# Proportional controller with state feedback controller

I have a transfer function G(s)=1/s(s+10) with sampling and holding, it is easy to relocate poles at 0.5 and -0.5 using a state feedback controller. But if the proportional controller is added to the transfer function, as in G(s)=K/s(s+10), how can the state feedback controller be designed?

• There are a couple problems here. 1. Why are you putting one of your poles at 0.5? Presumably you're referring to a continuous-time system, in which case all of your poles need to be left of the imaginary axis (i.e. negative). 2. What are you trying to do? Are you designing a state space controller or a proportional controller? Is your problem how you re-design the state-space controller when a constant gain K is added to G(s)? Please clarify – BarbalatsDilemma Jan 4 '17 at 19:43

Using given transfer function you can get your state space model by control canonical form and you get your A,B,C,D matrix after that you can derive your P gain or feedback control gain by this equation

P=1/(C*(B*K-1)^(-1)*B)

where K = Feedback control gain [-0.5 -0 5] and P = Proportional Control Gain (in your case it is K)