Can you help me get the graph I want in a PID control system given the transfer function and design? PLEASE HELP ME

I don't know how to set the initial value and range. Can you help me change the input and PID values in matlab simulink if needed and get the red line in the graph below? Thanks a lot.

Answer 1

[Sam Chak]

Hi @veysel burçak

Update: This basic signal (in veysel_problem.slx) produces the sawtooth pattern that starts from 0. Because there is no technical specification, you need to adjust the parameters by trial and error.

Based on the Grafik.PNG, the initial value of the simulated temperature (red) should be . The pattern looks like a sawtooth reference input signal.

Regarding your sliding mode design, while I don't understand your approach of using the transfer function, I managed to redesign some parts and tune some values to stabilize the temperature. Your existing design causes the temperature to rise like a ramp signal, indicating instability. I still prefer the PI controller.

[veysel burçak]

Thank you very much. In relation to the problem, if I can get the graphic here with the SMC I designed, I will have finished my project. Lamda and KSC my variables.

So I will compare results temprature level control with PID and my SMC controllor.I tried many times with the space state equation and transfer functions, but I could not get the result as in the graph above, by changing my variables.@Sam Chak

[Sam Chak]

@veysel burçak, The plot in Graph 2 only shows the red curve (representing the old controller) and the blue curve (representing the new controller), and it lacks informative axis tick values. Please provide more details. Furthermore, could you clarify what the terms 'old' and 'new' controllers refer to? In fact, both are noisy signals.

Answer 2

[veysel burçak]

The new controller for this graphic is the PLC controller described in this study:Identification and dynamic inversion-based control of a pressurizer at the Paks NPP

For my project, it will be my SMC control system. I also have the measured value without PI. I want to show PI Control result and SMC control result. How should I set the input of the transfer function I want from you so that I can get a red graph without PI and SMC controller?@Sam Chak Thank you. How can I design input signal to get red line without any controllor?

[veysel burçak]

Please try with transfer function of system because I can't get correct results in SMC control with steady space model. Thank you very much.

[veysel burçak]

When I simulate the system without PID, it does not respond correctly to the step signal, so I cannot test the system directly with SMC.

[Sam Chak]

Hi @veysel burçak

I'm unable to open the file because it was created with a newer version (R2022a) of Simulink. Actually, I don't understand the transfer function that you talked about. In fact, I am unsure about where you want to place the unique transfer function.

Regarding your simulation of the system (presumably the state-space, ) without the PID controller, the unit step response should reach a steady-state at , as shown below.

A   = [-4.46566e-3  4.45684e-3; 
        5.15227e-3 -5.15227e-3];
B   = [ 3.16315e-3;
        0];
C   = [ 1 0];
D   =   0;
sys = ss(A, B, C, D)

sys =
 
  A = 
              x1         x2
   x1  -0.004466   0.004457
   x2   0.005152  -0.005152
 
  B = 
             u1
   x1  0.003163
   x2         0
 
  C = 
       x1  x2
   y1   1   0
 
  D = 
       u1
   y1   0
 
Continuous-time state-space model.

dcgain(sys)

ans = 358.6338

step(sys)

Answer 3

[veysel burçak]

How should I design a signal generation to get the red line from the transfer function here? Input value starts from zero. Sawtooth input signal.

[veysel burçak]

@Sam Chak

[Sam Chak]

Hi @veysel burçak

I have updated the Answer with the generation of the sawtooth signal.

[veysel burçak]

Thank you very much I will study on it.