Optimal Control of Nonlinear Parametrically Excited Beam Vibrations by Spatially Distributed Sensors and Actors

1997 ◽  
Author(s):  
Andreas Kugi ◽  
Kurt Schlacher ◽  
Hans Irschik
Keyword(s):  
Axial Strain ◽  
Equations Of Motion ◽  
Nonlinear Formulation ◽  
Control Laws ◽  
Distributed Sensors ◽  
Infinite Dimensional ◽  
Infinite Dimensional Systems ◽  
Piezoelectric Layers ◽  
Spatially Distributed ◽  
Support Motion

Abstract This contribution is focused on a straight composite beam with multiple piezoelectric layers under the action of an axial support motion. In the sense of v. Karman a nonlinear formulation for the axial strain is used and the equations of motion are derived by means of the Hamilton formalism. This system turns out to be a special class of infinite dimensional systems, the so called Hamilton AI-systems with external inputs. In order to suppress the excited vibrations two infinite control laws are proposed. The first one is an infinite PD-feedback law and the second one is based on the nonlinear H∞-design, where an exact solution of the corresponding Hamilton Jacobi Isaacs equation is presented. The necessary quantities for the control laws can be measured by appropriate space-wise shaped sensors and the asymptotic stability of the equilibrium point can be proved.

Stabilization of Mechanical Structures With Distributed Sensors and Actuators: A Hamiltonian Approach

1999 ◽  
Author(s):  
Kurt Schlacher ◽  
Andreas Kugi
Keyword(s):  
Control Systems ◽  
Controller Design ◽  
Active Vibration Control ◽  
Sensors And Actuators ◽  
Distributed Sensors ◽  
Infinite Dimensional ◽  
Infinite Dimensional Systems ◽  
Spatially Distributed ◽  
Active Vibration ◽  
The Stability

Abstract Intelligent mechanical structures based on piezoelectricity form an important new group of actuators and sensors for active vibration control. Since this technology allows to construct spatially distributed devices, new design possibilities for the control systems open up. Now the design of the spatially distributed sensors and actuators becomes part of the controller design itself. Several well established approaches, like the PD-, H2- and H∞-design are adapted to solve this problem. They are based on infinite dimensional Hamiltonian systems in conjunction with collocated actuator and sensor pairing. Since this approach is based on the so called Poisson bracket only, one can unify the controller design for finite and for infinite dimensional systems. Of course, the stability investigations are much more complicated in the latter case. Finally, applications to beams and plates demonstrate the power and effectiveness of the proposed methods.

scholarly journals Enabling Cyber Physical Systems with Wireless Sensor Networking Technologies, Multiagent System Paradigm, and Natural Ecosystems

2015 ◽  
Vol 2015 ◽  
pp. 1-15 ◽  
Author(s):  
Nafaâ Jabeur ◽  
Nabil Sahli ◽  
Sherali Zeadally
Keyword(s):  
Cyber Physical Systems ◽  
Wireless Sensor ◽  
Natural Ecosystems ◽  
Distributed Sensors ◽  
Physical Systems ◽  
Structure Topology ◽  
Spatially Distributed ◽  
Engineered Systems ◽  
Networking Technologies ◽  
Living Organisms

Wireless sensor networks (WSNs) are key components in the emergent cyber physical systems (CPSs). They may include hundreds of spatially distributed sensors which interact to solve complex tasks going beyond their individual capabilities. Due to the limited capabilities of sensors, sensor actions cannot meet CPS requirements while controlling and coordinating the operations of physical and engineered systems. To overcome these constraints, we explore the ecosystem metaphor for WSNs with the aim of taking advantage of the efficient adaptation behavior and communication mechanisms of living organisms. By mapping these organisms onto sensors and ecosystems onto WSNs, we highlight shortcomings that prevent WSNs from delivering the capabilities of ecosystems at several levels, including structure, topology, goals, communications, and functions. We then propose an agent-based architecture that migrates complex processing tasks outside the physical sensor network while incorporating missing characteristics of autonomy, intelligence, and context awareness to the WSN. Unlike existing works, we use software agents to map WSNs to natural ecosystems and enhance WSN capabilities to take advantage of bioinspired algorithms. We extend our architecture and propose a new intelligent CPS framework where several control levels are embedded in the physical system, thereby allowing agents to support WSNs technologies in enabling CPSs.

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