Monitoring device and construction machine

Abstract

A monitoring system calculates, based on a contour data, a first slope angle representing an inclination angle of a slope to a ground surface on which a construction machine stands, detects a ground surface angle representing an inclination angle of the ground surface to a horizontal plane, calculates a second slope angle representing an inclination angle of the slope to the horizontal plane by adding the first slope angle to the ground surface angle, calculates a relative angle of a longitudinal direction of a lower traveling body to an inclination direction of the slope, and determines that the construction machine is in an unstable state when the second slope angle is larger than a first threshold and the relative angle is larger than a second threshold.

1 . A monitoring system for monitoring a state of a construction machine including: a lower traveling body which has a longitudinal direction and travels in the longitudinal direction; an upper slewing body configured to be slewable with respect to the lower traveling body; and a working device mounted on the upper slewing body, the monitoring system comprising:
 an acquisition part which acquires contour data representing a contour of a landform around the construction machine;   a first slope angle calculation part which calculates, based on the contour data, a first slope angle representing an inclination angle of the slope to a ground surface on which the construction machine stands;   an inclination sensor which detects a ground surface angle representing an inclination angle of the ground surface to a horizontal plane;   a second slope angle calculation part which calculates a second slope angle representing an inclination angle of the slope to the horizontal plane by adding the first slope angle to the ground surface angle;   a relative angle calculation part which calculates a relative angle of the longitudinal direction of the lower traveling body to an inclination direction of the slope; and   a state determination part which determines that the construction machine is in an unstable state when the second slope angle is larger than a first threshold and the relative angle is larger than a second threshold, and outputs a determination signal indicating a determination result.   
     
     
         2 . The monitoring system according to  claim 1 , further comprising an alarming device which outputs an alarm when the determination signal output from the state determination part indicates the unstable state. 
     
     
         3 . The monitoring system according to  claim 1 , further comprising a restriction part which restricts a traveling operation of the lower traveling body when the determination signal output from the state determination part indicates the unstable state. 
     
     
         4 . The monitoring system according to  claim 1 , further comprising:
 a slewing sensor which detects a first slewing angle representing a slewing angle of the upper slewing body to the lower traveling body, wherein   the state determination part calculates, based on the relative angle and the first slewing angle, a second slewing angle representing a slewing angle of the longitudinal direction of the upper slewing body to the inclination direction of the slope, and reduces at least one of the first threshold and the second threshold as the second slewing angle decreases.   
     
     
         5 . The monitoring system according to  claim 3 , wherein the restriction part suspends the lower traveling body from traveling in a direction of increasing a degree of the unstable state and permits the lower traveling body to travel in a direction of decreasing a degree of the unstable state when the state determination part determines the unstable state. 
     
     
         6 . A construction machine comprising:
 the monitoring system according to  claim 1 ;   a lower traveling body;   an upper slewing body configured to be slewable with respect to the lower traveling body; and   a working device mounted on the upper slewing body.