On-line fault judgment and early-warning method for displacement sensor based on dynamic soft reduction

The invention relates to an on-line fault judgment and early-warning method for a displacement sensor based on dynamic soft reduction, and belongs to the technical field of continuous casting equipment maintenance in the metallurgical industry. The technical scheme is as follows: operation and judgment are carried out in a central system-roll gap control system PLC (programmable logical controller) S7-400 of a continuous casting machine; and by presetting judgment conditions in advance, the roll gap control system PLCS7-400 judges the fault status of the displacement sensor, sends a signal toan execution mechanism at a sector segment so as to take measures and meanwhile sends early-warning prompt to a continuous-casting master control system. By adopting the method, faults at the sector segment can be pre-warned in advance and on-line fault judgment can be carried out on the displacement sensor, thus effectively preventing abnormal change of the roll gap at the sector segment caused by the faults of the displacement sensor, realizing comprehensive monitoring and automated management of key equipment during the whole continuous casting production process, keeping stable continuouscasting production, improving the process control level and the product quality and creating economic benefit.