# Multivariable Optimal Control
# Contents
- Review: Pole Placement Control Design for MIMO Systems – Limitations
- Infinite number of possible solutions for state feedback gain K
- Difficult to modify control effort like R.L. (k $\leftrightarrow$ u)
- Introduction to MIMO Linear Quadratic (LQ) Optimal Control – Quadratic cost functions – Solution of optimal u for Finite-horizon cost – infinite-horizon case
- Special LQ: Symmetric Root Locus for SISO systems – LQ cost for SISO systems – Design tradeoff between control effort and state convergence – Determine SLR from closed-loop characteristic equations
# Review: Pole placement Regulator design (CT, SISO)
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# Limitations 1
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# Introduce Optimal Control to pick one K
- A strategy for determining the feedback gains:
– Choose the “best” (optimal) K to optimize some closedloop performance, e.g.,:
- the control effort (maximum force; energy spent)
- the transient and/or steady-state errors
- the dollar cost of an operation
- … – Specify a cost function (performance index) in a optimization problem from which K can be solved by using mathematical optimization
# Pole-placement for MIMO systems-Limitations 2
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# Introduction to MIMO Linear Quadratic (LQ) Optimal Control
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# Special LQ: Symmetric Root Locus for SISO systems
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# Symmetric Root Locus SISO examples
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# Design tradeoff between control effort and state convergence through p
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# Easy way to plot SRL in Matlab
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# SRL for DT systems
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# SRL for CT& DT
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# Q, R selection rule of thumbs
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# Discrete Cost Equivalence
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# Settling time constraint
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# Modifying state feedback controllers (e.g. LQG): From regulator to tracking control
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