![]() | #451 | ||
BHPian Join Date: Jan 2013 Location: BBS/TVM
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| ![]() But, which one would you bet on in a given (say, emergency) situation? OT, I actually wanted to ask a similar question regarding Airbags as well. Quote:
![]() I did thorough research about ABS (thanks to tbhp) and came to the conclusion that I will not put money on a car without ABS. It eventually increased by budget, but, so be it. Quote:
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![]() | #452 |
BHPian ![]() Join Date: Apr 2013 Location: Yorkshire Dales
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| ![]() The driver psychology involved with increasing a car's safety in interesting. People tend to reduce their safety limits when driving cars which they know are laden with airbags, abs systems, stability control etc. That is to say, they drive up to a limit of safety, so with a car with many safety features they may feel they can travel faster in poor conditions. An additional problem is that people with expensive cars laden with safety-tech may wish to demonstrate their superiority of their machine by driving faster, overtaking more etc. We are all susceptible to this, and must be aware of it. Education should be a primary method of improving road safety. A car with poorly-maintained brakes, worn or cheap tyres, worn or cheap suspension componentry will still be unsafe no matter how many electronic aids you add to it, although of course, marginally less unsafe. As I mentioned earlier, a car with a spike protruding from the steering wheel would be driven with the ultimate care and attention. Last edited by FlatOut : 6th May 2013 at 19:12. Reason: typos |
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![]() | #453 | |
Senior - BHPian ![]() Join Date: Mar 2007 Location: Bangalore
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Incidentally, neither company *makes* these systems. Usually an automotive systems company does that, like Bosch, Denso, Delphi, etc. The car company defines the interfaces and functional specifications, which in reality are based on the Vendors' previous generation systems anyhow. This is not a difference between shirt brands where there could be a difference in the cloth used, which affects reliability and functionality of the shirt. | |
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![]() | #454 | |
Distinguished - BHPian ![]() | ![]() Quote:
But it's a free country, so if they think their skills and experiences offer, statistically, a better protection, by all means go ahead and disconnect those airbags. Jeroen | |
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![]() | #455 | |
BHPian ![]() Join Date: Apr 2013 Location: Yorkshire Dales
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| ![]() In the late 80s and early 90s, ABS systems were improving quickly, and more expensive cars often had later systems which were an improvement on previous incarnations. Now that the technology is mature, I imagine all the systems work extremely well, although some may be more suited to certain situations than others. I would suggest that the difference in ability between two different ABS setups is far less than the difference when comparing two otherwise identical cars but with different quality tyres and shock absorbers fitted. Quote:
Mod Note: Please use the EDIT or MULTI-QUOTE buttons instead of typing one post after another on the SAME THREAD! To know how to multi-quote, click here. Last edited by Rudra Sen : 8th May 2013 at 08:18. | |
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![]() | #456 | |
Distinguished - BHPian ![]() | ![]() Quote:
But somebody should tell them that statistically speaking: - The chances of that happening are less then remote - The chances of an airbag saving the day at less high speeds are considerable higher. Also, statistically speaking, unless they train for these high speed loss of control events, they are not very likely to take the correct action or to react fast enough. You drive 60.000 miles per year, but if you never train on these sort of accidents you are very unlikely to react properly. For instance, aviation has shown, again and again, its not experience that saves the day per say. It's safety conscientious and relentless training that does. Not just raking up the miles! Lets get back on topic: ABS, did they disable that too? Because as I stated in my earlier post a skilled and experienced driver can outperform the ABS easily!! That's Jeroen | |
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![]() | #457 | |
Distinguished - BHPian ![]() ![]() Join Date: Jun 2007 Location: Chennai
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| ![]() I think there are circumstances in which ABS does not work well. In general, I find it very hard to believe that any human can do what ABS claims (at least) to do, which is to keep the brakes working at maximum efficiency by keeping them just short of lock-up. I suspect that most skilled drivers just skid to a halt. I suspect that most skilled drivers can, somehow, do that better than I can, but not better than ABS can. Above all, most drivers are not skilled at levels above modest to average. Including me. Quote:
There is almost no awareness of kinetic energy is not understood, hence the reluctance to use seat belts, and the willingness to carry a child, in one arm, on the back of a motorbike. Last edited by Thad E Ginathom : 6th May 2013 at 22:40. | |
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![]() | #458 | |
Distinguished - BHPian ![]() | ![]() Quote:
That's why ABS is so great. Every bodies reflex is just to stomp on the brake pedal as hard as you can. No further thinking or nuance required. There are some situation where ABS does not work well, although it could probably be argued that regular braking would not work well either. | |
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![]() | #459 | |
BHPian ![]() | ![]() Quote:
ABS increases the braking distance and sometimes by good margin if its a loose gravel but the point is to provide the driver with enough drivabilty/steerability so that he/she can still maneuver the vehicle without getting locked. With the ABS equipped car, your reaction has to be faster/prompt than a non-ABS car since braking distance is increased, so thats the trade off. Some of the situations like slush/ice/loose surface, its not useful and technology is evloving to ensure that its not activated when during such siuations / offroading situations etc. It triggers based on the difference of speed on your wheels every seconds/few seconds (like an assert in software language or trying to detect a state that cant be handled) and modern ABS systems try and avoid situations when its not required to be engaged. Coming to a human simulating this technology, I dont believe until I see a research based analysis. So far, I havent seen one and that means its not possible. I may be wrong, but really need enough to convince myself. Now when you have a job getting done by technology, why cant we just use it, improve it and take that job off your already under pressure nervous system! If you have a technology say car, you would use it right! you wouldnt try to simulate by running @40kph to go from point-A to Point-B! EDIT: I read your earlier post on the prev page. I agree with pump braking one can customize the ABS effect to ones benefit. However, doesnt it involve opportunities for human errors and hard to compare with tehnology/system (that can fail too, but much more reliable than humans IMO). So, its good to know internals and learn whatever you can do to get yourself out of that panic situation, for 99.999% of drivers and 99% of panic situations it helps. Last edited by Ketan : 7th May 2013 at 01:14. | |
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![]() | #460 | ||||
Senior - BHPian ![]() Join Date: Mar 2007 Location: Bangalore
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| ![]() Quote:
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And you are right - no human can match the ABS system in pulsing the brakes on/off at around 20 cycles per second. Quote:
2. "slush/ice/loose surface, its not useful" - Incorrect, ABS actually reduces braking distance on such surfaces as compared to locked-wheels braking. Not sure what you mean by "loose surface", but gravel (with hard under-surface, like gravel on dry packed earth or road) is the only one where the braking distance could be larger (not always true, depends on what is below the gravel) 3. "its not activated when during such siuations" - where did you get this from??? It is incorrect to automatically / conditionally 'disable' systems like ABS - for ANY reason other than off-roading, which it is not designed to cater to. What would be the difference between off-roading and bad city roads w.r.t. ABS? Nothing, if you know the physics and maths of ABS. Quote:
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![]() | #461 | |
Team-BHP Support ![]() ![]() | ![]() Quote:
1. Driving on ice - The car does not stop at all. Due to nature of ABS system, wheels do not lock, and if you are on incline you will keep on sliding. 2. On dirt tracks, when wheels lock up dirt/gravel builds up providing additional stopping. These two cases where ABS is not very good are well documented, but since ABS is very useful in 99% of the cases, overall having ABS increases your ability to avoid crashing! | |
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![]() | #462 | |
Senior - BHPian ![]() Join Date: Mar 2007 Location: Bangalore
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True - IF the underlying surface is soft. Not on road - the gravel acts like millions of marbles on a hard floor. | |
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![]() | #463 |
Distinguished - BHPian ![]() ![]() Join Date: Jun 2007 Location: Chennai
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| ![]() The car with ABS does stop on ice: I've tried it. True that I only did this at around walking pace, but then it probably would not have been safe to drive on such a surface at any greater speed! There's a wonderful thread about learning to drive in a Scandinavian country, and passing the test there. I wonder what they teach about ABS? They are the experts: in UK we are barely taught at all how to cope with frozen/snow conditions. |
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![]() | #464 | ||||
BHPian ![]() | ![]() Quote:
I'm talking about the off-road situations caused by vehicles running off the road in accident situations and I'm not talking about situations where JeepThrills guys spend their weekends. I have not learnt this based on my experience but from whatever I read thru such threads and internet so some of the points may not be 100% correct but in this case the high level points that I'm trying to make is correct is my guess. Points like, - Humans cant simulate ABS - ABS increases braking distance to provide you steerability/control Quote:
- Again, this is based on what I read, we have Tanveer also commenting based on his experience that confirms what I have read is correct. - This is what I read from wikipedia and other research papers and its easy to digest without learning physics/maths - Not from my personal experience again, just based on what convinced me so far, if someone can prove otherwise, I'd love to learn the new technology you are talking about. "In gravel, sand and deep snow, ABS tends to increase braking distances. On these surfaces, locked wheels dig in and stop the vehicle more quicklyIn gravel, sand and deep snow, ABS tends to increase braking distances. On these surfaces, locked wheels dig in and stop the vehicle more quickly" source: http://en.wikipedia.org/wiki/Anti-lock_braking_system Quote:
- The evolution I'm talking about is 'brake assist', 'traction control system', 'emergency brake assist', 'brake distribution system' and finally ESP. I consider all of them as an extension to ABS. Lets not go by the name ABS but consider it to be 'enhanced braking systems' - Now we use more sensors compared to conventional ABS systems, the system doesnt just measure the deceleration ratios on your wheel but also measures the direction taken by the car is not indicate the one taken by driver's steering weheel which is ESP (an advanced version of braking system to me if you dont stick to the different names (ABS etc) provided by manufacturers). - Not sure which off-road situation you are comparing with the bad road situation here (JeepThrills or run-off-road situation during crashes). Either ways they are different categories and surfaces for me from speed, braking and vehicle control perspective, this may lead to some more discussions (and yes, some physics and maths too). Quote:
Like I said, its not based on my personal experience (as Tanveer could immediately comment based on his) but based on something I read from wiki and reference articles, I also read that vehicles with ABS and such advanced assist technologies are driven rashly, that point alone reduced the % of effectiveness of such systems which should purely be about the drivign habits you are talking about! Last edited by Ketan : 7th May 2013 at 17:10. | ||||
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![]() | #465 |
BHPian ![]() Join Date: Apr 2013 Location: Yorkshire Dales
Posts: 300
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| ![]() Some hard facts: A car will stop a little more quickly with all four wheel locked up on dry tarmac than with ABS deployed. But any steering ability is lost. A car will stop a little more quickly on uncompacted snow and in certain other condtions, including some types of ice, as mentioned above, without ABS. Indeed, using ABS down a hill on new snow may cause a run-away situation, whereas locking the front wheels will stop the car. Audi used to provide an ABS cut-out switch for just such winter conditions. I don't think they do anymore for the reason that it may subject them to litigation, since most people do not understand these subtleties of driving. ABS is becomiong universal since for most of the time, it provides a massive increase in motoring safety. Just remember that good tyres and shock-absorbers/suspension damping is equally important. As Jeroen mentions, it is possible to train yourself to bring the (front) roadwheels to the point of lock-up and hold them there. However that depends on a homogenous friction surface. It also means that only the front wheels will be providing maximum retardation - with ABS in play and your foot hard on the brake pedal, all four wheels will be on the point of lockup. The only cars I ever managed to successfully use his technique with were old Alfa Romeos, Saabs and most successfully in hydraulic Citroens - the DS, CX and GS (not the later Peugeot-based Xantia, XM and BX). I suspect that what these cars had in common was a lack of compliant rubber spoiling the front suspenion, so that there was little or no fore-aft movement of the wheel as tyre began to slow. The Citroens also had the most sublime braking with the pedal being a pressure modulator, allowing more or less high-pressure fluid to the calipers - rather than shoving a bit of brake fluid down the pipes, as in every other motor car. Its superiority (as with its famed suspension) was beyond belief - it's just that most people never drove their motor car hard or fast enough to fully realise the benefits of the technology. Electric sunroofs, electric windows, extra chrome and other salesroom clinchers are what sell to the masses, unfortunately. Safety features took a long time to arrive in Europe for the main manufacturers, those who had designed for safety such as Saab and Citroen were perceived as just weird. Some people just don't understand something which is different and refuse to be educated. |
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