flow of a behavior evaluation process. 
         FIG.  6    is a block diagram illustrating a system configuration of an information management system according to a modification example of the embodiment of the present invention. 
         FIG.  7    is a view illustrating another display example of the safety behavior evaluation information. 
     
    
    
     DETAILED DESCRIPTION 
     It is desirable to improve safety of a work site. 
     According to embodiments of the present invention, the safety of the work site can be improved. 
     Hereinafter, an embodiment according to the present invention will be described in detail with reference to the drawings. 
     Configuration of Excavator 
     First, a configuration of an excavator  100  according to the present embodiment will be described. The excavator  100  is an example of a work machine according to the embodiment of the present invention, and is configured to include a work machine information processing device according to the embodiment of the present invention. In this manner, a behavior of an operator when a risk occurs can be evaluated. 
       FIG.  1    is a side view of the excavator  100  according to the present embodiment. 
     As illustrated in the drawing, the excavator  100  includes a lower traveling body  1 , a rotating platform  3  mounted on the lower traveling body  1  to be capable of turning via a turning mechanism  2 , a boom  4 , an arm  5 , and a bucket  6  which serve as attachments, and a cabin  10  on which the operator rides. The attachments are not limited thereto as long as a work element (for example, the bucket, a crusher, or a crane apparatus) is provided. 
     For example, the lower traveling body  1  include a pair of right and left crawlers. Each of the crawlers is hydraulically driven by a traveling hydraulic motor (not illustrated) so that the excavator  100  travels. 
     The rotating platform  3  is driven by a turning hydraulic motor or an electric motor (both are not illustrated) to turn with respect to the lower traveling body  1 . 
     The boom  4  is pivotally attached to a front center of the rotating platform  3  to be capable of derricking, the arm  5  is pivotally attached to a tip of the boom  4  to be vertically pivotable, and the bucket  6  is pivotally attached to a tip of the arm  5  to be vertically pivotable. The boom  4 , the arm  5 , and the bucket  6  are respectively and hydraulically driven by a boom cylinder  7 , an arm cylinder  8 , and a bucket cylinder  9 . The cabin  10  is a cockpit on which an operator rides, and is mounted on a front left side of the rotating platform  3 , for example. 
       FIG.  2    is a block diagram illustrating a system configuration of the excavator  100 . 
     As illustrated in the drawing, in addition to the above-described configuration, the excavator  100  includes a controller  30 , an imaging device  40 , an operation/posture state sensor  42 , an in-vehicle camera  43 , a manipulation device  45 , a display unit  50 , a voice output unit  60 , an external notification device  70 , and a communication device  80 . The work machine information processing device according to the embodiment of the present invention is configured to include the controller  30 , the imaging device  40 , the operation/posture state sensor  42 , the in-vehicle camera  43 , the manipulation device  45 , the display unit  50 , and the voice output unit  60 . 
     The imaging device  40  is attached to an upper portion of the rotating platform  3 , images a periphery of the excavator  100 , and outputs an image thereof to the controller  30 . The imaging device  40  includes a rear camera  40 B, a left side camera  40 L, and a right side camera  40 R. 
     The rear camera  40 B is attached to a rear end upper portion of the rotating platform  3 , and images a rear side of the rotating platform  3 . 
     The left side camera  40 L is attached to a left upper end portion of the rotating platform  3 , and images a left side of the rotating platform  3 . 
     The right side camera  40 R is attached to a right end upper portion of the rotating platform  3 , and images a right side of the rotating platform  3 . 
     Each of the rear camera  40 B, the left side camera  40 L, and the right side camera  40 R is attached in an upper portion of the rotating platform  3  so that an optical axis faces obliquely downward, and has an imaging range (angle of view) in a vertical direction including an area from a ground surface near the excavator  100  to a distant place of the excavator  100 . 
     The rear camera  40 B, the left side camera  40 L, and the right side camera  40 R may be attached to an upper surface of the rotating platform  3 . The cameras  40 B,  40 L, and  40 R may be attached so that a portion of the rotating platform  3  is imaged and the optical axis faces obliquely downward in a state where the cameras  40 B,  40 L, and  40 R do not protrude from a side surface end portion of the rotating platform  3 . 
     An object to be imaged and a portion of the rotating platform  3  are simultaneously acquired as images. Accordingly, captured images can be intuitively determined as the images acquired by using the cameras provided in the excavator  100 . In addition, a sense of distance between the object to be imaged and the excavator  100  can be intuitively understood. 
     The operation/posture state sensor  42  is a sensor that detects an operation state or a posture state of the excavator  100 , and outputs a detection result to the controller  30 . The operation/posture state sensor  42  includes a boom angle sensor, an arm angle sensor, a bucket angle sensor, a triaxial inertial sensor (IMU: Inertial Measurement Unit), a turning angle sensor, and an acceleration sensor. 
     The sensors may be configured to include a cylinder stroke sensor of the boom and a sensor that acquires rotation information of a rotary encoder, or may be replaced by an acceleration (including a speed or a position) acquired by the IMU. 
     The arm angle sensor detects a pivot angle (hereinafter, referred to as an “arm angle”) of the arm  5  with reference to the boom  4 . 
     The bucket angle sensor detects a pivot angle (hereinafter, referred to as a “bucket angle”) of the bucket  6  with reference to the arm  5 . 
     The IMU is attached to each of the boom  4  and the arm  5 , and detects the acceleration of the boom  4  and the arm  5  along predetermined three axes and an angular acceleration of the boom  4  and the arm  5  around the predetermined three axes. 
     The turning angle sensor detects a turning angle with reference to a predetermined angular direction of the rotating platform  3 . However, the present invention is not limited thereto, and the turning angle may be detected, based on a GPS or the IMU sensor provided in the rotating platform  3 . 
     The acceleration sensor is attached to a position away from a turning axis of the rotating platform  3 , and detects the acceleration at the attached position of the rotating platform  3 . In this manner, based on a detection result of the acceleration sensor, it is possible to determine whether the rotating platform  3  is turned or whether the lower traveling body  1  travels. 
     The in-vehicle camera  43  is provided near the cockpit of the cabin  10 , and images an operation of the operator inside the cabin  10 . The in-vehicle camera  43  is installed to images a face of the operator from a front side so that a line of sight (eye movement) of the operator can be detected from the acquired image. 
     The manipulation device  45  is provided near the cockpit of the cabin  10  for the operator to operate each operation element (the lower traveling body  1 , the rotating platform  3 , the boom  4 , the arm  5 , and the bucket  6 ). In other words, the manipulation device  45  operates each hydraulic actuator that drives each operation element. For example, the manipulation device  45  includes a lever, a pedal, and various buttons, and outputs an operation signal corresponding to operation contents thereof to the controller  30 . 
     In addition, the manipulation device  45  also includes various setting units configured to operate the imaging device  40 , the operation/posture state sensor  42 , the in-vehicle camera  43 , the display unit  50 , the voice output unit  60 , the external notification device  70 , and the communication device  80 , and outputs an operation command for each unit to the controller  30 . 
     The display unit  50  is provided in the periphery of the cockpit inside the cabin  10 , and displays various image information to be notified to the operator under the control of the controller  30 . For example, the display unit  50  is a liquid crystal display or an organic electroluminescence (EL) display, and may be a touch panel type that also functions as at least a portion of the manipulation device  45 . 
     The voice output unit  60  is provided in the periphery the cockpit inside the cabin  10 , and outputs various voice information to be notified (informed) to the operator under the control of the controller  30 . For example, the voice output unit  60  is a speaker or a buzzer. 
     The external notification device  70  notifies a worker in the periphery of the excavator  100  or a supervisor in a work site. For example, the external notification device  70  may include a light source (lighting device) turned on and off toward the worker in the periphery of the excavator  100 . In addition, the external notification device  70  may include an external display unit that provides image information (character information or drawing information) for the worker in the periphery of the excavator  100 . In addition, the external notification device  70  may include an external voice output unit such as a speaker or a buzzer that outputs voice information to the worker in the periphery of the excavator  100 . 
     The communication device  80  transmit and receive various information to and from a remote external device or another excavator  100  through a predetermined communication network (for example, a mobile phone network whose end is a base station or the Internet network), based on predetermined wireless communication standards. 
     The controller  30  is a control device that performs driving control of the excavator  100  by controlling an operation of each unit of the excavator  100 . The controller  30  is mounted on the cabin  10 . A function of the controller  30  may be realized by any desired hardware, software, or a combination thereof, and the controller  30  is configured to mainly include a microcomputer including a CPU, a RAM, a ROM, and an I/O, for example. 
     In addition, as functional units that fulfill various functions, the controller  30  includes an object detection unit  301 , an instability detection unit  302 , a behavior detection unit  303 , a behavior evaluation unit  304 , and an information output unit  305 . In addition, the controller  30  includes a storage unit  310  serving as a storage region defined in an internal memory such as an electrically erasable programmable read-only memory (EEPROM). 
     Based on the image captured by the imaging device  40 , the object detection unit  301  detects a predetermined detection object within a predetermined region (for example, a range from excavator  100  to a predetermined distance) in the periphery of the excavator  100  to detect an entry of the detection object into the predetermined region. Specifically, the object detection unit  301  recognizes the detection object inside the captured image by applying various known image processing methods or a machine learning-based classifier, and identifies an actual position or a size of the recognized detection object. The detection object is an obstacle that exists in the periphery of the excavator  100  or may enter the predetermined region. The detection object includes a person such as the worker in the periphery of the excavator  100 , another work machine, a vehicle that carries out work in the periphery of the excavator  100 , or a construction material temporarily placed in the periphery of the excavator  100 . 
       FIG.  3    is a view illustrating an example of a detection range of the object detection unit  301 . 
     As illustrated in the drawing, the object detection unit  301  has detection ranges MAB, MAL, and MAR respectively corresponding to the rear camera  40 B, the left side camera  40 L, and the right side camera  40 R. 
     Here, the object detection unit  301  can change detection performance as follows. In response to a setting operation of the operator, a certain performance item relating to the detection performance of one detection unit is raised within a resource range of the controller  30 . Alternatively, the detection performance of one detection unit or the other detection unit is lowered. The detection performance includes performance items such as a range in which a monitoring object can be detected (detection range), detection accuracy, and detection frequency for each detection cycle (that is, the number of times for detecting the monitoring object within a detection cycle). 
     In addition, when the object detection unit  301  detects a detection object inside a predetermined region in the periphery of the excavator  100 , the object detection unit  301  causes the display unit  50  and/or the voice output unit  60  to outputs an image or a voice for notifying the operator of the detection result. An output mode in this case may be changed depending on a type of the detected detection object or a distance between the detection object and the excavator  100 . In addition, after the notification output starts, the object detection unit  301  stops (cancels) the output, based on a predetermined condition (for example, a fact that the detection object cannot be detected inside the predetermined region). 
     As illustrated in  FIG.  2   , the instability detection unit  302  detects occurrence of a state where stability relating to an operation of the excavator  100  falls below a predetermined reference (hereinafter, referred to as “unstable state”). Specifically, the instability detection unit  302  acquires information relating to a state of the excavator  100  (operation state or control state) from various sensors (for example, the imaging device  40 , the operation/posture state sensor  42 , the in-vehicle camera  43 , and the manipulation device  45 ) mounted on the excavator  100 , various actuators (for example, an electromagnetic valve that performs hydraulic control), or various control devices (for example, other functional units of the controller  30 ). Then, based on the acquired information, the instability detection unit  302  detects the occurrence of an unstable state of the excavator  100  by determining whether or not the stability relating to the operation of the excavator  100  falls below the predetermined reference. 
     For example, the unstable state of the excavator  100  includes a state where there is a high possibility that the excavator  100  (lower traveling body  1 ) may slide forward or rearward due to a reaction force applied to the attachment from the ground during excavation work or leveling work (unstable slipping state). 
     In addition, for example, the unstable state of the excavator  100  includes a state where there is a high possibility that a front portion or a rear portion of the excavator  100  (lower traveling body  1 ) may float due to excavation reaction force (unstable floating state). In addition, for example, the unstable state of the excavator  100  includes a state where there is a high possibility that vibration may be generated in a vehicle body (the lower traveling body  1 , the turning mechanism  2 , and the rotating platform  3 ) due to a change in the moment of inertia of the attachment in an aerial operation (operation in a state where the bucket  6  is not grounded) of the attachment of the excavator  100  (unstable vibrating state). 
     In addition, when the instability detection unit  302  detects an unstable state of the excavator  100 , the instability detection unit  302  causes the display unit  50  and/or the voice output unit  60  to output an image or a voice for notifying the operator of the detection result. The output mode in this case may be changed depending on a type or a degree of the detected unstable state. In addition, after the notification output starts, the instability detection unit  302  stops (cancels) the output, based on a predetermined condition (for example, a fact that the unstable state is eliminated). 
     The behavior detection unit  303  detects a behavior of the operator inside the cabin  10 , based on the output of the in-vehicle camera  43  and the manipulation device  45 . 
     The detected behavior of the operator includes a line of sight of the operator. The behavior detection unit  303  causes the in-vehicle camera  43  to image an eye movement of the operator. Based on image information, the behavior detection unit  303  detects the line of sight of the operator, for example, by using a positional relationship between a corneal reflex serving as a reference point and a pupil serving as a moving point, or between an inner corner of the eye serving as the reference point is and an iris serving as the moving point. 
     In addition, the detected behavior of the operator includes operation contents of the operator who operates the manipulation device  45 . The behavior detection unit  303  detects the operation contents of the operator who operates the excavator  100 , based on the output of the manipulation device  45 . 
     The behavior evaluation unit  304  evaluates the behavior of the operator which is detected by the behavior detection unit  303  from a viewpoint of whether or not the behavior contributes to safety in the periphery of the excavator  100 . Specifically, the behavior evaluation unit  304  calculates a safety behavior evaluation value obtained by quantitatively evaluating the behavior of the operator in terms of a degree of contribution to safety, and causes the storage unit  310  to store the safety behavior evaluation value as safety behavior evaluation information  3101 . A calculation method for the safety behavior evaluation value will be described later in detail. 
     The information output unit  305  appropriately outputs the safety behavior evaluation information  3101  calculated as the safety behavior evaluation value by the behavior evaluation unit  304  and stored in the storage unit  310 . For example, the information output unit  305  causes the display unit  50  to display the safety behavior evaluation information  3101 . 
     An output mode in this case is not particularly limited, and for example, only the safety behavior evaluation value may be displayed on the display unit  50 . 
     Alternatively, for example, as illustrated in  FIG.  4   , the information output unit  305  may collectively output a plurality of safety behavior evaluation information  3101  (safety behavior evaluation value) relating to the same operator, stored in the storage unit  310 , by using a graph comparing changes in each predetermined time unit (in the example of  FIG.  4   , a day, a week, or a month may be used). In this case, it is preferable to divide the graph in accordance with a risk type when the operator behaves. 
     In addition, the information output unit  305  may output the safety behavior evaluation information  3101  in a visually recognizable manner, and may cause a printer (not illustrated) to output the safety behavior evaluation information  3101  to a paper medium, for example. In this case, the information may be output from a printer provided inside the cabin  10  of the excavator  100 , or the information may be transmitted by the communication device  80  to a printer provided in a management center that manages the work so that the information is output from the printer. 
     In addition, when the information output unit  305  outputs the safety behavior evaluation information  3101 , the information output unit  305  may output work-related information relating to the work together when the safety behavior evaluation information  3101  is acquired (refer to  FIG.  4   ). The work-related information includes work information, date and time information, weather information, position information, machine body information, and operator information. The information output unit  305  appropriately acquires the work-related information, and stores the work-related information in the storage unit  310 . 
     The work information can include information such as a work (construction) name, a work place, a work content, an owner of the excavator, a subcontractor of the work, an intermediate person, and an end user relating to the work. For example, the information output unit  305  acquires work information, based on an input operation of the operator through the manipulation device  45 . 
     The date and time information includes the date, the day of the week, and the time of day. The information output unit  305  acquires the date and time information by using a timekeeper (for example, a real time clock (RTC)) inside the controller  30 . 
     The weather information is weather information in a place at the date and time during the work of the excavator  100 , and includes information relating to a weather classification such as sunny, cloudy, rainy, and snowy. The information output unit  305  acquires desired weather information from a server or website relating to the weather through the communication device  80 . Alternatively, the information output unit  305  may include an illuminance sensor or a raindrop detection sensor, and may acquire the weather information, based on illuminance or the presence or absence of the raindrop which is output by the sensors. 
     The position information is information on a position of the excavator  100 , and includes information relating to a longitude and a latitude. In addition, the position information may include more advanced information, or may be geocode information such as the Geohash. For example, the information output unit  305  may include global navigation satellite system (GNSS) device, and may acquire the position information of the excavator  100 , based on a signal from a satellite in the sky above the excavator  100 . 
     The machine body information is identification information of the excavator  100  for identifying the excavator  100 , and is a prescribed machine number or an ID of the excavator, for example. For example, the information output unit  305  acquires the machine body information by reading the machine number recorded in advance in the storage unit  310 . 
     The operator information is identification information of the operator for identifying the operator who operates the excavator  100 , and is a prescribed operator ID. For example, the information output unit  305  acquires the operator information, based on an input operation of the operator through the manipulation device  45 . 
     The work-related information (work information, date and time information, weather information, position information, machine body information, and operator information) is input by the input operation through the manipulation device  45  (information may directly be input or may be selected from information set in advance). However, the information may automatically be acquired by using a communication technology or an information processing technology. The work-related information may be stored in association with each other. 
     Operation of Excavator 
     Subsequently, an operation of the excavator  100  when a behavior evaluation process for evaluating the behavior of the operator is performed during occurrence of a risk will be described. 
       FIG.  5    is a flowchart illustrating a flow of the behavior evaluation process. 
     The behavior evaluation process is a process for evaluating safety of a work site and improving the safety of the work site by evaluating the behavior of the operator of the excavator  100  when the risk occurs, from a viewpoint of the safety, and outputting a result thereof so that work-related persons including the operator himself or herself can recognize the result. The behavior evaluation process is performed to cause the CPU to execute a program stored in an internal storage device by the controller  30 . 
     When the behavior evaluation process is performed, as illustrated in  FIG.  5   , the controller  30  first drives the excavator  100  to start the work (Step S 1 ). In this case, the display unit  50  inside the cabin  10  displays an image in the periphery of the excavator  100  which is captured by the imaging device  40 . 
     Next, the controller  30  determines whether or not a risk relating to a state of the excavator  100  or a surrounding environment thereof is detected (Step S 2 ). In the present embodiment, as the risk, an entry of an obstacle region (person, another work machine, or construction material) into a predetermined region in the periphery of the excavator  100 , an unstable state (unstable slipping state, unstable floating state, or unstable vibrating state) of the excavator  100  are detected. 
     Specifically, the object detection unit  301  of the controller  30  detects the entry of the obstacle into a predetermined region in the periphery of the excavator  100 , based on the image captured by the imaging device  40 . The object detection unit  301  identifies a position or a size of the obstacle from the captured image. 
     In addition, the instability detection unit  302  of the controller  30  detects the unstable state of the excavator  100 , based on a detection result of the operation/posture state sensor  42 . When a predetermined unstable operation that may cause the unstable state of the excavator  100  is detected, the instability detection unit  302  may determine that the unstable state occurs. 
     Then, when it is determined that no risk is detected (Step S 2 ; No), the process proceeds to Step S 1  described above, and the controller  30  continues the work. 
     When it is determined in Step S 2  that a risk relating to a state of the excavator  100  or the surrounding environment is detected (Step S 2 ; Yes), the controller  30  notifies the operator of the detected risk (Step S 3 ). Specifically, the controller  30  notifies the operator that the risk is detected, by outputting an alarm sound from the voice output unit  60  inside the cabin  10  or displaying alarm information on the display unit  50 . A notification mode in this case may be changed depending on a type or a degree of the detected risk (for example, loudness of the alarm sound may be changed depending on a distance between the detected obstacle and the excavator  100 ). 
     Next, the controller  30  detects the behavior of the operator (Step S 4 ). 
     Specifically, the behavior detection unit  303  of the controller  30  detects a line of sight of the operator, based on the image captured by the in-vehicle camera  43 , and identifies a visual object of the operator. In addition, the behavior detection unit  303  detects operation contents of the excavator  100  operated by the operator, based on an output of the manipulation device  45 . 
     Next, the controller  30  calculates the safety behavior evaluation value of the operator, based on the behavior of the operator which is detected in Step S 4  (Step S 5 ). As described above, the safety behavior evaluation value is a numerical value obtained by quantitatively evaluating the behavior taken by the operator during the occurrence of the risk in terms of a degree of contribution to safety in the periphery of the excavator  100 . In the present embodiment, as the safety behavior evaluation value is greater, the degree of contribution to safety is higher. 
     In Step S 5 , the behavior evaluation unit  304  of the controller  30  calculates the safety behavior evaluation value, based on the content of the risk detected in Step S 2  and the behavior of the operator which is detected in Step S 4 . Here, the content of the risk is a type of the risk (in the present embodiment, existence of the obstacle and the unstable state of the excavator  100 ), or a degree of the risk (for example, a type of the obstacle (person or thing), and a distance between the obstacle and the excavator  100 ). 
     Specifically, the behavior evaluation unit  304  calculates the safety behavior evaluation value by using a rule base. That is, the behavior evaluation unit  304  determines whether or not the behavior of the operator is coincident with a predetermined evaluation behavior set in advance, and when both are coincident with each other, the behavior evaluation unit  304  adds or deducts a point assigned to the coincident evaluation behavior. This process is performed for behaviors of all operators, and the safety behavior evaluation value is calculated as a total score in that case. 
     For example, the evaluation behavior to which the safety behavior evaluation value is added includes the following.
         The image of the imaging device  40  is confirmed by visually recognizing the display unit  50 .   The operation of the excavator  100  is carefully (gently) treated.   The operation of the excavator  100  is stopped.   The outside of the cabin  10  is visually confirmed.   The external notification device  70  is operated to notify the risk toward the periphery of the excavator  100 .   When the obstacle is detected in the periphery, the vehicle body (lower traveling body  1 , rotating platform  3 , and attachment) is operated in a direction away from the obstacle. Alternatively, the work is continued without bringing the vehicle body close to the obstacle.   When the unstable state of the excavator  100  is detected, the excavator  100  is operated to eliminate the unstable state. For example, an excavation point and a main body of the excavator are brought relatively close to each other so that the center of gravity is less likely to be separated. In addition, a traveling speed or an operation speed is slowed down.       

     For example, the evaluation behavior from which the safety behavior evaluation value is deducted includes the following.
         The excavation operation of the excavator  100  is continued as it is (no change is observed in the operation content).       

     The contents of the evaluation behavior may vary depending on the contents of the detected risk (type or degree thereof). In addition, even when the evaluation behaviors are the same as each other, different points may be set depending on the contents of the risk. 
     A point corresponding to a degree of contribution to safety is assigned to each of the evaluation behaviors. For example, a greater addition point may be assigned to the evaluation behavior for “stopping the operation of the excavator  100 ” than the evaluation behavior for “slowing down the operation of the excavator  100 ”, in that contact between the excavator  100  and the obstacle can more reliably be avoided. 
     For example, the evaluation behavior may be set by using machine learning such as naive Bayes or a neural network. 
     The calculated safety behavior evaluation value is stored in the storage unit  310  as the safety behavior evaluation information  3101 . In this case, the stored safety behavior evaluation value is stored in the storage unit  310  in association with the above-described work-related information relating to the work when the evaluation is made. The work-related information is acquired in advance or when needed by the information output unit  305 , and is stored in the storage unit  310 . 
     Thereafter, at least when the risk detected in Step S 2  is eliminated and the excavator  100  returns to a normal state, the controller  30  outputs the safety behavior evaluation value calculated in Step S 5  (Step S 6 ). 
     In this step, the information output unit  305  of the controller  30  uses a graph collectively illustrating the safety behavior evaluation value calculated in the Step S 5  and the past safety behavior evaluation value relating to the same operator (refer to  FIG.  4   ), for example. In this manner, the graph is displayed on the display unit  50 , or is output from a printer (not illustrated). For example, a result may be output in Step S 6  after the work is completed. 
     Next, the controller  30  determines whether or not the work is completed by the excavator  100  (Step S 7 ), and when the controller  30  determines that the work is not completed (Step S 7 ; No), the process proceeds to Step S 1  described above, and the controller  30  continues the work. In this manner, detection of the risk, notification thereof, detection of the behavior of the operator, and evaluation thereof are sequentially performed and repeated until it is determined that the work is completed. 
     In addition, when it is determined that the work is completed, for example, when a power source such as an engine of the excavator  100  is stopped by the operator, and at least in a state where an actuator of the attachment is not moved even when the actuator is operated (Step S 7 ; Yes), the controller  30  completes the behavior evaluation process. When electric storage unit is provided, in a state where the actuator is not moved even when the actuator is operated, the above-described process can be performed by activating the imaging device  40  or the controller  30 . 
     Technical Effects of Present Embodiment 
     As described above, according to the present embodiment, when the risk relating to a state of the excavator  100  or the surrounding environment is detected, the operator is notified of the risk, and the behavior of the operator after the notification is detected. Then, based on the contents of the detected risk and the behavior of the operator, the safety behavior evaluation value obtained by quantitatively evaluating the behavior of the operator in terms of a degree of contribution to safety is calculated. 
     In this manner, the behavior of the operator of the excavator  100  when the risk occurs can quantitatively be evaluated from a viewpoint of safety, and safety of the work site can be improved. 
     In addition, the calculated safety behavior evaluation value is output in a visually recognizable manner. Accordingly, the operator himself or herself or the work-related persons can recognize the safety behavior evaluation value, and can reflect the safety behavior evaluation value in improving safety of the work site. 
     In addition, the safety behavior evaluation value relating to the same operator is output as a graph comparing changes in each predetermined time unit (for example, a day). Accordingly, a change in the safety behavior of the operator can easily be recognized. 
     Modification Example 
     Subsequently, a modification example of the above-described embodiment will be described. 
     This modification example is different from the above-described embodiment in that the safety behavior evaluation information acquired by the plurality of excavators  100  is managed by a management server and can be read by using an information terminal. The same reference numerals will be assigned to component the same as those in the above-described embodiment, and description thereof will be omitted. 
       FIG.  6    is a block diagram illustrating a system configuration of an information management system  200  according to this modification example. 
     As illustrated in drawing, the information management system  200  is configured to include a plurality of excavators  100  ( 100 A,  100 B,  100 C, and  100 D in this modification example) configured to be similar to each other, a management server  400 , and an information terminal  500 . In  FIG.  6   , the configuration of the excavator  100  ( 100 B,  100 C, and  100 D) other than the excavator  100 A is omitted in the illustration. 
     The plurality of excavators  100  can transmit and receive various information to each other through the communication network  150  by each of the communication devices  80  provided therein, and can also transmit and receive various information to and from each of the management server  400  and the information terminal  500  through the communication network  150 . 
     The management server  400  is an example of an information management device according to the embodiment of the present invention, and for example, is a server device installed in a management center provided outside a work site where the plurality of excavators  100  carry out work. The management server  400  may be an in-house server operated by a business person who operates the information management system  200  or a related business person thereof, or may be a so-called cloud server. 
     Specifically, the management server  400  includes a communication device  410  and a control device  420 . 
     The communication device  410  can transmit and receive various information to and from each of the plurality of excavators  100  through the communication network  150 . 
     The control device  420  controls various operations in the management server  400 . The control device  420  includes a storage unit  421  serving as a storage region defined in an internal memory such as EEPROM, and stores and manages various information in the storage unit  421 . For example, the safety behavior evaluation value (safety behavior evaluation information  3101 ) calculated by each of the excavators  100  is stored (accumulated) in the storage unit  421  as the safety behavior evaluation information  4210 . 
     For example, the information terminal  500  is a mobile terminal such as a tablet or a smartphone possessed by a user. The user can access and read various work records inside the information management system  200  through the information terminal  500 . The information terminal  500  may be a stationary computer terminal or a portable computer terminal. 
     Specifically, the information terminal  500  includes a communication device  510 , a display unit  520 , and a control device  530 . 
     The communication device  510  can transmit and receive various information to and from each of the plurality of excavators  100  and the management server  400  through the communication network  150 . For example, the display unit  520  is a liquid crystal display or an organic electroluminescence (EL) display, and may be a touch panel type that also serves as an operation unit. The control device  530  controls various operations in the information terminal  500 . 
     In the information management system  200 , while each of the plurality of excavators  100  is operated in substantially the same manner as in the above-described embodiment, the safety behavior evaluation value (safety behavior evaluation information  3101 ) acquired by each of the excavators  100  is transmitted to the management server  400 . In this manner, all of the safety behavior evaluation values are stored in the management server  400  as the safety behavior evaluation information  4210 . 
     The user who possesses the information terminal  500  can read the safety behavior evaluation information  4210  stored in the management server  400  through the communication network  150 . In this case, the control device  530  of the information terminal  500  receives the desired safety behavior evaluation information  4210  from the management server  400  through the communication network  150 , stores (or temporarily stores) the desired safety behavior evaluation information  4210  in a storage unit (not illustrated), for example, and causes the display unit  520  to display the desired safety behavior evaluation information  4210 . 
     A display mode in this case is not particularly limited, and for example, as in the above-described embodiment, the safety behavior evaluation may collectively be displayed in one graph for each operator. Alternatively, for example, as illustrated in  FIG.  7   , the safety behavior evaluation values relating to a plurality of operators belonging to a business person may collectively be displayed (output) in one graph for each business person participating in a construction so that the operators can be compared with each other. In this manner, the plurality of operators can relatively be evaluated from a viewpoint of safety. 
     A timing at which information is transmitted from each of the excavators  100  to the management server  400  is not particularly limited, and for example, the timing may be after a series of the works is completed. 
     In addition, the safety behavior evaluation value and the work-related information may be associated with each other by each of the excavators  100  for which the safety behavior evaluation value is calculated, or may be associated with each other by the management server  400 . When being associated with each other by the management server  400 , the work-related information may be transmitted from the excavator  100  to the management server  400 . Alternatively, a configuration (partial function of the information output unit  305  in the excavator  100 ) which can acquire the work-related information may be provided in the management server  400 . 
     In addition, the management server  400  may perform the display in the same manner as the information display (output) on the information terminal  500 . In this case, the control device  420  of the management server  400  may output the information the same as that of the information terminal  500  described above from a display unit or a printer (not illustrated) provided in the management server  400 . 
     In addition, the safety behavior evaluation value may be calculated by the management server  400 . In this case, the management server  400  may store information required for calculation (evaluation behavior described above) in advance, may acquire information on the contents of the risk and the behavior of the operator from each of the excavators  100 , and may calculate the safety behavior evaluation value. 
     Others 
     Hitherto, the embodiment of the present invention has been described. However, the present invention is not limited to the above-described embodiment. 
     For example, in the above-described embodiment, as the risk relating to the state or the surrounding environment of the excavator  100 , the entry of the obstacle to the periphery of the excavator  100  and the unstable state of the excavator  100  are detected. However, for example, other risks such as inattentive driving of the operator may be included. In this case, when a configuration capable of detecting the risk is required, the configuration is provided in the excavator  100 . 
     In addition, in the above-described embodiment, the obstacle in the periphery of the excavator  100  is detected, based on the captured image of the imaging device  40 . However, instead of or in addition to the captured image of the imaging device  40 , the obstacle in the periphery of the excavator  100  may be detected, based on a detection result (distance image) of other sensors, for example, such as a millimeter wave radar, light detection and ranging (LIDAR), and a stereo camera. In this case, these other sensors are provided in the excavator  100 . 
     In addition, the work machine according to the embodiment of the present invention may be work machines other than the excavator, for example, such as a wheel loader, an asphalt finisher, a forklift, and a crane. 
     In addition, the information management system according to the embodiment of the present invention may include other work machines different therefrom. 
     In addition, details in the above-described embodiment can be appropriately changed within the scope not departing from the concept of the invention. 
     As described above, the work machine information processing device, the information management system, and the work machine information processing program according to the embodiment of the present invention are usefully adopted in improving safety of a work site. 
     It should be understood that the invention is not limited to the above-described embodiment, but may be modified into various forms on the basis of the spirit of the invention. Additionally, the modifications are included in the scope of the invention.