configuration- inductive loops - mixed traffic ( indian road conditions )- microcontrollers

Looks like you are considering making a large loop around the entire traffic flow. Could be a problem with unexpectedly high loads on some goods vehicles. Are you aiming at bulk traffic detection regardless of which, if any, lane it might appear in?

Appropriate sensor selection and design is always a factor in developing embedded systems. Have you considered the other technologies like ultra-sonic or microwave detection devices that are often used with the portable traffic light systems used at road-works. These might be simpler to install and be more effective in certain situations.

By making the sensor circuit an individual module of the traffic system you can use the same microcontroller part regardless of sensor type (it is after all only digital indication of traffic present/not present and perhaps an indication that the module is working properly.

Where do you plan to place the vertical components of the loops? If you put them on both sides of the road, you'll get a very non-specific indication of vehicle passage. If you put one in the center of the road, you'll still get non-specific info about vehicles going one way. If you put one between lanes, you're creating a traffic hazard and a source of outages when someone runs into it.

All things considered, it doesn't seem to be a very good idea.

There are other kinds of detectors -- optical, radar, etc.

Locally, there's been a problem of wiring rotting on the underground sensors. It seems to be a defective original installation, but is leading to failures nonetheless.

the problem with india roads is either a)they are really haphazard... and randomly located criss crossing.. or b)they are really in a bad state .. broken now for years.. mended again.. dug up.. broken.. mended.. and so uneven...

there cities like delhi and highways which have good roads... but these places dont need advanced traffic signals....

the places which need proper traffic signalling are places like Mumbai...where they keep diggin up the road...

now a days they found those interlocking tiles... which can be easily placed back after they have done their digging...

so it would really be better if you could use some buried sensor which can be simply be installed by taking out these tiles... placing the sensor loop.. and then puting the tiles back again...

Anurag

You show an overhead cable as part of the system. Is it possible to put the detection loop in a horizontal plane, but above the traffic (ie raised on poles)? If necessary, running non-conductive lines between the poles, to carry the active loop over a smaller area than that embraced by the poles? FWIW...

thanks to everybody for the valuable inputs. It certainly helped evaluate the possibilities.

Paul: As a start, bulk traffic measurement is what I am looking at. I would start with buried detectors with inductive signature based processing. searching for SME to assist in exploring alternative configuration at a later stage.

As far as lanes are concerned, there is no lane concept on indian roads just as there wasnt any concept of opinion in communist russia :P

Classification and parameter extraction, I intend to accomplish using DSP on a DSP core based chip. I would be able to modularize the system without creating tight coupling among the modules.

Will certainly add progress as it happens.

thanks ananth

Another thought on the detection system for this would use ordinary video cameras looking at the traffic from a nearby vantage point (on top of a post the other side of the junction perhaps). Fast DSP's or even Neral Net Chips could then be set up for image analysis to determine what you have in the chaotic traffic mix.