Control system and method of multi-roll straightening machine of cold-rolling recoiling unit

The invention provides a control system and method of a multi-roll straightening machine of a cold-rolling recoiling unit. A belt head position correction sensors are arranged at main detection points, an uncoiling motor is connected with an encoder, mode selectors are arranged on a plurality of operating tables, and a three-section tension selection procedure tensiometer and a belt head position calculation procedure are established in a PLC (programmable logic controller). When the straightening machine is put into operation, the maximum speed of an uncoiling, shearing and coiling motor is limited through an automatic control system and kept consistent with the maximum speed of the multi-roll straightening machine and a tension roll, so that the correction effect of the plate shape of a steel strip can be ensured; and when the straightening machine is not put into the operation, the purposes of assisting in penetrating the strip and declutching can be achieved by automatic control, the life cycle of a straightening roll is prolonged, the expenditure is reduced and the productivity of the recoiling unit with the multi-roll straightening machine can be improved. The production preparation time of the steel strip can be improved by above 70%, the energy consumption of the unit can be reduced by 50%, the grinding proportion of the straightening roll to the tension roll is reduced by 10%, and the design productivity of the recoiling straightening unit is upgraded by 30%-40%.