Driverless Cars

[buckeyefarmer]

I took a driving class once where we did braking with and without ABS. ABS was better, hands down.

 

[3930dave]

I took a driving class once where we did braking with and without ABS. ABS was better, hands down.

..... under certain conditions, but not all.......

"Although ABS generally offers improved vehicle control and decreases stopping distances on dry and slippery surfaces, on loose gravel or snow-covered surfaces, ABS may significantly increase braking distance, while still improving steering control."

Anti-lock braking system - Wikipedia

^ That one is a double whammy - it would be bad enough if ABS matched non-ABS performance under those particular bad road conditions, but it can actually perform worse. (This consideration was the reason for the Off switch, on those ancient Audis....).

Worth considering - ABS is a relatively simple technology, compared to driverless cars.....

Rgds, D.

 

[Travelover]

I took a driving class once where we did braking with and without ABS. ABS was better, hands down.

I had a similar experience. The cars were equipped with an ABS off switch, so we could do a back to back,and we were to stop fast and steer around cones on wet asphalt. Like you, I found the ABS to be a terrific feature for the average driver. But of course, most of us are above average.

 

[3930dave]

ABS does consistently deliver better steering control to most drivers. One of the best examples is with motorcycles - too many people get to find out how easy it is to wash out the front tire, even on the street.

Best way to become familiar with the limits of a technology is under controlled track conditions.

That's all I'm trying to highlight.... all technologies have their limits of performance.... just in this tiny thread, we've had several examples of exceeding those limits. Yes, limits do move with time.

Rgds, D.

 

[Jstpssng]

..... under certain conditions, but not all.......

"Although ABS generally offers improved vehicle control and decreases stopping distances on dry and slippery surfaces, on loose gravel or snow-covered surfaces, ABS may significantly increase braking distance, while still improving steering control."

Anti-lock braking system - Wikipedia

^ That one is a double whammy - it would be bad enough if ABS matched non-ABS performance under those particular bad road conditions, but it can actually perform worse. (This consideration was the reason for the Off switch, on those ancient Audis....).

Worth considering - ABS is a relatively simple technology, compared to driverless cars.....

Rgds, D.

I would like the ABS a lot more if it disabled itself below a certain speed. It's especially annoying when you're stuck in snow, and are slowly rocking the vehicle back and forth packing the snow. Often you will get a little movement working only to have the truck decide not to stop when you apply the brake; and you find yourself immobilized again.
I did an unscientific trial stopping from 45mph on a snow covered road in my 1998 GMC with ABS disabled, and with my (then new) 2005 F150.
First with the GMC, using the brakes judiciously to cut down through the 6" of snow; then I tried the F150 and just stomped on the brakes the way you are supposed to. The F150 travelled 50% farther before stopping. I've also seen times when one side of the truck was on snow and the other on gravel; you may as well not have brakes. Sometimes if you are in 4WD and can't stop it helps to slowly apply the parking brake; with all 4 wheels braking again it's amazing how quickly you stop. You also are at more risk of losing control though.

 

[bcp]

I have about 200 feet of 4-5% grade on my driveway. On packed snow, my 2012 Tacoma, 4wd high, will travel full length from the top at about 3mph with ABS fully engaged and chattering all the way. I can stop in 4wd low, but not high.

Bruce

 

[3930dave]

I would like the ABS a lot more if it disabled itself below a certain speed. It's especially annoying when you're stuck in snow, and are slowly rocking the vehicle back and forth packing the snow. Often you will get a little movement working only to have the truck decide not to stop when you apply the brake; and you find yourself immobilized again.
I did an unscientific trial stopping from 45mph on a snow covered road in my 1998 GMC with ABS disabled, and with my (then new) 2005 F150.
First with the GMC, using the brakes judiciously to cut down through the 6" of snow; then I tried the F150 and just stomped on the brakes the way you are supposed to. The F150 travelled 50% farther before stopping. I've also seen times when one side of the truck was on snow and the other on gravel; you may as well not have brakes. Sometimes if you are in 4WD and can't stop it helps to slowly apply the parking brake; with all 4 wheels braking again it's amazing how quickly you stop. You also are at more risk of losing control though.

Well said.

I get that it's hard for someone to relate to these issues, if they've never lived in serious snow country. Many a time I've used the rock/stop/roll back/repeat cycle to unstick a vehicle in snow, where the owner had already given up.

Gen I GM truck ABS was universally hated by anybody that owned them here - stopping distance in Winter was ridiculous.

When you lock up all 4 w/o ABS on deep snow or gravel, you are pushing snow/gravel ahead of all 4 wheels, dissipating a lot of energy. The vehicle continues in the same direction as when you hit the brake (great, so long as that is what you want to do) but may rotate about it's centre axis <- That's what freaks a lot of people out, and may lead to blocking an adjacent lane..... not what you want to do much of the time, but if you are on a deserted road and need to stop FAST, it can make the difference between crashing, or not.

Rgds, D.

 

[3930dave]

I have about 200 feet of 4-5% grade on my driveway. On packed snow, my 2012 Tacoma, 4wd high, will travel full length from the top at about 3mph with ABS fully engaged and chattering all the way. I can stop in 4wd low, but not high.

Bruce

Systems are less-intrusive now, and new drivers got used to ABS (as they didn't know anything else), but one of the original human-factor problems with ABS was that drivers would back off the pedal once they got force-feedback from the system.

Later partially addressed by enhanced Brake Force programming, under certain conditions.....

Rgds, D.

 

[Jstpssng]

Well said.

I get that it's hard for someone to relate to these issues, if they've never lived in serious snow country. Many a time I've used the rock/stop/roll back/repeat cycle to unstick a vehicle in snow, where the owner had already given up.

Gen I GM truck ABS was universally hated by anybody that owned them here - stopping distance in Winter was ridiculous.

When you lock up all 4 w/o ABS on deep snow or gravel, you are pushing snow/gravel ahead of all 4 wheels, dissipating a lot of energy. The vehicle continues in the same direction as when you hit the brake (great, so long as that is what you want to do) but may rotate about it's centre axis <- That's what freaks a lot of people out, and may lead to blocking an adjacent lane..... not what you want to do much of the time, but if you are on a deserted road and need to stop FAST, it can make the difference between crashing, or not.

Rgds, D.

You also learn to back off the brake when it starts to kick sideways. I've always held that the main purpose of ABS is to compensate for people who can't or won't learn proper driving techniques. Then again like so many guys when in HS, I always thought that it was fun to go into an empty parking lot and mess around in the snow; you learn a lot when your biggest concern is not going home to tell your father that you T-boned the car into a parking lot utility pole.

Systems are less-intrusive now, and new drivers got used to ABS (as they didn't know anything else), but one of the original human-factor problems with ABS was that drivers would back off the pedal once they got force-feedback from the system.

Later partially addressed by enhanced Brake Force programming, under certain conditions.....

Rgds, D.

I pulled the ABS fuses on my '98 GMC after bouncing through a washout at faster mph because the truck wouldn't stop. It cost me about $350 in front end damage.
On another occasion I came up a pitch on an unplowed road, only to find that it dropped off on the other side. I braced myself against the steering wheel and braked so hard that that I literally threw my back out while trying to stop the above mentioned F150, while rolling down the other side of the hill.
Then I had to turn around and go back again... after chaining up so that I could climb the hill.

 

[Soundguy]

I would like the ABS a lot more if it disabled itself below a certain speed. It's especially annoying when you're stuck in snow, and are slowly rocking the vehicle back and forth packing the snow. Often you will get a little movement working only to have the truck decide not to stop when you apply the brake; and you find yourself immobilized again.
I did an unscientific trial stopping from 45mph on a snow covered road in my 1998 GMC with ABS disabled, and with my (then new) 2005 F150.
First with the GMC, using the brakes judiciously to cut down through the 6" of snow; then I tried the F150 and just stomped on the brakes the way you are supposed to. The F150 travelled 50% farther before stopping. I've also seen times when one side of the truck was on snow and the other on gravel; you may as well not have brakes. Sometimes if you are in 4WD and can't stop it helps to slowly apply the parking brake; with all 4 wheels braking again it's amazing how quickly you stop. You also are at more risk of losing control though.

speaking of parking bakes, anyone remember those traction control systems? Any makers still use them? I drive an ancient 99 F350 DR. So no new tech stuff. I do like having the extra rubber on the road however..

 

[3930dave]

speaking of parking bakes, anyone remember those traction control systems? Any makers still use them? I drive an ancient 99 F350 DR. So no new tech stuff. I do like having the extra rubber on the road however..

Applying Parking brakes sometimes helps transfer power side to side in differentials..... just had to remember to take it off once unstuck :laughing: I do remember that era of traction control.

Some modern brake systems will apply individual brakes selectively, in terms of stability or traction control.

Rgds, D.

 

[Liquidsilver]

Since there must be lots of redundant systems ready to stop self-driving the car quickly... or even just the more common auto braking car...

am I the ONLY one surprised that some clever hacker hasn't developed a simple device to make the Mercedes slam on its brakes, marooning the driver in place to be robbed, or to force a rear end of the vehicle from a vehicle behind? A friend of mine was playing with his Mazda, amused that it wouldn't run into the bushes at the end of his driveway. It seems to me that either a sonic or electronic ghost bush could stop it as well. (??)

Even with the cellphone-distracted morons we share the road with... I still think I have more trust in the human. That could be misplaced trust, eh?

 

[vvanders]

Since there must be lots of redundant systems ready to stop self-driving the car quickly... or even just the more common auto braking car...

am I the ONLY one surprised that some clever hacker hasn't developed a simple device to make the Mercedes slam on its brakes, marooning the driver in place to be robbed, or to force a rear end of the vehicle from a vehicle behind? A friend of mine was playing with his Mazda, amused that it wouldn't run into the bushes at the end of his driveway. It seems to me that either a sonic or electronic ghost bush could stop it as well. (??)

Even with the cellphone-distracted morons we share the road with... I still think I have more trust in the human. That could be misplaced trust, eh?

What you're talking about is basically a slightly advanced radar jammer which is super-illegal. FCC/LE finds out your running one of those and they'll come down on you like a ton of bricks with a life-changing fine.

Also with TACC/AP enabled throttle still overrides the radar.

 

[3930dave]

Since there must be lots of redundant systems ready to stop self-driving the car quickly... or even just the more common auto braking car...

am I the ONLY one surprised that some clever hacker hasn't developed a simple device to make the Mercedes slam on its brakes, marooning the driver in place to be robbed, or to force a rear end of the vehicle from a vehicle behind? A friend of mine was playing with his Mazda, amused that it wouldn't run into the bushes at the end of his driveway. It seems to me that either a sonic or electronic ghost bush could stop it as well. (??)

Even with the cellphone-distracted morons we share the road with... I still think I have more trust in the human. That could be misplaced trust, eh?

Easy enough to do, for people with the right skills..... MB was the first one to put it into a production vehicle, but plenty of other manufacturers use CAN on board today.

The Jeep Hackers Are Back to Prove Car Hacking Can Get Much Worse | WIRED

Even with some attention being paid to vehicle "digital" securty, with more complexity and enhanced connectivity comes increased risks - at well below the Driverless Car level.

Rgds, D.

 

[vvanders]

Easy enough to do, for people with the right skills..... MB was the first one to put it into a production vehicle, but plenty of other manufacturers use CAN on board today.

The Jeep Hackers Are Back to Prove Car Hacking Can Get Much Worse | WIRED

Even with some attention being paid to vehicle "digital" securty, with more complexity and enhanced connectivity comes increased risks - at well below the Driverless Car level.

Rgds, D.

The way FCA built + handled that was a complete joke. At a bare minimum you need separate networks, ideally with a different protocol mechanism and a whitelist of anything that goes between them. Additionally not having any OTA mechanism but supporting complex software is a recipe for disaster.

If you want to know who's serious about software security look for who offers bug bounties and pays out if vulnerabilities are found. People will find those holes and more than likely get paid for them, ideally it's the manufacturer paying and not a blackhat group that's using them for less than legal ends.

 

[Soundguy]

I do remember the vehicle hacking issues.

 

[Liquidsilver]

What you're talking about is basically a slightly advanced radar jammer which is super-illegal. FCC/LE finds out your running one of those and they'll come down on you like a ton of bricks with a life-changing fine.

Also with TACC/AP enabled throttle still overrides the radar.

I understand, but today's carjackers don't seem to deterred by authorities or fines. I have a nephew that builds lasers in his basement that would be absolutely illegal to use. (With my FAA background I just tell him to never let it point near an aircraft. That's a federal felony and they don't play around with jail time.) The fact that it's illegal doesn't slow him down a bit. But I'm not talking about car hackers, I'm talking simple ways of confusing the existing outboard sensors of the car... or even simple situations that could confound the vehicle and cause a fatal outcome.

So, my friend's Mazda won't hit the bush, but if a tornado were approaching and he needs to run over the bush to escape, will the car eventually let him? Or if my wife is about to be pulled from her car by an angry mob of demonstrators blocking her escape, will the car let her move forward push them out of the way? Just wondering.

I'm just surprised it hasn't been an issue, that's all.

 

[3930dave]

I understand, but today's carjackers don't seem to deterred by authorities or fines. I have a nephew that builds lasers in his basement that would be absolutely illegal to use. (With my FAA background I just tell him to never let it point near an aircraft. That's a federal felony and they don't play around with jail time.) The fact that it's illegal doesn't slow him down a bit. But I'm not talking about car hackers, I'm talking simple ways of confusing the existing outboard sensors of the car... or even simple situations that could confound the vehicle and cause a fatal outcome.

So, my friend's Mazda won't hit the bush, but if a tornado were approaching and he needs to run over the bush to escape, will the car eventually let him? Or if my wife is about to be pulled from her car by an angry mob of demonstrators blocking her escape, will the car let her move forward push them out of the way? Just wondering.

I'm just surprised it hasn't been an issue, that's all.

Years ago, I remember the A320 debuting at the Paris airshow. IIRC, there was a group of VIPs onboard. The pilot made a landing approach and went to execute a planned go-around. The computer decided, "No, based on control inputs, we will land now", with the plane ending up on what was left on its wheels, some serious distance into the forest at the end of the runway.

And, that was a commercial airliner. Programming algorithms and thresholds....... not easy to get right, for every scenario, every time.

For business reasons, I was reading some Ford material about their vehicle's Lane Keeping feature. Setting dependent, it will try and nudge you back into your lane. Over many years and miles, I've had to make a few emergency lane changes - it would take quite a bit a bit of personal empty-road testing before I'd leave that feature fully switched On - the last thing I need when split-seconds count is to be wrestling with a counter-steering wheel...

Rgds, D.

 

[bcp]

Years ago, I remember the A320 debuting at the Paris airshow. IIRC, there was a group of VIPs onboard. The pilot made a landing approach and went to execute a planned go-around. The computer decided, "No, based on control inputs, we will land now", with the plane ending up on what was left on its wheels, some serious distance into the forest at the end of the runway.

Bruce

 

[rd_macgregor]

On top of known and potential threats to drivers and bystanders, I just ran across yet another issue that I hadn't thought of before:
Autonomous Vehicles Might Drive Cities to Financial Ruin | WIRED