前方车辆测距在自动驾驶汽车技术领域中起着至关重要的作用。针对目前基于单目视觉的车辆测距技术忽略了车辆与地面相接的下边沿问题，提出一种基于车辆下边沿估计和逆透视变换的单目视觉测距方法，实现了对前方车辆进行横向和纵向的高精度车距测量。该方法首先通过对车辆关键点估计和几何关系模型完成对车辆下边沿的估计，然后从中计算测距关键点，再利用基于点的逆透视变换测距模型进行距离计算。实验结果表明，与其他基于单目视觉的车辆测距方法相比，该方法提高了测距的精度和稳定性。

Front vehicle ranging plays a vital role in the field of autonomous vehicle technology. Aiming at the problem that the current vehicle ranging technology based on monocular vision neglects the lower edge of the vehicle connected to the ground, this paper proposes a monocular vision ranging model based on vehicle lower edge estimation and inverse perspective transformation, which realizes high- precision distance measurement of lateral and longitudinal directions of vehicles in front. Firstly, the vehicle's key point estimation and geometric relationship model are used to estimate the lower edge of the vehicle, then the distance measurement key points are calculated, and the point-based inverse perspective transformation distance measurement model is used to calculate the distance. The experimental results show that, compared with other monocular vision vehicle ranging algorithms, this method improves the accuracy and stability of ranging.