Indoor Location Estimation using Three Photodiodes and Ceiling LED Lights

In recent years, research on indoor autonomous mobile robots has been advanced. Accurate self-position estimation is necessary to enable autonomous movement. In this paper, we propose a method using LED lighting so that self-location can be estimated in various places. The experiment used 3 photodiodes and 2 LED lights modulated. First, I modulate each of the two lights. Each illumination is received by three photodiodes attached to the robot's head, and the illuminance of each is obtained. The obtained values ​​are fast Fourier transformed to distinguish between the two illuminations. Then, the radius is obtained from the illuminance and the position of the robot is estimated. The conventional LED lighting method could only detect the position within the reach of one light. Moreover, since it could not be used in a place where light such as sunlight was mixed, it was lacking in practicality. However, this time, it was possible to estimate the position among multiple light sources by using modulated light and three photodiodes. In addition, since the device itself uses an inexpensive thing called a photodiode, it enables low-cost self-location estimation.