Control engineering - load variation

[hanson]

Hi all!
I started my first control engineering course this semester. There are some terms that confused me.
I am now learning closed-loop systems. And the lecturer was discussing the reduced sensiticity to process disturbance and load variation of a closed-loop system when compared to a open-loop system.
But I am confused by the terms "load variation" and "process disturbance"...
Basically, what is a "load"? I was dealing with some input signal and output signal, and what role a "load" plays in a system?
To childish me, "load" is something that a system need to bare or withstand...

Please help.

 

[FredGarvin]

In most cases I can think of, LOAD = DEMAND. You should be developing a system based on the demand of something that needs to be supplied.

For example, if you are describing a system that delivers a certain amount of airflow for a number of air tools at a workshop, the load will be how many tools are operating and what their demand for air is.

Process disturbance in this case would be users turning on and off tools to cause fluctuations in the demand or the supply of air changing for some reason.