FEEDBACK CONTROL SYSTEMS

ECM2105 - Control Engineering Dr Mustafa M Aziz (2013)________________________________________________________________________________T d(s)V a(s)+ _10T m(s)−+T l(s)12s + 0.5Ω(s)0.1The block diagram can be simplified by moving the summing point ahead of the block with theconstant gain of 10:T d(s)1/10V a(s)−+_102s + 0.5Ω(s)0.1This can be further reduced by representing the feedback loop with an equivalent block:1/10T d(s)V a(s)+−102s + 1.5Ω(s)4.5. Simplicity versus accuracyWe must make a compromise between the simplicity of the model and the accuracy of the results ofthe analysis. In deriving a reasonably simplified mathematical model, we frequently find itnecessary to ignore certain parameters.4.6. Open-loop controlIntroducing the constant gain (proportional), K, block into the system (R – desired velocity):T d(s)Motor dynamics1/10R(s)KV a(s)−+102s + 1.5Ω(s)9