Research Of Sensor Fault Detection And Fault-tolerant Control On Vibration Control System Of Continuous Casting Mold

With the emergence and Application of fault diagnosis and fault-tolerance control,the security and reliability of the system have been improved.In recent years,the theory and application research of fault diagnosis and fault-tolerant control has attracted the attention of researchers at home and abroad.Progress has been achieved in many fields such as aerospace,wind power,etc.However,the theoretical research and practical application have not been reported in the field of continuous casting in the steel industry.Based on this,the theory and experimental research on fault detection and active fault-tolerant control are carried out for the sensor failure problem that may occur in the running process of continuous casting mold vibration control system.,the following aspects are mainly studied:Firstly,for the continuous casting mold vibration control system driven by a servo motor,an approximate mathematical model of the actual system under normal conditions is established,and the problems existing in the modeling are analyzed and processed.The problems that have occurred or may occur during the operation of the equipment are summarized.At the same time,the fault status space model of the control system is established.At the same time,the fault state space model of the control system is established,which lays a foundation for the fault detection and fault-tolerant control research in the subsequent chapters.Secondly,for the problem of sensor failure in continuous casting mold vibration control system,a sensor fault detection and diagnosis method based on sliding mode observer is studied.Combining the output state with the output filtering results in a new augmented state space system,which in turn transforms the sensor failures reflected in the output equations into imaginary actuator failures that are reflected in the state equations.By designing a sliding mode observer,the estimated values of different faults of the sensor are obtained.The estimated value of the sensor at different failures was obtained.Through the simulation,the designed sliding mode observer can achieve the purpose of fault detection.Thirdly,for the problem of position sensor failure in continuous casting mold vibration control system,we investigate the related researches on fault detection and active fault-tolerant control.By introducing a reference model,the residuals of system output were evaluated based on norm residuals,and fault tolerance was designed.Once the sensor fault is detected,it will be switched to the positioning shift curve,and the original closed-loop controller and feed-forward controller of the system will be adjusted to ensure that the system can still operate safely and stably under sensor fault conditions.The effectiveness of this method is verified through simulation.Finally,Aiming at the problem of position sensor failure in continuous casting mold vibration control system driven by servo motor,on the basis of understanding and mastering the laboratory experiment platform,the switching fault-tolerant control strategy of position sensor failure in the actual working environment is studied and tested.And use the upper computer monitoring interface to verify the effectiveness of the designed fault-tolerant control function.The effectiveness of fault-tolerant control methods is verified by using host computer monitoring interface.