水面无人艇可行域及障碍物快速分割算法研究

针对水面无人艇(USV)可行域及障碍物分割系统对图像处理过程的快速性和准确性要求,研究了一种根据无人艇机载视觉传感器对水上图像快速分割的算法。首先经过多地实验采集实验图像,经过数据清洗、图像去重和人工筛选构建原始数据库,并采用人在回路数据标注方法构造了无人船可行域及障碍物分割数据集,共5 620张图像和25 875个标签;其次实践了主流的基于深度学习的语义分割方法,包括FCN、DeeplabV3 Plus、U-Net;最后针对水上图像的特点和快速分割的任务需求,提出了一种基于改进DeeplabV3 Plus的快速分割网络DeeplabV3-CSPNet。网络学习实验、离线航行实验和模型部署结果表明,DeeplabV3-CSPNet算法取得快速且准确的分割效果,平均精度达到84.17%,运算速度达到49.26 fps,在边缘计算平台上运算速度达到45.45 fps。     

Improved Support Vector Machine Approach Based on Determining Thresholds Automatically

To improve the training speed of support vector machine （SVM）, a method called improved center distance ratio method （ICDRM） with determining thresholds automatically is presented here without reduce the identification rate. In this method border vectors are chosen from the given samples by comparing sample vectors with center distance ratio in advance. The number of training samples is reduced greatly and the training speed is improved. This method is used to the identification for license plate characters. Experimental resuhs show that the improved SVM method-ICDRM does well at identification rate and training speed.