A Brief History of Control Theory
Frequency domain based tools; stability via gain and phase margins.
Mainly useful for single-input-single-output (SISO) systems.
Still one of the main tools for the practicing engineer.
“State space” approach to linear control theory.
Works for SISO and multi-input-multi-output (MIMO) systems.
Performance and robustness measures are often made explicit.
Generalizes ideas in classical control to MIMO context.
Uses operator theory at its core, but can be easily interpreted in the frequency domain.
Specialized techniques for control of nonlinear systems.