Design Con 2015
Breaking News
Design How-To

The basics of control theory

8/16/2010 12:18 PM EDT
8 comments
NO RATINGS
Page 1 / 3 Next >
More Related Links
View Comments: Newest First | Oldest First | Threaded View
milezams
User Rank
Rookie
re: The basics of control theory
milezams   9/2/2010 7:29:02 AM
NO RATINGS
There are many modifications of PID algotham. Modern PID controlers implement other features in their work.

TT4
User Rank
Rookie
re: The basics of control theory
TT4   8/27/2010 5:11:25 AM
NO RATINGS
arent' the gain terms supposed to be multiplied with the error rather than subtracted

_hm
User Rank
CEO
re: The basics of control theory
_hm   8/25/2010 5:36:10 PM
NO RATINGS
John thanks for very informative article. I will be more interested in learning about tuning of PID loop. Will you please explain basic steps required. I will also like if you cover auto tune and self tune PID control algorithms. Are they available in library form? Can we employ and adept this PID controller for non-linear systems found in real life control?

prabhakar_deosthali
User Rank
CEO
re: The basics of control theory
prabhakar_deosthali   8/22/2010 6:42:18 AM
NO RATINGS
Thanks for this article. This article on PID control basics was like a refresher course for me . I developed PID control algorithms for motion control applications involving control of servo motors back in 90's . What I learnt then was that in Position Control using servo motors a simple position control loop with PID does not always work. To have the smooth motion of the robotic actuator we need to have velocity control loop ( with its PID parameters) along with the interpolation algorithm where the set point command is constantly moved along with the desired path and desired trajectory ( linear/circular) to reach the final position.

garyspang
User Rank
Rookie
re: The basics of control theory
garyspang   8/19/2010 4:48:21 PM
NO RATINGS
The description reads properly to me. The accumulator is a digital substitution for the amalog integrator or totaliser. The error E times a factor K (the Integral Gain ) is the amount that changes the current value of the integrator(accumulator) at uniform time intervals. K is independent of the error and determines how fast the integrator racks up values from the varying error E. Therefore E is integrated and the overall effect is modified by K to be larger or smaller than if the integral of E were to be applied directly (K=1).

Barnard
User Rank
Rookie
re: The basics of control theory
Barnard   8/19/2010 9:26:08 AM
NO RATINGS
Great, I liked the bit about pitfalls of the 'I' in particular. One point I don't get though; the text says the following: "The integral term, however, is produced by multiplying the current error by the integral gain and adding the result to an accumulator." To me, the text implies "?(E*Ki)", rather than "Ki * ?E" or am I missing something?

t.alex
User Rank
Rookie
re: The basics of control theory
t.alex   8/17/2010 4:37:10 PM
NO RATINGS
PID control is still the king in many applications. I still remember developing a simple PID loop on a 8-bit MCU. One of the tricky parts was to tune the parameters Kp, Ki, Kd to achieve the desire performance.

December 2014 Cartoon Caption Contest: White Smoke Is Rising!
December 2014 Cartoon Caption Contest: White Smoke Is Rising!
"Remember when someone promised us change a few years ago? That's all we have left!"
2 comments
Flash Poll
Like Us on Facebook

Datasheets.com Parts Search

185 million searchable parts
(please enter a part number or hit search to begin)
EE Times on Twitter
EE Times Twitter Feed
Top Comments of the Week