Research On Fault-Tolerant Control Of Vibration Displacement System Of Continuous Casting Mold Driven By Servo Motor

The steel industry plays an important role in today's rapidly developing China.The performance of the continuous caster directly affects the quality of the cast slab.The mold in the continuous caster provides the basic role of cooling and forming for the initial stage of the formation of the slab shell.The non-sinusoidal vibration of the continuous casting mold driven by the servo motor has the advantages of energy saving and consumption reduction,improvement of the quality of the cast slab,and increase of the drawing speed.Due to problems such as high ambient temperature and long-term wear and tear of mechanical equipment,failures of the sensors and actuators of the continuous casting mold vibration displacement system occur from time to time,and the performance of the system will decrease or even become unstable,which will cause problems such as production safety.In this paper,the fault diagnosis and fault-tolerant control of the continuous casting mold vibration displacement system driven by the servo motor are studied.The specific contents are as follows:First,according to the continuous casting mold vibration displacement system driven by the servo motor,the mechanism model of the continuous casting mold vibration displacement system is derived based on the servo motor speed closed loop system and the related mathematical model of the mechanical transmission part,and then the possible failures of the system The situation is modeled,and a nonlinear mathematical model of the continuous casting mold vibration displacement system with faults is obtained.Secondly,for the continuous casting mold vibration displacement system with uncertain parameters and partial failures of the actuator,an adaptive robust fault-tolerant control method is proposed.This method estimates the lower bound and sum of the actuator efficiency factor by designing an adaptive law Uncertain the upper bound of the parameter,and introduce the estimated value into the adaptive fault-tolerant controller for compensation,so as to reduce the influence of the uncertain parameter and actuator failure,and enhance the robustness of the system.Thirdly,for the continuous casting mold vibration displacement system with sensor failure,an observer-based fault diagnosis and fault-tolerant control strategy is proposed.The fault detection observer,the fault estimation filter and the dynamic output feedback fault-tolerant controller are used to judge,estimate and fault-tolerant control of the continuous casting mold vibration system sensor faults to ensure the system after the continuous casting mold vibration system displacement sensor failure occurs.The stability.Finally,for the continuous casting mold vibration displacement system with both actuator failure and sensor failure,a sliding mode fault-tolerant control method based on unknown input observer is designed.The method estimates the system failure by constructing unknown input observer Then,the sliding mode controller is designed to perform fault-tolerant control of the faulty system,and the unknown input observer and the design process of the sliding mode fault-tolerant controller are combined to simplify the design process and optimize the system performance.