On Sun, 26 Feb 2006 18:56:55 -0800, the renowned "Fred Marshall" <fmarshallx@remove_the_x.acm.org> wrote:> >"Paul Carpenter" <paul$@pcserviceselectronics.co.uk> wrote in message > >> "just put a big computer in there that will solve the problem" >> > >I must say that I've had this experience with folks who should have known >better. When asked: "How are you going to do that?" they would say: "well, >there will be a computer inside". They had NO idea what they were going to >do or how they would do it. If the SNR was infinitely low, "well, there >will be a computer inside". > >FredSort of the general case of the "put a PID controller in there", which somehow answers all the questions about sensor and actuator response etc. ;-) Best regards, Spehro Pefhany -- "it's the network..." "The Journey is the reward" speff@interlog.com Info for manufacturers: http://www.trexon.com Embedded software/hardware/analog Info for designers: http://www.speff.com
Closing Control Loops
Started by ●February 24, 2006
Reply by ●February 26, 20062006-02-26
Reply by ●February 27, 20062006-02-27
"Spehro Pefhany" <speffSNIP@interlogDOTyou.knowwhat> wrote in message news:rbs40296bv2clha3l7pcp02s8d6kt8qfct@4ax.com...> On Sun, 26 Feb 2006 18:56:55 -0800, the renowned "Fred > Marshall" > <fmarshallx@remove_the_x.acm.org> wrote: > >> >>"Paul Carpenter" <paul$@pcserviceselectronics.co.uk> wrote >>in message >> >>> "just put a big computer in there that will >>> solve the problem" >>> >> >>I must say that I've had this experience with folks who >>should have known >>better. When asked: "How are you going to do that?" they >>would say: "well, >>there will be a computer inside". They had NO idea what >>they were going to >>do or how they would do it. If the SNR was infinitely >>low, "well, there >>will be a computer inside". >> >>Fred > > Sort of the general case of the "put a PID controller in > there", which > somehow answers all the questions about sensor and > actuator response > etc. ;-)Even better: a "self-tuning" PID controller.
Reply by ●February 27, 20062006-02-27
Spehro Pefhany wrote:> On Sun, 26 Feb 2006 18:56:55 -0800, the renowned "Fred Marshall" > <fmarshallx@remove_the_x.acm.org> wrote: > > >>"Paul Carpenter" <paul$@pcserviceselectronics.co.uk> wrote in message >> >> >>> "just put a big computer in there that will solve the problem" >>> >> >>I must say that I've had this experience with folks who should have known >>better. When asked: "How are you going to do that?" they would say: "well, >>there will be a computer inside". They had NO idea what they were going to >>do or how they would do it. If the SNR was infinitely low, "well, there >>will be a computer inside". >> >>Fred > > > Sort of the general case of the "put a PID controller in there", which > somehow answers all the questions about sensor and actuator response > etc. ;-)"We'll refer it to a lawyer" comes up in other contexts. Jerry -- Engineering is the art of making what you want from things you can get. �����������������������������������������������������������������������
Reply by ●February 27, 20062006-02-27
In article <RrWdnVkaje9hCGLeRVn-tg@iswest.net>, padu@merlotti.com says...> Hi Tim > > > So, I've put the finishing touches on my book, and the publisher's > > marketing department is asking me questions. Some of them I don't have > > good answers to, because (a) I'm on the fringe of my target audience, and > > (b) everyone learns differently, and my way is through osmosis and > > thinking, which doesn't make it easy to cough up a bunch of specific > > information like conferences and magazines. > > > > The book's title is "Applied Control Theory for Embedded Systems", the > > subject should be self explanatory. So if you feel that you're in the > > target audience, and if you're in a generous mood, here are some questions > > I have for you: > > > > What do they call you at work (sorry -- what's your official job title?) > > They call me Software Engineer (they call me other names too when they find > bugs in the software, but I doubt you are interested in knowing), but my > business card says Software > Development Manager. > > > > What magazines do you read? > Nuts and Volt, Servo, Motorcyclist, Computer, IEEE Potentials, Dr. Dobbs > > > > Websites you visit regularly? > Google news, Orkut, CNN > > > > Do you go to conferences? Which ones? (this is the one that motivated > > this posting, by the way -- I only go to the Embedded Systems Conference; > > I know there's a circuit-related one in Silicon Valley but I can't > > remember the name, nor do I know if there are any ones anywhere else. > > Not so often, I wish I had the money/time to attend to more conferences. The > last one was IC-AI (International Conference on Artificial Intelligence) > which I published and presented a paper. > > > > Have you had to close a control loop recently? Did you do a web search? > > What keywords did you use? > > Yes. Yes. PID control; control theory; fuzzy control > > > > Have you read any related books? Was it just a college text, or was it > > specifically directed at closed loop control for the practicing embedded > > systems designer? What did you think of it? What was it? > > Yes. A couple of books actually. > Got some hints from Schaums for control theory, and two other books that I > borrowed from the university's library. > The problem with all of them is that they go deep on the math of control > theory but are not practical (no relationship between CT and embedded > devices) > > > > Do I get a free book? ;) > > Good luck with your publishing... A man has three missions on Earth: Have > kids, plant a tree and write a book. I accomplish the first two... someday > I'll write a book. >Hey, I'm 3 for 3. I heartily recommend doing the writing before the kids come along, or after they leave home. In the intervening 20+ years, content yourself with smaller projects and keep up with the tree planting! Mark Borgerson
Reply by ●February 27, 20062006-02-27
In article <sfp302hpha5kvif9dub3bmj3tsa1tbcnh5@4ax.com>, To-Email-Use- The-Envelope-Icon@My-Web-Site.com says... <<SNIP>>> Indeed! Though I don't use the material on any regular basis (*), I > had four semesters on non-linear control theory in grad school. Great > fun, the real world! > > (*) Though I recently was involved in a laser beam "wobulator"... a > mirror driven by a power amplifier... great fun tuning it up for > stability ;-)Hey, the local paper here (Corvallis Oregon) led me to believe that the "wobulator" was a local HP invention to double the resolution of their HDTV projection systems. Don't tell me that such a neat name actually got applied to more than one system! Mark Borgerson
Reply by ●February 27, 20062006-02-27
In article <rbs40296bv2clha3l7pcp02s8d6kt8qfct@4ax.com>, speffSNIP@interlogDOTyou.knowwhat says...> On Sun, 26 Feb 2006 18:56:55 -0800, the renowned "Fred Marshall" > <fmarshallx@remove_the_x.acm.org> wrote: > > > > >"Paul Carpenter" <paul$@pcserviceselectronics.co.uk> wrote in message > > > >> "just put a big computer in there that will solve the problem" > >> > > > >I must say that I've had this experience with folks who should have known > >better. When asked: "How are you going to do that?" they would say: "well, > >there will be a computer inside". They had NO idea what they were going to > >do or how they would do it. If the SNR was infinitely low, "well, there > >will be a computer inside". > > > >Fred > > Sort of the general case of the "put a PID controller in there", which > somehow answers all the questions about sensor and actuator response > etc. ;-) >I'm in the middle of "let's put a faster computer in there" to solve all the sensor noise and control response problems. The magic words seem to be "Extended Kalman Filter". ;-) Mark Borgerson
Reply by ●February 27, 20062006-02-27
Spehro Pefhany wrote:> On Sun, 26 Feb 2006 18:56:55 -0800, the renowned "Fred Marshall" > <fmarshallx@remove_the_x.acm.org> wrote: > > >>"Paul Carpenter" <paul$@pcserviceselectronics.co.uk> wrote in message >> >> >>> "just put a big computer in there that will solve the problem" >>> >> >>I must say that I've had this experience with folks who should have known >>better. When asked: "How are you going to do that?" they would say: "well, >>there will be a computer inside". They had NO idea what they were going to >>do or how they would do it. If the SNR was infinitely low, "well, there >>will be a computer inside". >> >>Fred > > > Sort of the general case of the "put a PID controller in there", which > somehow answers all the questions about sensor and actuator response > etc. ;-) > > > > Best regards, > Spehro PefhanyFrom Chapter 1, "The Basics": "A final 'problem' in this list is that control systems are not magic. Real systems have real limitations, and nothing � not even an automatic control system � can overcome the laws of physics. Limitations in the strength of your actuators, in the response speed of every part of the system, in your plant's tendency to allow itself to be driven nicely, and in your sensor's ability to deliver noise-free measurements will all limit the ultimate performance of your system." -- Tim Wescott Wescott Design Services http://www.wescottdesign.com Posting from Google? See http://cfaj.freeshell.org/google/
Reply by ●February 27, 20062006-02-27
Paul Carpenter wrote:> On Sunday, in article <v5adnZmFqdMffJzZRVn-qA@web-ster.com> > tim@seemywebsite.com "Tim Wescott" wrote: > >>Paul Carpenter wrote: >>--snip-->>If you were to write an article about this (beyond "think hard about >>your problem and deal with sensor failures") I'd be delighted to read it. > > > I don't know if I could really class my thoughts and experiences as an > 'article' (so many different meanings to article as in length and depth > of content). I could probably summarise a few of the major ones in a > 'War stories' page sometime. > > ..... >War stories would be nice -- particularly of battles won as well as lost. -- Tim Wescott Wescott Design Services http://www.wescottdesign.com Posting from Google? See http://cfaj.freeshell.org/google/
Reply by ●February 27, 20062006-02-27
Jerry Avins <jya@ieee.org> writes:> CBFalconer wrote: > > Jim Thompson wrote: > >><fmarshallx@remove_the_x.acm.org> wrote: > >>>"Jim Thompson" <To-Email-Use-The-Envelope-Icon@My-Web-Site.com> wrote > >>>>Tim Wescott <tim@seemywebsite.com> wrote: > >>>> > >>>>[snip] > >>>> > >>>>>My Thesis advisor once told me that the first time he visited WPI > >>>>>he spent about an hour on the interstate -- he was looking for > >>>>>Wu'sta. He passed by Wor-ches-ter several times before it sunk in... > >>>> > >>>>Pronounced just like the sauce ;-) > >>>> > >>>>And sort of like Gloucester. > >>>> > >>>>Then there's Wooster, OH ;-) > >>> > >>>and Warrik (RI) ... > >> > >>I used to take the New Haven... RR from Boston to DC, then switch to > >>the C&O on into Huntington. Trying to figure out those conductor > >>calls was quite a challenge. > > > > Montreal streetcars (remember them) used to roll along St. > > Catherine until they arrived at "GeeGuy". Sometimes > > "Laroogeeguy". Those are hard 'g's. > > I cot confused in Bawston when the MTA dispatcher told me to take the > Pack kah (rhymes with kaka). It took a while to sort that out.I had the reverse situation occur once. I was going to fly with an instructor one night at an airport where the runway lights were out of service for construction work. The instructor said he'd put a pot at the end of the runway so we could find it to land. I was puzzled as to how a /part/ (allowing for the instructor's heavy New England accent) was going to help us find the runway. As we taxied out to depart, I saw the pot and realized that when he'd said "pot", he meant "pot"! And there's the time the Texan was telling me how much he hated "all-filled" capacitors. [Show me a capacitor that isn't filled with something.]
Reply by ●February 27, 20062006-02-27
On Fri, 24 Feb 2006 20:21:10 +0000, Genome wrote:> "Tim Wescott" <tim@seemywebsite.com> wrote in message>> So, I've put the finishing touches on my book, and the publisher's >> marketing department is asking me questions. Some of them I don't have >> good answers to, because (a) I'm > > A self procreating fuck up? >Ole came home from work one day, just terribly sad. "Ole, what's wrong?" asks Lena. "Oh, Lena," says Ole, "You remember de oder night, vhen you vas on top o me, and ve vas havin such fun?" "Oh, yah, Ole, dat was great!" "Vell, Lena, ve can't do dat no more." "Huh?" "Yah, I'm so sorry, but da boss at vork today, he says, if I fuck up vun more time, I'm fired!" Cheers! Rich -- Elect Me President in 2008! I will: A. Fire the IRS, and abolish the income tax B. Legalize drugs C. Stand down all military actions by the US that don't involve actual military aggression against US territory D. Declare World Peace I.
