Automation of unmanned railway gates!

Thread Starter

hamza

Joined Feb 8, 2007
6
im starting work on a system in which the un-attended railway gates would get automated... the idea is, that wen the coming train would reach a certain point before the gate, some sensor would sense it, and the gate would shut down. and wen the train passes ahead, it would b detected by another sensor which would once again open the closed gate.. now can someone help me chose a better sensor?? which kind of sensors shoud i use?? ... i thought of using IR sensors, or LASER.. but someone told me that they both won't work properly.. im very new to this "automation" thing.. i need help in chosing a better sensor...

looking forward to ur advises. :)
hamza
 

mik3

Joined Feb 4, 2008
4,846
Is that a serious project for a company or just for demonstration?
 

steveb

Joined Jul 3, 2008
2,431
... i thought of using IR sensors, or LASER.. but someone told me that they both won't work properly..
Did they say why they wouldn't work? Also, how were you planning to use these two devices? The method is important.

A laser could have problems in fog or rain or snow conditions.

What kind of reliablity is needed? Is there a backup system in place in case this one fails?
 

KL7AJ

Joined Nov 4, 2008
2,208
im starting work on a system in which the un-attended railway gates would get automated... the idea is, that wen the coming train would reach a certain point before the gate, some sensor would sense it, and the gate would shut down. and wen the train passes ahead, it would b detected by another sensor which would once again open the closed gate.. now can someone help me chose a better sensor?? which kind of sensors shoud i use?? ... i thought of using IR sensors, or LASER.. but someone told me that they both won't work properly.. im very new to this "automation" thing.. i need help in chosing a better sensor...

looking forward to ur advises. :)
hamza

Well, before you go reinventing the wheel, see how it's been done for the past 100 years. Block signalling with supervisory rail currents has been EXTREMELY reliable.

#1 rule of electronics....."If it ain't broke, don't fix it."

(Unless you really want to!)

eric
 

Thread Starter

hamza

Joined Feb 8, 2007
6
im making my final year project at undergrad level.. this "gate closing and opening on detection" thing, is one part.. the other part is, that wen the train leaves a certain train station, an automated gsm based txt message will be sent to the next train station that the train has left and it will take a certain amount of time to reach.. (assuming that it would be travelling at a constant speed... i hvnt come up with anything to calculate the exact time actually) moreover, the idea is to run this whole system on solar power..

im in Pakistan and here we dnt hv any previous such systems installed in real life application.. this is jst goin to be a demonstration. so its very new..

yes fog and other weather conditions might be the problem that IR or LASER wont be suitable...

any other, more robust detector?? wot else can i use instead of IR... ??


thank u so much for rplying to my post :)
any other idea or advise to make this final year project would b of so much help aswell
 

Thread Starter

hamza

Joined Feb 8, 2007
6
thanks for that, but that article in wikipedia reffers to signalling systems... not crossings...

moreover, i asked wot kind of other sensing devicies i could use other than the IR...? can a distance sensor work? wot type?? or the sensor which the Line follower robot uses (i dnt know wot its called) ??? could someone help me on that plz.. wot type of sensors could i use!
 

RiJoRI

Joined Aug 15, 2007
536
There are sensors that get placed in or near driveways that detect the metal of an automobile passing by, and this signal is used to alert the homeowner that someone is coming. I would use a couple of these sensors spaced 20 or so feet (~7 meters) apart to detect the presence of a train. Use two sensors because sometimes the train may stop, with the area between cars near your sensor, and give a false "Train has passed" signal. The two signals should be combined and when a train is detected, the gate goes down.

There should be another set of sensors to raise the gate when the train has passed.

The logic is left as an exercise for the student.

--Rich
 

beenthere

Joined Apr 20, 2004
15,808
Please to note the Wikipedia article on RR grade crossings. Pay particular attention to the mention of the track circuit.

Of course, you might think of something more reliable and robust than the railroads have...
 
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