A nonlinear visual mapping model is presented to replace the image Jacobian relation for uncalibrated hand/eye coordination. A new visual tracking controller based on artificial neural network is designed. Simulation ...A nonlinear visual mapping model is presented to replace the image Jacobian relation for uncalibrated hand/eye coordination. A new visual tracking controller based on artificial neural network is designed. Simulation results show that this method can drive the static tracking error to zero quickly and keep good robustness and adaptability at the same time. In addition, the algorithm is very easy to be implemented with low computational complexity.展开更多
To avoid colliding with trees during its operation,a lawn mower robot must detect the trees.Existing tree detection methods suffer from low detection accuracy(missed detection)and the lack of a lightweight model.In th...To avoid colliding with trees during its operation,a lawn mower robot must detect the trees.Existing tree detection methods suffer from low detection accuracy(missed detection)and the lack of a lightweight model.In this study,a dataset of trees was constructed on the basis of a real lawn environment.According to the theory of channel incremental depthwise convolution and residual suppression,the Embedded-A module is proposed,which expands the depth of the feature map twice to form a residual structure to improve the lightweight degree of the model.According to residual fusion theory,the Embedded-B module is proposed,which improves the accuracy of feature-map downsampling by depthwise convolution and pooling fusion.The Embedded YOLO object detection network is formed by stacking the embedded modules and the fusion of feature maps of different resolutions.Experimental results on the testing set show that the Embedded YOLO tree detection algorithm has 84.17%and 69.91%average precision values respectively for trunk and spherical tree,and 77.04% mean average precision value.The number of convolution parameters is 1.78×10^(6),and the calculation amount is 3.85 billion float operations per second.The size of weight file is 7.11MB,and the detection speed can reach 179 frame/s.This study provides a theoretical basis for the lightweight application of the object detection algorithm based on deep learning for lawn mower robots.展开更多
为实现轨道车辆螺栓松动智能检测与螺栓预紧力实时监测,提高轨道车辆生产、运维中螺栓的预紧精度,提出一种基于机器视觉技术的螺栓松动角度非接触定量测量方法,基于该方法探究螺栓在预紧过程中各参量之间的关系模型。首先,进行相机内参...为实现轨道车辆螺栓松动智能检测与螺栓预紧力实时监测,提高轨道车辆生产、运维中螺栓的预紧精度,提出一种基于机器视觉技术的螺栓松动角度非接触定量测量方法,基于该方法探究螺栓在预紧过程中各参量之间的关系模型。首先,进行相机内参标定;然后实时获取螺栓图像,对获取到的图像后进行透视变换、滤波降噪等预处理,通过设定特定的通道阈值来提取图像的感兴趣区域(Region of interest,ROI),使用Sklansky算法在ROI平面点集进行凸包迭代,找出最少点集的矩形特征,同时利用旋转卡尺算法Rotating calipers返回凸包的最小面积外接矩形轮廓,以矩形中心点与Width边为特征计算出矩形特征的旋转角度θ;最终通过实验构建螺栓预紧力、拧紧力矩分别与旋转角度、螺杆行径量关系模型,以及预紧力与拧紧力矩关系模型。结果表明螺栓松动角度检测方法最大测量偏差为0.54°,最大相对误差为3.25%。该方法具备测量精度高,系统成本低、部署方便的特点,满足轨道车辆大批量的螺栓松动角度的非接触与自动化检测要求。轨道车辆螺栓智能精准预紧新工艺预紧力、拧紧力矩的计算精度达到90%以上,比传统的扭矩−转角法预紧精度高15%~40%。研究成果为轨道车辆螺栓松动智能运维提供技术支撑。展开更多
基金This project was supported by the National Natural Science Foundation (No. 69875010).
文摘A nonlinear visual mapping model is presented to replace the image Jacobian relation for uncalibrated hand/eye coordination. A new visual tracking controller based on artificial neural network is designed. Simulation results show that this method can drive the static tracking error to zero quickly and keep good robustness and adaptability at the same time. In addition, the algorithm is very easy to be implemented with low computational complexity.
基金the National Natural Science Foundation of China (No.51275223)。
文摘To avoid colliding with trees during its operation,a lawn mower robot must detect the trees.Existing tree detection methods suffer from low detection accuracy(missed detection)and the lack of a lightweight model.In this study,a dataset of trees was constructed on the basis of a real lawn environment.According to the theory of channel incremental depthwise convolution and residual suppression,the Embedded-A module is proposed,which expands the depth of the feature map twice to form a residual structure to improve the lightweight degree of the model.According to residual fusion theory,the Embedded-B module is proposed,which improves the accuracy of feature-map downsampling by depthwise convolution and pooling fusion.The Embedded YOLO object detection network is formed by stacking the embedded modules and the fusion of feature maps of different resolutions.Experimental results on the testing set show that the Embedded YOLO tree detection algorithm has 84.17%and 69.91%average precision values respectively for trunk and spherical tree,and 77.04% mean average precision value.The number of convolution parameters is 1.78×10^(6),and the calculation amount is 3.85 billion float operations per second.The size of weight file is 7.11MB,and the detection speed can reach 179 frame/s.This study provides a theoretical basis for the lightweight application of the object detection algorithm based on deep learning for lawn mower robots.
文摘为实现轨道车辆螺栓松动智能检测与螺栓预紧力实时监测,提高轨道车辆生产、运维中螺栓的预紧精度,提出一种基于机器视觉技术的螺栓松动角度非接触定量测量方法,基于该方法探究螺栓在预紧过程中各参量之间的关系模型。首先,进行相机内参标定;然后实时获取螺栓图像,对获取到的图像后进行透视变换、滤波降噪等预处理,通过设定特定的通道阈值来提取图像的感兴趣区域(Region of interest,ROI),使用Sklansky算法在ROI平面点集进行凸包迭代,找出最少点集的矩形特征,同时利用旋转卡尺算法Rotating calipers返回凸包的最小面积外接矩形轮廓,以矩形中心点与Width边为特征计算出矩形特征的旋转角度θ;最终通过实验构建螺栓预紧力、拧紧力矩分别与旋转角度、螺杆行径量关系模型,以及预紧力与拧紧力矩关系模型。结果表明螺栓松动角度检测方法最大测量偏差为0.54°,最大相对误差为3.25%。该方法具备测量精度高,系统成本低、部署方便的特点,满足轨道车辆大批量的螺栓松动角度的非接触与自动化检测要求。轨道车辆螺栓智能精准预紧新工艺预紧力、拧紧力矩的计算精度达到90%以上,比传统的扭矩−转角法预紧精度高15%~40%。研究成果为轨道车辆螺栓松动智能运维提供技术支撑。
