Shameless Plug

I will be presenting two topics at the 2005 Embedded Systems Conference 
San Francisco next March -- see http://www.esconline.com/sf/ for show 
details.

"Basic Control Theory for the Software Engineer" is as much information 
on the z-transform as I can fit into 90 minutes.  It gives a 
high-altitude overview of designing software control loops in a 
systematic manner.

"PID Without a PhD" is a primer on developing PID controllers in 
software, tuning them without using higher math, and avoiding some of 
the common pitfalls for this popular controller form.


-- 

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com

On Mon, 29 Nov 2004 16:43:55 -0800, Tim Wescott
<tim@wescottnospamdesign.com> wrote:

>I will be presenting two topics at the 2005 Embedded Systems Conference 
>San Francisco next March -- see http://www.esconline.com/sf/ for show 
>details.
>
>"Basic Control Theory for the Software Engineer" is as much information 
>on the z-transform as I can fit into 90 minutes.  It gives a 
>high-altitude overview of designing software control loops in a 
>systematic manner.
>
>"PID Without a PhD" is a primer on developing PID controllers in 
>software, tuning them without using higher math, and avoiding some of 
>the common pitfalls for this popular controller form.

I would sure like to receive copies of each!

                                        ...Jim Thompson
-- 
|  James E.Thompson, P.E.                           |    mens     |
|  Analog Innovations, Inc.                         |     et      |
|  Analog/Mixed-Signal ASIC's and Discrete Systems  |    manus    |
|  Phoenix, Arizona            Voice:(480)460-2350  |             |
|  E-mail Address at Website     Fax:(480)460-2142  |  Brass Rat  |
|       http://www.analog-innovations.com           |    1962     |
             
I love to cook with wine.      Sometimes I even put it in the food.

Jim Thompson wrote:

> On Mon, 29 Nov 2004 16:43:55 -0800, Tim Wescott
> <tim@wescottnospamdesign.com> wrote:
> 
> 
>>I will be presenting two topics at the 2005 Embedded Systems Conference 
>>San Francisco next March -- see http://www.esconline.com/sf/ for show 
>>details.
>>
>>"Basic Control Theory for the Software Engineer" is as much information 
>>on the z-transform as I can fit into 90 minutes.  It gives a 
>>high-altitude overview of designing software control loops in a 
>>systematic manner.
>>
>>"PID Without a PhD" is a primer on developing PID controllers in 
>>software, tuning them without using higher math, and avoiding some of 
>>the common pitfalls for this popular controller form.
> 
> 
> I would sure like to receive copies of each!
> 
>                                         ...Jim Thompson

The source material for both is on my website -- 
http://www.wescottdesign.com/articles/pidwophd.html gets you one click 
away, and 
http://www.wescottdesign.com/articles/zTransform/z-transforms.html is 
the z-domain stuff.

-- 

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com

Hi Tim,

Just let us know what day and time. Do you plan to publish these? The 
PID session sounds very interesting.

BTW, Scott Adams (Dilbert) is going to speak as well.

Regards, Joerg

http://www.analogconsultants.com

On Mon, 29 Nov 2004 17:22:07 -0800, Tim Wescott
<tim@wescottnospamdesign.com> wrote:

>Jim Thompson wrote:
>
>> On Mon, 29 Nov 2004 16:43:55 -0800, Tim Wescott
>> <tim@wescottnospamdesign.com> wrote:
>> 
>> 
>>>I will be presenting two topics at the 2005 Embedded Systems Conference 
>>>San Francisco next March -- see http://www.esconline.com/sf/ for show 
>>>details.
>>>
>>>"Basic Control Theory for the Software Engineer" is as much information 
>>>on the z-transform as I can fit into 90 minutes.  It gives a 
>>>high-altitude overview of designing software control loops in a 
>>>systematic manner.
>>>
>>>"PID Without a PhD" is a primer on developing PID controllers in 
>>>software, tuning them without using higher math, and avoiding some of 
>>>the common pitfalls for this popular controller form.
>> 
>> 
>> I would sure like to receive copies of each!
>> 
>>                                         ...Jim Thompson
>
>The source material for both is on my website -- 
>http://www.wescottdesign.com/articles/pidwophd.html gets you one click 
>away, and 
>http://www.wescottdesign.com/articles/zTransform/z-transforms.html is 
>the z-domain stuff.

Thanks, Tim.  I last took a non-linear control systems course in 1968,
but I actually enjoyed it, still have my notes ;-)

                                        ...Jim Thompson
-- 
|  James E.Thompson, P.E.                           |    mens     |
|  Analog Innovations, Inc.                         |     et      |
|  Analog/Mixed-Signal ASIC's and Discrete Systems  |    manus    |
|  Phoenix, Arizona            Voice:(480)460-2350  |             |
|  E-mail Address at Website     Fax:(480)460-2142  |  Brass Rat  |
|       http://www.analog-innovations.com           |    1962     |
             
I love to cook with wine.      Sometimes I even put it in the food.

Tim Wescott wrote:
>
>I will be presenting two topics at the 2005 Embedded Systems Conference 
>San Francisco next March -- see http://www.esconline.com/sf/ for show 
>details.
>
>"Basic Control Theory for the Software Engineer" is as much information 
>on the z-transform as I can fit into 90 minutes.  It gives a 
>high-altitude overview of designing software control loops in a 
>systematic manner.
>
>"PID Without a PhD" is a primer on developing PID controllers in 
>software, tuning them without using higher math, and avoiding some of 
>the common pitfalls for this popular controller form.

 Cool!  From many years teaching "practical PID" to technicians 
 and engineers, here are some questions that came up a lot:

 "Why do so many of the setups around here have only P and I
 or have D set to zero?  How do I decide when to use D?"   

 "Why do some controller boards have an option to reverse the
 phase of the D?  What is that good for?"

 "How do I describe a thermostat with hysteresis using the same
 language that I use to describe a PID controller?  It seems 
 like P is infinity." 

 "Why do half the engineers call it Proportional-Integral-Derivative"
 and others call it "Proportional-Integral-Differential?"  When I 
 did a Google search on "proportional integral differential" I got
 18,600 hits while "proportional integral differential" only had
 3,060 hits, but most of the "proportional integral differential"
 hits seem to be by scientists and equipment manufacturers. 
 Which is correct?" 

BTW. for what it's worth, I found that relating position servos
and velocity servos to a person controlling a car (speed and
position within the lane) was helpful.  I also found it helpful
to show how to use a stopwatch and odometer to derive speed with 
no speedometer, a stopwatch and speedometer to derive distance 
without an odometer, and a speedometer and odometer to derive
elapsed time with no stopwatch.  Your audience is different, 
of course - this worked really well with mechanical engineers,
but software engineers are quite different.

Another gotcha that sometimes trips up software engineers: 
non-monotonic ADCs causing a "bad spot" that has positive 
feedback.  

Guy Macon wrote...
>
> "Why do half the engineers call it Proportional-Integral-Derivative"
> and others call it "Proportional-Integral-Differential?"  When I 
> did a Google search on "proportional integral differential" I got
> 18,600 hits while "proportional integral differential" only had
> 3,060 hits, but most of the "proportional integral differential"
> hits seem to be by scientists and equipment manufacturers. 
> Which is correct?" 

 proportional integral derivative - 253,000 hits = correct
 proportional integral differential - 315,000 hits = wrong


-- 
 Thanks,
    - Win

Try a searching the whole phrase

Google for "proportional integral derivative" gets 18,600

Google for "proportional integral differential" gets 3,060

Search for both and you get 47

It was originally Derivative, and still is to me.

"Winfield Hill" <hill_a@t_rowland-dotties-harvard-dot.s-edu> wrote in 
message news:cohse107bd@drn.newsguy.com...
> Guy Macon wrote...
>>
>> "Why do half the engineers call it Proportional-Integral-Derivative"
>> and others call it "Proportional-Integral-Differential?"  When I
>> did a Google search on "proportional integral differential" I got
>> 18,600 hits while "proportional integral differential" only had
>> 3,060 hits, but most of the "proportional integral differential"
>> hits seem to be by scientists and equipment manufacturers.
>> Which is correct?"
>
> proportional integral derivative - 253,000 hits = correct
> proportional integral differential - 315,000 hits = wrong
>
>
> -- 
> Thanks,
>    - Win 

> Why do half the engineers call [PID] "Proportional-Integral-Derivative"
> and others call it "Proportional-Integral-Differential?"

In 'Control Speak':

 Differential: the amount of hysteresis in an on/off controller, such
               as a home thermostat.

 Derivative:   The term D * dPV/dT in a PID controller where:  D == derivative
               gain; PV = process variable; T == time.  Some controllers
               use D * dE/dT where E == error.

 Lesson:       Half of everything is bunk.

-- 
Nicholas O. Lindan, Cleveland, Ohio
Consulting Engineer:  Electronics; Informatics; Photonics.
Remove spaces etc. to reply: n o lindan at net com dot com
psst.. want to buy an f-stop timer? nolindan.com/da/fstop/

Francis wrote...
>
> Try a searching the whole phrase
>
> Google for "proportional integral derivative" gets 18,600
> Google for "proportional integral differential" gets 3,060

 Phew, that's a relief.


-- 
 Thanks,
    - Win