Volvo Brake test goes wrong

[crockers]

OOppppsssss

Volvo safety demonstration fail - Autoblog UK

 

[Stratman]

I do believe Mercedes did the same thing when demonstrating the S-Class automatic braking system in fog. The problem was the driver forgot to activate it

 

[KillerHERTZ]

The problem was the driver forgot to activate it

The driver wasnt told that it had to be switched on to work

 

[davidjpowell]

I do believe Mercedes did the same thing when demonstrating the S-Class automatic braking system in fog. The problem was the driver forgot to activate it

Mercedes did it twice. First time the driver forgot to switch it on, the second (spare car) was confused by the steel in the building and also crashed!

 

[corned]

Mercedes did it twice. First time the driver forgot to switch it on, the second (spare car) was confused by the steel in the building and also crashed!

An expensive day out!

 

[Diesel Benz]

An expensive day out!

If I remember right, MB used an S-class as a stationary object instead of a truck like Volvo did. I guess an S-class costs less for MB than a truck like the one Volvo was using.

Could be that Volvo hired these press demo experts from MB.

 

[KillerHERTZ]

Here's the video, it was actually a Televison presenter:

[YOUTUBE]f0yX36dlcyA[/YOUTUBE]

 

[wemorgan]

I was once organising a roll over test for a tractor. On the way to the test site the tractor partially fell through a series of concrete paving slabs. Oops.

 

[KillerHERTZ]

Surely its impossible for a tractor to roll over?

 

[wemorgan]

Surely its impossible for a tractor to roll over?

It's quite difficult. Statically they can hold near gravity deifying angles, but dynamically the game changes. Consider a farmer cutting grass on a steep field. With a long heavy mass hanging off the rear, if he turns a corner too sharply the cutter acts as a pendulum and swings him over, or if he goes over a bump too quickly the softly sprung tractor bounces too high and again rolls over. The obvious conclusion to the tests is that it's better to wear a lap belt than not.

 

[crockers]

It's quite difficult. Statically they can hold near gravity deifying angles, but dynamically the game changes. Consider a farmer cutting grass on a steep field. With a long heavy mass hanging off the rear, if he turns a corner too sharply the cutter acts as a pendulum and swings him over, or if he goes over a bump too quickly the softly sprung tractor bounces too high and again rolls over. The obvious conclusion to the tests is that it's better to wear a lap belt than not.

Surely the conclusion is - its better to get an employee to cut your field if the slope is steep and go have a cup of tea..

 

[prprandall51]

MB's Follow-to-Stop Distonic system cannot detect stationary objects (or, rather, ignores them) - so, as far as I can see, the Journalists' test was always destined to fail from the start. I am amazed that MB didn't immediately disown it as a farce.

I think the Volvo system demonstration is somewhat different (don't Honda have a similar technology?) in that is is a "Don't hit the stationary vehicle in front" system working up to approx 20mph? In this video it would appear that the rear of the truck offered little in the way of surface to bounce the detectors' signals back to the car.

 

[KillerHERTZ]

It cant ignore them otherwise they wouldnt have done the test. The test being that it was meant to show that a car hidden in fog would stop the car.

 

[prprandall51]

That's what I cannot understand. What technology did they think they were demonstrating? I think the video shows that the system can and does ignore stationary objects - at least to the extent that it is incapable of stopping before hitting them. I am not aware of an Adaptive Cruise Control system that does claim to stop for stationary objects - that would require a very long range radar and it would inevitably be constantly triggered by false positives.

 

[Diesel Benz]

MB's Follow-to-Stop Distonic system cannot detect stationary objects (or, rather, ignores them) - so, as far as I can see, the Journalists' test was always destined to fail from the start. I am amazed that MB didn't immediately disown it as a farce.

I think the Volvo system demonstration is somewhat different (don't Honda have a similar technology?) in that is is a "Don't hit the stationary vehicle in front" system working up to approx 20mph? In this video it would appear that the rear of the truck offered little in the way of surface to bounce the detectors' signals back to the car.

It cant ignore them otherwise they wouldnt have done the test. The test being that it was meant to show that a car hidden in fog would stop the car.

I guess both comments are correct in some aspects if not all. We should note that there are two implementations on released 221 cars. Earlier ones (like mine) do not brake autonomously at all except when cruise is active and the car is following one ahead. My understanding is that in this mode the car ignores stationary objects. Of there is a bicycle, the car tends to slow down even if the bicycle is not exactly blocking the lane ahead but if there is a stationary object at the same distance, that would not affect CC.

The later models (already well before face lift) also brake autonomously and this should happen even if the object ahead is stationary if it is blocking the lane. Mine only gives a warning beep. The new ones give a beep first and start braking a bit later if necessary (no intention to be always able to stop the car before the object but to at least minimise consequences).

Honestly I have not taken the car to any extremes, the most obvious thing that can be observed (when CC is not active) is a warning at relatively close distance (a few tens of metres) if a stationary object appears ahead, typically when the road actually turns just before the object but the car does not know that if the driver has not turned steering yet. I assume the later models would even apply brakes if this object comes too close.

My understanding is that the W221 at the demonstration was supposed to behave like current (later) W221 models but because of the performance issues, this autonomous braking feature was disabled from early cars and reintroduced later after improvements. Actually is anyone aware of a possibility to activate this feature for older models, through a later SW and version coding?