面向自动驾驶汽车的交通标线使用状况评估方法

Road Markings Condition Assessment Method for Intelligent Vehicles

随着自动驾驶技术的不断进步和普及,道路上将会出现越来越多具有自动驾驶技术的汽车,交通标线的服务对象将逐渐从驾驶员向自动驾驶汽车过渡。现有的交通标线使用状况评估方法不但需要耗费大量的人力去巡查、测量和评估,而且评估指标也是基于生物视觉研究而得,不符合基于机器视觉的自动驾驶汽车的特点;针对上述的问题,文中提出了一种面向自动驾驶汽车的交通标线使用状况评估方法。首先,基于自动驾驶汽车的特性,运用查阅文献、类比推理和逻辑推理等方法初步确定峰值信噪比(PSNR)作为评估指标;其次,为了快速且准确地获取峰值信噪比,提出了基于图像修复的峰值信噪比的计算方法,该方法先利用基于条件生成对抗网络的DeblurGAN模型在图像层面复原破损的交通标线,进而利用破损和复原后的交通标线图像计算出峰值信噪比,同时,文中提出了一种可以真实地合成破损的交通标线图像的数据增强方法去提高图像修复模型的性能。然后,以AlexNet网络为基准模型设计对照实验去研究峰值信噪比与交通标线的识别准确率的关系;最后,将研究成果应用到实际的交通标线使用状况的评估工作中,并与现行规范的评估方法比较。实验结果表明:与基于人工修复图像的峰值信噪比的计算方法对比,文中所提的方法得到的平均峰值信噪比只相差约2.24%,但获取速度却提高了约418倍;峰值信噪比影响交通标线的识别准确率,当平均PSNR相差约43.66%时,平均识别准确率相差了约36.27%,峰值信噪比可以衡量交通标线的使用状况;文中所提出的评估方法使工作效率约提高了6.5倍且耗费更少的人力,也更符合自动驾驶汽车的特点,但规范中的评估方法更加详尽。

With the continuous advancement and popularization of autonomous driving technology,more and more vehicles with autonomous driving technology will appear on the road,and the service objects of road markings will gradually transition from drivers to autonomous vehicles.On the one hand,the method of road markings condition assessment requires a lot of manpower to inspect,measure and evaluate;on the other hand,the evaluation index is based on biological vision research,which does not conform to the characteristics of automatic driving vehicles based on machine vision.To solve the above problems,this paper proposed a method of road markings condition assessment for autonomous vehicles.First,PSNR(peak signal-to-noise ratio)was initially determined as the evaluation index by means of literature review,analogical reasoning and logical reasoning.Secondly,to quickly obtain PSNR,this paper proposes a calculation method of the PSNR based on image inpainting,which utilizes the Deblur‐GAN model restores the damaged road markings at the image level,and then uses the damaged and restored road markings images to calculate the PSNR.In addition,this paper proposed a data augmentation method that can realis-tically synthesize damaged road markings images to improve the performance of image inpainting models.Then,the AlexNet network was used as the benchmark model to design experiments to study the relationship between the PSNR and the recognition accuracy of road markings.The experimental results show that,compared with the calculation method of the PSNR based on the artificially restored image,the average PSNR obtained by the method pro‐posed in this paper only differs by about 2.24%,but the acquisition speed is increased by about 418 times;when the average PSNR differs by about 43.66%,the average recognition accuracy differs by about 36.27%.Therefore,the PSNR can measure the use of road markings.Compared with the evaluation method of the current standard,the evaluation method proposed in this paper improves the work efficiency by about 6.5 times and consumes less manpower.And it is more in line with the characteristics of self-driving cars,but the evaluation methods are more detailed in the specification.