analysis and control of a conservation law with …analysis and control of a conservation law with...
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![Page 1: Analysis and control of a conservation law with …Analysis and control of a conservation law with nonlocal velocity Zhiqiang WANG Fudan University, Shanghai, China February 3, 2012](https://reader036.vdocuments.site/reader036/viewer/2022081522/5f0398047e708231d409d222/html5/thumbnails/1.jpg)
Introduction Main results Future work
Analysis and control of a conservation lawwith nonlocal velocity
Zhiqiang WANG
Fudan University, Shanghai, China
February 3, 2012Laboratoire Jacques-Louis Lions
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Introduction Main results Future work
Acknowledgements
Séminaire du Groupe de Travail ContrôleLaboratoire Jacques-Louis LionsFondation Sciences Mathématiques de Paris2009 Benasque Summer School2010 Triemestre IHP
Joint work with J.-M. Coron, M. Gröschel, M. Gugat, M. Kawski,A. Keimer, G. Leugering and P. Shang
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Introduction Main results Future work
Outline
1 IntroductionMotivationProblems
2 Main resultsAnalysis
Well-posedness of Forward SystemWell-posedness of Adjoint System
ControlExact (State) ControllabilityTime-optimal Transition Between EquilibriaNodal Profile ControllabilityStabilizationOptimal Control Problems
3 Future work
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Introduction Main results Future work
Motivation
Semiconductor wafer manufacture system
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Introduction Main results Future work
Motivation
Semiconductor wafer manufacture system
The semiconductor manufacturing system which has a highlyre-entrant character.
very high volume (number of parts manufactured per unittime) at each processvery large number of consecutive production steps
Cycle time: 6 weeks Work steps: 500 WIP: 60,000 wafers
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Introduction Main results Future work
Problems
Model
1-D hyperbolic system (conservation law with nonlocal velocity)[Armbruster et al., 2006]
ρt(t , x) + (ρ(t , x)λ(W (t)))x = 0, (t , x) ∈ (0, T )× (0, 1),
ρ(0, x) = ρ0(x), x ∈ (0, 1),
ρ(t , 0)λ(W (t)) = u(t), t ∈ (0, T ).
(1)with W (t) =
∫ 10 ρ(t , x)dx .
λ(·) ∈ C1([0,+∞); (0,+∞)) and is usually decreasing.A typical special case: λ(W ) = 1
1+W .
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Introduction Main results Future work
Problems
The space variable x ∈ [0, 1] represents the wholemanufacture process. x = 0 corresponds to the entry ofthe factory (manufacture line) while x = 1 corresponds tothe exit of the factory (manufacture line).ρ(t , x) ≥ 0 is the density of product at time t and stage x.ρ(t , ·) (t ≥ 0) is called the state in exact controllabilityproblem.The control u(t) of this system is acted on the influxρ(t , 0)λ(W (t)), the rate of products entering the factory.The natural output is the outflux y(t) := ρ(t , 1)λ(W (t)), therate of products exiting the factory.
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Introduction Main results Future work
Problems
Some control problems (I)
Exact (state) Controllability ProblemPossibility to drive arbitrary initial state ρ0 to arbitrary finalstate ρ1 over some [0, T ].Time-optimal Transition ProblemFind time-optimal control to drive given initial state ρ0 togiven final state ρ1.Stabilization ProblemPossibility to obtain asymptotic stability of the closed-loopsystem by constructing a feedback control. Naturalfeedback u(t) = ky(t). ‖ρ(t , ·)− ρ‖ → 0 as t →∞.
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Introduction Main results Future work
Problems
Some control problems (II)
Nodal Profile (Outflux) Controllability ProblemPossibility to drive the system, which starts from arbitraryinitial state ρ0, to reach exactly some given value yd for theoutflux y over [T1, T2].Demand Tracking ProblemMinimize the Error Signal ‖y − yd‖,the difference between the actual outflux y(t) and a givendemand forecast yd(t).Backlog ProblemMinimize the Accumulated Error Signal ‖β‖,β(t) =
∫ t0 y(s) ds −
∫ t0 yd(s) ds.
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Introduction Main results Future work
Problems
Related work
1 D. Armbruster, D. Marthaler, C. Ringhofer, K. Kempf andT.-C. Jo, A continuum model for a re-entrant factory, Oper.Res., 2006.
2 M. La Marca, D. Armbruster, M. Herty, and C. Ringhofer,Control of continuum models of production systems, IEEETrans. Automatic Control, 2010.
3 R. Colombo, M. Herty, and M. Mercier, Control of thecontinuity equation with a non local flow, ESAIM ControlOptim. Calc. Var., 2010.
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Introduction Main results Future work
Analysis
Definition of weak solution in L1
Let T > 0, ρ0 ∈ L1(0, 1) and u ∈ L1(0, T ) be given. A weaksolution of the system (1) is a function ρ ∈ C0([0, T ]; L1(0, 1))such that, for every τ ∈ [0, T ] and every ϕ ∈ C1([0, τ ]× [0, 1])such that
ϕ(τ, x) = 0,∀x ∈ [0, 1] and ϕ(t , 1) = 0,∀t ∈ [0, τ ],
one has ∫ τ
0
∫ 1
0ρ(t , x)(ϕt(t , x) + λ(W (t))ϕx(t , x))dxdt
+
∫ τ
0u(t)ϕ(t , 0)dt +
∫ 1
0ρ0(x)ϕ(0, x)dx = 0.
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Introduction Main results Future work
Analysis
Well-posedness in L1
Theorem
If ρ0 ∈ L1+(0, 1) and u ∈ L1
+(0, T ), then system (1) admits aunique weak solution ρ ∈ C0([0, T ]; L1
+(0, 1)), which is alsononnegative almost everywhere in Q = [0, T ]× [0, 1].
Proof sketch.1 Existence and uniqueness of local solution
Characteristic method + fixed point argument bycontraction mapping principle.Explicit expression of ρ in terms of ξ(t) :=
∫ t0 λ(W τ))dτ .
2 Existence of global solutionUniform a priori estimate of ‖ρ(t , ·)‖L1(0,1).
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Introduction Main results Future work
Analysis
Regularity
Remark (Hidden regularity)
ρ ∈ C0([0, T ]; L1(0, 1)) ⊂ L1(0, 1; L1(0, T )) ρ ∈ C0([0, 1]; L1(0, T )).
Remark (Lp Regularity)
ρ0 ∈ Lp+(0, 1) and u ∈ Lp
+(0, T ) (1 ≤ p < ∞)=⇒ ρ ∈ C0([0, T ]; Lp
+(0, 1)) ∩ C0([0, 1]; Lp+(0, T )).
Remark (W 1,p Regularity)
ρ0 ∈ W 1,p+ (0, 1) and u ∈ W 1,p
+ (0, T ) (1 ≤ p < ∞) withρ0(0) = u(0)
=⇒ ρ ∈ C0([0, T ]; W 1,p+ (0, 1)) ∩ C0([0, 1]; W 1,p
+ (0, T )).
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Introduction Main results Future work
Analysis
Adjoint system
Suppose that ρ ∈ C0([0, T ]; W 1,p+ (0, 1)) ∩ C0([0, 1]; W 1,p
+ (0, T ))is solution to (1). The adjoint system is defined as
qt(t , x) + (q(t , x)λ(W (t)))x
= −λ(W (t))∫ 1
0 ρ(t , s)qx(t , s)ds, (t , x) ∈ (0, T )× (0, 1),
q(T , x) = q0(x), x ∈ (0, 1),
q(t , 1) = v(t), t ∈ (0, T ).
(2)where W (t) =
∫ 10 ρ(t , x)dx .
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Introduction Main results Future work
Analysis
Well-posedness of adjoint system
Theorem
Let p ∈ [1,∞), q0 ∈ W 1,p(0, 1) and v ∈ W 1,p(0, T ) withq0(0) = v(0), then (2) has a unique solutionρ ∈ C0([0, T ], W 1,p(0, 1)) ∩ C0([0, 1], W 1,p(0, T )).
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Introduction Main results Future work
Analysis
Proof sketch (I)
Step 1It suffices to study
qt(t , x) + α(t)qx(t , x)
= −∫ 1
0 γ(t , s)qx(t , s)ds, (t , x) ∈ (0, T )× (0, 1),
q(0, x) = q0(x), x ∈ (0, 1),
q(t , 0) = v(t), t ∈ (0, T ).
(3)
where α ∈ C0([0, T ]; (0,∞)) and γ ∈ C0+([0, T ]× [0, 1]).
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Introduction Main results Future work
Analysis
Proof sketch (II)
Step 2Differentiate (3) with respect to x :
qx t(t , x) + α(t)qx x(t , x) = 0, (t , x) ∈ (0, T )× (0, 1),
qx(0, x) = q′0(x), x ∈ (0, 1),
qx(t , 0) == − 1α(t) ·
(v ′(t) +
∫ 10 γ(t , s)qx(t , s)ds
), t ∈ (0, T ).
(4)Let f (t) :=
∫ 10 γ(t , s)qx(t , s)ds.
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Introduction Main results Future work
Analysis
Proof sketch (III)
Step 3
f (t) = g(t) +
∫ t
0k(t , τ) f (τ)dτ, (5)
where k(t , τ) := −γ(
t ,∫ tτ α(r)dr
)and
g(t) :=−∫ t
0γ(
t ,∫ t
τα(r)dr
)v ′(τ)dτ
+
∫ 1−R t
0 α(r)dr
0γ(t , s +
∫ t
τα(r)dr)q′0(s)ds
are continuous.
(5) =⇒ f(4)
=⇒ qx
R x0=⇒ q.
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Introduction Main results Future work
Control
Definition of exact (state) controllability
Exact (State) Controllability
State ρ(t , ·) ∈ Lp+(0, 1).
Does there exists Control u(t) ∈ Lp+(0, T ) to drive the
hyperbolic system (1): ρ0 ∈ Lp+(0, 1) ρ1 ∈ Lp
+(0, 1) on [0, T ],i.e.,
ρ(T , x) = ρ1(x), x ∈ (0, 1).
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Introduction Main results Future work
Control
Classical result can not be applied
Li-Rao’s constructive method.Key idea: ut + A(u)ux = 0 ⇐⇒ ux + A−1(u)ut = 0 when A(u)has no zero eigenvalues.
Tatsien Li, Bopeng Rao, Exact boundary controllability forquasi-linear hyperbolic systems, SIAM J. Control Optim.,41(6):1748–1755 (electronic), 2003.Tatsien Li, Controllability and observability for quasilinearhyperbolic systems, volume 3 of AIMS Series on AppliedMathematics. American Institute of Mathematical Sciences(AIMS), Springfield, MO, 2010.
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Introduction Main results Future work
Control
Local controllability around ρ
Theorem
Let ρ ≥ 0 be the given constant equilibrium and T0 := 1λ(ρ) .
Then, for any T > T0, and any p ≥ 1, the system (1) is locallycontrollable.
Proof sketch.1 Controllability for linear control system
ξ =⇒ u =⇒ ρ
2 Fixed point argument by contraction mapping principleξ =⇒ u =⇒ ρ =⇒ F (ξ) = ξ
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Introduction Main results Future work
Control
Global controllability
Theorem
For any p ∈ [1,+∞), any ρ0 ∈ Lp+(0, 1) and any ρ1 ∈ Lp
+(0, 1),there exists T1 > 0 (depending on ρ0 and ρ1) such that for anyT ≥ T1, the system (1) is controllable.
Proof sketch.1 Drive the state from ρ0 at t = 0 to some equilibrium ρ at
t = Tf .Input control u(t) can be induced by natural state controlρ(t , 0) ≡ ρ.
2 Drive the system from ρ at t = Tf to ρ1 at t = T := Tf + Tbby using the reversibility of the hyperbolic system(t , x , ρ(t , x)) → (T − t , 1− x , ρ(T − t , 1− x)).
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Introduction Main results Future work
Control
Transition between equilibria
Exact controllabilityDrive the system from one equilibrium ρ0 to another ρ1.Admissible control set.
Time-optimal controlThe global controllability time is not optimal.What is the optimal control time to drive the system (1) fromone equilibrium state ρ0 to another equilibrium state ρ1.What is the control?
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Introduction Main results Future work
Control
An intuitive time-optimal control
Choose the intuitive density controlρt(t , x) + (ρ(t , x)λ(W (t)))x = 0, (t , x) ∈ (0, T )× (0, 1),
ρ(0, x) = ρ0, x ∈ (0, 1),
ρ(t , 0) = ρ1, t ∈ (0, T )
for the special case: λ(W ) = 11+W .
ρ(T , x) ≡ ρ1 for T ≥ 1 + ρ0+ρ12
u(t) = ρ1√(1+ρ0)2+2t(ρ1−ρ0)
, t ∈ (0, T ).
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Introduction Main results Future work
Control
Time-optimal control of transition between equilibria
TheoremThe minimum time to transfer the state from one equilibrium ρ0to the other equilibrium ρ1 using nonnegative influx controlu ∈ L1
+(0,∞) is T = 1 + ρ0+ρ12 . The time-optimal control is
indeed the natural one u(t) = ρ1√(1+ρ0)2+2t(ρ1−ρ0)
, t ∈ (0, T ).
Proof.Direct computations.
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Introduction Main results Future work
Control
Definition of nodal profile controllability
Where it comes?Nodal profile controllability was originally introduced by M.Gugat et al. for gas demanding control. This kind ofcontrollability was later named by T. Li and generalized for firstorder quasilinear hyperbolic systems.
DefinitionFor any given initial data ρ0, boundary data yd and any T1, Twith 0 < T1 < T , to find suitable suitable controlu : (0, T ) 7→ [0,+∞) such that the solution ρ to the system (1)satisfies also the nodal profile condition:
ρ(t , 1)λ(W (t)) = yd(t), t ∈ (T1, T ). (6)
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Introduction Main results Future work
Control
Nodal profile controllability
Theorem
Let ρ ≥ 0 be the given constant equilibrium and let T0 := 1λ(ρ) .
For any p ∈ [1,+∞), and any T1, T with T0 < T1 < T , thereexists ν > 0 such that the following holds: For any ρ0 ∈ Lp
+(0, 1)and any yd ∈ Lp
+(T1, T )
‖ρ0(·)− ρ‖Lp(0,1) ≤ ν, ‖y(·)− ρλ(ρ)‖Lp(T1,T ) ≤ ν,
there exists u ∈ Lp+(0, T ) such that the weak solution
ρ ∈ C0([0, T ]; Lp(0, 1)) to the system (1) satisfies the out-fluxcondition (6).
Proof sketch.Nodal profile controllability for linear systemFixed point argument.
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Introduction Main results Future work
Control
Output feedback stabilization
Definition of output feedback stabilization
ρt(t , x) + (ρ(t , x)λ(W (t)))x = 0, (t , x) ∈ (0,∞)× (0, 1),
ρ(0, x) = ρ0(x), x ∈ (0, 1),
u(t)− ρλ(ρ) = k(y(t)− ρλ(ρ)), t ∈ (0,∞).
(7)with W (t) =
∫ 10 ρ(t , x)dx , u(t) = ρ(t , 0)λ(W (t)), y(t) =
ρ(t , 1)λ(W (t)).
Can we find k such that ‖ρ− ρ‖ → 0 as t →∞?
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Introduction Main results Future work
Control
Simple observation
Does k = 0 work?u(t) = ρλ(ρ).
For ρ = 0, YES, it works!u(t) = 0 ⇐⇒ ρ(t , 0) = 0While for ρ 6= 0, NOT clear!
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Introduction Main results Future work
Control
Linearization near constant ρ ≥ 0
Linearized systemLet
d :=ρλ′(ρ)
λ(ρ). (8)
The difference function ρ := ρ− ρ. Omitting , then ρ satisfiesρt(t , x) + ρx(t , x) = 0, t ∈ (0,∞), x ∈ (0, 1),
ρ(0, x) = ρ0(x), x ∈ (0, 1),
ρ(t , 0) = kρ(t , 1) + (k − 1)dW (t), t ∈ (0,∞),
(9)
where W (t) =∫ 1
0 ρ(t , x)dx and
λ(ρ) = 1
without loss of generality.
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Introduction Main results Future work
Control
IFF condition for stabilization
Theorem
Let ρ ≥ 0. Then, ρ ∈ L2(0, 1) is exponentially stable in L2(0, 1)for the control system (9) if and only if d > −1 and |k | < 1.That is to say: if and only if d > −1 and |k | < 1, there existconstants C = C(d , k) > 0 and α = α(d , k) > 0 such that thefollowing holds: For any ρ0 ∈ L2(0, 1), the weak solutionρ ∈ C0([0,∞); L2(0, 1)) to the system (9) satisfies
‖ρ(t , ·)‖L2(0,1) ≤ Ce−αt · ‖ρ0‖L2(0,1), ∀t ∈ [0,∞). (10)
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Introduction Main results Future work
Control
Proof by spectral analysis
Characteristic equationLet µ ∈ C and φ 6= 0 be an eigen pair s.t.
µφ(x) + φ′(x) = 0, x ∈ (0, 1),
φ(0) = kφ(1) + (k − 1)d ·∫ 1
0φ(x)dx .
which impliesφ(x) = e−µx ,
1− ke−µ + (1− k)d ·∫ 1
0e−µxdx = 0.
(11)
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Introduction Main results Future work
Control
Spectral condition
Proposition(11) has no solution (µ, φ) such that <(µ) ≥ 0 and φ 6= 0 if andonly if d > −1 and |k | < 1.
Proof sketch.Degree theory homotopic functions
1 d = −1 and k ∈ R or d 6= −1 and k = 1. ∃µ = 02 d 6= −1 and |k | > 1. ∃<(µ) > 03 d < −1 and |k | < 1 or k = −1. ∃µ ∈ (0,∞)
4 d > −1 and k = −1. ∃µ = ib, b ∈ R, b 6= 05 d > −1 and |k | < 1. No <µ ≥ 0
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Introduction Main results Future work
Control
Lyapunov function approach
Case |d | < 1 and |k | < 1
Define
L(t) :=
∫ 1
0e−βxρ2(t , x)dx + aW 2(t), (12)
By letting β → 0+, a := e−β−k1−k d > 0,
L(t) ≤ − β
C[1− d2(eβ − 1)2e−ββ−2] · L(t) ≤ −αL(t),
since 1− d2(eβ − 1)2e−ββ−2 → 1− d2 > 0 as β → 0+.
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Introduction Main results Future work
Control
Lyapunov function approach
Case d ≥ 1 and |k | < 1
Define
V1(t) :=
∫ 1
0ρ2(t , x)dx + bW 2(t), (13)
Choose b = d , then
V1(t) = (k2 − 1)ξ2(t , 1) ≤ 0, ∀t ≥ 0,
whereξ(t , x) := ρ(t , x) + dW (t)
satisfiesξt(t , x) + ξx(t , x) = dW (t), t ∈ (0,∞), x ∈ (0, 1),
ξ(0, x) = ρ0(x)− ρ + dW (0), x ∈ (0, 1),
ξ(t , 0) = kξ(t , 1), t ∈ (0,∞).
(14)
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Introduction Main results Future work
Control
Lyapunov function approach
Case d ≥ 1 and |k | < 1
Define
V2(t) :=
∫ 1
0e−xξ2(t , x)dx , (15)
thenV2(t) ≤ −
12
V2(t) + Aξ2(t , 1).
LetV (t) :=
A1− k2 V1(t) + V2(t). (16)
Then
V (t) =A
1− k2 V1(t) + V2(t) ≤ −12
V2(t) ≤ −αV (t), ∀t ≥ 0.
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Introduction Main results Future work
Control
Stabilization to ρ = 0 for nonlinear system
ρ = 0 =⇒ d = 0.
TheoremFor any k ∈ (−1, 1) and any R > 0, there exist constantsC = C(k , R) > 0 and α = α(k , R) such that for anyρ0 ∈ L2((0, 1); [0,∞)) with
‖ρ0‖L1(0,1) ≤ R, (17)
the solution ρ ∈ C0([0,∞); L2(0, 1)) to the system with feedback
u(t) = ky(t)
satisfies
‖ρ(t , ·)‖L2(0,1) ≤ Ce−αt · ‖ρ0‖L2(0,1), ∀t ∈ [0,∞). (18)
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Introduction Main results Future work
Control
Proof by Lyapunov approach
Proof.Define
L(t) :=
∫ 1
0e−βx |ρ(t , x)|2dx , ∀t ∈ [0,∞),
then
L(t) =− βλ(W (t))L(t) + (λ(W (t)))−1(k2 − e−β)y2(t),≤ −αL(t), t ∈ (0,∞)
by β → 0+ and
0 ≤ W (t) ≤ ‖ρ0‖L1(0,1) ≤ R, ∀t ∈ [0,∞).
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Introduction Main results Future work
Control
Stabilization to ρ > 0 for nonlinear system
TheoremLet d > −1. For any k ∈ (−1, 1), there exist constantsε = ε(d , k) > 0, C = C(d , k) > 0 and α = α(d , k) > 0 such thatthe following holds: For any ρ0 ∈ L2((0, 1); [0,∞)) with
‖ρ0(·)− ρ‖L2(0,1) ≤ ε,
the weak solution ρ ∈ C0([0,∞); L2(0, 1)) to the system with
u(t)− ρλ(ρ) = k(y(t)− ρλ(ρ)), t ∈ (0,∞)
satisfies
‖ρ(t , ·)− ρ‖L2(0,1) ≤ Ce−αt · ‖ρ0(·)− ρ‖L2(0,1), ∀t ∈ [0,∞).
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Introduction Main results Future work
Control
Proof by Lyapunov approach
Case d ∈ (−1, 1) and |k | < 1 .
Define L(t) as (12), then
L(t) ≤ − β
C2
(1− d2(eβ − 1)2e−ββ−2 + O(ε)
)· L(t)
≤ −αL(t),
letting first β = β(d , k) → 0+ and then ε = ε(d , k) → 0+, since1− d2(eβ − 1)2e−ββ−2 → 1− d2 > 0 as β → 0+.
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Introduction Main results Future work
Control
Proof by Lyapunov approach
Case d ≥ 1 and |k | < 1 .
Define V1(t), V2(t), V (t) as (13),(15),(16), then
V (t) ≤ (−12
+ O(ε))V2(t) ≤ −αV (t), ∀t ≥ 0
by letting ε = ε(d , k) → 0+.
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Introduction Main results Future work
Control
Optimal Control Problem (I)
Optimal Control Problem without constrains
For any fixed Demand Forecast yd ∈ L2+(0, T ) and initial data
ρ0 ∈ L2+(0, 1), we look for solution to the optimal control
problem:
minu∈L2
+(0,T )J(u) := ‖u‖2
L2(0,T ) + ‖y − yd‖2L2(0,T ),
where y(t) = ρ(t , 1)λ(W (t)) is the outflux corresponding to theinflux u ∈ L2
+(0, T ) and initial data ρ0 ∈ L2+(0, 1).
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Introduction Main results Future work
Control
Solution to optimal control problem
Theorem
The infimum of the functional J(u) in L2+(0, T ) is achieved, i.e.,
there exists u∞ ∈ L2+(0, T ) such that J(u∞) = infu∈L2
+(0,T ) J(u).
Proof sketch.1 Choose a minimizing sequence un∞n=1.
Take a subsequence un u∞ weakly in L2+(0, T ).
2 Solve system (1) corresponding to influx un (resp., u∞) toobtain solution ρn (resp., ρ∞).Prove that yn(·) := λ(Wn(·))ρn(·, 1) y∞(·):= λ(W∞(·))ρ∞(·, 1) weakly in L2(0, T ).
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Introduction Main results Future work
Control
Optimal Control Problem (II)
Optimal control problem with constrains
minu∈U,y∈Y
J(u, y)
subject toρt(t , x) + (ρ(t , x)λ(W (t)))x = 0, (t , x) ∈ (0, T )× (0, 1),
ρ(0, x) = ρ0(x), x ∈ (0, 1),
ρ(t , 0)λ(W (t)) = u(t), t ∈ (0, T ),
ρ(t , 1)λ(W (t)) = y(t), t ∈ (0, T ),
with W (t) =∫ 1
0 ρ(t , x)dx .
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Introduction Main results Future work
Control
Basic setting of cost functional J
Basic setting of J
For given U ⊆ L2+(0, T ) and Y ⊆ L2
+(0, T ), J : U × Y → R isassumed to be Fréchet differentiable in L2(0, T ) and∂J(u,y)
∂u , ∂J(u,y)∂y ∈ H1(0, T ).
Example
U = Y ⊆ H1+(0, T )
J(u, y) = κ2‖u − ud‖2
L2(0,T )+ ν
2‖y − yd‖2L2(0,T )
, with
ud , yd ∈ H1(0, T ) and κ, ν ∈ (0,∞).∂J(u,y)
∂u = κ(u − ud), ∂J(u,y)∂y = ν(y − yd).
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Introduction Main results Future work
Control
Lagrange approach
Definition of Lagrange functional
L : (u, y , ρ, q) ∈ U × Y × H1(ΩT )× H1(ΩT ) 7→ R
with
L(u, y , ρ, q) :=J(u, y)− < qt + λ(W (·))qx , ρ >L2(ΩT )
+ < q(T , ·), ρ(T , ·) >L2(0,1) − < q(0, ·), ρ0 >L2(0,1)
+ < q(·, 1), y >L2(0,T ) − < q(·, 0), u >L2(0,T ) .
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Introduction Main results Future work
Control
KKT conditions
TheoremThe minimizer (u, y) ∈ U × Yof J satisfies problems
ρt(t , x) + (ρ(t , x)λ(W (t)))x = 0, (t , x) ∈ (0, T )× (0, 1),
ρ(0, x) = ρ0(x), x ∈ (0, 1),
ρ(t , 0)λ(W (t)) = u(t), t ∈ (0, T ),
ρ(t , 1)λ(W (t)) = y(t), t ∈ (0, T ),
qt(t , x) + (q(t , x)λ(W (t)))x
= −λ(W (t))∫ 1
0 ρ(t , s)qx(t , s)ds, (t , x) ∈ (0, T )× (0, 1),
q(T , x) = 0, x ∈ (0, 1),
q(t , 1) = −∂J(u,y)∂y , t ∈ (0, T )
q(t , 0) = ∂J(u,y)∂u , t ∈ (0, T ).
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Introduction Main results Future work
Control
KKT conditions tell what?
How to find optimal control
u(1)
=⇒ ρ =⇒ W , y(2)
=⇒ q =⇒ q(t , 0) =∂J∂u
(u∗, y) =⇒ u∗
Example
U = Y ⊆ H1+(0, T )
J(u, y) = κ2‖u − ud‖2
L2(0,T )+ ν
2‖y − yd‖2L2(0,T )
, with
ud , yd ∈ H1(0, T ) and κ, ν ∈ (0,∞).
∂J∂u
(u∗, y) = κ(u∗ − ud) =⇒ u∗ = ud +1κ
q(t , 0)
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Introduction Main results Future work
Our articles related to this work
J.-M. Coron, M. Kawski, Z. Wang, Analysis of aconservation law modeling a highly re-entrantmanufacturing system, Discrete Contin. Dyn. Syst. Ser. B,2010.P. Shang, Z. Wang, Analysis and control of a scalarconservation law modeling a highly re-entrantmanufacturing system, J. Differential Equations, 2011.J.-M. Coron, Z. Wang, Controllability for a scalarconservation law with nonlocal velocity, J. DifferentialEquations, 2012.
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Introduction Main results Future work
Work in progress
J.-M. Coron, Z. Wang, Output feedback stabilization for ascalar conservation law with nonlocal velocity, in prepare.M. Gröschel, A. Keimer, G. Leugering, Z. Wang, Regularitytheory and adjoint based optimality conditions for anonlinear transport equation with nonlocal velocity, inprepare.M. Gugat, A. Keimer, Z. Wang, Optimal control of anetwork of re-entrant factories with input and capacityconstraints, in prepare.
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Introduction Main results Future work
Future work
Other applicationParticle synthesis process, Follicle ovulationGeneralizationNetworks, Coupled systems, Higher dimensionNumerical experimentsStabilization with other types of feedbackOptimal control problems with constrains
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Introduction Main results Future work
Thank you for your attention!
!
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Introduction Main results Future work
GBKkai