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Explore issues in optimal control such as insufficient information, overspecialization, and long-term planning vs. greediness. Develop algorithms for online control and discuss current research trends. Discover the complexities of dynamic discrete-event systems.
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Issues in Optimal Control of Dynamic DESs Lenko Grigorov and Karen Rudie Queen’s University Kingston, Canada
DynamicDiscrete-Event Systems Lenko Grigorov and Karen Rudie, Queen's University
DynamicDiscrete-Event Systems Lenko Grigorov and Karen Rudie, Queen's University
DynamicDiscrete-Event Systems Lenko Grigorov and Karen Rudie, Queen's University
DynamicDiscrete-Event Systems Lenko Grigorov and Karen Rudie, Queen's University
Online Control Online Controller Control options Events Discrete-Event System Lenko Grigorov and Karen Rudie, Queen's University
Look-ahead tree 5 2 6 controllable uncontrollable 1 3 7 8 4 Lenko Grigorov and Karen Rudie, Queen's University
Simple Optimal Algorithm Value: v(x) v(5)= v+v v(2)=max(v(5),v(6)) v(3)=max(v(7),v(8)) v(1)=min(v(3),v(4)) 5 2 6 1 3 7 8 4 Lenko Grigorov and Karen Rudie, Queen's University
Issues with Optimal Control • Insufficient information vs. Overspecialization • Long-term planning vs. Greediness Lenko Grigorov and Karen Rudie, Queen's University
Example system Small truck, 10 logs Big truck, 10 or 20 logs Photo courtesy of Daniel Janzen Photo by Patrick Higgins Lenko Grigorov and Karen Rudie, Queen's University
Values of events v(goS) = -100 v(goB) = -150 v(fetch10) = 500 v(fetch20) = 1000 Lenko Grigorov and Karen Rudie, Queen's University
Specifications • Different number and types of trucks available. • We can rent only one truck at a time. • We need 40 logs. Lenko Grigorov and Karen Rudie, Queen's University
Insufficient information Depth = 1 Lenko Grigorov and Karen Rudie, Queen's University
Overspecialization Depth = 4 Time 0 Future Lenko Grigorov and Karen Rudie, Queen's University
Overspecialization • Real situation: T0: T2: T4: • Algorithmic solution (v=1600): T0: T2: T4: • Best solution (v=1650): T0: T2: T4: Lenko Grigorov and Karen Rudie, Queen's University
Long-term planning vs. Greediness Depth = 3 Lenko Grigorov and Karen Rudie, Queen's University
Discussion • Optimal control for static systems is not suitable for dynamic systems • Less emphasis on strings far in the future • Greedy approach Lenko Grigorov and Karen Rudie, Queen's University
Current research • Online control with normalization Loss of optimality Speedup Tree depth Tree depth Lenko Grigorov and Karen Rudie, Queen's University
Queen’s University Lenko Grigorov and Karen Rudie, Queen's University