Continue to Site

Eng-Tips is the largest engineering community on the Internet

Intelligent Work Forums for Engineering Professionals

Register Log in
  • Congratulations GregLocock on being selected by the Eng-Tips community for having the most helpful posts in the forums last week. Way to Go!

Tesla Autopilot, fatal crash into side of truck 6

Status
Not open for further replies.
Interesting, but do they work on the trucks with trailers? The doubles and triples.

Local deliveries would not make as much since as the long haul where there is a shortage of drivers. And the long haul is where the changing weather, and road conditions, weigh stations, fuel stops, and self reliance are required. Granted over 50% of long haul is by rail, much of it is not.

In fact UPS does put trucks on rail from CA to NY. But there are still routes between cities that don't have direct rail service (Kansas city to Denver comes to mind).


 
"we're only confronted with that situation a few months out of each year"

we wish ;-) typically, it's only about 35 rainy days per year. The storms are so spaced out that we typically take a couple of storms before everyone is acclimated to rainy driving, and the oil sheen has washed out.

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert! faq731-376 forum1529
 
Perhaps, but you have to admit that those "35 rainy days" are spread over "a few months" each year...

John R. Baker, P.E. (ret)
EX-Product 'Evangelist'
Irvine, CA
Siemens PLM:
UG/NX Museum:

The secret of life is not finding someone to live with
It's finding someone you can't live without
 
LOL, of course ABS works ~perfectly~ in sunny California. Too bad it fails when presented with other real-world driving challenges.
 
The maximum braking force is generated just before the tire starts to slide or skid. I see ABS as a second chance and a warning to ease off the brakes and apply just a little less force on the brake pedal.
I have verified this by experiment. Coming up to the corner stop sign at at the same speed and distance from the stop sign, apply the most braking that I can without triggering the ABS one time and letting the ABS buzz away the next time. Yes, 3 or 4 time as much braking distance with ABS.
Use ABS as a warning and back off the d___ brake pedal.

Interesting, but do they work on the trucks with trailers? The doubles and triples.
Well a "Super B Tridem" will have 30 tires available for braking and only 8 tires available for pulling traction. The automatic chains are just used on the driving wheels.
Ever watched "Ice Road Truckers"? At time they are only running with chains on 2 or 4 out of 8 driving tires.

They still running demolition-derbies at county fairs?
Out here we run "Combine Crunches" at the rodeos. Instead of cars we use old agricultural combine-harvesters.
While we seem to be losing more rights and privileges every year, out here it is still legal to operate a motor vehicle while under the influence of country music.

Bill
--------------------
"Why not the best?"
Jimmy Carter
 
Ever hear of the American Auto Duelist Association? Great testing for self driving cars.
 
waross said:
The maximum braking force is generated just before the tire starts to slide or skid.
Click to expand...

This is not actually the case. Maximum force between a tire and paved surface is achieved at a non-zero slip ratio, between 10%-20% slip depending on tire design, surface type, and other variables.

waross said:
Yes, 3 or 4 time as much braking distance with ABS.
Click to expand...

3 or 4 TIMES?

As in, if stopping under threshold braking took 50 feet, an ABS stop took 200 feet?

I don't believe you. IF that is the case, your vehicle has something very severely wrong with it.

The point of ABS is NOT to achieve the shortest possible braking distance- the point of ABS is to minimize braking distances for the vast overwhelming majority of drivers, who in an emergency situation will slam the brake pedal down with every muscle fiber they possess.
 
jgKRI - In certain snow conditions, maximum braking force is generated with the wheels locked. And yes, I can achieve MANY times less braking distance compared to the way the ABS wants to do it. The main purpose of ABS is not to achieve minimum braking, it's to help maintain control of the vehicle while ramming down the brake pedal as hard as you can. The problem is when it decides to achieve this goal by almost not applying the brakes.
 
I can't swear to the actual % increase in stopping distance, But when I first got an SUV (Yukon) it scared me in the distance it required for a panic stop. Like Waross says, I had to relearn to "let off". while replacing the factory supplied tires helped a lot, it wasn't till I pulled the ABS fuse that I felt I could get a decent emergency stop.

I am now scared when I have a SUV full of kids tailgating as I KNOW it can not stop if needed to.
 
Happens on dry surfaces, too. It feels like those old GM cars where the harder you pushed the brakes, the more they faded and the less they worked. You learned to ride them just at the fade point. ABS is the same!?
 
Well it is a fairly easy test to set up, so we can quit the hand waving, and I'd agree that some ABS systems are worse than others on snow and gravel. But I am a bit surprised to hear that people think they can beat ABS on dry hard surfaces, in normal traffic situations. Equally I doubt the ABS would beat a reasonably skilled driver who was primed for the braking event and not fatigued. I doubt it was banned from Formula 1 because it made the cars uncompetitive.



Cheers

Greg Locock


New here? Try reading these, they might help FAQ731-376
 
If WAROSS was referring to a gravel road or an icy road and his ABS/no ABS braking test (he didn't say) then I would have to agree. I've tried this myself and especially on ice but also on gravel the ABS causes longer braking distance. Quite a disturbing amount at times.

As Waross says, ease off the brake just below ABS threshold to get a good stop, if the road surface is anything but bare and dry pavement. It takes some practice on various roads and conditions before you get a feel for it for any given car or truck. I tend to do this "practice" when nobody else is in the car with me. However, I have made it a point to test the ABS on pavement during test-drives, with the dealership salesman beside me. I enjoy scaring those guys.



STF
 
That one seems odd; there's no reason for neither the TV nor radar to detect the sweeper, unless it wasn't actually turned on.

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert! faq731-376 forum1529
 
And Uber is planning on using self-driving cars for taxis. It will have a driver, but will they really be paying attention?
 
Which "driver"?

Or do you mean both of them?


Norm
 
coloeng, I'd say not, see: GregLocock (Automotive), 3 Jul 16 09:26 & 12 Jul 16 18:45 for example.

Few things are more disengaging than riding heard on automated systems, i.e. watch, but don't touch.

Regards,

Mike


The problem with sloppy work is that the supply FAR EXCEEDS the demand
 
Status
Not open for further replies.

Similar threads

LittleInch
  • Question
Korean airplane crash
2 3
Replies
48
Views
12K
XR250
XR250
Alistair_Heaton
  • Question
DHL 737-400 crash
Replies
11
Views
5K
3DDave
3DDave
M
  • Question
2023 Osprey crash in Japan - failure report
Replies
1
Views
2K
drwebb
drwebb
JohnRBaker
  • Locked
  • News
A plane crash in Brazil, near Sao Paulo...
Replies
15
Views
309
Alistair_Heaton
Alistair_Heaton
JohnRBaker
  • Locked
  • News
28 cars crash during a single accident at a NASCAR event...
Replies
10
Views
357
drawoh
drawoh

Part and Inventory Search

Sponsor

Back
Top Bottom