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

# Shameless Plug

Started by ●November 29, 2004

Reply by ●November 29, 20042004-11-29

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.

Reply by ●November 29, 20042004-11-29

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 ThompsonThe 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

Reply by ●November 29, 20042004-11-29

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

Reply by ●November 29, 20042004-11-29

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.

Reply by ●November 30, 20042004-11-30

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.

Reply by ●November 30, 20042004-11-30

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

Reply by ●November 30, 20042004-11-30

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

Reply by ●November 30, 20042004-11-30

> 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/

Reply by ●November 30, 20042004-11-30