LINE FOLLOWER VEHICLE WITH SCANNING HEAD

An automatically guided vehicle wherein a guide line is positioned in a predetermined path on the floor and the vehicle has a sensing head positioned over the guide line to detect the position of the guide line with respect to the vehicle and to generate an error signal representative of the vehicle position with respect to the guide line. A control circuit is also provided on the vehicle to steer the vehicle responsive to the error signal generated by the sensing head. The sensing head includes a scanning head to scan across the guide line and to generate an output signal representative of the detected light values at discreet positions of the scan. The control circuit is adapted to steer the vehicle along the right edge, left edge or center of the guide line and is responsive to control codes positioned on the floor adjacent the guide line. The control circuit preferably includes a microprocessor which is programmed to compensate the output signals for any nonlinearity of the light source, variations in scan distance from the scanning head to the floor surface and for any variations in the port size of the light-detecting device on the vehicle. The microprocessor includes a data storage bank for storing a data table relating to the position of the vehicle with respect to the guide line and has the ability to compare the data table for one scan with the data table of subsequent scans to determine the presence of a valid guide line and to update the position of the guide line with respect to the vehicle.