Abstract
A scheme is proposed for the feedback control of distributed-parameter systems with unknown boundary and volume disturbances and observation errors. The scheme consists of employing a nonlinear filter in the control loop such that the controller uses the optimal estimates of the state of the system. A theoretical comparison of feedback proportional control of a styrene polymerization reactor with and without filtering is presented. It is indicated how an approximate filter can be constructed, greatly reducing the amount of computing required.
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Abbreviations
- a(t):
-
l-vector noisy dynamic input to system
- A(t, a):
-
l-vector function
- A′:
-
frequency factor for first-order rate law (5.68×106 sec−1)
- b :
-
distance to the centerline between two coil banks in the reactor (4.7 cm)
- B :
-
k-vector function defining the control action
- c(χ, τ):
-
concentration of styrene monomer, molel −1
- C p :
-
heat capacity (0.43 cal · g−1 · K−1)
- C ij :
-
constants in approximate filter, Eqs. (49)–(52)
- E :
-
activation energy (20330 cal · mole−1)
- ℰ :
-
expectation operator
- f(t,...):
-
n-vector function
- g 0,g 1(t,...):
-
n-vector functions
- h(t, u):
-
m-vector function relating observations to states
- H(t):
-
function defined in Eq. (36)
- k :
-
dimensionality of control vectorv(x, t)
- k i :
-
constants in approximate filter, Eqs. (49)–(52)
- K :
-
dimensionless proportional gain
- l :
-
dimensionality of dynamic inputa(t)
- m :
-
dimensionality of observation vectory(t)
- n :
-
dimensionality of state vectoru(x, t)
- P (vv)(x, s, t):
-
n×n matrix governed by Eq. (9)
- P (va)(x, t):
-
n×l matrix governed by Eq. (10)
- P (aa)(t):
-
l×l matrix governed by Eq. (11)
- q i (t):
-
diagonal elements ofm×m matrixQ(x, s, t)
- Q(x, s, t):
-
m×m weighting matrix
- R :
-
universal gas constant (1.987 cal · mole−1 · K−1)
- R(x, s, t):
-
n×n weighting matrix
- R i (t):
-
n×n weighting matrix
- s :
-
dimensionless spatial variable
- S(x, s, t):
-
matrix defined in Eq. (11)
- t :
-
dimensionless time variable
- T(χ, τ):
-
temperature, K
- u(x, t):
-
n-dimensional state vector
- u c (t):
-
wall temperature
- u d :
-
desired value ofu 1(1,t)
- u c *:
-
reference control value ofu c
- u max c :
-
maximum value ofu c
- u min c :
-
minimum value of c
- v(x, t):
-
k-dimensional control vector
- W(t):
-
l×l weighting matrix
- x :
-
dimensionless spatial variable
- y(t):
-
m-dimensional observation vector
- α i :
-
constants in approximate filter, Eqs. (49)–(52)
- β :
-
dimensionless parameter defined in Eq. (29)
- ΔH :
-
heat of reaction (17500 cal · mole−1)
- ε :
-
dimensionless activation energy, defined in Eq. (29)
- δ(x):
-
Dirac delta function
- η(x, t):
-
m-dimensional observation noise
- κ :
-
thermal conductivity (0.43×10−3 cal · cm−1 · sec−1 · K−1)
- ρ :
-
density (1 g · cm−3)
- τ :
-
time, sec
- φ :
-
dimensionless parameter defined in Eq. (29)
- χ :
-
spatial variable, cm
- *:
-
reference value
- ^:
-
estimated value
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Communicated by R. Jackson
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Yu, T.K., Seinfeld, J.H. Control of stochastic distributed-parameter systems. J Optim Theory Appl 10, 362–380 (1972). https://doi.org/10.1007/BF00935400
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DOI: https://doi.org/10.1007/BF00935400