The Displacement Tracking Control For Vibration System Of Continuous Casting Mold Driven By Servo Motor

The continuous casting mold is the key device of continuous casting technique. The vibration of continuous casting mould according to the expectations of non sinusoidal(or sine) wave vibration has an important role to improve the casting slab quality and increase the casting speed, which has been recognized as one of the key technologies for the development of high efficiency continuous casting. Aiming at the problems of nonlinear and uncertain disturbance in the system, the theoretical and simulation study on the tracking control of continuous casting mold vibration displacement is completed. The relevant control procedures have been further improved on the basis of the vibration control system of continuous casting mold, which is developed in the laboratory, and then the field application test is carried out. The main work of this paper is as follows:Firstly, the overall structure and working principle of vibration system is described, and then the general mathematical model of servo motor driven continuous casting mold vibration displacement system is given; for the non-uniqueness of the nonlinear inverse relationship from the position angle of eccentric shaft to the displacement of continuous casting mold, a kind of mapping function is proposed to lay the foundation for the later chapters mold displacement tracking control.Secondly, Aiming at the problems of the measurement error of reduction ratio, load torque disturbances and the initial deviation of the eccentric shaft mechanical zero, which exist in displacement system of the continuous casting mold driven by servo motor, a backstepping control method based on prescribed performance is desigened. Equivalent displacement system error model is established through the error transformation and then selecting the appropriate backstepping function based on the Lyapunov stability theory to design the prescribed performance controller to guarantee the transient and steady state performance of the system. In addition, the nonlinear extended state observer status is structured to real-time estimate eccentric shaft speed and integrated disturbance to ensure the system’s interference. The effectiveness of the controller is verified by comparing simulation experiments.Thirdly, further studies is researched on the overall model of the vibration displacement system of continuous casting mould in this chapter, a backstepping sliding mode controller based on the extended state observer and double power reaching law is designed. A second-order sliding mode characteristics and double exponential reaching law convergencing in finite time is used to improve the convergence speed and weaken the chattering. And the simulation results are compared and verified, which shows that the controller designed in this chapter can achieve asymptotic displacement tracking control of crystallize and have robustness to the disturbance of system.Finally, in familiar and improvement of the original servo motor driver based on continuous casting crystallizer vibration control system in laboratory, and then application of control system equipment to the industrial field of Xuanhua Steel Corp. Experimental of motor parameter auto-tuning, switching between the vibration waveform and switching the mode of displacement sensors is researched in the actual work environment. Using real-time curve of pc monitored software and the actual sample data of drawn steel to verify the above procedure.