Patent ID: 9725874
Date: 2017-08-08
CPC Classifications: E02F

Claim:
1. An area limiting excavation control system for construction machines comprising: a multi-joint work implement assembly configured by connecting a plurality of driven members that can each rotate about a rotating shaft provided on a joint; a plurality of hydraulic actuators each adapted to drive one of the plurality of driven members to rotate about the rotating shaft; a plurality of operating units each adapted to give a motion instruction to one of the plurality of hydraulic actuators in accordance with a operation amount thereof; a plurality of flow control valves each driven in response to an operation signal output in accordance with the operation amount of one of the plurality of operating units to control a flow rate and a flow direction of a hydraulic fluid supplied to one of the plurality of hydraulic actuators; and a control unit configured to execute an area limiting control which controls at least one of a driving direction and a driving speed of at least one of the plurality of hydraulic actuators based on the operation amount of each of the plurality of operating units and a posture and a position of each of the driven members such that the closer a distance from a boundary of a set area within which a tip portion of the work implement assembly can move, to the tip portion to zero, the closer a speed vector component of the tip portion perpendicular to the boundary to zero, the area limiting excavation control system further comprising: a first sensor group consisting of a plurality of sensors for detecting rotation angles of the plurality of driven members relative to the respective rotating shafts, respectively; and a second sensor group consisting of a plurality of sensors for detecting tilting angles of the plurality of driven members relative to a reference plane, respectively, the control unit configured to select, during execution of the area limiting control, from among the first sensor group and the second sensor group, a sensor to use for calculating a posture and a position of each of the plurality of driven members, in accordance with a magnitude of speed of at least one of the plurality of driven members.