24,729 research outputs found
Fault-tolerant control under controller-driven sampling using virtual actuator strategy
We present a new output feedback fault tolerant control strategy for
continuous-time linear systems. The strategy combines a digital nominal
controller under controller-driven (varying) sampling with virtual-actuator
(VA)-based controller reconfiguration to compensate for actuator faults. In the
proposed scheme, the controller controls both the plant and the sampling
period, and performs controller reconfiguration by engaging in the loop the VA
adapted to the diagnosed fault. The VA also operates under controller-driven
sampling. Two independent objectives are considered: (a) closed-loop stability
with setpoint tracking and (b) controller reconfiguration under faults. Our
main contribution is to extend an existing VA-based controller reconfiguration
strategy to systems under controller-driven sampling in such a way that if
objective (a) is possible under controller-driven sampling (without VA) and
objective (b) is possible under uniform sampling (without controller-driven
sampling), then closed-loop stability and setpoint tracking will be preserved
under both healthy and faulty operation for all possible sampling rate
evolutions that may be selected by the controller
New advances in Hâ control and filtering for nonlinear systems
The main objective of this special issue is to
summarise recent advances in Hâ control and filtering
for nonlinear systems, including time-delay, hybrid and
stochastic systems. The published papers provide new
ideas and approaches, clearly indicating the advances
made in problem statements, methodologies or applications
with respect to the existing results. The special
issue also includes papers focusing on advanced and
non-traditional methods and presenting considerable
novelties in theoretical background or experimental
setup. Some papers present applications to newly
emerging fields, such as network-based control and
estimation
Discussion of the technology and research in fuel injectors common rail system
Common rail is one of the most important components in a diesel and gasoline direct injection system. It features a high-pressure (100 bar) fuel rail feeding solenoid valves, as opposed to a low-pressure fuel pump feeding unit injectors. Third-generation common rail diesels now feature piezoelectric injectors for increased precision, with fuel pressures up to 2,500 bar. The purpose of this review paper is to investigate the technology and research in fuel injectors common rail system. This review paper focuses on component of common rail injection system, pioneer of common rail injection, characteristics of common rail injection system, method to reduce smoke and NOx emission simultaneously and impact of common rail injection system. Based on our research, it can be concluded that common rail injection gives many benefit such as good for the engine performance, safe to use, and for to reduce the emission of the vehicle. Fuel injection common rail system is the modern technology that must be developed. Nowadays, our earth is polluting by vehicle output such as smoke. If the common rail system is developed, it can reduce the pollution and keep our atmosphere clean and safe
Process operating mode monitoring : switching online the right controller
This paper presents a structure which deals with
process operating mode monitoring and allows the control law reconfiguration
by switching online the right controller. After a short
review of the advances in switching based control systems during
the last decade, we introduce our approach based on the definition
of operating modes of a plant. The control reconfiguration
strategy is achieved by online selection of an adequate controller,
in a case of active accommodation. The main contribution lies
in settling up the design steps of the multicontroller structure
and its accurate integration in the operating mode detection and
accommodation loop. Simulation results show the effectiveness
of the operating mode detection and accommodation (OMDA)
structure for which the design steps propose a method to study the
asymptotic stability, switching performances improvement, and
the tuning of the multimodel based detector
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