FIXED TENSION CONTROL SYSTEM OF TYPE SYSTEM CABLE ENGINE

PURPOSE:To make the stable set tension control by adding feedforward control, which the speed of ship is converted into a feedforward signal, to feedback control making a proportional plus integral control for variation between set tension and cable tension. CONSTITUTION:A ship speed signal S19 to be obtained from a ship speed sensor 18 and a variation signal between a set tension signal S1 and a detected tension signal S2, in other words, a cable speed command signal S3 outputted from comparator 3, are added to an adder 20. This adding signal S20 is inputted to a speed controller 4 and an operational amplifier 21 for forming a feedforward signal. The signal 20 is compared with a cable speed detected signal S3 at the speed controller 4, PI operational control of its variation is made at a PI(proportional plus integral) controller 5. Then, an output signal of the operational amplifier 21 and an output signal of the PI controller 54 are added to an adding and subtracting machine 6. Accordingly, cable tension is not subjected to a major variation against a set point.