Why do modern cars have wing mirrors?
Discussion
maffski said:
shakotan said:
If you move your head around, the area of reflected image changes so you can see a larger propertion of the road behind you. This wouldn't happen with a camera/screen arrangement. Depth perception also doesn't work as well on a projected image in comparison to a reflected image.
Its akin to looking out of a window compared to looking at the image of a camera looking out of the same window.
A wide angle lens would take care of that - and probably do a better job reducing blind spots.Its akin to looking out of a window compared to looking at the image of a camera looking out of the same window.
And depth perception would just be repurposing parking sensors, people seem fine with reversing cameras and coloured bars.
Al U said:
Until the cost of the cameras, screens and other necessary hardware becomes cheaper than a conventional mirror assembly then they will not be there on mainstream cars. Even on high cost low volume cars, budgets still have to be met and unless there is a chief engineer or executive that decides they wan't cameras/screens instead of mirrors (such as the XL1 which was a demonstration of a very low drag vehicle) then it won't happen.
The only other way I can see it happening is if a slightly premium brand like Audi for example decide one day that on all of their models they will have cameras/screens instead of mirrors, then BMW/Merc will probably follow suit to make sure their car matches the competition in terms of technological advances.
But before we debate costs, we'd have to know what the comparable costs of the R&D on a wing mirror design. I imagine that its not as insignificant as people believe...The only other way I can see it happening is if a slightly premium brand like Audi for example decide one day that on all of their models they will have cameras/screens instead of mirrors, then BMW/Merc will probably follow suit to make sure their car matches the competition in terms of technological advances.
ging84 said:
who told you they were terrible for aero?
Agree with this in principle of modern cars.My old Nissan from 1991 has clear and audible mirror noise/air rumble.
While my Renault from 2010 does not, cant here the slightest whisper from the mirrors.
Reading some aerodynamic papers from the automative engineering world, door mirrors are even incorporated into the aerodynamic profile of a car and can essentially aid the boundary layer down the flanks of the car. Theyre a key component in wind tunnel testing it would seem.
So people can fold them in and not worry about whats around them...?
I suppose you could do away with them, but a mirror is such a cheap and easy solution. And you can always look around you without having to have a source of power (electrical).
Also, I should like to point out that humans, for many 10's of thousands of years, have had the ability to move their head side to side, and even swivel their body a bit to check their blind spots.
I suppose you could do away with them, but a mirror is such a cheap and easy solution. And you can always look around you without having to have a source of power (electrical).
Also, I should like to point out that humans, for many 10's of thousands of years, have had the ability to move their head side to side, and even swivel their body a bit to check their blind spots.
I was responsible for the detail design of door mirrors for a well known high cost low volume vehicle. Trust me on this, the cost of a mirror arm, mirror scalp (even in carbon) and head is much lower than that of a camera/screen system. With a camera and screen system on top of the higher price of the component parts in the system you also have the cost of the design and development of the electrical systems that run it, even when you take into account the saving of the removal of the folding mirror mechanism (which is usually off the shelf and incorporated into the design) it would still be higher.
On top of this, another thing to think about is of the two systems which is more likely to fail? And I am talking without intervention such as being hit etc. A camera, screen and an electrical system or a piece of mirror? Although a failure of this type could be argued to not be safety critical it is one that would cause significant annoyance to the customer. At the moment if a car breaks your mirror 90% of the population are able to go and buy a new it of glass and fit it, much less would be capable of repairing the camera/screen.
I do think they may become mainstream eventually but I think we are still a long way from that, the current solution which is cheaper does not have enough downsides to be changed. Someone said that they don't have much aero impact but on high speed vehicles they really spoil the flow at the side of the vehicle and the shape of them is optimised to minimise this. I think the main driver for them becoming mainstream is if there is such a crack down on emissions targets that vehicle engineers will be forced down more drastic drag reduction strategies such as removal of mirrors.
On top of this, another thing to think about is of the two systems which is more likely to fail? And I am talking without intervention such as being hit etc. A camera, screen and an electrical system or a piece of mirror? Although a failure of this type could be argued to not be safety critical it is one that would cause significant annoyance to the customer. At the moment if a car breaks your mirror 90% of the population are able to go and buy a new it of glass and fit it, much less would be capable of repairing the camera/screen.
I do think they may become mainstream eventually but I think we are still a long way from that, the current solution which is cheaper does not have enough downsides to be changed. Someone said that they don't have much aero impact but on high speed vehicles they really spoil the flow at the side of the vehicle and the shape of them is optimised to minimise this. I think the main driver for them becoming mainstream is if there is such a crack down on emissions targets that vehicle engineers will be forced down more drastic drag reduction strategies such as removal of mirrors.
Cameras and screens will use electricity and will never be as inherently reliable as a sheet of glass with a metallic coating on one side.
It's just another thing to cost a phenominal amout of money to fix when it inevitably fails. It's also not like a heated steering wheel stopping working - you can't really drive the car safely on today's roads without effective rear vision.
Also, anyone who has a reversing camera will know how much a small spec of dirt on the camera lense obscures your view.
I would actively avoid cars without proper door mirrors.
It's just another thing to cost a phenominal amout of money to fix when it inevitably fails. It's also not like a heated steering wheel stopping working - you can't really drive the car safely on today's roads without effective rear vision.
Also, anyone who has a reversing camera will know how much a small spec of dirt on the camera lense obscures your view.
I would actively avoid cars without proper door mirrors.
The current mirror technology works really well even when the cars ignition is off, so when you open the drivers door you can easily see behind you before you swing the door open and step out into the path of a truck or cyclist etc. Using a camera system would mean the image wouldn't be available...
I think the way we drive cars is importan in this. we mostly glance in the side mirror without even thinking about it. If some way can be found of projecting a virtual image into the same space the mirror occupies, this would be a good idea. But that's all very expensive, as apposed to the mirror which works and is cheap.
I think the way we drive cars is importan in this. we mostly glance in the side mirror without even thinking about it. If some way can be found of projecting a virtual image into the same space the mirror occupies, this would be a good idea. But that's all very expensive, as apposed to the mirror which works and is cheap.
I've got cameras on each side of my new lorry, they're absolute rubbish. Utterly pointless at night as they ruin your night vision and useless in anything other than optimum conditions during the day. Sun glare/surface spray makes it impossible to see anything, this is with a nice quality big lcd screen. Cameras are no competition for a couple of pieces of glass yet.
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