Abstract
This paper emphasizes the importance of the influences of local dynamics on the global dynamics of a control system. By considering an actuator as an individual, nonlinear subsystem connected with a nonlinear process subsystem in cascade, a structure of interconnected nonlinear systems is proposed which allows for global and local supervision properties of the interconnected systems. To achieve this purpose, a kind of interconnected observer design method is investigated, and the convergence is studied. One major difficulty is that a state observation can only rely on the global system output at the terminal boundary. This is because the connection point between the two subsystems is considered unable to be measured, due to physical or economic reasons. Therefore, the aim of the interconnected observer is to estimate the state vector of each subsystem and the unmeasurable connection point. Specifically, the output used in the observer of the actuator subsystem is replaced by the estimation of the process subsystem observer, while the estimation of this interconnection is treated like an additional state in the observer design of the process subsystem. Expression for this new state is achieved by calculating the derivatives of the output equation of the actuator subsystem. Numerical simulations confirm the effectiveness and robustness of the proposed observer, which highlight the significance of the work compared with state-of-the-art methods.
Highlights
A modern system often consists of a series of interconnected dynamical units and, very complicated dynamics are exhibited [1]
The topic of observer design for separate nonlinear systems has been widely discussed in the literature, like high-gain observers [2,3,4], sliding mode observers [5,6], adaptive observers [7,8,9], and unknown input observers (UIOs) [10,11,12]
The goal of the design methodology is to enable or simplify observer design for systems that are otherwise difficult to handle by allowing the designer to focus on a smaller, nonlinear subsystem
Summary
A modern system often consists of a series of interconnected dynamical units (sensors, actuators and system components) and, very complicated dynamics are exhibited [1]. The topic of observer design for separate nonlinear systems has been widely discussed in the literature, like high-gain observers [2,3,4], sliding mode observers [5,6], adaptive observers [7,8,9], and unknown input observers (UIOs) [10,11,12] These methodologies are typically centralized monitoring systems where intelligence is either at the system level or at the field device level of the processing plant. A modern control system is an interconnected system, while the centralized observer just enables an individual component to monitor internal dynamics locally. The problem of state estimation for interconnected nonlinear dynamic systems is studied.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
