| 摘要 |
The present invention is intended to reduce the effect of a backlash in a swivel joint (7) for rotation of a feeder (3) on a boom (2) in a drilling rig, when the feeder (3) is to be brought into a new spatial position, through a measure and means to rapidly rotate the drive member, at least in the swivel joint (7) which has the greatest susceptibility to said backlash, into a position in which further adjustment results in a physical movement of the feeder (3). This is achieved in that when a movement of the relevant swivel joint (7) is ordered by the control system, a control loop in the drilling rig control system is initiated, which for a short time adjusts and drives the drive member in the swivel joint (7) at a high rate of adjustment until a movement of the feeder (3) can be detected, following which the control system adjusts the entire movement of the boom (2) and the feeder (3) at the speed ordered by the control system. |
