Master Builders Policy & Advocacy Blueprint 2012

Dgorinev

Description

• cours - matière potentielle : for economic recovery
• revision
• exposé

Master Builders Policy & Advocacy Blueprint 2012 With around 9,000 members, we are the voice of the building and construction industry in Queensland. KEY AREAS OF REFORM FOR REBUILDING QUEENSLAND'S BUILDING AND CONSTRUCTION INDUSTRY.

• builders
• queensland
• workplace relations system
• track approval processes
• consistency for development
• construction industry
• building
• policy
• government

Sujets

• Révision
• Exposé
• Australie
• Industry
• Building
• Development
• Approval
• System

Informations

• Publié par: edwui
• Nombre de lectures: 23

Extrait

Lecture 11 - Processes with Deadtime,
Internal Model Control
• Processes with deadtime
• Model-reference control
• Deadtime compensation: Dahlin controller
•IMC
• Youla parametrization of all stabilizing controllers
• Nonlinear IMC
– Receding Horizon - MPC - Lecture 14
EE392m - Spring 2005 Control Engineering 11-1
GorinevskyProcesses with Deadtime
• Examples: transport deadtime in paper, mining, oil
• Deadtime = transportation time
EE392m - Spring 2005 Control Engineering 11-2
GorinevskyProcesses with Deadtime
• Example: transport deadtime in food processing
EE392m - Spring 2005 Control Engineering 11-3
GorinevskyProcesses with Deadtime
• Example: resource allocation in computing
Computing
Difference
Tasks
Equation
Modeling
Desired
Resource
Performance
Queues
Resource Feedback Control
EE392m - Spring 2005 Control Engineering 11-4
GorinevskyControl of process with deadtime
-
C P
y y
d
• PI control of a deadtime process
-5
PLANT: P = z ; PI CONTROLLER: k = 0.3, k = 0.2
P I
−sT
D
P = e
1
continuous time
0.8
−d
0.6
P = z discrete time
0.4
0.2
0
0 5 10 15 20 25 30
DEADBEAT CONTROL
• Can we do better?
1
PC 0.8
–Make
−d
= z
0.6
1+ PC 0.4
0.2
– Deadbeat controller
0
−d
0 5 10 15 20 25 30
z
1
PC =
C =
u(t) = u(t − d ) + e(t)
−d
−d
1− z
1− z
EE392m - Spring 2005 Control Engineering 11-5
GorinevskyModel-reference Control
• Deadbeat control has bad robustness, especially w.r.t.
deadtime
• More general model-reference control approach
– make the closed-loop transfer function as desired
P(z)C(z)
Q(z)
is the reference model
= Q(z)
1+ P(z)C(z)
for the closed loop
1 Q(z)
-
C(z) = ⋅
C P
y y
d
P(z) 1− Q(z)
• Works if Q(z) includes a deadtime, at least as large as in
P(z). Then C(z) comes out causal.
EE392m - Spring 2005 Control Engineering 11-6
GorinevskyCausal Transfer Function
M M −1
B(z) b z + b z + ... + b
0 1 N
C(z) = =
N N −1
A(z) z + a z + ... + a
1 N
M −N M − N −1 − N
b z + b z + ... + b z
0 1 N
=
−1 −N
1 + a z + ... + a z
1 N
• Causal implementation requires that N ≥ M
−1 − N M − N M − N −1 − N
()( )
1 + a z + ... + a z u(t) = b z + b z + ... + b z e(t)
1 N 0 1 N
1424 4434 4 4 1424 4 4 4434 4 4 4 4
A( z ) B ( z )
EE392m - Spring 2005 Control Engineering 11-7
GorinevskyDahlin’s Controller
• Eric Dahlin worked for IBM in San Jose (?) then for Measurex
in Cupertino.
1 Q(z)
C(z) = ⋅
• Dahlin’s controller, 1967
P(z) 1− Q(z)
g(1− b)
−d
• plant, generic first order response
P(z) = z
−1
1− bz
with deadtime
1−α
−d
st
Q(z) = z
• reference model: 1 order+deadtime
−1
1−αz
−1
1− bz 1−α
C(z) = ⋅ • Dahlin’s controller
−1 −d
g(1− b) 1−αz − (1−α)z
α - tuned controller
• Single tuning parameter:
a.k.a. λ - t
EE392m - Spring 2005 Control Engineering 11-8
GorinevskyDahlin’s Controller
• Dahlin’s controller is broadly used through paper industry
in supervisory control loops - Honeywell-Measurex, 60%.
• Direct use of the identified model parameters.
CLOSED-LOOP STEP RESPONSE WITH DAHLIN CONTROLLER
• Industrial tuning
1
0.8
guidelines:
T =2.5T
0.6 a D
T =1.5T
a D
Closed loop time 0.4
Open-loop
0.2
constant = 1.5-2.5
0
0 10 20 30 40 50 60
deadtime.
CONTROL STEP RESPONSE
1.5
1
0.5
0
0 10 20 30 40 50 60
EE392m - Spring 2005 Control Engineering 11-9
GorinevskyInternal Model Control - IMC
General controller design approach; some use in process industry
e
P
P
0
e = r − ( y − P u)
Q
0
C =
1− QP
u = Qe
0
• continuous time s
Reference model:
T = QP
0
• discrete time z
Filter Q
Internal model: P
0
EE392m - Spring 2005 Control Engineering 11-10
Gorinevsky