| 摘要 |
<p>An area where a front device (1A) is allowed to move is set beforehand and the operation of the front device is controlled so that the front device will not go out of the set area. For this control process, an arm cylinder speed calculating portion (9d) of a control unit (9) estimates an arm cylinder speed for use in control by taking the sum of a low-frequency component of an arm cylinder speed which is derived through coordinate transformation and differentiation of an arm rotational angle detected by an angle sensor (8b), and a high-frequency component of an arm cylinder speed which is derived from a command value applied from a control lever unit (14b) to a flow control valve (15b) for an arm and a flow rate characteristic of the flow control valve (15b). The control unit controls the operation of the front device with the estimated operating speed. The operation of the front device is thereby controlled smoothly and accurately regardless of change in any parameters, such as load and fluid temperature, affecting the flow rate characteristic of the flow control valve. <IMAGE></p> |
