3D Motion Analysis based on Optical Doppler Imaging

基于光学多普勒成像的 3D 运动分析

• 批准号: 21K17758
• 负责人: 胡 云普
• 金额: $ 2.5万
• 依托单位: The University of Tokyo
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Early-Career Scientists
• 财政年份: 2021
• 资助国家: 日本
• 起止时间: 2021-04-01 至 2022-03-31
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-21K17758/
• 关键词: Velocity sensing; Doppler effect; Time-of-Flight Camera; Motion sensing

This year, the research concentrated on the principles of heterodyne-mode time-of-flight cameras. Heterodyne-mode time-of-flight cameras encode the target radial velocity into the measurement, which is unique compared with conventional time-of-flight sensing, and is promising for high-speed velocity sensing. The proposed method greatly extends the conventional method, making it more accurate, more robust, and more accessible.In this study, a new framework that can simultaneously decode distance and velocity from four measurements is built. With a novel theoretical discussion, I proposed a heterodyne frequency that is optimal for velocity sensing. For the first time, it was made clear that the target distance has a huge influence on the velocity sensing precision. Finally, I proposed two decoding methods, including an optimization-based decoding and a fast decoding method. The proposed method is validated on a hardware platform composed of commercially available devices and has obvious improvement compared with conventional work in terms of accuracy and robustness.This work is the first thorough theoretical discussion on heterodyne-mode time-of-flight cameras for velocity sensing. I pointed out the limitations and mistakes of the conventional work, and proposed an advanced method based on the theoretical discussion. The proposed method is the only method that can make instantaneous, full-field imaging of velocity, which will have a huge impact in the field such as sensing and robotics. This study is provisionally accepted by a top journal in the related field.

今年，研究集中在外差式飞行时间相机的原理上。外差式飞行时间相机将目标的径向速度编码到测量中，这与传统的飞行时间传感相比是独一无二的，在高速速度传感方面具有广阔的应用前景。该方法极大地扩展了传统方法，使其更准确、更稳健、更易于使用。通过一种新颖的理论讨论，我提出了一个最适合速度传感的外差频率。首次明确了目标距离对测速精度有很大影响。最后提出了两种译码方法，包括基于优化的译码方法和快速译码方法。该方法在由商用器件组成的硬件平台上得到了验证，在精度和稳健性方面与常规工作相比有了明显的提高。这是首次对外差式飞行时间相机进行深入的理论探讨。指出了常规工作的局限性和误区，并在理论探讨的基础上提出了一种先进的方法。该方法是唯一一种可以对速度进行瞬时、全场成像的方法，将在传感和机器人等领域产生巨大的影响。这项研究暂时被相关领域的顶级期刊接受。