Distance Measuring device

I've heard about research into car collision warning systems but nobody seems to have made a commercial device. I would think that radar would be the technology of choice for these units.

Accuracy of ultrasonics types are affected by temperature and humidity. There are parking sensors available but these only work at very short distances like 6 feet or so.

Lasers might be a viable technology but these would have to scan left to right if you want to be sure of detecting vehicles from as wide an angle as possible. Radar can be configured to do that easily.

http://www.wipo.int/pctdb/en/wo.jsp?wo=2002045998

http://ieeexplore.ieee.org/Xplore/login.jsp?url=/iel5/11162/35826/01700379.pdf

Some years ago there was a wonderful exhibit on top of one of the roundabouts on the A130 north of Chelmsford - a brand-new Renault car all battered and mangled. The car arrived on top of the roundabout principally as a result of the driver producing more speed than the road condtions dictated were safe, in fog. (S)He was probably very popular with his/her insurance company.

So any fog sensor system would do well to detect all of the following obstructions in the road as well:

• cyclists
• pedestrians
• stray dogs
• stray farmyard animals
• stray wild animals
• fallen tree branches
• fallen road signs
• parked vehicles
• vehicles stationary as a consequence of earlier accidents
• level crossing gates
• farmyard gates
• roundabouts and their signs
• stuff that falls off other vehicles
• scraps of tyre shed from other vehicles
• etc., etc.

So far, no-one has invented a sensor system that will do all this, and the Mk.1 eyeball and an intelligent, trained brain is the best system around.

I've been watching "Air Crash Investigations" on the National Geographic channel and I was shocked to learn that, in cases where the plane crashed into a mountain, hill, or similar, the computer voice that says "warning terrain" usually sounded off only a few seconds before impact. The pilots never had chance even when they immediately react to the warning.

So if my car has a collision warning system, would it be able to warn me if:

• a kid is running after his ball and is about to run across the road. Ergo, give me time to react.
• the oncoming car is weaving left and right and is probably driven by a drunk and warns me to get out of the way.

Johan I noted that you are in South Africa as well. Do you know if there are any commercial geyser control mechanisms presently available in the market that would allow household geyesers to keep a constant current flow going, rather than the spiking that occurs when load shedding is applied. I am based in Somerset West and would appreciate comment from people in the know as we are looking at the in-line application of our technology with that of geyser design. Thanks Leon (072 926 0487)

Sorry, no I do not know of such a thing.

Ripple control is being done to switch geysers off during peak demand periods, but I assume that you are familiar with this.

Yes, Unfortunately I am. Ek is eintlik opsoek na iets wat ons kan omskep in 'n energie pak vir 'n geyser. Ons het alreeds die RD gedoen op battery tegnologie (gelyktydige lading en ontlading). Our problem to a great degree is that you need to bring a commercial solution to the table and there are simply not enough players in our market looking at the potentail power reduction within geysers.

Most simple solution is to put in a lower rating element, this will reduce the current but will take longer to heat the water.