Before operation control device for an excavator with three joints

摘要

Two operating lever devices (11, 12) are provided for operating a first arm (3), a second arm (4) and a third arm (5) of a three-joint type work front (2), and signals (132, 133) from the two operating lever devices are forwarded to a controller (131). In the controller (131), a two-joint type work front having a first virtual arm (13) and a second virtual arm (14) are virtually provided, a relationship between the both work fronts is set so that the second virtual arm (14) and the third arm (5) move as if they form a rigid body, command values φ1, φ2, φ3 of the respective actual first arm (3), second arm (4) and third arm (5) are determined and outputted to proportional pressure reducing valves (129, 130) of a hydraulic drive device as drive command signals so that an angular velocity of the second virtual arm, when the two operating lever devices (11, 12), respectively, are caused to function as the first operating lever device (11) for the first virtual arm (13) and as the second operating lever device (12) for the second virtual arm (14), can be obtained as an angular velocity of the actual third arm. Accordingly, it is possible to operate the three-joint type work front (2) in a range of an operator's normal skill with an operating sense which is identical to that for the two-joint type work front.