Optical Characterization of the Beams Generated by 3-D LiDARs: Proposed Procedure and Preliminary Results on MRS1000

IEEE Trans. Instrum. Meas.

et al. 2021

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LiDARs are considered essential for the environmental sensing required by most ADAS, including autonomous driving. Such has led to significant investments resulted in the availability of countless measuring systems that are increasingly performing and less expensive. Nevertheless, the extremely high speed of light still leads to a non-negligible quantization error in the direct time-of-flight (ToF) measure at the base of pulsed LiDARs -the leading technology for automotive applications. Hence, pulsed 3D-LiDARs analyze the surrounding by approximating and deforming it on concentric spheres whose radii are quantized with a quantization step that, for most commercial systems, is on the order of some centimeters. The deformation and error introduced by such quantization can thus be significant. In this study, we point out the approximations and assumptions intrinsic to 3D-LiDARs and propose a measurement procedure that, through the analysis of the fine variations of the target position, allows an accurate investigation of the axial resolution and error -probably among the few limitations still affecting this technology. To the best of our knowledge, this is the first study focused on the detailed analysis of the quantization error in 3D-LiDARs. The proposed method has been tested on one of the most popular 3D-LiDARs -namely the MRS 6000 by Sick. The obtained results revealed for the MRS 6000 a quantization step of about 6 cm (ToF quantization of about 0.4 ns) and an axial error normally distributed with experimental standard deviation of about 30 mm.

Section: Receive Pulsementioning

confidence: 99%

Analysis, Quantification, and Discussion of the Approximations Introduced by Pulsed 3-D LiDARs

Cattini¹,

IEEE Trans. Instrum. Meas.

et al. 2021

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“…The increasing number of products on the market raises the need to characterize their performances and capabilities to select suitable systems for specific applications. This has led and is leading to the publication of many studies aimed at the characterization and comparison of LiDAR systems [1]- [6]. Furthermore, several studies aimed at evaluating LiDARs performances in the detection of pedestrians and objects have been proposed in recent years e.g.…”

Section: Introductionmentioning

confidence: 99%

LiDARs detected signal and Target distance estimation: measurement errors from Target reflectance and multiple echos

Cattini

2022 IEEE International Workshop on Metrology for Automotive (MetroAutomotive)

et al. 2022

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The use of LiDARs in automotive is increasingly widespread. In order to operate in a critical environment such as that of mobility, these systems must offer increasingly high performance. In particular, the ability to estimate the position of objects regardless of their reflectance and presence of diffusing backgrounds is a very sought-after feature by manufacturers. In commercial systems various strategies are used to make the measurement as insensitive as possible to these effects, however, it is not possible to fully compensate for the measurement errors caused by them. In this paper, we propose two simple experimental setups to verify the presence of these measurement errors in two scenarios. Moreover, we report the performance of a commercial LiDAR (MRS 6000 by Sick) using certified reflectance standards (Spectralon® Diffuse Reflectance Standards, by Labsphere). For this LiDAR, the results obtained show that a logarithmic variation of the reflectance of the target of 1.26-log at a target distance 2.4 m provides incompatible measurements. Furthermore, the presence of a background at a distance shorter than 11 cm, 12 cm and 13 cm respectively with 50 %, 75 % and 99 % reflectance also provides incompatible measurements for a target distance of 1.3 m from the LiDAR.

A simple method for the preliminary analysis and benchmarking of automotive LiDARs in fog

Cattini

2022 IEEE International Instrumentation and Measurement Technology Conference (I2MTC)

et al. 2022

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The vast multitude of LiDAR systems currently available on the market makes the need for methods to compare their performances increasingly high. In this study, we focus our attention on the development of a method for the analysis of the effects induced by the fog, one of the main challenges for Advanced Driver Assist Systems (ADASs) and autonomous driving. Large experimental setups capable of reconstructing adverse weather conditions on a large scale in a controlled and repeatable way are certainly the best test conditions to analyze and compare LiDARs performances in the fog. Nonetheless, such large plants are extremely expensive and complex, therefore only available in a few sites in the world. In this study, we thus propose a measurement method, a data analysis procedure and, an experimental setup that are extremely simple and inexpensive to implement. The achievable results are reasonably less accurate than those obtainable with large plants. Nevertheless, the proposed method can allow to easily and quickly obtain a preliminary estimate of the performance in the presence of fog and a rapid benchmarking of different LiDAR systems.