Construction machine control system and method of controlling construction machine

Abstract

A control method includes: detecting an attitude of a work machine including a boom, an arm, and a bucket; operating an operating device to drive a movable member including the arm and the bucket; detecting an amount of operation of the operating device; generating position data of a cutting edge of the bucket based on the detected attitude; acquiring a target shape of an excavation object to be excavated by the work machine and calculating a distance between the cutting edge and the target shape based on the position data and the target shape; setting a limited amount of operation limiting a speed of the movable member based on the detected amount of operation; and outputting a signal to a valve that adjusts an amount of operating oil supplied to a hydraulic cylinder driving the work machine so that the movable member is driven with the limited amount of operation.

1 . A construction machine control system comprising:
 a detector that detects an attitude of a work machine that includes a boom, an arm, and a bucket;   an operating device that is operated to drive a movable member that includes at least one of the arm and the bucket;   a detection device that detects an amount of operation of the operating device;   a control valve that adjusts an amount of operating oil supplied to a hydraulic cylinder that drives the work machine;   a bucket position data generating unit that generates cutting edge position data indicating a position of a cutting edge of the bucket based on a detection result of the detector;   a distance acquiring unit that acquires a target excavation landform indicating a target shape of an excavation object to be excavated by the work machine and calculates a distance between the cutting edge of the bucket and the target excavation landform based on the cutting edge position data and the target excavation landform;   a limit value setting unit that sets a limited amount of operation for limiting a speed of the movable member based on a detection result of the detection device; and   a movable member control unit that outputs a control signal to the control valve so that the movable member is driven with the limited amount of operation.   
     
     
         2 . The construction machine control system according to  claim 1 , wherein
 the limit value setting unit sets the limited amount of operation so that the larger the distance, the larger the limited amount of operation.   
     
     
         3 . The construction machine control system according to  claim 1 , further comprising:
 a timer that starts time measurement based on the detection result of the detection device, wherein   the limit value setting unit sets the limited amount of operation so that the longer a time elapsed from a start time of the time measurement of the timer, the larger the limited amount of operation.   
     
     
         4 . The construction machine control system according to  claim 3 , wherein
 the movable member control unit outputs a control signal so that the movable member is driven with the limited amount of operation in a predetermined period from the start time of the time measurement of the timer.   
     
     
         5 . The construction machine control system according to  claim 4 , wherein
 the start time of the time measurement of the timer includes at least one of a start time of an operation of the operating device, time at which a detection value of the detection device exceeds a threshold value, and a time at which an amount of increase per unit time of the detection value of the detection device exceeds an allowable value.   
     
     
         6 . The construction machine control system according to  claim 4 , wherein
 the driving based on the limited amount of operation is disabled when the predetermined period has elapsed from the start time of the time measurement.   
     
     
         7 . The construction machine control system according to  claim 3 , wherein
 the limited amount of operation in a first half of the predetermined period is smaller than the limited amount of operation in a second half.   
     
     
         8 . The construction machine control system according to  claim 1 , further comprising:
 a boom limiting unit that determines a speed limit according to the distance and limits a speed of the boom so that a speed at which the work machine approaches the target excavation landform is equal to or smaller than the speed limit; and   a hydraulic system that includes a first hydraulic actuator for driving the boom, a second hydraulic actuator for driving the movable member, and the control valve that adjusts an amount of operating oil supplied to the second hydraulic actuator, wherein   in an excavation operation of the bucket, the hydraulic system is operated so that the boom is raised and the arm is lowered, and   the arm is driven with the limited amount of operation when the arm is lowered.   
     
     
         9 . The construction machine control system according to  claim 8 , wherein
 the hydraulic system includes:   a hydraulic pump that supplies operating oil; and   a pump control unit that controls the hydraulic pump so that the operating oil is supplied with a first largest discharge capacity from the hydraulic pump in a first operation mode and the operating oil is supplied with a second largest discharge capacity smaller than the first largest discharge capacity from the hydraulic pump in a second operation mode, and   the limited amount of operation in the second operation mode is smaller than the limited amount of operation in the first operation mode.   
     
     
         10 . The construction machine control system according to  claim 1 , wherein
 the movable member is replaceable, and   the limited amount of operation when the movable member of a first weight is connected to the boom is smaller than the limited amount of operation when the movable member of a second weight smaller than the first weight is connected.   
     
     
         11 . The construction machine control system according to  claim 1 , wherein
 the output of the control signal is started so that the movable member is driven with the limited amount of operation when an amount of increase per unit time of the detection value of the detection device exceeds an allowable value, and   the amount of increase includes a difference between the amount of operation of the operating device and a processing amount generated by low-pass filtering of the amount of operation.   
     
     
         12 . The construction machine control system according to  claim 1 , wherein
 the construction machine includes a vehicle body that supports the boom, and   the limited amount of operation when the work machine is driven so that a distance between the bucket and a reference position of the vehicle body is a first distance is smaller than the limited amount of operation when the work machine is driven so that the distance between the bucket and the reference position is a second distance shorter than the first distance.   
     
     
         13 . The construction machine control system according to  claim 1 , wherein
 the output of the control signal is started so that the movable member is driven with the limited amount of operation when an amount of increase per unit time of the detection value of the detection device exceeds an allowable value, and   the amount of increase includes a difference between the amount of operation of the operating device and a processing amount generated by low-pass filtering of the amount of operation.   
     
     
         14 . A method of controlling a construction machine, comprising:
 detecting, by a detector, an attitude of a work machine that includes a boom, an arm, and a bucket;   operating an operating device to drive a movable member that includes at least one of the arm and the bucket;   detecting, by a detection device, an amount of operation of the operating device;   generating cutting edge position data indicating a position of a cutting edge of the bucket based on a detection result of the detector;   acquiring a target excavation landform indicating a target shape of an excavation object to be excavated by the work machine and calculating a distance between the cutting edge of the bucket and the target excavation landform based on the cutting edge position data and the target excavation landform;   setting a limited amount of operation for limiting a speed of the movable member based on a detection result of the detection device; and   outputting a control signal to a control valve that adjusts an amount of operating oil supplied to a hydraulic cylinder that drives the work machine so that the movable member is driven with the limited amount of operation.