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In this article, we present an event-triggered boundary control scheme for hyperbolic systems. The trigger condition is based on predictions of the state on determinate sets, and the control input … In this article, we present an event-triggered boundary control scheme for hyperbolic systems. The trigger condition is based on predictions of the state on determinate sets, and the control input is updated only when the predictions deviate from the reference by a given margin. Nominal closed-loop stability, the absence of Zeno behavior, and robustness to uncertainty and disturbances, are all established analytically. For the special case of linear systems, the trigger condition can be expressed in closed-form as an <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$L_{2}$</tex-math></inline-formula> -scalar product of kernels with the distributed state. The presented controller can also be combined with existing observers to solve the event-triggered output-feedback control problem. A numerical simulation demonstrates the effectiveness of the proposed approach.
We present an event-triggered boundary control scheme for hyperbolic systems. The trigger condition is based on predictions of the state on determinate sets, where the control input is only updated … We present an event-triggered boundary control scheme for hyperbolic systems. The trigger condition is based on predictions of the state on determinate sets, where the control input is only updated if the predictions deviate from the reference by a given margin. Closed-loop stability and absence of Zeno behaviour is established analytically. For the special case of linear systems, the trigger condition can be expressed in closed-form as an $L_2$-scalar product of kernels with the distributed state. The presented controller can also be combined with existing observers to solve the event-triggered output-feedback control problem. A numerical simulation demonstrates the effectiveness of the proposed approach.
We present a predictive feedback control method for a class of quasilinear hyperbolic systems with one boundary control input. Assuming exact model knowledge, convergence to the origin, or tracking at … We present a predictive feedback control method for a class of quasilinear hyperbolic systems with one boundary control input. Assuming exact model knowledge, convergence to the origin, or tracking at the uncontrolled boundary, are achieved in finite time. A robustness certificate is provided, showing that at least under more restrictive assumptions on the system coefficients, the control method has inherent robustness properties with respect to small errors in the model, measurements and control input. Rigorous, although conservative conditions on the time derivative of the initial condition and on the design parameter controlling the convergence speed are given to ensure global existence of the solution for initial conditions with arbitrary infinity-norm.
We present a predictive feedback control method for a class of quasilinear hyperbolic systems with one boundary control input. Assuming exact model knowledge, convergence to the origin, or tracking at … We present a predictive feedback control method for a class of quasilinear hyperbolic systems with one boundary control input. Assuming exact model knowledge, convergence to the origin, or tracking at the uncontrolled boundary, are achieved in finite time. A robustness certificate is provided, showing that at least under more restrictive assumptions on the system coefficients, the control method has inherent robustness properties with respect to small errors in the model, measurements and control input. Rigorous, although conservative conditions on the time derivative of the initial condition and on the design parameter controlling the convergence speed are given to ensure global existence of the solution for initial conditions with arbitrary infinity-norm.
We present a control design for semilinear and quasilinear 2x2 hyperbolic partial differential equations with the control input at one boundary and a nonlinear ordinary differential equation coupled to the … We present a control design for semilinear and quasilinear 2x2 hyperbolic partial differential equations with the control input at one boundary and a nonlinear ordinary differential equation coupled to the other. The controller can be designed to asymptotically stabilize the system at an equilibrium or relative to a reference signal. Two related but different controllers for semilinear and general quasilinear systems are presented and the additional challenges in quasilinear systems are discussed. Moreover, we present an observer that estimates the distributed PDE state and the unmeasured ODE state from measurements at the actuated boundary only, which can be used to also solve the output feedback control problem.
Recently, the first result on backstepping-based adaptive control of a 1-D linear hyperbolic partial differential equation (PDE) with an uncertain transport speed was presented. The system also had an uncertain, … Recently, the first result on backstepping-based adaptive control of a 1-D linear hyperbolic partial differential equation (PDE) with an uncertain transport speed was presented. The system also had an uncertain, constant in-domain coefficient, and the derived controller achieved convergence to zero in the L <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">∞</sub> -sense in finite time. In this paper, we extend that result to systems with a spatially varying in-domain coefficient, achieving asymptotic convergence to zero in the L <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">∞</sub> -sense. Additionally, for the case of having a constant in-domain coefficient, the new method is shown to have a slightly improved finite-time convergence time. The theory is illustrated in simulations.
An adaptive observer design for a system of n + 1 coupled 1-D linear hyperbolic partial differential equations with an uncertain boundary condition is presented, extending previous results by removing … An adaptive observer design for a system of n + 1 coupled 1-D linear hyperbolic partial differential equations with an uncertain boundary condition is presented, extending previous results by removing the need for sensing collocated with the uncertainty. This modification is important and motivated by applications in oil & gas drilling where information about the down-hole situation is crucial in order to prevent or deal with unwanted incidents. Uncertainties are usually present down-hole while measurements are available top-side at the rig, only. Boundedness of the state and parameter estimates is proved in the general case, while convergence to true values requires bounded system states and, for parameter convergence, persistent excitation. The central tool for analysis is the infinitedimensional backstepping method applied in two steps, the first of which is time-invariant, while the second is time-varying induced by the time-varying parameter estimates.
We will now consider the $$ n + m $$ system ( 18.1 ), but for simplicity restrict ourselves to constant coefficients, that is $$u_t(x, t) + \varLambda ^+ u_x(x, … We will now consider the $$ n + m $$ system ( 18.1 ), but for simplicity restrict ourselves to constant coefficients, that is $$u_t(x, t) + \varLambda ^+ u_x(x, t) = \varSigma ^{++} u(x, t) + \varSigma ^{+-} v(x, t)$$
We consider here anModel reference adaptive control adaptive version of the output tracking results established in Sect. 3.5 , and solve a model reference adaptive control problem where the goal … We consider here anModel reference adaptive control adaptive version of the output tracking results established in Sect. 3.5 , and solve a model reference adaptive control problem where the goal is to make a measured signal track a reference signal from minimal knowledge of the system parameters. Consider system ( 2.1 ), which we restate here $$u_t(x, t) - \lambda (x) u_x(x, t) = f(x) u(x, t) + g(x) u(0, t) \nonumber + \int _{0}^{x} h(x, \xi ) u(\xi , t) d\xi $$
We now proceed by investigating systems of coupled linear hyperbolic PDEs. The simplest type of such systems are referred to as $$ 2 \times 2 $$ systems, and consists of … We now proceed by investigating systems of coupled linear hyperbolic PDEs. The simplest type of such systems are referred to as $$ 2 \times 2 $$ systems, and consists of two PDEs convecting in opposite directions. $$u_t(x, t) + \lambda (x) u_x(x, t) = c_{11}(x) u(x, t) + c_{12}(x) v(x, t)$$ $$v_t(x, t) - \mu (x) v_x(x, t) = c_{21}(x) u(x, t) + c_{22}(x) v(x, t)$$ $$u(0, t) = q v(0, t)$$ $$v(1, t) = \rho v(1, t) + U(t)$$ $$u(x, 0) = u_0(x)$$ $$v(x, 0) = v_0(x)$$
Systems of hyperbolic partial differential equations (PDEs) describe flow and transport phenomena. Typical examples are transmission lines (Curró, Fusco, Manganaro, J Phys A: Math Theor, 44(33):335205, (2011)), road traffic (Amin, … Systems of hyperbolic partial differential equations (PDEs) describe flow and transport phenomena. Typical examples are transmission lines (Curró, Fusco, Manganaro, J Phys A: Math Theor, 44(33):335205, (2011)), road traffic (Amin, Hante, Baye, Hybrid systems computation and control, Springer, pp 602–605, (2008)), heat exchangers (Xu, Sallet, ESAIM: Control Optim Calc Var, 7:421–442, (2010)) Heat exchangers , oil wells (Landet, Pavlov, Aamo, IEEE Trans Control Syst Technol, 21(4):1340–1351, (2013)), multiphase flowMultiphase flow (Di Meglio, Dynamics and control of slugging in oil production. Ph.D. thesis, MINES ParisTech, (2011)); (Diagne, Diagne, Tang, Krstić, Automatica, 76:345–354, (2017)), time-delaysTime-delay (Krstić, Smyshlyaev, Syst Control Lett, 57(9):750–758, (2008b)) and predator–prey systems ( Wollkind, Math Model, 7:413–428, (1986)), to mention a few. These distributed parameter systems give rise to important estimation and control problems, with methods ranging from the use of control Lyapunov functions (Coron, d'Andréa Novel, Bastin, IEEE Trans Autom Control, 52(1):2–11, (2007)), Riemann invariants (Greenberg, Tsien, J Differ Equ, 52(1):66–75, (1984)), frequency domain approaches (Litrico, Fromion, 45th IEEE conference on decision and control, San Diego, CA, USA, (2006)) and active disturbance rejection control (ADRC) (Gou, Jin, IEEE Trans Autom Control, 60(3):824–830, (2015)). The approach taken in this book makes extensive use of Volterra integral transformations, and is known as the infinite-dimensional backstepping approach.
We extend recent results regarding disturbance rejection control of n+m linear hyperbolic partial differential equations (PDEs) in a number of ways: 1) We allow spatially varying coefficients; 2) The disturbance … We extend recent results regarding disturbance rejection control of n+m linear hyperbolic partial differential equations (PDEs) in a number of ways: 1) We allow spatially varying coefficients; 2) The disturbance is allowed to enter in the interior of the domain, and; 3) Rejection is achieved in minimum time. Additionally, we solve a tracking problem, where the tracking objective is achieved in finite, minimum time. We use a recently derived Fredholm transformation technique in addition to infinite-dimensional backstepping in our design.
We derive a state-feedback controller for a scalar 1-D linear hyperbolic partial differential equation (PDE) with a spatially-and time-varying interior-domain parameter. The resulting controller ensures convergence to zero in a … We derive a state-feedback controller for a scalar 1-D linear hyperbolic partial differential equation (PDE) with a spatially-and time-varying interior-domain parameter. The resulting controller ensures convergence to zero in a finite time d <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1</sub> , corresponding to the propagation time from one boundary to the other. The control law requires predictions of the in-domain parameter a time d <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1</sub> into the future. The state-feedback controller is also combined with a boundary observer into an output-feedback control law. Lastly, under the assumption that the interior-domain parameter can be decoupled into a time-varying and a spatially-varying part, a stabilizing adaptive output-feedback control law is derived for an uncertain spatially varying parameter, stabilizing the system in the L <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> -sense from a single boundary measurement only. All derived controllers are implemented and demonstrated in simulations.
We solve the problem of controlling a class of one-dimensional semilinear 2 × 2 hyperbolic systems to the origin in minimum time using actuation at both boundaries of the domain. … We solve the problem of controlling a class of one-dimensional semilinear 2 × 2 hyperbolic systems to the origin in minimum time using actuation at both boundaries of the domain. The control method can also be used to solve a class of tracking problems. For the special case of time-invariant linear systems, the state-feedback control law can be written explicitly as the inner product of kernels with the state. We further design an observer to estimate the distributed state from measurements at both boundaries, also in minimum time. The state-feedback controller and observer are combined to solve the output-feedback control problem. A numerical example is given to demonstrate the controller performance.
We extend recent results on adaptive state feedback stabilization of systems described as linear 2 × 2 hyperbolic partial differential equations (PDEs), by offering a solution for the case of … We extend recent results on adaptive state feedback stabilization of systems described as linear 2 × 2 hyperbolic partial differential equations (PDEs), by offering a solution for the case of having spatially varying in-domain coefficients. Proof of L <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> -boundedness, as well as boundedness and asymptotic convergence to zero pointwise in space for all signals in the closed loop are offered, and the theory is demonstrated in a simulation.
In this paper, we solve an adaptive control problem for a class of 2 × 2 linear hyperbolic partial differential equations, where sensing and actuation are restricted to the boundary … In this paper, we solve an adaptive control problem for a class of 2 × 2 linear hyperbolic partial differential equations, where sensing and actuation are restricted to the boundary anticollocated with an uncertain parameter. This is done by combining a recently derived adaptive observer for the system states and the uncertain parameter, with an adaptive control law. Proof of L2-boundedness for all signals in the closed loop is given, and the system states are proved to converge to zero pointwise in space. The theory is demonstrated in a simulation.
We combine a swapping-based adaptive observer with a controller to stabilize a system of n + 1 coupled linear hyperbolic partial differential equations (PDEs) with uncertain boundary parameters from boundary … We combine a swapping-based adaptive observer with a controller to stabilize a system of n + 1 coupled linear hyperbolic partial differential equations (PDEs) with uncertain boundary parameters from boundary sensing only. Boundedness of all signals in the closed loop system in the L <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> -sense is proved. The theory is demonstrated in a simulation.
We combine a swapping-based adaptive observer with a backstepping-based control law to stabilize a system of $ n + m $ coupled linear hyperbolic partial differential equations (PDEs) with uncertain … We combine a swapping-based adaptive observer with a backstepping-based control law to stabilize a system of $ n + m $ coupled linear hyperbolic partial differential equations (PDEs) with uncertain boundary parameters, using boundary sensing only. Proof of boundedness and square integrability in the $ L_2 $-sense of all signals in the closed loop is given, and the theory is demonstrated in a simulation.
In this paper, we solve the problem of rejecting a harmonic disturbance containing unknown frequencies and bias entering a linear hyperbolic system of 1-D partial differential equations at one boundary, … In this paper, we solve the problem of rejecting a harmonic disturbance containing unknown frequencies and bias entering a linear hyperbolic system of 1-D partial differential equations at one boundary, using boundary sensing and actuation anticollocated with the disturbance. By combining a full state feedback controller with an adaptive observer that estimates system states and the disturbance's bias, frequencies, amplitudes, and phases with exponential convergence, the effect of the disturbance is rejected exponentially fast. The theoretical results are applied to a relevant problem from the oil and gas industry, and the performance is demonstrated in a computer simulation.
We establish a control law that manages to adaptively stabilize a system of 2 × 2 linear hyperbolic partial differential equations (PDEs) from sensing and control anti-collocated with an uncertain … We establish a control law that manages to adaptively stabilize a system of 2 × 2 linear hyperbolic partial differential equations (PDEs) from sensing and control anti-collocated with an uncertain boundary parameter. We do this by combining a recently derived adaptive observer with a backstepping-based control law, and prove closed loop stability in the L <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> -sense. The theory is demonstrated in a simulation.
Using a series of invertible transformations, we bring a system of 2 × 2 linear hyperbolic partial differential equations (PDEs) to an observer canonical form. With transport delays as the … Using a series of invertible transformations, we bring a system of 2 × 2 linear hyperbolic partial differential equations (PDEs) to an observer canonical form. With transport delays as the only information assumed known about the system parameters, a filter based adaptive output feedback control law is designed for the transformed system. Pointwise boundedness of all signals in the closed loop system and pointwise convergence of the system states to zero are established. The theory is demonstrated in a simulation.
In this paper, we use swapping design filters to bring systems of n + 1 coupled partial differential equations of the hyperbolic type to static form. Standard parameter identification laws … In this paper, we use swapping design filters to bring systems of n + 1 coupled partial differential equations of the hyperbolic type to static form. Standard parameter identification laws can then be applied to estimate unknown parameters in the boundary conditions. Proof of boundedness of the adaptive laws are offered, and the results are demonstrated in simulations.
In this paper, we develop an adaptive observer for n + 1 coupled first-order 1-D hyperbolic PDEs for estimation of unknown parameters appearing in the left boundary condition using only … In this paper, we develop an adaptive observer for n + 1 coupled first-order 1-D hyperbolic PDEs for estimation of unknown parameters appearing in the left boundary condition using only measurements at the right boundary. Proof of boundedness of the estimated parameters and sufficient conditions for convergence are offered and the result is demonstrated in a simulation.
In this paper, we use swapping design filters to bring systems of n+1 partial differential equations of the hyperbolic type to static form. Standard parameter identification laws can then be … In this paper, we use swapping design filters to bring systems of n+1 partial differential equations of the hyperbolic type to static form. Standard parameter identification laws can then be applied to estimate unknown parameters in the boundary conditions. Proof of boundedness of the adaptive laws are offered, and the results are demonstrated in simulations.
We develop an adaptive observer that estimates boundary parameters and the system states in general heterodirectional linear systems of m+n coupled hyperbolic partial differential equations. The observer uses boundary sensing … We develop an adaptive observer that estimates boundary parameters and the system states in general heterodirectional linear systems of m+n coupled hyperbolic partial differential equations. The observer uses boundary sensing only, and is based on the swapping design, where filters are constructed that can be used to express the system states as linear static combinations of the unknown parameters and the filters states. Standard parameter identification laws can then be applied. Proof of boundedness of the estimates is offered, and sufficient conditions ensuring exponential convergence to their true values is derived. The theory is verified in a simulation.
We solve a tracking problem for general heterodirectional linear 1-D hyperbolic partial differential equations. A full state feedback controller and an observer generating full state estimates from sensing co-located with … We solve a tracking problem for general heterodirectional linear 1-D hyperbolic partial differential equations. A full state feedback controller and an observer generating full state estimates from sensing co-located with the actuation are designed. Both converge in finite, minimum time. The two are then combined into an output feedback law achieving tracking in finite time given by the sum of the convergence times of the controller and observer.
We derive a full state feedback law and a state observer for a class of disturbance rejection problems for n+1 linear coupled partial differential equations (PDEs). The disturbance enters the … We derive a full state feedback law and a state observer for a class of disturbance rejection problems for n+1 linear coupled partial differential equations (PDEs). The disturbance enters the system at one boundary, while the actuation and sensing are limited to the opposite boundary. We solve this by separately designing a state feedback controller and an observer, and show that they can be combined into an output feedback control law that rejects the effect of the disturbance with exponential decay. The performance of output feedback controller is demonstrated in a simulation.
In this technical note, we develop a full state feedback law for disturbance rejection in systems described by linear 2 × 2 partial differential equations of the hyperbolic type, with … In this technical note, we develop a full state feedback law for disturbance rejection in systems described by linear 2 × 2 partial differential equations of the hyperbolic type, with the disturbance modelled as an autonomous, finite dimensional linear system affecting the PDE's left boundary, and actuation limited to the right boundary. The effect of the disturbance is rejected at an arbitrary point in the domain within a finite time. The performance is demonstrated through simulation.
This paper considers the boundary stabilization problem for a class of nonlinear pseudo-parabolic partial differential equations. The proposed control laws are used to achieve semi-global exponential stability for the nonlinear … This paper considers the boundary stabilization problem for a class of nonlinear pseudo-parabolic partial differential equations. The proposed control laws are used to achieve semi-global exponential stability for the nonlinear systems in the H <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1</sup> -sense. An H <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> bound of the solution for the nonlinear systems is also derived. A numerical example is included to illustrate the application of the proposed control laws.
Many interesting problems in the oil and gas industry face the challenge of responding to disturbances from afar. Typically, the disturbance occurs at the inlet of a pipeline or the … Many interesting problems in the oil and gas industry face the challenge of responding to disturbances from afar. Typically, the disturbance occurs at the inlet of a pipeline or the bottom of an oil well, while sensing and actuation equipment is installed at the outlet, only, kilometers away from the disturbance. The present paper develops an output feedback control law for such cases, based on modelling the transport phenomenon as a 2 <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$\times$</tex></formula> 2 linear partial differential equation (PDE) of hyperbolic type and the disturbance as a finite-dimensional linear system affecting the left boundary of the PDE. Sensing and actuation are co-located at the right boundary of the PDE. The design provides a separation principle, allowing a disturbance attenuating full-state feedback control law to be combined with an observer. The results are applied to a relevant problem from the oil and gas industry and demonstrated in simulations.
Many interesting problems in the oil and gas industry face the challenge of responding to disturbances from afar. Typically, the disturbance occurs at the inlet of a pipeline or the … Many interesting problems in the oil and gas industry face the challenge of responding to disturbances from afar. Typically, the disturbance occurs at the inlet of a pipeline or the bottom of an oil well, while sensing and actuation equipment is installed at the outlet, only, kilometers away from the disturbance. The present paper develops an output feedback control law for such cases, based on modelling the transport phenomenon as a 2×2 linear partial differential equation (PDE) of hyperbolic type and the disturbance as a finite-dimensional linear system affecting the left boundary of the PDE. Sensing and actuation are co-located at the right boundary of the PDE. The design provides a separation principle, allowing a disturbance attenuating full-state feedback control law to be combined with an observer.
Unidirectional propagation of long waves in nonlinear dispersive systems may be modeled by the Benjamin-Bona-Mahony-Burgers equation, a third order partial differential equation incorporating linear dissipative and dispersive terms, as well … Unidirectional propagation of long waves in nonlinear dispersive systems may be modeled by the Benjamin-Bona-Mahony-Burgers equation, a third order partial differential equation incorporating linear dissipative and dispersive terms, as well as a term covering nonlinear wave phenomena. For higher orders of the nonlinearity, the equation may have unstable solitary wave solutions. Although it is a one dimensional problem, achieving a global result for this equation is not trivial due to the nonlinearity and the mixed partial derivative. In this paper, two sets of nonlinear boundary control laws that achieve global exponential stability and semi-global exponential stability are derived for both linear and nonlinear cases.
In this paper, we continue the development of state feedback boundary control laws based on the backstepping methodology, for the stabilization of unstable, parabolic partial differential equations. We consider the … In this paper, we continue the development of state feedback boundary control laws based on the backstepping methodology, for the stabilization of unstable, parabolic partial differential equations. We consider the linearized Ginzburg--Landau equation, which models, for instance, vortex shedding in bluff body flows. Asymptotic stabilization is achieved by means of boundary control via state feedback in the form of an integral operator. The kernel of the operator is shown to be twice continuously differentiable, and a series approximation for its solution is given. Under certain conditions on the parameters of the Ginzburg--Landau equation, compatible with vortex shedding modelling on a semi-infinite domain, the kernel is shown to have compact support, resulting in partial state feedback. Simulations are provided in order to demonstrate the performance of the controller. In summary, the paper extends previous work in two ways: (1) it deals with two coupled partial differential equations, and (2) under certain circumstances handles equations defined on a semi-infinite domain.
We will be studying the behavior of a fluid contained in the domain Ω, as shown schematically in Figure 2.1. Associated with the fluid is its density, ρ : Ω … We will be studying the behavior of a fluid contained in the domain Ω, as shown schematically in Figure 2.1. Associated with the fluid is its density, ρ : Ω × ℝ+→ ℝ. At every time instant t > 0, and to every point p ∈ Ω, we assign a vector valued quantity which is the velocity, W, of the fluid at that point in time and space. That is, we are interested in the evolution of a vector field W : Ω× ℝ+→ ℝn, where n is thedimension of the problem. Associated with the velocity field is a pressure field, which is a scalar valued function P : Ω × ℝ+→ ℝ. We will study problems in 2 and 3 dimensions (2D and 3D), using cartesian and cylindrical coordinates. In cartesian coordinates, we denote a point p ∈ Ω with (x, y) in 2D and (x, y, z) in 3D. In cylindrical coordinates, we denote a point p ∈ Ω with (r, θ, z). The two coordinate systems are shown schematically in Figure 2.1. The velocity field is denoted W(x, y, z, t) = (U(x, y, z, t), V(x, y, z, t), W(x, y, z, t)) in 3D cartesian coordinates, where U ,V,and W are the velocity components in the x, y and z directions, respectively (W (x, y, t) = (U(x, y, t), V(x, y, t)) in 2D). In cylindrical coordinates, we denote the velocity field W (r, θ, z, t) = (V r(x, y, z, t), V θ(x, y, z, t), V z (x, y, z, t)), where Vr, Vθ, and Vz are the velocity components in the r, B and z directions, respectively. The density, ρ, and the pressure, P, take the same arguments as the velocity, but are scalar valued. Below we will derive the conservation equations in cartesian coordinates, and state the corresponding equations in cylindrical coordinates. The derivation follows [31].

Commonly Cited References

Research on stabilization of coupled hyperbolic PDEs has been dominated by the focus on pairs of counter-convecting (“heterodirectional”) transport PDEs with distributed local coupling and with controls at one or … Research on stabilization of coupled hyperbolic PDEs has been dominated by the focus on pairs of counter-convecting (“heterodirectional”) transport PDEs with distributed local coupling and with controls at one or both boundaries. A recent extension allows stabilization using only one control for a system containing an arbitrary number of coupled transport PDEs that convect at different speeds against the direction of the PDE whose boundary is actuated. In this paper we present a solution to the fully general case, in which the number of PDEs in either direction is arbitrary, and where actuation is applied on only one boundary (to all the PDEs that convect downstream from that boundary). To solve this general problem, we solve, as a special case, the problem of control of coupled “homodirectional” hyperbolic linear PDEs, where multiple transport PDEs convect in the same direction with arbitrary local coupling. Our approach is based on PDE backstepping and yields solutions to stabilization, by both full-state and observer-based output feedback, and trajectory tracking problems.
Many interesting problems in the oil and gas industry face the challenge of responding to disturbances from afar. Typically, the disturbance occurs at the inlet of a pipeline or the … Many interesting problems in the oil and gas industry face the challenge of responding to disturbances from afar. Typically, the disturbance occurs at the inlet of a pipeline or the bottom of an oil well, while sensing and actuation equipment is installed at the outlet, only, kilometers away from the disturbance. The present paper develops an output feedback control law for such cases, based on modelling the transport phenomenon as a 2 <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$\times$</tex></formula> 2 linear partial differential equation (PDE) of hyperbolic type and the disturbance as a finite-dimensional linear system affecting the left boundary of the PDE. Sensing and actuation are co-located at the right boundary of the PDE. The design provides a separation principle, allowing a disturbance attenuating full-state feedback control law to be combined with an observer. The results are applied to a relevant problem from the oil and gas industry and demonstrated in simulations.
We solve the problem of stabilization of a class of linear first-order hyperbolic systems featuring n rightward convecting transport PDEs and one leftward convecting transport PDE. We design a controller, … We solve the problem of stabilization of a class of linear first-order hyperbolic systems featuring n rightward convecting transport PDEs and one leftward convecting transport PDE. We design a controller, which requires a single control input applied on the leftward convecting PDE's right boundary, and an observer, which employs a single sensor on the same PDE's left boundary. We prove exponential stability of the origin of the resulting plant-observer-controller system in the spatial L <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> -sense.
In this paper we study the problem of boundary feedback stabilization for the unstable heat equation ut(x,t) = uxx(x,t)+a(x) u(x,t). This equation can be viewed as a model of a … In this paper we study the problem of boundary feedback stabilization for the unstable heat equation ut(x,t) = uxx(x,t)+a(x) u(x,t). This equation can be viewed as a model of a heat conducting rod in which not only is the heat being diffused (mathematically due to the diffusive term uxx) but also the destabilizing heat is generating (mathematically due to the term a u with a >0). We show that for any given continuously differentiable function a and any given positive constant $\l$ we can explicitly construct a boundary feedback control law such that the solution of the equation with the control law converges to zero exponentially at the rate of $\l$. This is a continuation of the recent work of Boskovic, Krstic, and Liu [IEEE Trans. Automat. Control, 46 (2001), pp. 2022--2028] and Balogh and Krstic [European J. Control, 8 (2002), pp. 165--176].
In this note, a feedback boundary controller for an unstable heat equation is designed. The equation can be viewed as a model of a thin rod with not only the … In this note, a feedback boundary controller for an unstable heat equation is designed. The equation can be viewed as a model of a thin rod with not only the heat loss to a surrounding medium (stabilizing) but also the heat generation inside the rod (destabilizing). The heat generation adds a destabilizing linear term on the right-hand side of the equation. The boundary control law designed is in the form of an integral operator with a known, continuous kernel function but can be interpreted as a backstepping control law. This interpretation provides a Lyapunov function for proving stability of the system. The control is applied by insulating one end of the rod and applying either Dirichlet or Neumann boundary actuation on the other.
In this technical note, we develop a full state feedback law for disturbance rejection in systems described by linear 2 × 2 partial differential equations of the hyperbolic type, with … In this technical note, we develop a full state feedback law for disturbance rejection in systems described by linear 2 × 2 partial differential equations of the hyperbolic type, with the disturbance modelled as an autonomous, finite dimensional linear system affecting the PDE's left boundary, and actuation limited to the right boundary. The effect of the disturbance is rejected at an arbitrary point in the domain within a finite time. The performance is demonstrated through simulation.
Generalized simple wave solutions to quasilinear hyperbolic nonhomogeneous systems of PDEs are obtained through the differential constraint method. These solutions prove to be flexible enough to solve generalized Riemann problems … Generalized simple wave solutions to quasilinear hyperbolic nonhomogeneous systems of PDEs are obtained through the differential constraint method. These solutions prove to be flexible enough to solve generalized Riemann problems where discontinuous initial data are involved. Within such a theoretical framework, the governing model of nonlinear transmission lines is investigated throughout.
We propose an adaptive observer scheme to estimate boundary parameters in first-order hyperbolic systems of Partial Differential Equations (PDE). The considered systems feature an arbitrary number of states traveling in … We propose an adaptive observer scheme to estimate boundary parameters in first-order hyperbolic systems of Partial Differential Equations (PDE). The considered systems feature an arbitrary number of states traveling in one direction and one counter-convecting state. Uncertainties in the boundary reflection coefficients and boundary additive errors are estimated relying on a pre-existing observer design and a novel Lyapunov-based adaptation law.
Summary The adaptive boundary stabilization is investigated for a class of systems described by first‐order hyperbolic PDEs with unknown spatially varying parameter. Towards the system unknowns, a dynamic compensation is … Summary The adaptive boundary stabilization is investigated for a class of systems described by first‐order hyperbolic PDEs with unknown spatially varying parameter. Towards the system unknowns, a dynamic compensation is first given by using infinite‐dimensional backstepping method, adaptive techniques, and projection operator. Then an adaptive controller is constructed by certainty equivalence principle, which can stabilize the original system in a certain sense. Moreover, the effectiveness of the proposed method is illustrated by a simulation example. Copyright © 2015 John Wiley &amp; Sons, Ltd.
In this work, we consider the problem of boundary stabilization for a quasilinear $2\times2$ system of first-order hyperbolic PDEs. We design a new full-state feedback control law, with actuation on … In this work, we consider the problem of boundary stabilization for a quasilinear $2\times2$ system of first-order hyperbolic PDEs. We design a new full-state feedback control law, with actuation on only one end of the domain, which achieves $H^2$ exponential stability of the closed-loop system. Our proof uses a backstepping transformation to find new variables for which a strict Lyapunov function can be constructed. The kernels of the transformation are found to verify a Goursat-type $4\times4$ system of first-order hyperbolic PDEs, whose well-posedness is shown using the method of characteristics and successive approximations. Once the kernels are computed, the stabilizing feedback law can be explicitly constructed from them.
We consider the problem of boundary stabilization of a 1-D (one-dimensional) wave equation with an internal spatially varying antidamping term. This term puts all the eigenvalues of the open-loop system … We consider the problem of boundary stabilization of a 1-D (one-dimensional) wave equation with an internal spatially varying antidamping term. This term puts all the eigenvalues of the open-loop system in the right half of the complex plane. We design a feedback law based on the backstepping method and prove exponential stability of the closed-loop system with a desired decay rate. For plants with constant parameters the control gains are found in closed form. Our design also produces a new Lyapunov function for the classical wave equation with passive boundary damping.
In this paper, we use swapping design filters to bring systems of n+1 partial differential equations of the hyperbolic type to static form. Standard parameter identification laws can then be … In this paper, we use swapping design filters to bring systems of n+1 partial differential equations of the hyperbolic type to static form. Standard parameter identification laws can then be applied to estimate unknown parameters in the boundary conditions. Proof of boundedness of the adaptive laws are offered, and the results are demonstrated in simulations.
Using a result on the existence and uniqueness of the semiglobal C1 solution to the mixed initial-boundary value problem for first order quasi-linear hyperbolic systems with general nonlinear boundary conditions, … Using a result on the existence and uniqueness of the semiglobal C1 solution to the mixed initial-boundary value problem for first order quasi-linear hyperbolic systems with general nonlinear boundary conditions, we establish the exact boundary controllability for quasi-linear hyperbolic systems if the C1 norm of initial and final states is small enough.
We derive a full state feedback law and a state observer for a class of disturbance rejection problems for n+1 linear coupled partial differential equations (PDEs). The disturbance enters the … We derive a full state feedback law and a state observer for a class of disturbance rejection problems for n+1 linear coupled partial differential equations (PDEs). The disturbance enters the system at one boundary, while the actuation and sensing are limited to the opposite boundary. We solve this by separately designing a state feedback controller and an observer, and show that they can be combined into an output feedback control law that rejects the effect of the disturbance with exponential decay. The performance of output feedback controller is demonstrated in a simulation.
In this paper, we present a state-feedback and a state-observer for disturbance attenuation problems for a class of n + 1 coupled linear hyperbolic partial differential equations. The disturbance and … In this paper, we present a state-feedback and a state-observer for disturbance attenuation problems for a class of n + 1 coupled linear hyperbolic partial differential equations. The disturbance and the sensing are located at the left boundary of the system while the actuation is located at the right boundary of the system (anti-collocated setup). The designs are based on the backstepping method and rely on boundary measurement only. The feedback control law is found by utilizing the fact that the closed-form solution of the equivalent target system can be obtained. Furthermore, by defining a modified L <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> -norm, we show the observer is exponentially stable. A numerical example inspired from an oil well drilling problem is presented to validate the results.
This monograph explores the modeling of conservation and balance laws of one-dimensional hyperbolic systems using partial differential equations. It presents typical examples of hyperbolic systems for This monograph explores the modeling of conservation and balance laws of one-dimensional hyperbolic systems using partial differential equations. It presents typical examples of hyperbolic systems for
In this paper, a problem of boundary stabilization of a class of linear parabolic partial integro-differential equations (P(I)DEs) in one dimension is considered using the method of backstepping, avoiding spatial … In this paper, a problem of boundary stabilization of a class of linear parabolic partial integro-differential equations (P(I)DEs) in one dimension is considered using the method of backstepping, avoiding spatial discretization required in previous efforts. The problem is formulated as a design of an integral operator whose kernel is required to satisfy a hyperbolic P(I)DE. The kernel P(I)DE is then converted into an equivalent integral equation and by applying the method of successive approximations, the equation's well posedness and the kernel's smoothness are established. It is shown how to extend this approach to design optimally stabilizing controllers. An adaptation mechanism is developed to reduce the conservativeness of the inverse optimal controller, and the performance bounds are derived. For a broad range of physically motivated special cases feedback laws are constructed explicitly and the closed-loop solutions are found in closed form. A numerical scheme for the kernel P(I)DE is proposed; its numerical effort compares favorably with that associated with operator Riccati equations.
This paper is an assessment of the current state of controllability and observability theories for linear partial differential equations, summarizing existing results and indicating open problems in the area. The … This paper is an assessment of the current state of controllability and observability theories for linear partial differential equations, summarizing existing results and indicating open problems in the area. The emphasis is placed on hyperbolic and parabolic systems. Related subjects such as spectral determination, control of nonlinear equations, linear quadratic cost criteria and time optimal control are also discussed.
Previous article Next article Boundary Controllability of Nonlinear Hyperbolic SystemsMarco CirinàMarco Cirinàhttps://doi.org/10.1137/0307014PDFBibTexSections ToolsAdd to favoritesExport CitationTrack CitationsEmail SectionsAbout[1] A. G. Butkovskii and , L. N. Poltavskii, Optimal control of wave … Previous article Next article Boundary Controllability of Nonlinear Hyperbolic SystemsMarco CirinàMarco Cirinàhttps://doi.org/10.1137/0307014PDFBibTexSections ToolsAdd to favoritesExport CitationTrack CitationsEmail SectionsAbout[1] A. G. Butkovskii and , L. N. Poltavskii, Optimal control of wave processes, Avtomat. i Telemekh., 27 (1966), 48–53 Google Scholar[2] M. Cirina, Nonlinear hyperbolic problems: a priori bounds and solutions on preassigned sets, Rep., 960, University of Wisconsin, Math. Res. Center, Madison, Wisconsin Google Scholar[3] Roberto Conti, On some aspects of linear control theoryMathematical Theory of Control (Proc. 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Math., 10 (1962), 229–245 MR0154422 0107.11401 LinkISIGoogle Scholar Previous article Next article FiguresRelatedReferencesCited ByDetails Internal Controllability of First Order Quasi-linear Hyperbolic Systems with a Reduced Number of ControlsSIAM Journal on Control and Optimization, Vol. 55, No. 1 | 8 February 2017AbstractPDF (510 KB)Infinite-Dimensional Predictive Control for Hyperbolic SystemsSIAM Journal on Control and Optimization, Vol. 52, No. 6 | 13 November 2014AbstractPDF (578 KB)Some Results on the Controllability of Coupled Semilinear Wave Equations: The Desensitizing Control CaseSIAM Journal on Control and Optimization, Vol. 49, No. 3 | 24 May 2011AbstractPDF (250 KB)Global Controllability of Nonviscous and Viscous Burgers-Type EquationsSIAM Journal on Control and Optimization, Vol. 48, No. 3 | 1 May 2009AbstractPDF (312 KB)Optimal Control in Networks of Pipes and CanalsSIAM Journal on Control and Optimization, Vol. 48, No. 3 | 10 June 2009AbstractPDF (300 KB)Exact Controllability for Multidimensional Semilinear Hyperbolic EquationsSIAM Journal on Control and Optimization, Vol. 46, No. 5 | 17 October 2007AbstractPDF (349 KB)Boundary Controllability between Sub- and Supercritical FlowSIAM Journal on Control and Optimization, Vol. 42, No. 3 | 26 July 2006AbstractPDF (275 KB)Exact Boundary Controllability for Quasi-Linear Hyperbolic SystemsSIAM Journal on Control and Optimization, Vol. 41, No. 6 | 26 July 2006AbstractPDF (117 KB)Exact Controllability Theorems and Numerical Simulations for Some Nonlinear Differential EquationsSIAM Journal on Control and Optimization, Vol. 19, No. 6 | 17 February 2012AbstractPDF (1902 KB)Controllability and Stabilizability Theory for Linear Partial Differential Equations: Recent Progress and Open QuestionsSIAM Review, Vol. 20, No. 4 | 17 February 2012AbstractPDF (9779 KB)A General Theory of Observation and ControlSIAM Journal on Control and Optimization, Vol. 15, No. 2 | 18 July 2006AbstractPDF (2824 KB)Controllability of the Nonlinear Wave Equation in Several Space VariablesSIAM Journal on Control and Optimization, Vol. 14, No. 1 | 3 August 2006AbstractPDF (634 KB)Boundary Value Control of the Higher-Dimensional Wave EquationSIAM Journal on Control, Vol. 9, No. 1 | 18 July 2006AbstractPDF (1178 KB) Volume 7, Issue 2| 1969SIAM Journal on Control179-365 History Submitted:14 November 1968Published online:18 July 2006 InformationCopyright © 1969 Society for Industrial and Applied MathematicsPDF Download Article & Publication DataArticle DOI:10.1137/0307014Article page range:pp. 198-212ISSN (print):0036-1402Publisher:Society for Industrial and Applied Mathematics
In this paper, we solve an adaptive control problem for a class of 2 × 2 linear hyperbolic partial differential equations, where sensing and actuation are restricted to the boundary … In this paper, we solve an adaptive control problem for a class of 2 × 2 linear hyperbolic partial differential equations, where sensing and actuation are restricted to the boundary anticollocated with an uncertain parameter. This is done by combining a recently derived adaptive observer for the system states and the uncertain parameter, with an adaptive control law. Proof of L2-boundedness for all signals in the closed loop is given, and the system states are proved to converge to zero pointwise in space. The theory is demonstrated in a simulation.
We solve the problem of controlling a class of one-dimensional semilinear 2 × 2 hyperbolic systems to the origin in minimum time using actuation at both boundaries of the domain. … We solve the problem of controlling a class of one-dimensional semilinear 2 × 2 hyperbolic systems to the origin in minimum time using actuation at both boundaries of the domain. The control method can also be used to solve a class of tracking problems. For the special case of time-invariant linear systems, the state-feedback control law can be written explicitly as the inner product of kernels with the state. We further design an observer to estimate the distributed state from measurements at both boundaries, also in minimum time. The state-feedback controller and observer are combined to solve the output-feedback control problem. A numerical example is given to demonstrate the controller performance.
In this paper, we develop an adaptive observer for n + 1 coupled first-order 1-D hyperbolic PDEs for estimation of unknown parameters appearing in the left boundary condition using only … In this paper, we develop an adaptive observer for n + 1 coupled first-order 1-D hyperbolic PDEs for estimation of unknown parameters appearing in the left boundary condition using only measurements at the right boundary. Proof of boundedness of the estimated parameters and sufficient conditions for convergence are offered and the result is demonstrated in a simulation.
By means of a result on the semi-global C1 solution, we establish the exact boundary controllability for the reducible quasilinear hyperbolic system if the C1 norm of initial data and … By means of a result on the semi-global C1 solution, we establish the exact boundary controllability for the reducible quasilinear hyperbolic system if the C1 norm of initial data and final state is small enough.
We detail in this paper the importance of a change of strategy for the delay robust control of systems composed of two linear first-order hyperbolic equations. One must go back … We detail in this paper the importance of a change of strategy for the delay robust control of systems composed of two linear first-order hyperbolic equations. One must go back to the classical tradeoff between convergence rate and delay robustness. More precisely, we prove that, for systems with strong reflections, canceling the reflection at the actuated boundary will yield zero delay robustness. Indeed, for such systems, using a backstepping controller, the corresponding target system should preserve a small amount of this reflection to ensure robustness to a small delay in the loop. This implies, in some cases, giving up finite time convergence.
-This is a short presentation of the freefem++ software. In Section 1, we recall most of the characteristics of the software, In Section 2, we recall how to to build … -This is a short presentation of the freefem++ software. In Section 1, we recall most of the characteristics of the software, In Section 2, we recall how to to build the weak form of a partial differential equation (PDE) from the strong form. In the 3 last sections, we present different examples and tools to illustrated the power of the software. First we deal with mesh adaptation for problems in two and three dimension, second, we solve numerically a problem with phase change and natural convection, and the finally to show the possibilities for HPC we solve a Laplace equation by a Schwarz domain decomposition problem on parallel computer.
Using a series of invertible transformations, we bring a system of 2 × 2 linear hyperbolic partial differential equations (PDEs) to an observer canonical form. With transport delays as the … Using a series of invertible transformations, we bring a system of 2 × 2 linear hyperbolic partial differential equations (PDEs) to an observer canonical form. With transport delays as the only information assumed known about the system parameters, a filter based adaptive output feedback control law is designed for the transformed system. Pointwise boundedness of all signals in the closed loop system and pointwise convergence of the system states to zero are established. The theory is demonstrated in a simulation.
By means of a direct and constructive method based on the theory of semi-global C1 solution, the local exact boundary observability is established for one-dimensional first order quasilinear hyperbolic systems … By means of a direct and constructive method based on the theory of semi-global C1 solution, the local exact boundary observability is established for one-dimensional first order quasilinear hyperbolic systems with general nonlinear boundary conditions. An implicit duality between the exact boundary controllability and the exact boundary observability is then shown in the quasilinear case.
We consider the isothermal Euler equations with friction that modelthe gas flow through pipes. We present a method of time-delayedboundary feedback stabilization to stabilize the isothermal Eulerequations locally around a … We consider the isothermal Euler equations with friction that modelthe gas flow through pipes. We present a method of time-delayedboundary feedback stabilization to stabilize the isothermal Eulerequations locally around a given stationary subcritical state on afinite time interval. The considered control system is a quasilinearhyperbolic system with a source term. For this system we introduce aLyapunov function with delay terms and develop time-delayed boundarycontrols for which the Lyapunov function decays exponentially withtime. We present the stabilization method for a single gas pipe andfor a star-shaped network of pipes.
This paper develops an extension of infinite-dimensional backstepping method for parabolic and hyperbolic systems in one spatial dimension with two actuators. Typically, PDE backstepping is applied in 1-D domains with … This paper develops an extension of infinite-dimensional backstepping method for parabolic and hyperbolic systems in one spatial dimension with two actuators. Typically, PDE backstepping is applied in 1-D domains with an actuator at one end. Here, we consider the use of two actuators, one at each end of the domain, which we refer to as bilateral control (as opposed to unilateral control). Bilateral control laws are derived for linear reaction-diffusion, wave and 2X2 hyperbolic 1-D systems (with same speed of transport in both directions). The extension is nontrivial but straightforward if the backstepping transformation is adequately posed. The resulting bilateral controllers are compared with their unilateral counterparts in the reaction-diffusion case for constant coefficients, by making use of explicit solutions, showing a reduction in control effort as a tradeoff for the presence of two actuators when the system coefficients are large. These results open the door for more sophisticated designs such as bilateral sensor/actuator output feedback and fault-tolerant designs.