Multi-Angle Camera Assisted Received Signal Strength Algorithm for Visible Light Positioning

A camera assisted received signal strength (CA-RSS) algorithm is proposed for visible light positioning (VLP) systems. The basic idea of CA-RSS is to use simultaneously visual and strength information of visible lights to achieve accurate positioning at low computational cost. With rectangular LED layout, the irradiance angles of the visible lights can be estimated by visual information. Based on the estimated irradiance angles, the distances between the LEDs and the receiver can be obtained. Then, the two-dimensional (2D) position of the receiver can be calculated using a linear least square method. In addition, based on the solid geometry theory, we propose an independent solution method for three-dimensional (3D) positioning, which can avoid error propagation issue when compared with dependent solution method. To extend further CA-RSS for scenarios having different LED orientations and heights, we then propose a generalized CA-RSS algorithm for broader applications. Moreover, considering the imperfect channel model in practice, we propose a calibration method of Lambertian model for practical uses. Simulation results show that the proposed algorithm can achieve 90th percentile accuracies of less than 12.5 cm for 3D positioning regardless of the orientation of the receiver and the orientation and the height of the LEDs. In addition, experimental results show that using the calibration method, the proposed algorithm achieves an average 3D positioning error of 6.31 cm with different receiver orientations.