Composition Control Adding Dynamics in the Feedback oop Other information can be obtained by introducing dynamics in the feedback loop n integrator giy a differentiator gives @270 1+m Closed Loop Experiments Summary of Relay Feedback Close to industrial operation Controler · One-button tuning Easy to expl Works well for standard loops An integrator can also be added Little prior information ery robust Generates automatically a perturbation signal with a lot of energy at 180 Many possibilities not exploited O K.J.Astrom and BWittenmarkComposition Control Adding Dynamics in the Feedback Loop Other information can be obtained by introducing dynamics in the feedback loop • An integrator gives ω90 • A differentiator gives ω270 Process –1 1 s Σ a) Process –1 1 s Σ b) Closed Loop Experiments Controller Process –1 –1 Σ Σ An integrator can also be added –1 Im L(iω) Re L(iω) L(iω) B A Summary of Relay Feedback • Close to industrial operation • Easy to use • One-button tuning • Easy to explain to users • Works well for standard loops • Little prior information • Very robust • Generates automatically a perturbation signal with a lot of energy at ω180 • Many possibilities not exploited c K. J. Åström and B. Wittenmark 4