Research On Fault Detection And Fault Tolerance Control Of Vibration Displacement System Of Continuous Casting Mold

The continuous casting mold is one of the important equipment in the steel forming process,and its stable and safe operation has a positive effect on the entire steel industry.However,due to the harsh working environment and the long maintenance cycle of equipment,aging of equipment components and motor failures are common.These problems will lead to a decrease in the displacement tracking accuracy of the mold displacement system,and even a steel breakout accident,which will affect the quality of the billet and even endanger the safety of the staff.Therefore,this paper studies the fault detection and fault-tolerant control for possible sensor faults and actuator faults.The main work is as follows:Firstly,a fault detection method based on an unknown input interval observer is proposed to solve the problems of displacement sensor and rotational speed sensor faults and motor load disturbance in the system.An unknown input observer is designed for the system without sensor failure,which isolates the motor load disturbance structurally.On this basis,an interval observer is designed to obtain the upper and lower bounds of the state in the state of no sensor failure.By judging whether the system state is The upper and lower bounds of the interval observer are exceeded to judge whether the sensor is faulty.The effectiveness of the proposed fault detection method is verified by theoretical derivation and simulation comparison.Then,aiming at the problem of displacement sensor failure and motor load disturbance in the system under noise condition,a fault detection method based on particle swarm optimization particle filter algorithm is proposed.The estimated value of the system is obtained from the data collected by the system by using the particle swarm optimization particle filter algorithm,and the residual error is constructed with the system observation value,and whether the displacement sensor fault occurs in the system is judged by judging whether the residual error exceeds the set threshold.The introduction of non-linear change weight and adaptive mean speed update makes the algorithm improve the global exploration ability and local development ability of the algorithm,and maintain the balance between the two.The effectiveness of the proposed fault detection method is verified by comparative simulation.Finally,aiming at the problem of displacement sensor and actuator failure and motor load disturbance in the system,an output feedback fault-tolerant control method based on generalized state observer is designed.The proposed generalized state observer can estimate the system state and fault conditions at the same time,then introduces the intermediate variable to eliminate the derivative term in the observer,improves the accuracy of the state observer,uses the estimated state generated by the observer,and uses the output Feedback fault-tolerant control method to construct fault-tolerant controllers.The effectiveness of the proposed observer and controller is verified by simulation comparison with PI control method.