Lab 01: Feedforward control
CHEN4011: Advanced modeling and Control
Objectives
To design a feedforward controller in combination with a feedback controller
To evaluate the performances with and without feedforward controller in the cases of setpoint tracking and disturbance rejection.
To develop Matlab Simulink model for the combined feedforward-feedback control strategy
Process information
The transfer functions for the process and disturbance are
\[ \begin{aligned} \text { Process: } G_p(s) &= \frac{10 \exp (-2 s)}{(10 s+1)(1.5 s+1)} \\ \text { Disturbance: } G_d(s) &= \frac{-8 \exp (-3 s)}{20 s+1} \end{aligned} \tag{1}\]
Simulation
Develop the Simulink models for the feedback control only and feedforward-feedback control strategies. Design the feedback (PID) controller using the PID tuner app. Also, design the feedforward controller using the idealized method.
Evaluate the control performance for:
Setpoint tracking
Disturbance rejections for both input and output disturbances
A second-order model can be reduced using the Skogestad’s half rule (Skogestad 2003) given by Equation 2.
\[ G(s)=\frac{K_p e^{-\theta_p s}}{\left(\tau_1 s+1\right)\left(\tau_2 s+1\right)} \cong \frac{K_p e^{-\theta_e s}}{\tau_1 s+1} \text { where } \tau_1>\tau_2 \text { and } \theta_e=\theta_p+\tau_2 \tag{2}\]
Report Format
Show the MATLAB Simulink Model of the combined feedforward-feedback control strategy. Briefly explain the model. [2 marks]
Show the PID controller and feedforward controllers (using idealized method). [2 marks]
Compare and comment on the control performances (setpoint tracking and disturbance rejection) of the two control strategies: (1) feedback control only, and (2) combined feedbackfeedforward control (idealized method). Show the plots of the controlled variable under the two different control strategies. [6 marks]
Does the implementation of the feedforward controller improve the setpoint or disturbance rejection performance?
Will the control system remain stable when subjected to the 10% modelling errors?
Which feedforward controller that gives the best result, based on the unified or idealized method?
References
Citation
@online{utikar2023,
author = {Utikar, Ranjeet},
title = {Lab 01: {Feedforward} Control},
date = {2023-07-30},
url = {https://amc.smilelab.dev//content/labs/lab-01},
langid = {en}
}