Reply to: First Tesla Autopilot Death

[NigelJK]

I'd love to disagree, but TBH I've never used the hand brake "flap" on my Jag, as it seems to know when to apply the handbrake.

(I _presume_ - Does putting an automatic vehicle in park automatically apply the hand brake?!)

I leave the XJ HB on auto. There's an indicator on the dash to tell you when it's applied, which seems to be when the ignition is off and key pulled out for normal stops.
All of my previous Jags have locked the Diff in 'P'. Not sure what the XJ now does but it feels the same (if you are on an incline you have a small roll in that direction).

Wasn't aware of the emergency HB, I'll check the technical manual, but did one one occasion in a Merc have to apply the manual HB in a hurry when the main brakes failed approaching traffic lights. I can tell you that added another stain to the drivers seat and there was no chance of an HB turn, this was an ancient 280SE so maybe the HB wasn't that good to start.

Just for reference the Bembo braked Jags have a separate set of pads for the HB which get actuated differently.

Apologies for the : post must need a Top Gear fix or something.

[WTFH]

Oh what a bad design

Oh Suity... have you ever worked for Tesla?

[vetran]

No, my impression from that thread is that 2 seconds is the wait time before the handbrake even kicks in!

Oh what a bad design

We need an EMERGENCY brake, lets wait 2 seconds for it. Must be one of Zeity's favorite ex customers.


Not Pull & twist through notches to override the safety? That would be better.

[OwlHoot]

2 seconds at 60 mph is about right.

0.67seconds=18m thinking distance

56m= stopping distance is 3.0555' * 18m.

3.0555' * 0.67 = 2.0472 seonds.

No, my impression from that thread is that 2 seconds is the wait time before the handbrake even kicks in!

So you have:

* 0.67 seconds to twig that sharp braking is in order, and lift the handbrake flap or hold the button down

* 2 seconds when nothing whatever happens, besides the fact that you're rapidly approaching the overturned lorry or pile up ahead!

* The handbrake is suddenly applied, and the usual stopping time applies

and that doesn't count the possible extra time flooring the normal brake and finding it doesn't work, which may well be the reason you're using the handbrake in the first place

[portseven]

BTW if anyone is in mind to order one, use this referral code feel free, £750 off your car

http://ts.la/mark8506

[vetran]

Oh, posters on this PistonHead thread said that holding the flap/button for two seconds fully engages the hand brake and brings the car to a stop ASAP in the direction it was pointing when the breaking started.

Apparently the idea is for a backup breaking system if the main brakes fail, or for emergency use by a passenger if the driver is incapacitated somehow

(Two seconds sounds like an awfully long time to wait if the vehicle is at high speed, although perhaps it starts kicking in more gently earlier and builds up.)

Speed, speed limits and stopping distances - Brake the road safety charity

The distances above are based on a reaction time of 0.67 seconds, which assumes the driver is alert, concentrating and not impaired. Driving when tired, distracted or impaired significantly increases reaction times, so the thinking distances above should be regarded as minimums.

2 seconds at 60 mph is about right.

0.67seconds=18m thinking distance

56m= stopping distance is 3.0555' * 18m.

3.0555' * 0.67 = 2.0472 seonds.

[vetran]

Maybe, but what happens if they park in a 1 in 2 hill to enjoy the view and want to sit in the car munching a sandwich or something?

Actuallty, the more I think about these flap hand brakes, the less I like them.

It would be interesting to know when it is (a) Safe and actually desirable to use them, if ever, and (b) When is it dangerous to use them!

I mean does one _ever_ have to use them, or are they there only for show and reassurance, or some bizarre situation one would never face in practice.

They put the handbrake on manually by pressing the button.

I'm adding functionality not removing it. If you get out of the car the handbrake goes on. If you want to turn it on or off you press the illuminated button.

[OwlHoot]

Oh, posters on this PistonHead thread said that holding the flap/button for two seconds fully engages the hand brake and brings the car to a stop ASAP in the direction it was pointing when the breaking started.

Apparently the idea is for a backup breaking system if the main brakes fail, or for emergency use by a passenger if the driver is incapacitated somehow

(Two seconds sounds like an awfully long time to wait if the vehicle is at high speed, although perhaps it starts kicking in more gently earlier and builds up.)

[MrMarkyMark]

You think you'd have an audience for your smut video? Not exactly amputee midget p0rn is it?

With a few tweaks, for sure, it has potential.

Website being worked on in Chennai and Crowdstarter page going up, as we speak.

[OwlHoot]

OK, to partially or mostly answer my own questions above. this article appears to suggest that an flap/button (electronic) handbrake cannot be engaged while the vehicle is in motion, even if you pull the flap (or, depending on the make, press the button):

2016-01-04 What is an electronic handbrake?

So it's reassuring to know that I won't be doing any vehicular pirouettes on the motorway by accidently engaging while at high speed!

(Well, reassuring only in so far as one trusts electronics and software, unless the handbrake disk also has a mechanical governor to prevent it engaging while in motion ..)

[LondonManc]

So, you're getting it on on the front and as well as trying to film it on an IPhone, you have another, in your hand, trying to control the vehicles brake?

Call me a Luddite, but I can't see that working

You think you'd have an audience for your smut video? Not exactly amputee midget p0rn is it?

[MrMarkyMark]

You're all so prehistoric. The car will be controlled by an app, surely.

So, you're getting it on on the front and as well as trying to film it on an IPhone, you have another, in your hand, trying to control the vehicles brake?

Call me a Luddite, but I can't see that working

[LondonManc]

You're all so prehistoric. The car will be controlled by an app, surely.

[VectraMan]

Autos lock up the gearbox when you select park so that's kind of the same as the handbrake.

I don't know the 'touching the flap' reference, but I drove my Dad's Espace and had a nightmare time with the e-brake. I was trying to balance the clutch and throttle and release the brake as you would with a normal handbrake with the added complication that it was a LHD car. He told me afterwards that you just drive off and it automatically released.

[MrMarkyMark]

No, I understood vetran's idea of a seat weight sensor was that the handbrake would be applied only when there was no human sitting on the seat.

My point was that it might need to be applied when people stayed in the car while it was parked, especially if it was on a slope. Also, what about a toddler left in the seat, or a dog jumping about, or a large potted plant bought from a garden centre?

For reference, here is part of his post, on the previous page:

Indeed.

My angle on your point was slightly different, two people enjoying the view, or something, may not provide constant supply of weight on the seats.
It would depend on what they were up to

Therefore Vetrans system could fail.