Hi,
I am Looking for a suggestion as a part of project in order to have accurate readings for an car which is moving on a fixed rail of 100m moves in a straight line. The barriers which can cause inaccuracy are dust, passing people (sometimes) and heat a lot of heat. around (50-100 deg. Celsius)
I was using Laser based sensors that may be accurate but gives 3-4 m error which is caused due to dust, heat, refraction of light which is not helpful. The sensor must not be on the car but on the other end where temperature and other factors are less affective.
Any suggestion on based of measuring the distance.0 so i could program the car based on speed, time of arrival, position, and some more requirement i would do further.
But it works only if i am getting proper readings.
Thank you for helping out a rookie.
As a thought i was thinking for limit switches for different ends on the rail but still its not possible as a matter of lot of dusts. and heavy slag on the rail not possible any suggestions would be grateful.
not an automobile, preferably its an industrial car. All instruments are covered in cooling agents. internal temperatures are less than 55 deg Celsius.
just a suggestion i was thinking rf frequency which have a range for 10 m each. each barrier crossed will have a different action to perform. in collaboration with lidar pre installed on the car. is it possible.
Can you tell us how often you need to measure the distance?
If the environment interferes with laser light enough to give you a 3-4m error, I'm not sure other technologies would fare much better. Can you increase the reflectiveness of the target on the car or the power for the laser, and reduce the sensitivity of the laser detector to reduce the relative noise? Maybe widen/focus the laser beam so it detects a larger/smaller area on the car?
Ultrasonics or a string potentiometer.
continuously 24x7
there is no picture, looking for a conceptual framework in how could i figuratively make it possible.
I suppose this devices exists everywhere.
On the highway, cars put some label on the front window/glass. Its some kind of antenna. It just reflects the incident signal from the monitoring station.
Maybe you could use somethiing like this.
This, and of course, lots of maths.
Also, Rf triangulation technique uses 3 receptors (2 stationary, 1 mobile) used to detect illegal radio station.
Sounds serious! Consider some redundancy in your project design.
Slag on the rail, coolants on the instruments suggests tombstones/pallets for rough machining. Again, look at ultrasonics or a string pot.
But what is the largest movement increment that will work for you? What is the maximum speed of the car? What is the acceleration/deceleration of the car?
I have used LASER Range Finders for target shooting out to 500 meters and also LASER Range Finders are popular in the game of golf. I am just not sure as to the dust you mentioned. I suggest you Google LASER Range Finder and find something hackable or one with an analog signal out or I2C. I am also not sure about the temp extremes.
Ron
Have you considered RADAR (Radio Detection And Ranging)? I recall working with RADAR technology a few years ago for collision avoidance systems in cars. It could be a great option for your project. Look into X-band MMICs (Monolithic Microwave Integrated Circuits) for building low-cost RADAR systems; they are commonly used in such applications and offer a reliable solution.
Does the "car" roll on rollers / wheels, slide, float on a liquid?
What moves the "car", on board motor, winch, jet engine?
link?
we are still in the dark. What drives the car forward, (so does it slip?) how fast does it accelerate, what is its highest velocity.
Can the position be measured with eg an optical track and a sensor on the car (yes i read this but..)
and to save designing a camel, why are you doing this?
Hi, @shivam_jangss
How is the movement of the car powered?
Can you put an encoder on the drive system if the system is at the end of the track and is cable driven?
Thanks.. Tom.. 
Then make a drawing of your concept and post it on the forum. And begin answering questions.