From: mailbox@dmitry-kazakov.de   
      
   On Mon, 15 Sep 2008 09:53:42 -0500, root wrote:   
      
   > My company designs and produces advanced technology diesel engines for   
   > several markets. We design and build our own common rail fuel injection   
   > electronics, from hardware to software.   
   >   
   > We currently use PID control implemented in software. While this works   
   > adequately, the number of conditions that I must impose on the inputs   
   > and outputs, and the amount of pre and post processing that must be done   
   > on them, results in very complex code.   
   >   
   > I had heard that fuzzy logic controls often could produce better results   
   > than PID so I started investigating. This is fascinating stuff. From   
   > what I presently understand, it does seem as if fuzzy logic controls may   
   > work as well as PID in our case.   
      
   I am intrigued. OK, motor control is not my area of interest, but I am   
   working tightly with people whose area it is. I saw and even reviewed the   
   code deployed there. It is not mere a PID.   
      
   > I've come here to ask help in pointing me in the correct direction to   
   > further my studies. Specifically;   
   >   
   > 1. Do, or can, fuzzy logic systems respond well to system lag. In engine   
   > control we have the worst case scenario for PID control.   
      
   AFAIK, this issue is independent on whether you use fuzzy or crisp control.   
   But see above.   
      
   > That is, a   
   > system that has a high response delay and then a non-linear response. In   
   > my research I have not seen any examples that are used in these kind of   
   > systems. Any opinions about the suitability of fuzzy logic controls for   
   > this type of application would be greatly appreciated. I'd love to see   
   > some demos or real world apps.   
      
   I know of some attempts to deploy fuzzy control for fuel injection in   
   automotive area. Although these were studies. We participated in one, but   
   as you understand it is under NDA.   
      
   > 2. I came across some software called 'Fuzzy Tech'. Any opinions about   
   > this software and/or company. I have attempted to contact them on   
   > several occasions with no response. Having a commercially available   
   > package would be a benefit to me.   
      
   What is your target system? PC simulation, motor simulator, R&D engine   
   control devices, production devices? I doubt that except for the first you   
   could get an off-the-shelf product.   
      
   > On the other hand, like anyone else, I   
   > don't wish to spend a lot of money before I have some idea as to whether   
   > or not it will work.   
      
   That puzzles me a much. Fuel injection control (for cars) is a huge   
   research area with monstrous budgets. Certainly you would start a studio,   
   then several pilot projects etc, before you do the fist move. Comparing to   
   the money spent on software licenses in just one laboratory, I don't   
   believe that one could not buy one additional product or two...   
      
   --   
   Regards,   
   Dmitry A. Kazakov   
   http://www.dmitry-kazakov.de   
      
   --- SoupGate-Win32 v1.05   
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