Patent ID: 8768559

Claim:
A method for guiding an automatically guided vehicle along a floor, comprising: a. providing an automatically guided vehicle, said automatically guided vehicle including, i. a sensor for sensing a line on said floor, and ii. a steering mechanism that uses information from said sensor to steer said automatically guided vehicle along said line on said floor; b. providing a plurality of line projectors, wherein each of said line projectors includes, i. a laser emitting a beam, ii. a diverging lens in the path of said beam, wherein said diverging lens creates a diverging fan of coherent light from said laser, c. wherein at least one of said line projectors further includes, i. a mask positioned to occlude at least a portion of said diverging fan, ii. said diverging fan having a first diverging boundary, iii. said mask having a first side proximate said first diverging boundary, iv. said first side of said mask being movable with respect to said lens; d. mounting said plurality of line projectors so that said diverging fan of each of said line projectors is orientated toward said floor; e. switching on at least some of said plurality of line projectors including said at least one line projector having said movable mask, so that each of said diverging fan produces a projected line on said floor, with said projected lines joining to form a defined path; f. moving said first side of said mask within said at least one of said line projectors with respect to said diverging lens in said at least one of said line projectors, thereby altering a length of said projected line produced by said at least one line projector and altering a location of a first line boundary for said projected line produced by said at least one line projector; g. locating said automatically guided vehicle on said defined path; and h. activating said automatically guided vehicle so that said automatically guided vehicle travels along said defined path.