An extended robust model predictive control approach for input constrained discrete uncertain nonlinear systems with time-delay based on a class of uncertain T-S fuzzy models that satisfy sector bound condition is pre...
详细信息
An extended robust model predictive control approach for input constrained discrete uncertain nonlinear systems with time-delay based on a class of uncertain T-S fuzzy models that satisfy sector bound condition is presented. In this approach, the minimization problem of the “worst-case” objective function is converted into the linear objective minimization problem in- volving linear matrix inequalities (LMIs) constraints. The state feedback control law is obtained by solving convex optimization of a set of LMIs. Sufficient condition for stability and a new upper bound on robust performance index are given for these kinds of uncertain fuzzy systems with state time-delay. Simulation results of CSTR process show that the proposed robust predictive control approach is effective and feasible.
Chemical process variables are always driven by random noise and disturbances. The closed-loop con-trol yields process measurements that are auto and cross correlated. The influence of auto and cross correlations on s...
详细信息
Chemical process variables are always driven by random noise and disturbances. The closed-loop con-trol yields process measurements that are auto and cross correlated. The influence of auto and cross correlations on statistical processcontrol (SPC) is investigated in detail by Monte Carlo experiments. It is revealed that in the sense of average performance, the false alarms rates (FAR) of principal component analysis (PCA), dynamic PCA are not affected by the time-series structures of process variables. Nevertheless, non-independent identical distribution will cause the actual FAR to deviate from its theoretic value apparently and result in unexpected consecutive false alarms for normal operating process. Dynamic PCA and ARMA-PCA are demonstrated to be inefficient to remove the influences of auto and cross correlations. Subspace identification-based PCA (SI-PCA) is proposed to improve the monitoring of dynamic processes. Through state space modeling, SI-PCA can remove the auto and cross corre-lations efficiently and avoid consecutive false alarms. Synthetic Monte Carlo experiments and the application in Tennessee Eastman challenge process illustrate the advantages of the proposed approach.
Due to the low price and robustness resulting from its wide acceptance and deployment, ISO/IEC 8802-3 based Ethernet is becoming the de-facto network in DCS and PLC, and is being attempted to connect field devices. It...
详细信息
ISBN:
(纸本)1424403324
Due to the low price and robustness resulting from its wide acceptance and deployment, ISO/IEC 8802-3 based Ethernet is becoming the de-facto network in DCS and PLC, and is being attempted to connect field devices. It is difficult to build a real-time field control network based on Ethernet because it has unpredictable delay characteristics due to packet collisions. To resolve this problem, some papers and reports presented the so-called hardware methods to improve real-time performance but they changed the circuits of Ethernet. Some other authors designed the so-called software methods (e.g. static or dynamic traffic smoothers by giving Ethernet packets priority) which only reduced the packet collision without avoiding collision. In addition, these methods are designed based on some presuppositions or preconditions and are difficult to be implemented and used in real control systems. Considering that some real-time packets can be divided in two types: (1) cyclic packets (e.g. measurement and control data) which shall be transferred at each communication cycle, and (2) acyclic packets (e.g. configuring data and alert/alarm data) which are transferred randomly, we define a EPA-based Communication Scheduling Management Entity (EPA_CSME) beyond Ethernet MAC protocol referring to ISO/OSI model to avoid collisions in Ethernet system. With the precise time synchronization based on IEC61588 protocol with the same time server, each node has the same absolute time in the whole system. During configuration, the time offset relative to the beginning of each communication cycle can be assigned and downloaded into each node for cyclic real-time packet transmission while the priority is defined for each type of acyclic real-time packets and the non real-time packet has lowest priority. Each communication cycle is divided into two phases: cyclic transferring phase and acyclic transferring phase. During cyclic transferring phase, each node sends its local measurement or/and control
A very concise method is presented to simplify the implementation of adaptive muldvariable generalized predictive control (MGPC). If a physically realizable multivariable process can be described by a controlled auto-...
详细信息
The problem of kernel parameters selection for one-class classifier, v-SVM, is studied. An improved constrained particle swarm optimization (PSO) is proposed to optimize the RBF kernel parameters of the v-SVM and two ...
详细信息
A new 18-lump kinetic model for naphtha catalytic reforming reactions is discussed. By developing this model as a user module, a whole industrial continuous catalytic reforming process is simulated on Aspen plus plat-...
详细信息
A new 18-lump kinetic model for naphtha catalytic reforming reactions is discussed. By developing this model as a user module, a whole industrial continuous catalytic reforming process is simulated on Aspen plus plat-form. The technique utilizes the strong databases, complete sets of modules, and flexible simulation tools of the Aspen plus system and retains the characteristics of the proposed kinetic model. The calculated results are in fair agreement with the actual operating data. Based on the model of the whole reforming process, the process is opti-mized and the optimization results are tested in the actual industrial unit for about two months. The test shows that the process profit increases about 1000yuan·h-1 averagely, which is close to the calculated result.
In this paper a novel 7-lump kinetic model is proposed to describe residual oil catalytic cracking, in which coke is lumped separately for accurate prediction. The reactor block is modeled as a combination of an ideal...
详细信息
In this paper a novel 7-lump kinetic model is proposed to describe residual oil catalytic cracking, in which coke is lumped separately for accurate prediction. The reactor block is modeled as a combination of an ideal pipe flow reactor (PFR) and a continuously stirred tank reactor (CSTR). Unit factors are designed to correct the deviation between model predictions and practical plant data and tuned by modified Levenberg-Marquardt algorithm. The parameters estimated are reliable and good agreement between the model predictions and plant observations is observed. The model helps us get good insight into the per- formance of an industrial riser reactor that would be useful for optimization of residual oil catalytic cracking.
The problem of stability analysis for switched linear systems is studied based on the properties of the quadratic form. Sufficient conditions for asymptotical stability, instability under arbitrary switching sequence ...
详细信息
The problem of stability analysis for a class of switched linear systems is studied in this paper based on the properties of matrix measure. The matrix measures of all subsystems are used to determine the stability of...
详细信息
Network random delays directly cause the degradations of networked control systems. A methodology based on model predictive control (MPC) is proposed to overcome the non-deterministic delays in data communication of t...
详细信息
暂无评论