Investigation of the Hydraulic Servo System of the Rolling Mill Using Nonsingular Terminal Sliding Mode-Active Disturbance Rejection Control

Abstract

In order to improve the disturbance rejection ability and tracking accuracy of the hydraulic servo system of the rolling mill, this study combines nonsingular terminal sliding mode control (NTSMC) with active disturbance rejection control (ADRC). A fourth-order extended state observer was designed to estimate the disturbance of the system in real time. The stability of the control system was tested using the Lyapunov method. System effectiveness was verified through simulation experiments. Simulation results showed that the designed state observer can estimate the total disturbance of the system in real time and that the chattering of the control input can be eliminated by the introduction of a state observer. In terms of uncertainty in the system model caused by load changes and external interference signals, the nonsingular terminal sliding mode-active disturbance rejection control method exhibited better disturbance rejection capacity and a higher tracking accuracy than NTSMC.

Application of Modern Multimedia and Sensing Technology in Fault Detection and Diagnosis of Hydraulic Agricultural Machinery

“…The method trains and learns the data dictionary through iterative calculation and can continuously modify the atoms in the dictionary based on the sparse decomposition coefficient during the training process and finally obtain an overcomplete data dictionary. The training speed of the K-SVD algorithm is fast, the compatibility is strong, and it can be coupled with most tracking algorithms, as shown in formula (6). The K-SVD algorithm dictionary learning process is as follows:…”

“…Hydraulic systems are widely used in agricultural machinery, many agricultural machineries such as tractors, harvesters, and sprayers are equipped with hydraulic systems, and hydraulic systems also play an important role in the function of agricultural machinery [6]. The hydraulic system cannot only realize the rapid transmission of power but also assist agricultural machinery to achieve various functions; it can be said that the normal operation of agricultural machinery is inseparable from the hydraulic system [7].…”

Fixed‐time prescribed performance optimization control for the speed and tension system of the cold strip rolling mill with output constraints

“…In Reference 8, the command filtered method was employed to solve the problem of the “differential explosion”, and the finite‐time controller based on the backstepping control method was designed to guarantee the tracking errors converge in finite time, which exhibited faster convergence speed and stronger robust stability for the system. In Reference 9, a fourth‐order extended state observer was used to dynamically observe the disturbance of the rolling mill system, and a nonsingular terminal sliding mode controller was designed, which enabled the system states to converge in finite time and achieve relatively high control accuracy.…”

“…It should be noted that most of the controller design methods in References 4–9 can only achieve asymptotic or finite‐time convergences of the system states. Among them, the former is when $$$ t\to \infty $$$, the system states can converge to equilibrium point or neighbors near equilibrium point, while it is difficult to meet people's requirements on the convergence speed and control accuracy of the rolling mill system in practice.…”

“…In addition, References 4–9 mainly focused on improving the steady‐state performance of the cold strip rolling mill system, but the transient‐state performance and output constraints of the system were not fully considered. For the cold strip rolling mill system in this article, if the speed and tension output states are constrained and stably operate in feasible range, then the impact on the rolling mill equipment during rolling production can be reduced, and belt breaking, steel stacking and other production accidents can be avoided.…”