Yuanwei Jing

Torsional Vibration Suppression of Rolling Mill with Constrained Model Predictive Control

Vibration suppression and disturbance rejection in torsional vibration system are important issue in rolling mill control. The two-mass resonant system which has a motor and a load connected with a flexible shaft is proposed. Model predictive control is applied to two-mass resonant system. The optimization problem with constraints is solved. The simulation results show that the proposed design improves dynamic performance and suppresses torsional vibration of rolling mill system. The validity of this design is confirmed

Application of IMC-Smith Controller in the Large-Delay Network Congestion Control

At present, the transmission delay of network brings disadvantages to network congestion control, and the existent algorithms depend on exactitude model excessively. Therefore, a new delay expiration controller is proposed. The controller is used in the active queue management (AQM) algorithm. The new controller combines inner mode controller (IMC) and Smith estimate controller of control theory to AQM algorithm. The new algorithm can compensate time delay beforehand, so it could control the network congestion in time. The stability and robustness of network system can be ensured by the new algorithm under the condition of the parameter changing in a wide range. The simulation results of the algorithm under different conditions show the superiority of the IMC-Smith AQM algorithm

Active Queue Management Algorithm Based on Neuron Dynamical Compensation PID Control

An active queue management (AQM) scheme based on neuron dynamical compensation PID control is proposed, it combines the advantages of neural network and traditional PID control. Through the way of learning and controlling on line to solve the insufficiency of traditional PID, and the controlled parameters can be adjusted online to ensure the stability of the network system around the desired operating point. Using the Jury stability standard gives the conditions to ensure the controlled system stability around its desired operating point. Simulation results demonstrate that this control scheme can lead to the convergence of the queue length to the desired value quickly and maintain the oscillation small. The results also show that this scheme is very robust to disturbance and outperforms the traditional PID controller significantly

On Time-Critical Data Transmission of EtherNet/IP

Ethernet industrial protocol (EtherNet/IP) is the network based on carrier sense multiple access/collision detected (CSMA/CD), and its application layer employs CIP certified to IEC61158, which satisfies the requirements of transferring time-critical I/O data in industrial field. The transferring mechanism of time-critical data was analyzed, thus the problem of uncertainty of data transferring is resolved

Feedback controller design for T-S fuzzy control systems based on Lyapunov approach

In this paper, the problems of relaxed robust quadratic stability conditions for a class of nonlinear systems described by T-S fuzzy model are proposed. Firstly, new quadratic robust stability condition is obtained by designing state feedback controller for T-S fuzzy systems with uncertainties. The condition is represented in the form of linear matrix inequalities (LMIs). Secondly, it presents dynamic output feedback control designs of complex nonlinear system which can be represented by T-S fuzzy systems. The new method considers the interactions among all fuzzy subsystems. Finally, the validity and applicability of the proposed approach are successfully demonstrated in the control of a continuous-time nonlinear system.

Discrete-Time Fuzzy Sliding Mode Control of Nonlinear Systems

This paper addresses the control problem of nonlinear systems based on the Takagi-Sugeno (T-S) fuzzy model. T-S model was adopted for fuzzy modeling of the nonlinear system. The global T-S fuzzy model of nonlinear systems was transformed into linear uncertain system model. So the stability problem of nonlinear systems becomes the robust stabilization problem of linear uncertain systems. Discrete-time sliding mode control approach was employed to guarantee robust stability of linear uncertain systems. The stable sliding surface was designed by using linear matrix inequalities to reduce the influence of mismatched uncertainties. The sufficient condition for the existence of stable sliding surface in terms of LMI was derived and the sliding mode control law was presented also, which guaranteed the global stability of the systems

Dual-rate inferential predictive control based on state-space model

Based on state-space model, a kind of method of designing inferential predictive control for dual-rate systems is given. The method has preferable robust stability. State estimator is introduced into dual-rate inferential predictive controller based on state-space model to estimate immeasurable state and solve the problem caused by immeasurable state when designing dual-rate inferential predictive control law. The simulation results show feasibility of the proposed method.

The Design of Robust H ∞ Filtering for Stochastic Uncertain Systems

The robust Hinfin filtering problem is considered for stochastic uncertain systems subject to norm-bounded parameter uncertainties in both state and output matrices of the state space model. The aim is to design a filter by auxiliary systems, which ensures both the robustly stochastic stability and prescribed level of Hinfin performance for the filtering error dynamics for all admissible uncertainty. The sufficient conditions for existing filter are derived. An LMI method for designing filter is given by matrix transformations, so it is convenient to obtain the expression of filter. At last, a numerical example shows that the method is effective and feasible

Robust Variable Structure Control for Uncertain Interconnected Systems Based on LMIs Approach

The problem of decentralized control was investigated for a class of mismatched uncertainties interconnected systems. Based on linear matrix inequalities approach, a sufficient condition of existing a group of linear sliding surfaces was given for uncertainties interconnected systems, and the variable structure controllers were designed. The controllers can guarantee that the state trajectory is directed towards to the linear sliding surfaces, sliding mode exists and the closed-loop systems are globe asymptotically stable. The design approach of controllers is simple, and the formation of the sliding surface is explicit. Finally, a simulation on the model of two inverted pendulums illustrates the proposed design approach

Modeling and State Observation Design of Simulated Moving Bed Process

Simulated moving bed (SMB) chromatography has become a widely used separation technology in the pharmaceutical and fine chemical industries. In particular, the separation of enantimeric mixtures has received recently great interest because it can achieve good performances and high productions. However, there are a lot of difficulties in the modeling of SMB chromatography process because of the great number of parameters involved and the computational burden needed for the solution of these models. To overcome these difficulties, a simplified SMB concentration model is derived which comprises a linear time-variant discrete-time state-space model. Furthermore, toward some parameter measurement limited, for example, discrete-time concentration, a state observation based on this model is designed. Simulation results are presented to show the applicability of the developed observer in the surrounding of the stationary operation point