Derive transfer function of control system with disturbance.

In summary, the conversation is about a revision question regarding the derivation of a transfer function from first principles. The person has attached a block diagram and part of the answer, but is unsure about a specific part of the equation. They ask for help and suggest using a loop-formula expression and defining variables to simplify the problem. They also question if the system is linear and if superposition would apply.
  • #1
StevieNewRoad
2
0
This is a revision question rather than homework as I have the answer and working.

I have attached the block diagram and first part of the answer which explains how to derive the transfer function from first principles. I understand the principles behind this and how the RHS of the equation was derived, but I am unsure of why the left hand side is:

C(s)2.4s rather than C(s)/2.4s

I will be able to remember this for my exam, but I would rather know why.

Any help much appreciated

regards

SNR
 

Attachments

  • Question.docx
    73.8 KB · Views: 390
Physics news on Phys.org
  • #2
The document doesn't explain the derivation from first principles, it just present a result. So. Time to get out your pencil and paper :smile:

Start by writing the loop-formula expression for the system to obtain the transfer function. Save a lot of pencil lead by defining a couple of variables to represent the portions of interest:

attachment.php?attachmentid=64125&stc=1&d=1384961185.gif


What do you get for C(s) = H(s)R(s) in terms of f and a?
 

Attachments

  • Fig1.gif
    Fig1.gif
    6.3 KB · Views: 1,437
  • #3
Another comment: is your system linear? Would superposition apply?
 
  • Like
Likes 1 person

FAQ: Derive transfer function of control system with disturbance.

1. What is a transfer function in control systems?

A transfer function is a mathematical representation of the relationship between the input and output of a control system. It describes how the output of the system responds to changes in the input.

2. How do disturbances affect the transfer function of a control system?

Disturbances can affect the transfer function by introducing external factors that can disrupt the system's response to the input. This can lead to errors or deviations in the output of the system.

3. What is the process for deriving the transfer function of a control system with disturbance?

The process involves identifying the input, output, and disturbances of the system, and then using mathematical techniques such as Laplace transforms to obtain the transfer function. This typically involves solving differential equations and manipulating the resulting equations to obtain the transfer function.

4. Are there any assumptions made when deriving the transfer function of a control system with disturbance?

Yes, there are usually some simplifying assumptions made in the derivation process, such as linearization of the system and neglecting certain non-linearities or higher order terms. These assumptions may not accurately reflect the behavior of the actual system, but they allow for a more manageable and practical transfer function.

5. How is the transfer function used in control systems?

The transfer function is used to analyze the behavior of a control system and design controllers that can improve its performance. It allows for predicting the response of the system to different inputs and disturbances, and can also be used to tune the system to meet certain performance specifications.

Similar threads

Oven controller block diagram, transfer function and temperature calcs
Replies
24
Views
3K
From differential equations to transfer functions
Replies
5
Views
2K
Engineering Control System mass spring damper
Replies
0
Views
1K
Process Control (transfer function) problem
Replies
1
Views
1K
Engineering Analyzing the Nyquist Curve for a 5th Order System
Replies
3
Views
1K
Engineering Converting a series connected transfer function to the state space model
Replies
1
Views
1K
Factoring Higher Order Polynomials: A Practical Method for Control System Design
Replies
1
Views
2K
Does the transfer function exist for an unforced system?
Replies
12
Views
2K
Engineering Robust Stability: criterion for inverse multiplicative uncertainty
Replies
1
Views
770
Steps from state space to transfer function
Replies
3
Views
3K

Hot Threads

Recent Insights

Back
Top