PART A- FUZZY DECISION-MAKING
Consider the process relating to muscle relaxation, as seen in your Laboratory Session
PART A, represented by the following Equations [PLEASE NOTE THE NEW VALUE
RELATING TO THE PREDOMINANT TIME-CONSTANT- CHANGE IT IN YOUR
MATLAB-SIMULINK MODEL]:
(A.1)
(A.2)
where Y is the overall output of the system (muscle relaxation), U is the input to the system
(amount of drug infused).
The main objective is to design a closed-loop control strategy which should maintain a steady
level of muscle relaxation (output ‘Y’) by manipulating the level of drug infused (input ‘U’),
given a reference target of muscle relaxation (‘Ref’)- see Figure A1- Use a reference target
of 0.8 all throughout and a simulation time of 300 minutes:
a) Simulate this process in closed-loop, via SIMULINK, just by using a simple negative
feedback loop and show/explain how difficult it is to maintain an accurate level of
muscle relaxation (output) in response to a target relaxation value.
[3 MARKS]
b) Design a Fuzzy PI-type controller, as shown in Figure A1, via a fuzzy rule-base which
should include 25 fuzzy rules with Gaussian Membership Functions.
[The candidate is expected to use: 1. the fuzzy 3D surface to tune the rules; 2.
His/her knowledge of tuning the PID tuning factors, all in order to obtain the best
possible outcome for the output response in terms of minimum overshoot, fast
rise-time and fast settling-time; include simulations with disturbances].
[16 MARKS]
c) Transform the fuzzy rule-base designed in A)b) into a Fuzzy PD-type controller which
should also include 25 fuzzy rules with Gaussian Membership Functions.
[The candidate is expected to use: 1. the fuzzy 3D surface to tune the rules; 2.
His/her knowledge of tuning the PID tuning factors, all in order to obtain the best
possible outcome for the output response in terms of minimum steady-state
error, minimum overshoot, fast rise-time and fast settling-time; include
simulations with disturbances]PART A- FUZZY DECISION-MAKING
Consider the process relating to muscle relaxation, as seen in your Laboratory Session
PART A, represented by the following Equations [PLEASE NOTE THE NEW VALUE
RELATING TO THE PREDOMINANT TIME-CONSTANT- CHANGE IT IN YOUR
MATL
AB-SIMULINK MODEL]:
(A.1)
(A.2)
where Y is the overall output of the system (muscle relaxation), U is the input to the system
(amount of drug infused).
The main objective is to design a closed-loop control strategy which should maintain a steady
level of muscle relaxation (output ‘Y’) by manipulating the level of drug infused (input ‘U’),
given a reference target of muscle relaxation (‘Ref’)- see Figure A1- Use a reference target
of 0.8 all throughout and a simulation time of 300 minutes:
a) Simulate this process in closed-loop, via SIMULINK, just by using a simple negative
feedback loop and show/explain how difficult it is to maintain an accurate level of
muscle relaxation (output) in response to a target relaxation value.
[3 MARKS]
b) Design a Fuzzy PI-type controller, as shown in Figure A1, via a fuzzy rule-base which
should include 25 fuzzy rules with Gaussian Membership Functions.
[The candidate is expected to use: 1. the fuzzy 3D surface to tune the rules; 2.
His/her knowledge of tuning the PID tuning factors, all in order to obtain the best
possible outcome for the output response in terms of minimum overshoot, fast
rise-time and fast settling-time; include simulations with disturbances].
[16 MARKS]
c) Transform the fuzzy rule-base designed in A)b) into a Fuzzy PD-type controller which
should also include 25 fuzzy rules with Gaussian Membership Functions.
[The candidate is expected to use: 1. the fuzzy 3D surface to tune the rules; 2.
His/her knowledge of tuning the PID tuning factors, all in order to obtain the best
possible outcome for the output response in terms of minimum steady-state
error, minimum overshoot, fast rise-time and fast settling-time; include
simulations with disturbances]
d) Using the closed-loop data from A)b) derive an ANFIS based controller for the process,
which is described by Equations (A.1) and (A.2), to achieve a similar control
performance as that in b).
[10 MARKS]
e) Compare the controllers in A)b), A)c), and A)d) in terms of: flexibility in the structure
(controller type) and performance (accuracy). For the latter you can rely on one or
more performance indices, e.g. Mean Absolute Error (MAE), Mean Square Error
(MSE), and Root-Mean Square Error (RMSE).
[5 MARKS]