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Line follower bot location

I am working on a line follower bot that travels on a map consist of nodes But the confusion is how to let the bot know that at which node he is standing, in other words, what approach should be taken to feed the map to the bot so that it knows every node of the map and also know which node he is at present time.

I searched over the internet a lot but that doesn't seem to be worthy.

Solution

  • Line followers usually do not have any map. Instead they usually have a pair of front sensors pointing downwards (usually IR photo diodes and LEDs) which detects line crossing from left and right side and the robot just turns toward the line.

    line follower

    Its usually done by controlling the speed of left and right motor with brightness of detected light from right and left sensor (usually without any MCU or CPU, the analog version uses just 2 comparators and power amplifier to drive motors which results in much more smooth movement instead of the zig-zag like pattern)

    Better bots have also in-build algorithms to search for line if it has gaps (that usually requires CPU or MCU).

    If you insist on having map then you need interface to copy it in (ISP for example) however to detect where the robot is needs to actually follow the line remembering the trajectory and compare it against map until detected trajectory corresponds to only one location and orientation in the map however you will just end up with more complex and less reliable robot that has more or less the same or worse properties than simple line follower.

    Another option is to use positioning system so either there is a build in positioning system on the maze or map (can be markers or transponders or whatever) or you place your robot to predetermined position and orientation and hit reset button Or you use accelerometers and gyros to integrate the position over time however as mentioned I see no benefit in any of this for line follower. This kind of stuff is better for unknown maze solver robots (they usually uses the SONAR or also IR photodiode+LED however oriented forward and to sides instead of downwards).