electronic throttle
in [Technical]
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From: dizzy on 15 Mar 2010 21:35 clare(a)snyder.on.ca wrote: > dizzy wrote: > >>>When you have really sloppy conditions >> >>Interesting theory, with zero proof. >> >>I'd like to see the theory put to the test. Slipping tires does not >>equal shortest stop. > >I don't understand what you are saying and agreeing or dissagreeing >with. Assertions have been made that ABS "doesn't work so well" in "slippery" or "really sloppy" conditions", which I believe are absurd. It's provably better than the alternative in some ways (stability and control), while being (I believe) no worse in ultimate stopping ability. There's a lot of handwaving in here, but no reference to any independant tests which show that ABS "doesn't work so well" at what it's design to do.
From: C. E. White on 15 Mar 2010 21:44 ----- Original Message ----- From: "Rodan" <Rodan(a)Verizon.NOT> > The possibilities are endless. Isn't progress wonderful. > Are you tired of pulling a cord to raise > your venetian blinds? Do it with a servo control system just like the > electronic throttle. Done. http://www.yourblinds.com/motorized_remote_blinds.asp > How about your lawnmower starter cable? Done - called an electric starter, http://shopping.yahoo.com/713009843-toro-recycler-electric-start-lawn-mower/;_ylt=A2KJ389K3J5L8TQARBgbFt0A > Your church bell rope? Done at least two ways - mechanically operated real bells and electrically synthesized bells. http://www.electrictime.com/controls_and_chimes/bell_hammer_actuator_50lbs_22_7kg http://www.verdin.com/carillons/ http://www.schulmerich.com/products_towers_overview.php > Your light fixture pull chain? Done. They call it a wall switch. I think Edison had them. But they also have remotely operated light controls. http://www.securitystoreusa.com/Safety+Technology+Inc.+HW2165D+Wireless+Light+Sock-p/491371.htm > Your tampon string? Not my area of interest.... > As our lives are impacted by their leadership, the wisdom of the throttle > cable replacement scientists will be demonstrated again and again. Are you old enough to remember the good old days? Spark ignition, carburetors, etc.... I am . I'll stick with the current stuff. Hard for me to diagnosis, but then I can't remember the last time I had a problem that needed diagnosing that was related to a problem with the electronics other than failed mechanical bits (like connectors). Consider this - if a mechanical throttle is jammed open, the driver must intervene. A properly designed electronic system can recognize a conflict and shut the engine down without driver intervention. I've actually had a mechanical throttle fail. I've never had it happen with an electrically controlled one. I know this doesn't prove anything, but I see no reason to believe that an electronically controlled throttle can't be much safer and more reliable than a mechanical system. And the electronic systems do have advantages other than improved safety. Ed
From: C. E. White on 15 Mar 2010 23:18 "dizzy" <dizzy(a)nospam.invalid> wrote in message news:2rntp5dqtgbe1ck077l0lgg5mfuslnq2oa(a)4ax.com... > clare(a)snyder.on.ca wrote: > >> dizzy wrote: >> >>>>When you have really sloppy conditions >>> >>>Interesting theory, with zero proof. >>> >>>I'd like to see the theory put to the test. Slipping tires does not >>>equal shortest stop. Actually maximum braking force on dry pavement is achieved when the tires are "slipping" slightly. See http://insideracingtechnology.com/tirebkexerpt2.htm figure 6.8. Also http://code.eng.buffalo.edu/dat/sites/tire/img55.gif http://f1elites.com/4d/?p=54 >>I don't understand what you are saying and agreeing or dissagreeing >>with. > > Assertions have been made that ABS "doesn't work so well" in > "slippery" or "really sloppy" conditions", which I believe are absurd. > It's provably better than the alternative in some ways (stability and > control), while being (I believe) no worse in ultimate stopping > ability. Some ABS systems do have problems under some low traction conditions. Many tests have shown that some ABS system perform poorly on dirt and gravel roads and on sorft snow compared to non-ABS system. Toyota actually claims their ABS systems "includes a sophisticated gravel road strategy, which in the special circumstance of braking on a gravel road ensures the tyres brake through the loose gravel to maximise stopping power." > There's a lot of handwaving in here, but no reference to any > independant tests which show that ABS "doesn't work so well" at what > it's design to do. On the other hand evidence that ABS has actually improved highway safety is not conclusive. From http://www-nrd.nhtsa.dot.gov/Pubs/811182.PDF : "Statistical analyses based on data for calendar years 1995 to 2007 from the Fatality Analysis Reporting System (FARS) and the General Estimates System (GES) of the National Automotive Sampling System (NASS) estimate the long-term effectiveness of antilock brake system (ABS) for passenger cars and LTVs (light trucks and vans) subsequent to the 1995 launch of public information programs on how to use ABS correctly. ABS has close to a zero net effect on fatal crash involvements. Fatal run-off-road crashes of passenger cars increased by a statistically significant 9 percent (90% confidence bounds: 3% to 15% increase), offset by a significant 13-percent reduction in fatal collisions with pedestrians (confidence bounds: 5% to 20%) and a significant 12-percent reduction in collisions with other vehicles on wet roads (confidence bounds: 3% to 20%). ABS is quite effective in nonfatal crashes, reducing the overall crashinvolvement rate by 6 percent in passenger cars (confidence bounds: 4% to 8%) and by 8 percent in LTVs (confidence bounds: 3% to 11%). The combination of electronic stability control (ESC) and ABS will prevent a large proportion of fatal and nonfatal crashes." NHTSA spent millions trying to figure out why ABS wasn't providing a significant net safety benefit. They finally gave up. However, it is irrelevant whether it is a net safety benefit or not, all new light vehicles will soon have ABS since ABS is an integral part of the ESC systems that NHTSA has mandated. I have always felt that ABS and ESC are not cost effective means for achieving the goal of improved traffic safety. Installing these components in all vehicle will cost Consumers billions of dollars per year. Spending this amount of money on better tires, improved driver training, highway improvements, etc., in my opinion, all have the potential for improving traffic safety more than ABS and ESC. I have no problem with ABS and ESC being offered as options, I just don't agree that they should be mandatory. Ed
From: jim beam on 16 Mar 2010 00:07 On 03/15/2010 12:32 PM, Bob Cooper wrote: > In article<r8ssp5dka698va7vhhnu27dq9ovc8r67u0(a)4ax.com>, peter2 > @hipson.net says... >> >> On Mon, 15 Mar 2010 11:49:38 -0500, Bob Cooper<bc(a)nowhere.com> wrote: >> >> >>> I want to hear the justification - in concrete technical language - of >>> why pedal/sensor/ecu/servo motor throttle control is in any way better >> >> Consider issues of time lag, fuel mix coordination, etc. >> > Nothing the TPS can't signal a microsecond later. so it should process a wrong pedal application immediately? er, ok. > Haven't seen anything that shows a difference, and I doubt it exists. the scientific approach... > Face it, they just want to replace the cable/hardware and the hole. > Cables can be greasy and icky. > The biggest actual measurable "benefit" is to eliminate cruise control > hardware. that's a side benefit. the biggest reason is control for the auto transmission - it can be built cheaper if it doesn't need to take the loads placed on it by full throttle shifting. oh, and it'll be smoother too. > BTW, speaking of lag, a friend notices a lag when punching down the gas > pedal up his '06 F-150 with throttle-by-wire. Hasn't caused him > problems, but he likes to befuddle the computer now and then, even if > it's only between half a second and a second. Cheap thrills. > I've read that lag is noticed by many drivers. > Maybe the ECU is "considering" other issues than what the driver wants. yes it is. two reasons - 1. it mitigates "dithering" wear on the actuator at the throttle body 2. it reduces gas consumption by throttle stabbers - those that constantly speed up and slow down. > >>> or safer than pedal/cable/spring throttle control with TPS feedback to >>> the ECU. And I dumbed up throttle-by-wire there - it's worse. >> >> worse than what? >> > Than the pedal/sensor/ecu/servo motor elements I mentioned. > A schematic of the electron flow through wires, sensors, resistors, etc, > and the lines of code contolling actions taken by demand from a foot, > compared to a throttle cable schematic has to make you scatch your head > and say "Why did they do this?" you don't understand. why do people that don't understand have opinions but not ask questions? > >>> Eliminate a cable and spring for mass confusion? >> >> Seems only a few are confused, certainly not the masses. And 'fly by >> wire' has been around for a very long time, and worked very well in >> most cases. >> >>> That's what happens when you let computer geeks design control systems >>> overriding the normal seat of the pants, hand/eye coordination and foot >>> control which is the essence of car driving. >> >> So now computer engineers are incompentent? OK... >> > Didn't say that. well, you effectively did. > What I said is what I said. I'm sure Toyota is happy > with the competence of those who designed a throttle system that is now > costing them billions. toyota's problem is political, not electrical. > That was a great collaboration of computer, > electrical and mechanical engineers brought together to overthrow the > humble cable and spring. 1. "humble" is not as reliable. 2. "humble" offers no control advantages. > >>> I'll bet there was a big fight at Toyota between the geeks and the >>> drivers about that one. And not just at Toyota. >> >> Bet there wasn't... >> > You may be right. But I hope I'm not the only one who wants direct > throttle control. do you ever drive diesels? you've never had direct control on a diesel, so what's your problem with gasoline control? [rhetorical] > >>> Anything separating physical feedback is bad enough, but taking over >>> control of the basic driving actions is a re-incarnation of HAL 9000. >> >> Bwa-ha-ha-ha... Now that's funny. Noting beats a confusion between >> (old) science FICTION and reality. Nothing at all. > > Does that mean you believe an ECU is always obedient? > Not my experience. your only "experience" is that of a failed education system. > But I do like the ECU that that adjusts fuel/air ratio on my FI car, and > it's nice enough to toss a code now and then to tell me what to fix. > I'm all in with most recent car innovations that aren't fluff. > I like to control throttle all by my lonsesome. ever driven a diesel? you should try it. > Like manual windows too. Just because there's no electrics to fail. > here's a "manual" you could try: http://www.amazon.com/Control-Systems-Engineering-Norman-Nise/dp/0471794759/ref=sr_1_3/178-7851286-0899705?ie=UTF8&s=books&qid=1268707535&sr=8-3 -- nomina rutrum rutrum
From: jim beam on 16 Mar 2010 00:07
On 03/15/2010 10:39 AM, PeterD wrote: > On Mon, 15 Mar 2010 07:16:14 -0700, jim beam<me(a)privacy.net> wrote: > >> On 03/15/2010 06:08 AM, Bob Cooper wrote: >>> In article<806g3mFtd8U1(a)mid.individual.net>, bptn(a)kinez.net says... >>>> >>>> Rodan wrote: >>>>> This electronic throttle thing is great. If you believe everything that >>>>> could be invented has already been been invented, do this: Replace >>>>> something already invented with something else already invented >>>>> and call it a new invention. >>>>> >>>>> This has been successfully done in automobiles by throwing away the >>>>> familiar throttle cable and replacing it with a whole new system of >>>>> electromechanical parts;... >>>> >>>> Is it not true that the drive-by-wire systems have a cable connecting >>>> the accelerator pedal to the first electronic part? If so, a chain is >>>> only as strong as its weakest link - literally in this case. If that's >>>> the case, they'd be foolish to say that one benefit of the hi-tech >>>> solution is the elimination of the cable. I can believe some of the >>>> claims of better control of engines systems for power and emissions and >>>> possibly enhanced safety if it's done right, but they should leave out >>>> the part about eliminating the mechanical linkage. >>> >>> The real issue is giving sensors, computers, servos, etc, control over >>> throttle opening, instead of a direct and simple mechanical link to the >>> human foot. >> >> no it's not. there is not a single diesel ever used that gives an >> operator direct link to fuel injection - it's all done via a control >> module. > > Huh? Have you lost your mind? Electronic controls on diesel engines > are relatively new, within the last 15-20 years. Prior to that *ALL* > diesels had direct control of fuel, and even today many still do. Me > thinks you have been sampling too much of your name sake. no i haven't lost my mind. and you obviously don't know about diesel injection systems or you'd not make the above fundamentally incorrect statement. all diesels, from day one, have had a control system [otherwise known as a governor] between the driver's foot and the injection stroke commander. it limits revs and controls injector stroke depending on load. [example - the driver can have their foot at 100%, but the governor is only injecting 5%. or the driver can have the pedal at 30% and the injector can be at 100%. the final say with the amount of fuel injected rests with the control system, not with the driver.] these controls, while simple, are successors to the early watts governors found on steam engines. http://oldenginehouse.users.btopenworld.com/watt.htm > >> should we get rid of control on all diesels? of course not. >> >> there is absolutely nothing wrong with the principle of using a control >> system. oh, and mechanical systems are much more unreliable than >> electrical. > > Any properly designed system is capable of being reliable. not to the same extent as an electronic control it's not. as you'd know if you had enough experience or grounding in electronics. -- nomina rutrum rutrum |