Three Phase Ranging Algorithm Based on Time of Flight Principle

Based on the TOF ranging principle, this paper introduces a novel three-phase integral ranging method, which effectively improves the frame rate by refining the four-phase sampling technique. The proposed technique uses sinusoidal continuous wave modulation of the light source as the transmit signal. On the receiving side, the signal is directly integrated over a quarter-cycle length at three distinct intervals. The method can quickly obtain the phase difference and then calculate the distance. The algorithm operates with speed and efficiency, circumventing traditional point-sampling distance measurement and lessening sensor requirements. The simulation was conducted in a noise-free environment, and the distance error accuracy reached 30um within a measurement distance of 15m, and the error at different distances is basically consistent. In the experiment introducing random Gaussian white noise, the ranging accuracy approached several millimeters at a signal-to-noise ratio of 20dB. This paper also conducted a ranging experiment with additional integration of N integer periods. The results proved that the algorithm has certain robustness to the number of integration periods, potentially reducing sensor exposure time requirements. The proposed ranging algorithm is also suitable for TOF cameras for three-dimensional imaging.