Highly precise AMCW time-of-flight scanning sensor based on digital-parallel demodulation

TL;DR

This paper introduces a novel AMCW ToF scanning sensor using digital-parallel demodulation, achieving high distance measurement precision, high SNR, and crosstalk removal, validated through experiments.

Contribution

The paper presents a new AMCW ToF sensor design with digital-parallel demodulation that enhances measurement precision and reduces crosstalk, enabling high-quality 3D depth sensing.

Findings

High demodulation contrast maintained

Enhanced optical SNR achieved

Validated precise 3D depth measurement

Abstract

In this paper, a novel amplitude-modulated continuous wave (AMCW) time-of-flight (ToF) scanning sensor based on digital-parallel demodulation is proposed and demonstrated in the aspect of distance measurement precision. Since digital-parallel demodulation utilizes a high-amplitude demodulation signal with zero-offset, the proposed sensor platform can maintain extremely high demodulation contrast. Meanwhile, as all cross correlated samples are calculated in parallel and in extremely short integration time, the proposed sensor platform can utilize a 2D laser scanning structure with a single photo detector, maintaining a moderate frame rate. This optical structure can increase the received optical SNR and remove the crosstalk of image pixel array. Based on these measurement properties, the proposed AMCW ToF scanning sensor shows highly precise 3D depth measurement performance. In this study, this precise measurement performance is explained in detail. Additionally, the actual measurement performance of the proposed sensor platform is experimentally validated under various conditions.