Fault-tolerant control of a polyethylene reactor

Gani, Adiwinata; Mhaskar, Prashant; Christofides, Panagiotis D.

doi:10.1109/acc.2006.1657687

Cited by 9 publications

(19 citation statements)

References 51 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Having demonstrated the application of the proposed fault‐tolerant controller on the illustrative example, we next consider a more complex process, specifically, an industrial gas‐phase polyethylene reactor system (see Figure 8). This reactor was also studied in39 in the context of faults in the control actuator (under assumption of continuous availability of process measurements).…”

Section: Fault‐tolerant Control Subject To Sensor Data Lossesmentioning

confidence: 99%

See 1 more Smart Citation

Fault‐tolerant control of nonlinear process systems subject to sensor faults

et al. 2007

View full text Add to dashboard Cite

in Wiley InterScience (www.interscience.wiley.com).The problem of control of nonlinear process systems subject to input constraints and sensor faults (complete failure or intermittent unavailability of measurements) is considered. A fault-tolerant controller is designed that utilizes reconfiguration (switching to an alternate control configuration) in a way that accounts for the process nonlinearity, the presence of constraints and the occurrence of sensor faults. To clearly illustrate the importance of accounting for the presence of input constraints, first the problem of sensor faults that necessitate sensor recovery to maintain closed-loop stability is considered. We address the problem of determining, based on stability region characterizations for the candidate control configurations, which control configuration should be activated (reactivating the primary control configuration may not preserve stability) after the sensor is rectified. We then consider the problem of asynchronous measurements, that is of intermittent unavailability of measurements. To address this problem, the stability region (that is, the set of initial conditions starting from where closed-loop stabilization under continuous availability of measurements is guaranteed), as well as the maximum allowable data loss rate which preserves closed-loop stability for the primary and the candidate backup configurations are computed. This characterization is utilized in identifying the occurrence of a destabilizing sensor fault, and in activating a suitable backup configuration that preserves closed-loop stability. The proposed method is illustrated using a chemical process example and demonstrated via application to a polyethylene reactor.

show abstract

Section: Fault‐tolerant Control Subject To Sensor Data Lossesmentioning

confidence: 99%

“…For the definition of all the variables used in Eqs. 13–14, the values of the process parameters, and details on controller design, see 39. The open‐loop system at the nominal operating condition exhibits an unstable equilibrium point surrounded by a limit cycle.…”

Section: Fault‐tolerant Control Subject To Sensor Data Lossesmentioning

confidence: 99%

Fault‐tolerant control of nonlinear process systems subject to sensor faults

et al. 2007

View full text Add to dashboard Cite

show abstract

“…They employed a tanks-in-series model to characterize the flow pattern in the reactor. In fluidized bed polymerization reactors, the challenges of design and control are related to achieving adequate heat removal and production rate [14][15][16]. Also, other approaches were explored which dealt with grade transition, molecular weight and density control of the polymer [17][18][19][20].…”

Section: Introductionmentioning

confidence: 99%

Dynamic simulation and control of two-series industrial reactors producing linear low-density polyethylene

2019

View full text Add to dashboard Cite

One of the leading routes for producing polyolefins is through gas-phase catalytic fluidized bed reactors. In this study, the industrial gas-phase ethylene polymerization reactor series of Jam Petrochemical Company has been dynamically analyzed, modeled and controlled. The copolymerization of ethylene with 1-butene is defined on Zeigler-Natta catalyst, assuming a double active site mechanism. To serve this purpose, pseudo-kinetic rate constants and the method of moments have been employed. The proposed model is capable of predicting the unsteady-state behavior of each reactor in addition to the properties of the product such as melt flow index (MFI), dispersion index, and molecular weight distribution (MWD). The verification of the model has been conducted with plant data to prove the accuracy of the model-estimated MWD and MFI. The controllability of the process control configuration has been examined through analyzing the dynamic behavior of the process under conventional feedback PID controllers. It has been observed that the control structure delivers a convincing performance for disturbance rejection.

show abstract

“…Fault-tolerant control has been developed to keep systems stable, regardless of the occurrence of a fault . Fault detection is designed to detect the occurrence of a fault in a process by observing the deviation of the process states from the expected closed-loop behavior . Fault diagnosis is primarily concerned with recognizing anomalous behavior in the functioning of process components, such as sensors and actuators, and abnormal trends in process parameters .…”

Section: Introductionmentioning

confidence: 99%

Isolating Non-predefined Sensor Faults by Using Farthest First Traversal Algorithm

Altınışık

Yildirim

Erkan

2012

Ind. Eng. Chem. Res.

View full text Add to dashboard Cite

In this study, we propose a knowledge-based approach for detection and isolation of predefined and nonpredefined sensor faults in fault tolerant control (FTC) of a three-tank system. Farthest first traversal algorithm (FFTA) of data mining is used for the first time for the classification of faults in a FTC system. Predefining here means that features of a fault and its effects are known before the fault is seen on the system. Therefore, if a predefined fault is detected on the system, it is isolated into a known fault cluster and predefined action for that cluster can be taken to tolerate the fault. However, in a working system, there may be some other faults, which are not predefined. Those may be inaccurately isolated into available known clusters, since the clusters are determined according to predefined faults instead of non-predefined ones. In our work, we also propose a method for isolating the non-predefined faults that rearranges the clusters of predefined faults, online. In order to show the efficiency of proposed method, seven predefined and thirteen non-predefined fault scenarios are applied to a closed-loop FTC system. While three of the non-predefined faults are not accurately isolated without the proposed method, all of the faults are isolated correctly with the proposed method.

show abstract

Fault-tolerant control of a polyethylene reactor

Cited by 9 publications

References 51 publications

Fault‐tolerant control of nonlinear process systems subject to sensor faults

Fault‐tolerant control of nonlinear process systems subject to sensor faults

Dynamic simulation and control of two-series industrial reactors producing linear low-density polyethylene

Isolating Non-predefined Sensor Faults by Using Farthest First Traversal Algorithm

Contact Info

Product

Resources

About