| 摘要 |
An area where a front device 1A is movable is set beforehand. A control unit 9 calculates the position and posture of the front device lA based on signals from angle sensors 8a - 8c, etc. When the front device is inside the set area near the boundary thereof, the control unit 9 calculates a limit value a of a bucket tip speed so that a moving speed of the front device in the direction vertical to the boundary of the set area is restricted, and then modifies the limit value a depending on a load pressure of an arm cylinder 3b detected by a pressure sensor 41a. It further calculates, from the limit value a, a limit value of the component of a boom-dependent bucket tip speed vertical to the boundary of the set area, and then modifies a boom operation signal so that the boom-dependent bucket tip speed will not exceed the above limit value. Thus, the ground can be excavated to the boundary of the set area without being affected by hardness of the ground to be excavated, while resoring to a simple program. <IMAGE> |
