Joint Position and Orientation Estimation for Visible Light Positioning Using Extended Kalman Filters

In this work, an extended Kalman filter (EKF) is applied to solve the problem of joint estimation of object position and orientation for indoor visible light positioning (VLP) systems. It is assumed that light emitting diode (LED) lamps are installed on the room ceiling, with their illuminations following the Lambertian emission pattern. A receiver is located on the floor, with three photo diodes (PDs) mounted on a pyramid structure. Mathematical expressions for EKF related computations are derived. Numerical results from 10,000 random receiver positions and orientations in an 8m-by-8m area under nine LED lamps are used to evaluate the estimation accuracy. The results indicate that, in the considered room scenario, the position estimation error is within 0.18 m while the orientation estimation error is within 12.5 degree for 95% of the time. Finally, object tracking using the EKF is demonstrated when the receiver moves along a circular path, indicating a potential of EKF based joint position and orientation estimation in a dynamic environment.