josey Posted May 13, 2016 Report Share Posted May 13, 2016 Hi guys,i need help fine tuning PID settings on my ethrottle.maybe problem is that i have too big throttle body and too small engine So it is 2.0 liters engine, and 75mm throttle body (audi - vw W12 6.0 liter TB) in open loop i get kind of smooth idle but cant get it in closed loop.this post can be used as tutorial? my settings are defaultproportional gain: 7Integral gain: 0.145Derivative gain: 25and idle is bit jumpy (unstable, it overshooting idle target for 400rpm or more it drops below 800 and than jumps to 1200)DBW idle position is about 3.0% for 1000rpm on fully warmed engine (3.1 is about 1100)by searching forum, i found few topics, and i guess lowering integral gain to about 0.4-0.5 should solve the problem ? Please, can you quick guide me how to properly setup DBW to get smooth idle and have good response on throttle?Also can you help me to get slow return to idle after full throttle?What is happening now is, in neutral when i depress throttle, rpm drops fast and drops below idle target and engine almost shuts down. (i can achieve this in main dbw table?) thanks Quote Link to comment Share on other sites More sharing options...
Scott Posted May 13, 2016 Report Share Posted May 13, 2016 Hi Josey,Before going into the idle control configuration you need to make sure that the TPS is tracking the E-throttle target correctly. The best way to see this is using PCLogging and the timeplot. Can you record a PCLog where you change throttle position rapidly and then more slowly, then take a couple of screenshots from the timeplot and post them here.Here is an example of what yours might look like: Quote Link to comment Share on other sites More sharing options...
josey Posted May 13, 2016 Author Report Share Posted May 13, 2016 ok, thanksand curves must overlay perfectly ? Quote Link to comment Share on other sites More sharing options...
Scott Posted May 13, 2016 Report Share Posted May 13, 2016 Ideally yes, but there will always be a very small amount of lag on the TPS. Quote Link to comment Share on other sites More sharing options...
josey Posted May 13, 2016 Author Report Share Posted May 13, 2016 so im rising proportional gain untill i get good response ?then im braking it with derivative gian when it overshoot?and than fine tune it / trim it with integral gain? for now with this settings i have very good throttle response.P: 7I: 0.145D: 25 thanks Scott i will give a try and let you know Quote Link to comment Share on other sites More sharing options...
josey Posted May 15, 2016 Author Report Share Posted May 15, 2016 here are 3 logsthis isP: 6I: 0.05D: 25 two logs withP: 7I:0.145D: 25 this looks same for me on6 - 0.05 - 25 and 7 - 0.145 - 25 Quote Link to comment Share on other sites More sharing options...
Simon Posted May 15, 2016 Report Share Posted May 15, 2016 When you are setting it up. Back the max target back from 100% so that you can see an over shoot if it happens.Other wise the throttle might be wanting to over shoot the target but cant as it is stopped mechanically.Be sure to hit enter after changing the values to have them take effect. Quote Link to comment Share on other sites More sharing options...
josey Posted May 16, 2016 Author Report Share Posted May 16, 2016 on last log (3rd screenshot) tp main is 65% tp target is 65% - 65.1% yes changes saved between loging Quote Link to comment Share on other sites More sharing options...
Scott Posted May 16, 2016 Report Share Posted May 16, 2016 Hi josey,Looking at the last screenshots the tracking of the throttle plate to the target looks pretty good, no massive overshoots and oscillations.Now try and see if you can get the idle stable using open loop idle speed control. Quote Link to comment Share on other sites More sharing options...
josey Posted May 16, 2016 Author Report Share Posted May 16, 2016 thing is that in open loop is stableas soon i change settings to closed loop idle becomes unstable, and its overshooting idle target.and motor dc% is same for open/ closed loop. that is why i open this topic and asking for help. afr is stable at about 14.2-14.7 ign 14deg Quote Link to comment Share on other sites More sharing options...
Scott Posted May 16, 2016 Report Share Posted May 16, 2016 Can you record a PCLog of the idle on closed loop and upload it here with your base-map? If the file is too large to upload please email it to us at [email protected]. If you do email it please include a link to this thread so we can know the background.Thanks,Scott. Quote Link to comment Share on other sites More sharing options...
josey Posted May 16, 2016 Author Report Share Posted May 16, 2016 no problem thnx Scott Quote Link to comment Share on other sites More sharing options...
lekonna Posted May 18, 2016 Report Share Posted May 18, 2016 sorry for the slight OT, but does the support team have some list of recommended e-throttles to use that have been proven to work well ? Quote Link to comment Share on other sites More sharing options...
Scott Posted May 18, 2016 Report Share Posted May 18, 2016 Hi lekonna, PCLink Help > Wiring Information > Output Wiring > E-Throttle > Specific E-Throttle Applications has some pinout and setup values for various e-throttle bodies.Basically any e-throttle body that outputs two different analog voltages in the range of 0v to 5v, and uses a motor that draws less than 10 amps should work. Quote Link to comment Share on other sites More sharing options...
josey Posted May 20, 2016 Author Report Share Posted May 20, 2016 (edited) ok i think my probčlems are related with that my e-throttle works only in "setup mode" it cant work in ON mode.problem described heretoday situation -somehow i get idle in closed loop to work smooth,and i get engine running for half hour,fully warmed up, water 94c, oil 90cengine is idling smooth on 1000rpm +- 50rpm at 2.6-2.8% TPSthan i rev it to redline, and release throttle,what happened, i noticed TPS closed to near 0% although in ethrottle target table value is 2.5%and than again CL idle control started to play from 1.5% to about 4%, ok, why 1.5% when minimum value is 2.5% in ethrottle target table?ok first question on my mind was, why TPS is dropping below 2.5% at first place? then i change e-throttle mode from "setup mode" to ONand e-throttle just shut down, and tps moved to if i recall 3.9% which is some default value when dbw motor is not powered.F4 - pressing throttle pedal - nothing, shut down engine, start it again, nothing, throttle is dead, change from "ON" to "setup mode", DBW motor started again and returned TP to 2.7% and smooth 1000rpm. ok, so DBW is not working in ON mode for me i dont care, but how can i prevent TP to drop below desired value? in this case lets say 2.5%? this is actually my main question now.and is really my problem in e-throttle mode, because it cant work in ON mode? thanks Edited May 22, 2016 by josey Quote Link to comment Share on other sites More sharing options...
Scott Posted May 23, 2016 Report Share Posted May 23, 2016 In ON mode all the e-throttle safety limits are applied, so for example there is a different in % between the sub and main channels on either the TPS or APS then the ECU will shut down the e-throttle. Have a look and see which fault code comes up when you switch from Setup mode to ON mode. When Idle control is in closed loop mode a closed loop trim gets applied on top of the base position from the e-throttle target table and Idle base position table. This closed loop trim is trying to achieve the target RPM you have specified in the Idle Target RPM table, and it's value can be positive or negative (as required). Quote Link to comment Share on other sites More sharing options...
josey Posted May 23, 2016 Author Report Share Posted May 23, 2016 Scott i understand you completelybut i dont understand why is throttle blade dropping below 2.5%? that should be something like screw on mechanical TB? ill try to play with settings little bit, thanks Scott Quote Link to comment Share on other sites More sharing options...
Scott Posted May 24, 2016 Report Share Posted May 24, 2016 If the CL Trim was a large enough negative value then the TP(Main) reading could go less than the value in the e-throttle table. If you post a PClog of the problem happening and your base-map we'll be able to advise. Quote Link to comment Share on other sites More sharing options...
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