How Do I Fix This Fuzzy Gain Scheduling System?

Here I attached The System by following this paper that i find. I can not run the system because of the error.

Answer 1

[Sam Chak]

Hi @Isyraf Izuddin

The error occurs because the Plant Transfer Function block can ony accept 1 INPUT, instead 3 SEPARATE Inputs.

The PID controller produces only 1 Output, despite it has 3 Components, namely Proportional, Derivative, and Integral actions.

Important node: Fixing this issue should allow you to run the simulation without error message.

You have designed 3 Fuzzy Systems for the Nonlinear Gain Schedules of Kp, Kd, and Ki. Unknowingly, I suspect that you created outputs {, , α} for each of the Fuzzy System.

So, please ensure that each Fuzzy System has only one corresponding Output as shown in the figure below, and the problem should be fixed. Whether the results are satisfactory or not, this is a different unrelated issue that requires some tuning of the fuzzy membership functions and the rules. In fact, you shouldn't directly follow the proposed values {10000}, {500}, and {1} in the paper if your Plant model is different. I understand that you may want to get it run successfully first, and then tune them later.

[Isyraf Izuddin]

there still 1 error that i dont understand

[Sam Chak]

@Isyraf Izuddin

Your simulation stops at time T = 1, and it says the value to the Transfer Fcn1 block is not finite. However, I don't see any division-by-zero component. So, most likely this is caused by some blocks that blow up the numerical value, in which your Transfer Fcn1 block is unable to perform the integration.

Do this to troubleshoot the problem according to the Error message:

• Right-click the arrow signals and then toggle on the "Show Value Label of Selected Port".
• Instead of clicking Run the simulation directly, click on the Step forward to display port value at each time step. The figure below shows the port values at time T = 0.

• Continue clicking the Step Forward until time T = 1, and look for any funny values (i.e., very large values) as shown below.
• The Error message will pop up when you can't click on the Step Forward anymore. The displayed port value at the input to the Transfer Fcn1 block is the last value before the simulation terminates.
• In this example, the very large value displayed at the derivative port is caused a sudden jump in the error signal from 0 to 1 at T = 1, due to the Step function block. In other words, the slope of the rate of change in error is very steep.

[Isyraf Izuddin]

So how do i settle this?

[Sam Chak]

Didn't I advise to perform the troubleshooting first? The step-by-step procedure is provided.

Need to find out the actual issue causing the error message. Show the findings here later.

[Isyraf Izuddin]

okay thank you

[Sam Chak]

@Isyraf Izuddin

Discovered that there is a possibility of Division-by-zero to occur in these paths that come from and α. Please check.

[Isyraf Izuddin]

Thank you for your time but i proceed with another system

Thank You Very Much....

[Sam Chak]

No worries. Hope you design a good fuzzy system.