The present invention relates to a low-cost device for measuring the position and orientation of mobile robots indoors. The device comprises a transmitter located on a wall in the environment and a receiver on top of the robot. The transmitter is a laser pointer that acts as a rotating beacon, and the receiver is a combination of photocells forming a cylinder. The robot's position and orientation are obtained by measuring the times at which the laser light strikes each of the photocells. The device consists primarily of three distinct blocks:
1) Emitting subsystem that generates the laser light that moves in the horizontal plane.
2) A receiver subsystem, which consists of a set of sensors grouped in a cylinder to cover all possible directions of laser light impact. The sensor array must be at the same height as the emitter so that the laser light strikes the sensors. Inside the cylinder formed by the sensors is the electronics that identify the cells on which the laser strikes, as well as the time and duration of the laser's impact on each cell.
3) A laptop on the robot performs the final calculations and provides the location and orientation data.