# How to program a tracking line sensor on Labview?

In the autonomus period the only thing bots may do is tracking line and hanging ubertubes. Line tracking sensor would help much. Can you please help me programming our bot for the autonomous period ?

Kubilay Elmaci
Team 2905

Try looking at and understanding the given autonomous vi (if you’re using labview).

The way I’d do it with skid steer is to drive both motors full power if the middle sensor sees the line, and turn in the corresponding direction if one of the other sensors sees it. If all three see the line, you’re at the T, so stop (or you’re at the Y… I’d say use an encoder to give the robot an idea of where you should be… ie if the robot has gone for 8 seconds, it’s probably at the Y and if it’s 10 seconds it’s probably at the T.)

I actually don’t see an advantage of using 3 sensors over 2,… although I guess lining up with the post could be easier.

Check the following Post:

Then Post:

:]

Basically you want to make a truth table for when the sensors are on the line. If the middle sensor is on it would be FTF, assuming you have all 3 sensors on the robot. if you make a Boolean array of the sensors, and convert it to binary (use the “Boolean array to #” from the Boolean pallet). it will take all the segments of the array and make then a 1 or a 0 in a binary number, so FTF become 010. 010 in binary is 2 in our base 10 system. Google how to convert binary if you don’t know. then create a truth table for all the different numbers (0 - 7), and set the motor outputs depending on what it sees.

By the way, you may need to reverse data from the sensors (negate) depending which wire you used from the sensors, true on black or true on white.

Hope it helps. good luck from team 2865.