# Talk:Control theory

## Cruise control

I fail to see the correctness of

"(Does not apply to manual transmission vehicles.)"

What specifically does not apply? Holding the throttle fixed works the same for a automatic and manual transmission. Removing sentence and call for further clarification. Cburnett 00:07, 6 Jan 2005 (UTC)

Locking the throttle on an automatic transmission does not lock speed, due to losses in the torque convertor. --Sponge! 04:10, 12 Jan 2005 (UTC)

Locking the throttle on an engine does not lock in speed; it doesn't matter what the transmission is. Change in angle changes the torque on the engine, which changes the speed. So I still don't see how the quote is relevant... Cburnett 05:15, 12 Jan 2005 (UTC)

It is good to put an edit summary when you write something. When I saw that this page was modified, and no summary was put, I thought it was vandalism (it happens all too often unfortunately). Besides, putting an edit summary helps people who have this article on their watchlist understand what you are up to. This is just a thought. Oleg Alexandrov 05:25, 12 Jan 2005 (UTC)

By the way, do you know anything about optimal control? That page needs some work. See that page and its history. Oleg Alexandrov 05:25, 12 Jan 2005 (UTC)

Ugh, of all the control classes I've taken....optimal control was my least favorite. I'll add it to my list. Cburnett 05:42, 12 Jan 2005 (UTC)

## Explanation

I find many of the explanations here extremely deficient. For example the link between impulse response and control theory is entirely unexplained: so the meaning of the equation ${\displaystyle x[n]=0.5^{n}u[n]}$ simply cannot be deduced. What is x here? Or n? Have we implicitly moved to an iterative/difference equation scheme rather than an ODE model?

What is (s), used as an argument to P(s), etc? A Laplace transform variable? What variable is the Laplace transform carried out with respect to? As a PhD mathematician with only a little control theory, I found myself no wiser after reading the middle few sections. Having said that, the control strategies section and introduction are much clearer. -- GWO

# Introductory section reference to transfer function

The statement, "The input and output of the system are related to each other by what is known as a transfer function", is not true in general. More generally the input and output are related by nonlinear differential equations and perhaps by both nonlinear differential equations and discrere equations. When the input and output are related by a transfer function, it is usually the result of linearization of the nonlinear system at a trim point. RHB100 (talk) 02:38, 21 February 2012 (UTC)

## Overview - citation needed

Does the Citation Needed tag apply to Social Science only, or to the whole list? Regarding the whole list, we could add physiology. Financial System and economics would be possibly redundant? Constant314 (talk) 18:56, 16 May 2015 (UTC)

I have added citation to the whole list - this reference includes psychology, economics, etc. I have also added the next citation required, but I think there is something more problematic here. This part is taken directly from Schmidt, R. A., & Wrisberg, C. A. (2007). Motor learning and performance w/web study guide: A situation-based learning approach. Human Kinetics. First of all, I am not sure if this is a reliable source for control theory article; second of all, it looks a bit like plagiarism, because those exact words can be found in google Scherschu (talk) 19:05, 13 June 2017 (UTC)

If you think that it was plagiarism, remove it now. Then we can discuss whether it was OK and possibly put it back. Constant314 (talk) 23:11, 13 June 2017 (UTC)

## Suggestion for more clarity

Where it says "the systems above can be analysed using the Laplace transform on the variables", perhaps it would be more definitive to say "the systems above can be analysed by taking the Laplace transform of each signal, and of the impulse response of each system, for straightforward algebraic manipulation. Note that the output of each system is the convolution in the time domain of its input signal with its impulse response, and the Laplace transform of the convolution of two functions is the algebraic multiplication of their separate Laplace transforms." — Preceding unsigned comment added by 58.109.72.54 (talk) 04:37, 17 April 2016 (UTC)