![]() | #571 |
Senior - BHPian Join Date: Jul 2009 Location: Calcutta
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![]() | #572 | ||||
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The Swift came with 165/80-R14 wheels, which means that at 10 Kmph, the wheel RPM is ~ 1.4 RPS ( is 1 RPS at 7 Kmph ). But then came across this IEEE document which I think indicates the real reason. RotationalSensors.PDF To quote from the document [ Page 19 ] : Quote:
. Last edited by im_srini : 12th August 2015 at 20:58. | ||||
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![]() | #573 | ||
Senior - BHPian ![]() Join Date: Mar 2007 Location: Bangalore
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... they are just giving an approximate vehicle speed below which the WSS pulses may no longer be reliable for the functioning of the ABS. ...[/quote] Quote:
The lower limit is just an arbitrarily declared figure to put the monkey on someone else's shoulder. Not sure I understand why it would be required, but no, Prof! Manually? There is no switch, unless a switch is manually added by vehicle owner in his off-roader. ABS doesn't act on a wheel only if that wheel's sensor is faulty. There is no other way to switch ABS off. | ||
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![]() | #574 | |
BHPian ![]() Join Date: May 2014 Location: Driver seat!
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![]() I am curious why most bikes equipped with ABS provide a facility to switch it off, while cars only have an ESP off switch. To enable pulling off stunts maybe! | |
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![]() | #575 | |||
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What Sutripta was talking about was turning off the ABS through the software logic below a certain speed which again I personally don't think, is the case. Even at <5 kph, if there is a big enough slip (an example being hard braking on wet ice), ABS control will start. Cheers | |||
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![]() | #576 |
BANNED Join Date: Nov 2014 Location: Bengaluru
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| ![]() Can ABS be fitted into a non ABS vehicle? I have a 2013 Dzire VDI which did not have ABS, however the newer model of Dzire VDI has ABS. |
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![]() | #577 | |
Distinguished - BHPian ![]() ![]() Join Date: Jun 2007 Location: Chennai
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As I understand it, ABS operates just before wheel lockup, to prevent the wheels becoming locked. It must work then, when the wheel rotation speed is almost zero. I don't see any relevance in the original speed of the car at the moment that the breaks are applied. Am I missing something? | |
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![]() | #578 |
BHPian ![]() Join Date: May 2014 Location: Driver seat!
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![]() | #579 | |||
Senior - BHPian ![]() Join Date: Mar 2007 Location: Bangalore
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Which company, may one ask? Quote:
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The key criteria is the rate at which the (rotating) wheel is slowing down. The ABS ECU just calculates angular speed difference every few milliseconds. If the deceleration rate is higher than a trigger point (which is a pointer to impending wheel lockup), ABS acts. It has nothing to do with the speed of the vehicle. | |||
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![]() | #580 |
Team-BHP Support ![]() ![]() Join Date: Jul 2010 Location: Bangalore
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| ![]() ABS works on the (sensor-measured) likelihood of losing traction and locking wheels, not driving speeds! Someone better acquainted with the technicalities can explain the exact mechanism, but that's the gist of it. If an ABS-equipped vehicle loses traction at single-digit speeds, ABS will still kick in. Last edited by Chetan_Rao : 13th August 2015 at 14:32. |
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![]() | #581 |
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![]() | #582 |
Senior - BHPian ![]() | ![]() In my Cruze, ABS definitely works regardless of speed. Just this morning outside my sons' school, I parked at around 5 km/hr and the ABS immediately kicked in as there was a layer of very slippery mud. My overall take is that even at very low speeds on icy/muddy roads, ABS will avert the common rear-ending incidents because 99% of Indian drivers don't know how to maintain a safe distance in such conditions. |
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![]() | #583 |
BHPian ![]() Join Date: Mar 2014 Location: Bangalore
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| ![]() One of my friend's Ritz ZXi (ABS) suddenly lost the brakes on a downhill as she was unable to stop by pressing the pedal.Some how she stopped the car and she went in to tears as there were school children in front of her car.She couldn't bear the fact that, if something had happened to those kids, how will she live with that. Later on, upon inspection,we found that the car had no fuel and may be because of that, the vehicle had lost the brakes. Even if the vehicle is switched off,there will be some amount of brake.Then why did this happen? Currently, there is no issue with the brakes.The car is braking and running good.Can the experts comment ? |
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![]() | #584 | |
Senior - BHPian ![]() Join Date: Feb 2011 Location: SG
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![]() All vehicles now a days have power assisted brakes. Which means the brakes will cease to function/ become extremely hard if the engine is switched off. The residual vaccum in the system may help you with some braking action initially but as you keep pumping the brakes you will lose that too in no time. Only hope might be to literally stand on the pedals. It is highly unsafe to coast downhill on a car with no power. Last edited by vibbs : 13th August 2015 at 15:16. | |
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![]() | #585 | ||
Distinguished - BHPian ![]() ![]() Join Date: Dec 2012 Location: Ranchi
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Regards, Saket | ||
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