Line following algorithm

void followUntil(Robot &r, float distance, linefollowTerminator *terminator = & until_junction)

Follow a line until an event.

For example: 

followUntil(robot, 0.6, until_junction)   // follow the line to a junction 60cm away
followUntil(robot, 0.2, until_xjunction)  // follow the line to a cross-junction 20cm away
followUntil(robot, 0.2, until_bumper)     // follow the line until the bumper is pressed 20cm away
followUntil(robot, 0.2, NULL)             // follow the line for exactly 20cm
Parameters
  • r: A reference to a Robot
  • distance: The expected distance to drive, in meters, before the event occurs
  • terminator: A function taking (Robot&, const LineSensors::Reading&) that returns true when the robot should stop. If NULL, stop after distance has been travelled
Exceptions
  • LineLost: The target line couldn’t be found, recovery failed.
  • Timeout::Expired: It’s taking more than 25% longer than expected to reach the target

void turnAtJunction(Robot &r, int turns, bool goForward = true)

Turns the robot at a junction.

Parameters
  • r: A reference to a Robot
  • turns: The number of 90 degree turns to go through, counter-clockwise being positive.
  • goForward: false if the robot already has its wheelbase over the junction
Exceptions
  • LineLost: The target line couldn’t be found, recovery failed.