Torsional Vibration Control of the Main Drive System of a Rolling Mill Based on an Extended State Observer and Linear Quadratic Control

Abstract

In the main drive system of a rolling mill, shaft torsional vibration is often generated when a motor and a roll are connected with a flexible shaft. State feedback control can effectively suppress the torsional vibration of the main drive system of a rolling mill. Because of the difficulty of measuring the load speed and the shaft torque, and moreover the sensitivity of the Luenberger observer to the model uncertainties and the noise include in the detected signal, in this paper, we propose an extended state observer (ESO), a new observer, to estimate the unknown states and the load torque disturbance. We propose an ESO and linear quadratic (LQ) based speed controller with an integrator and load torque feedforward compensation for torsional vibration suppression in a two-mass main drive system of a rolling mill. The simulation results show the controller effectively improves the performances of command following, torsional vibration suppression, and robustness to parameter variation. This is the first time that the ESO has been utilized in torsional vibration control of the main drive system of a rolling mill, and its validity and superiority is verified in comparison with the conventional proportional integral (PI) controller and the state feedback controller based on a reduced-order state observer.

Extended-State-Observer-Based Control of Flexible-Joint System With Experimental Validation

“…The application of ESO in disturbance rejection control for uncertain multivariable systems with time delay [24], a DSP-based active disturbance rejection control design for a power converter [25], robotic hand-eye coordination [26], control of flexible-joint system [23], precision motion control [27], aircraft attitude control [28], and torsional vibration control of the main drive system of a rolling mill [29] are some examples to mention. In this section, a brief review of this approach and its application to state and uncertainty estimation for the present problem are presented.…”

Experimental validation of robust predictive controller

“…The ESO can estimate the effect of uncertainties along with the states of the system enabling disturbance rejection. The approach has been used in a large number of applications in diverse fields such as in robust control for MEMS Gyroscopes [22], speed control of induction motor drive [23], motion control of a Stewart platform [24], torsional vibration control of main drive system of a rolling mill [25], robotic hand-eye coordination [26], control of flexible joint system [19], [27], pitch autopilot design for tactical missiles [16], [28], height control system for sea-skinuning missiles [29]. In this section, the approach is employed to robustify the predictive controller (12).…”

Research on dynamic load characteristics and active control strategy of electro-mechanical coupling powertrain of drum shearer cutting unit under impact load

“…The torsional vibration responses of system were obtained, and the influences of the nonlinear damping and nonlinear stiffness of shafting on vibration responses of the rolling mill's drive system were discussed. Additionally, a new control concept was proposed by Zhang et al [15] for the drive system of a rolling mill to achieve vibration suppression and disturbance rejection based on extended state observer (ESO) and linear quadratic (LQ) controllers. Its validity and superiority was verified in comparison with a conventional PI controller.…”