@ johnny 2007

[conny]

I regularly drive a friends Golf - it’s a diesel automatic with ACC. In heavy, stop start traffic, I set the CC to 30mph and just take my feet off everything! No brake, no accelerator. It will follow the car in front, accelerating and braking, even coming to a full stop and starting off again without me touching any pedals. It’s like being towed by an invisible tow rope!

Scares me that people actually put so much trust in these gadgets.
Nothing beats common sense driving and concentrating on what you, and others around you, are doing.
I wonder what the driving test pass rate would be if all you people who used/relied on these gizmos had to take a re-test using a basic model car without these aids fitted.

 

[Harry Bloomfield]

(So they do call it "radar")

Radar is microwave, so either term is correct.

 

[gas112]

just off to put my dinner in the radar oven

 

[RandomGrinch]

just off to put my dinner in the radar oven

 

[Dork Lard]

No, no NO. Radio waves, microwaves RADAR & Lidar are all the same fing innit guv'.

 

[Justin Passing]

Radar as most know is RAdio Detection And Ranging.
Ovens are irrelevant.
Microwave implies a particular wavelength/ frequency range, around one meter to one millimeter, corresponding to frequencies between 300 MHz and 300 GHz.
So no, radar isn't microwave, or vice versa.
LIDAR uses a laser, which is a different way of transmitting electromagnetic radiation, from an antenna . The frequency range is from UV through the visible into infrared. Err, 250 to 1200nm or so - I haven't checked current extremes. IR is good because it goes though fog etc.

The shorter the wavelength, the higher the resolution. IR Lidar is a few cm at 100m. I've seen "car radar" quoted as a few metres at I think 24Ghz or so.

 

[Justin Passing]

No, no NO. Radio waves, microwaves RADAR & Lidar are all the same fing innit guv'.

No, wrong.

 

[JohnD]

I don't think the dork knew what the "L" meant.

 

[JohnD]

....it will almost always be camera.

The sales brochure for your car of choice might call it radar, but it is most definitely NOT radar.

Utter nonsense from the dork.

 

[Justin Passing]

There's Detection and Ranging
there's a rather vague unit of wavelength
there are ovens
there are cameras
there are lasers
there are antennas.
Some can be combined, but don't mix em up, one doesn't imply another.
You could claim Lidar is a category of Radar.

Many cars have Detection and Ranging with none of the others.....

Maybe dork and gas think there's a small white oven behind the grille.

 

[Justin Passing]

I regularly drive a friends Golf - it’s a diesel automatic with ACC. In heavy, stop start traffic, I set the CC to 30mph and just take my feet off everything! No brake, no accelerator. It will follow the car in front, accelerating and braking, even coming to a full stop and starting off again without me touching any pedals. It’s like being towed by an invisible tow rope!

Is that the sort of thing which killed someone, a cyclist I think, because it didn't recognize the hazard? Cue court action.

 

[JohnD]

You could claim Lidar is a category of Radar.

Light may be a category of radiation, but few would accept that a laser is a radio device.

 

[bernardgreen]

Tesla driver dies in first fatal crash while using autopilot mode

The autopilot sensors on the Model S failed to distinguish a white tractor-trailer crossing the highway against a bright sky

www.theguardian.com

Against a bright spring sky, the car’s sensors system failed to distinguish a large white 18-wheel truck and trailer crossing the highway, Tesla said. The car attempted to drive full speed under the trailer, “with the bottom of the trailer impacting the windshield of the Model S”, Tesla said in a blogpost.

Which suggests the sensor system is ( was ) camera(s) and image processing. A radar sensor would have detected the truck.

 

[IT Minion]

Tesla driver dies in first fatal crash while using autopilot mode

The autopilot sensors on the Model S failed to distinguish a white tractor-trailer crossing the highway against a bright sky

www.theguardian.com

Against a bright spring sky, the car’s sensors system failed to distinguish a large white 18-wheel truck and trailer crossing the highway, Tesla said. The car attempted to drive full speed under the trailer, “with the bottom of the trailer impacting the windshield of the Model S”, Tesla said in a blogpost.

Which suggests the sensor system is ( was ) camera(s) and image processing. A radar sensor would have detected the truck.

Nope.

ACC radars can typically only manage a difference in speed of around 50mph. The radar has a set pulse rate and if you approach something faster than 50mph then there isn't time for the system to hit the object enough times to realise it is getting closer.

Back then Tesla were using Radar for ACC and backing it up with vision, both failed there. Tesla then switched to vision only but are apparently quietly going back to Radar + Vision.

 

[Mottie]

Is that the sort of thing which killed someone, a cyclist I think, because it didn't recognize the hazard? Cue court action.

Possibly, but at 5mph on the A13 in nose to tail traffic in rush hour with a cycle lane off the road, there’s not much chance of me doing it.