electronic throttle
in [Toyota]
|
Prev: Toyota Provided No Evidence of Testing Electronic Throttle toUS Congress
Next: Increase your penis size and feel better about yourself!!
From: clare on 7 Mar 2010 23:09 On Sun, 07 Mar 2010 18:16:23 -0500, Bill Putney <bptn(a)kinez.net> wrote: >clare(a)snyder.on.ca wrote: > >> One throttle position sensor of the simplest design (a simple >> potentiometer) can provide 2 signals - one the inverse of the other. > >Clare - I followed the rest of your explanation, but, as a circuit >designer, I had trouble following that part. That would have to be two >potentiometers ganged on one shaft? You're not saying that one >potentiometer provides two signals, right? I'm picturing a TPS pot. >with ground on one end, Vref on the other, and the wiper signal. I >don't see getting two signals from the one pot, inverse or otherwise. >What did I miss? Just raise the ground so the 5 volt reference is , say, 6 volts above ground, and the "ground" is 1 volt above ground and measure the voltage between the wiper and ground and between the wiper and "ref" At idle the wiper to "ground" will be one volt, and between the wiper and "ref" will be 5 volts. At half throttle you will have roughly 3 volts from either wiper to ref, or wiper to ground, and at WOT you will have 0 volts wiper to ref, and 6 volts wiper to ground. Can also be done without raising the "ground", but then a zero volt is possible at idle as a legitimate signal. With a raised ground, a open anywhere in the ref circuit would give you a 0 volt reading which is not a legitimate signal, so would trigger an error without having to compare any other voltages.. Without the raised ground, idle position voltage is undiscernable from a fault voltage untill the pedal is depressed, so a closed throttle sensor is required to verify that the throttle is, in fact, closed. So there you have it. Simple, isn't it?? (once you get your head around it)
From: clare on 7 Mar 2010 23:10 On Sun, 07 Mar 2010 18:29:44 -0500, Bill Putney <bptn(a)kinez.net> wrote: >Bill Putney wrote: >> clare(a)snyder.on.ca wrote: >> >>> One throttle position sensor of the simplest design (a simple >>> potentiometer) can provide 2 signals - one the inverse of the other. >> >> Clare - I followed the rest of your explanation, but, as a circuit >> designer, I had trouble following that part. That would have to be two >> potentiometers ganged on one shaft? You're not saying that one >> potentiometer provides two signals, right? I'm picturing a TPS pot. >> with ground on one end, Vref on the other, and the wiper signal. I >> don't see getting two signals from the one pot, inverse or otherwise. >> What did I miss? > >Actually, after some thought, I can see how it might be done with a >single pot: Pot wiper gets tied to ground, and you run constant current >into each end terminal. The voltages read at the two end terminals will >be inverse of each other (as wiper is moved in one direction, voltage of >one end terminal goes from 0 to R x I, voltage of the other end goes in >the opposite direction). > >Not saying that the designers would have realized that it could be done >like that, but that's the only way I could think of using a single pot. That works too.
From: clare on 7 Mar 2010 23:14 On Sun, 7 Mar 2010 16:43:22 -0800, "Jeff Strickland" <crwlrjeff(a)yahoo.com> wrote: > >"jim beam" <me(a)privacy.net> wrote in message >news:5PGdnb1nWsX2hQnWnZ2dnUVZ_qednZ2d(a)speakeasy.net... >> On 03/07/2010 11:21 AM, Jeff Strickland wrote: >>> "jim beam"<me(a)privacy.net> wrote in message >>> news:F4udnU6SrZ0kZQ7WnZ2dnUVZ_vQAAAAA(a)speakeasy.net... >>>> On 03/07/2010 09:52 AM, Jeff Strickland wrote: >>>>> "jim beam"<me(a)privacy.net> wrote in message >>>>> news:xbWdnV8Xic4E3Q7WnZ2dnUVZ_rGdnZ2d(a)speakeasy.net... >>>>>> On 03/06/2010 08:36 PM, Bill Putney wrote: >>>>>>> Jeff Strickland wrote: >>>>>>> >>>>>>>> ...We have not explored the interaction of traction control and >>>>>>>> antilock brakes preventing the brakes from stopping a car with a >>>>>>>> throttle intent on being set to the maximum setting. We also have >>>>>>>> not >>>>>>>> looked at the issue of brake fade that comes from the brakes getting >>>>>>>> hot. If the brakes locked the front tires, the ABS would sense this >>>>>>>> and unlock them. The driver might keep his foot planted firmly on >>>>>>>> the >>>>>>>> brake pedal which has sunk to the floor, but the car still would not >>>>>>>> stop. The brakes get hot and fade badly, and the car wouldn't even >>>>>>>> slow down... >>>>>>> >>>>>>> Read my previous post. With throttle applied (even partial throttle), >>>>>>> the booster vacuum gets depleted *rapidly*. There is no way to use >>>>>>> the >>>>>>> brakes to stop a car with an engine of any power at all with throttle >>>>>>> applied since, with throttle applied, intake vacuum drops to close to >>>>>>> zero. No vacuum = essentially no brakes. Try the experiment I >>>>>>> described >>>>>>> in my previous post. >>>>>>> >>>>>> >>>>>> no dude. even with no engine running to replenish vacuum, there is >>>>>> still >>>>>> sufficient vacuum reserve in the booster to apply the brakes full-on >>>>>> three >>>>>> times. unless you have a leak of course, which could also be >>>>>> affecting >>>>>> your experience. >>>>>> >>>>> >>>>> >>>>> Doesn't matter. Even if the driver holds the brake pedal, the brakes >>>>> get >>>>> hot >>>>> and fade, and this will cause them to stop doing the job they are >>>>> supposed >>>>> to do. >>>> >>>> if the brakes fade badly enough, even vacuum assist won't help much. >>>> >>>> >>> >>> Which is why a driver might not be able to stop a runaway car. You keep >>> saying that a driver can always stop a car by standing onthe brakes, the >>> facts are that this is not absolutely true. It's not even generally true, >>> but I'll give you the point that it's theoretically possible that a car >>> can >>> be stopped while the throttle is held open and the brakes are held down. >>> As >>> a practical matter, I don't think most people can manage such a >>> situation. >>> >> >> maybe this isn't something you and i have discussed before, but >> underbraked domestics are a recurrent theme that's been done to death. >> [and i'm sure, literally.] just because someone has one experience with a >> certain vehicle doesn't mean it's representative of all vehicles. >> >> and it is generally true that most vehicles have a design spec of roughly >> 3:1 braking power vs. engine power. >> > >But if the goal of stopping the car is not accomplished before the brakes >get so hot as to fade out, then you can stand on the pedal as hard as you >want and the car isn't going to stop. Brakes are designed to stop a car >that's not actively engaged in trying to go to its maximum capability. >That's the key to having somebody be able to stop a car or not. > >I accpet that you and I could stop a car that was intent on barrelling down >the highway at full throttle. We are comfortable with the machine, and have >no doubt that we could pursuade it to do what we want instead of what it >wants. But what if there is a driver that isn't as comfortable with his or >her machine, and the machine was insisiting on doing its own thing? Thats >where the problems come in. > >The throttle control MUST perform the tasks of speeding or slowing the >engine, and it must do it without fail each and every time it is called >upon. The issue here, for me, isn't that the Toyota throttle system works or >not, I'd like it to work but that's not the point. The issue for me is >Toyota's apparent RESPONSE to the problem. It is hiding behind the notion >that the Black Box data is proprietary, and it settles out of court so that >it does not have to divulge what the data shows. I'm okay with settling out >of court, but Toyota appears to not have gone back and looked at the system >design and fixed it. I worked for a Japanese company that settled out of >court, but I was in the service department, and was tasked in finding out >what went wrong so we could makek sure it stopped going wrong. That's what >Toyota should be doing, but by all appearances seems ot not be doing. That's >my beef. > >I am convinced that a fly-by-wire throttle is a perfectly sound automotive >breakthrough. There's no reason that it can't be used safely, but we have a >significant number of people that are having problems with vehicles from >Toyota that are so equipped. I'm more concerned with the appearance of >covering up the problem than I am that there IS a problem. And, there might >not be a problem but I happen to think there is, mostly because in my world >I think a California Highway Partol Officer should be as able or more able >than I am to operate a runaway vehicle. Were it not for the CHP officer, I'd >probably go along with sticky pedals and moved mats, but a cop should not be >killed by these kinds of things. > > > > Know any cops? I do. Several have demolished more than one cruiser in their carreers, and not in a chase situation. And a few I would not chose to drive with under any situation. Just plain scary.
From: News on 7 Mar 2010 23:58 clare(a)snyder.on.ca wrote: > On Sun, 07 Mar 2010 18:05:07 -0500, News <News(a)Groups.Name> wrote: > >> clare(a)snyder.on.ca wrote: >>> On Sun, 7 Mar 2010 11:10:20 -0800, "theref" <theref(a)seanet.com> wrote: >>> >>>> "Grumpy AuContraire" <GrumpyOne(a)GrumpyvilleNOT.com> wrote in message >>>> news:99adnZJAetdSdQ7WnZ2dnUVZ_qidnZ2d(a)giganews.com... >>>>> bjn wrote: >>>>>> On Sat, 06 Mar 2010 10:38:19 -0500, Bill Putney <bptn(a)kinez.net> wrote: >>>>>> >>>>>>> jim beam wrote: >>>>>>>> if you buy all this fear-mongering idiocy that electronic throttle is a >>>>>>>> problem, and that brakes, transmissions and ignition kill switches can >>>>>>>> all simultaneously fail causing a driver to lose control, it might be >>>>>>>> worth auto manufacturers of all stripes to adopt a slightly different >>>>>>>> implementation of electronic throttle [e.t.] - if not for mechanical >>>>>>>> reasons, but to shut the idiots up... >>>>>>> The lawyers, politicians, and news media can convince the public of the >>>>>>> impossible (failure even a totally fail safe system) any time they >>>>>>> decide to do it depending on political or monetary motivation. IOW - >>>>>>> the people and companies who do a good job of designing are going to get >>>>>>> punished anyway (unless they know how to play the game in a corrupt >>>>>>> system). There are people in our society whose life goal is to make >>>>>>> sure that that happens. >>>>>> The problem is that now lawyers, politicians and news media are driving >>>>>> (no >>>>>> pun intended) solution. The way I see them talking, cars will wind up >>>>>> with >>>>>> a fail-safe throttle that is more fail-safe than the controls of a jumbo >>>>>> passenger jet. >>>>>> >>>>> I'm not sure about this but for sure... The causes you cite certainly >>>>> contributed in getting to where we're at! >>>>> >>>>> Oh, don't forget that little incident when a B-777's engines went to idle >>>>> about a minute before touch down at Heathrow about a year ago. Aircraft >>>>> was totaled but there were no major injuries. >>>>> >>>>> Cause has been assessed to software/computer glitch. >>>>> >>>>> JT >>>> I believe that was traced to icing in the fuel system. SOP now is to cycle >>>> fuel after prolonged low temp at altitude. >>> Icing on a JET????????? >>> Don't think so. >> >> Absolutely. Determined to be cause of BA 777 landing short at Heathrow. > > OK - I looked it up. Technically this was fuel jelling - common with > diesel fuel in arctic conditions. In the case of the Rolls turbines, > it was a design fault in the fuel pre-heater unit which resulted in a > mandatory replacement with a redesigned heat exchanger. > > Different than the carb icing on a prop plane. It was ice in the fuel blocking the pre-heater, not fuel jelling. Get it straight.
From: Jim Warman on 8 Mar 2010 00:21
Nothing I love more than seeing someone with egg on their face... Ford Escape was a precursor... and now, anything with active park assist... Please don't make me dig through the option lists... Taurus would be another and likely MKZ, Edge... maybe Flex... Electric power steering is the future coming to life... from an NVH standpoint as well as other considerations... FWIW, I can't comment for other marques... Vehicles are far too complex these days for anyone to call himself an "all make" technician. BTW... I'm sorry I didn't make you scroll to the bottom of a whole bunch of drivel you already read just to read my reply... Everyone wants to "bottom post" but they all want to butt in front of me in line at the bank... "Jeff Strickland" <crwlrjeff(a)yahoo.com> wrote in message news:hmum00$agr$1(a)news.eternal-september.org... > > "jim beam" <me(a)privacy.net> wrote in message > news:ntSdnbrMg8YIRw_WnZ2dnUVZ_jEAAAAA(a)speakeasy.net... >> On 03/06/2010 01:30 PM, Bob Cooper wrote: >>> In article<hmuep4$qd2$1(a)news.eternal-september.org>, >>> crwlrjeff(a)yahoo.com says... >>>> >>>> >>>> This is the most important part? >>>> >>>> It's nonsense! The gas pedal does two things, opens the throttle plate >>>> and >>>> closes the throttle plate. Period. >>>> >>>> You should ride the bus. >>> >>> Nonsense? Where have I heard that before? >>> This is what you get if you're foolish enough to to let somebody who >>> names himself after a whiskey, whose logic is limited to the HTML >>> programming he's done for a Toyota fanboy website, and thinks EPS uses a >>> pump - design automobile throttling. >>> Don't worry, nobody in charge of such things is that foolish. >>> Well, maybe Toyota was. And look where it got them. >> >> get some experience bob. some cars do use electric pumps for power >> steering. toyota is one of them. not all models, but some. >> > > Cite. > > Toyota's electric steering does not use an electric motor to drive a > hydraulic pump. There are makes that use such a system, but Toyota isn't > among them, and certainly the Corolla does not use that system, which is > the model that is having steering problems. > > > > > |