摘要 |
A torque command is computed by a proportional-plus-integral control element or a speed controller, which has proportional gain only, on the basis of a difference between a speed command signal, which is obtained by subtracting a damping controlled speed command compensating signal computed by adding a damping factor to a computed value of load torque of a travelling motor for driving a trolley or a computed value of deflection angle of a rope determined on the basis of a detected speed of the travelling motor from a speed command signal outputted from a speed commander in the travelling motor through a linear commander, and a detected speed signal of the travelling motor. The speed of the travelling motor is controlled in accordance with the torque command mentioned above. A damping factor is generated from the rotary shaft of the travelling motor with respect to the deflecting movement of the rope. This invention aims at preventing the deflection of the rope of a suspended type crane having a driving controller provided with the above-mentioned three functions, a lifting motor for hoisting a suspended load and a driving controller for this lifting motor. This invention enables the vibration of the rope occurring during the travelling, acceleration, and decelaration of the trolley to be minimized, and a crane in which the travelling speed of a trolley is maintained at a high level to be automatically operated. <IMAGE> |