Straight Skeleton Filling Algorithm of Slice Contour for Thin-walled Parts by Additive Manufacturing

针对增材制造薄壁件采用传统轮廓填充算法易导致内部缺陷的问题，研究了增材制造薄壁件分层轮廓直骨架填充算法。该算法首先对截面分层轮廓进行简化、平滑等预处理，然后对预处理之后的多边形轮廓进行直骨架计算，并提取直骨架半边数据结构中由所有内等分线构成的直骨架主线串。在对直骨架主线串进行膨胀操作和多边形合并操作之后，最后应用轮廓平行偏置算法获得薄壁件分层轮廓直骨架偏置填充轨迹。提出的算法较好解决了薄壁零件增材制造由于轨迹填充不合理导致的内部缺陷。</p

Influence of Autonomous Sailboat Dual-Wing Sail Interaction on Lift Coefficients

To analyze the influence of the chord length ratio and angle of attack on lift coefficients and explore the interaction mechanism between the two, we established a calculation model of the pressure distribution coefficient on the airfoil surface and lift coefficient of a dual-wing sail on the basis of the vortex panel method. Computational fluid dynamics was used in auxiliary calculation and analysis. Results revealed a reciprocal interference between the front-wing and rear-wing sails. The total lift coefficient of the dual-sail increased with an increase in the front sail chord length. The lift coefficient of the rear sail decreased with an increase in the front sail chord length or angle of attack. The front sail wake affected the pressure distribution on the upper and lower surfaces of the rear sail leading edge.</p

Probabilistic Riemannian quantification method with log-Euclidean metric learning

在许多机器学习应用中，需要分析的数据可能由对称正定矩阵构成，而经典的欧氏机器学习算法处理这种数据的性能较差。针对此问题，提出一种新的基于对数欧氏度量学习的概率黎曼空间量化方法。该方法将对称正定矩阵看做对数欧氏度量下的黎曼流形上的点，采用对数欧氏度量学习距离函数将概率学习矢量量化方法从欧氏空间推广到对称正定黎曼空间。在BCI IV 2a脑电数据集上，该方法相较于概率学习矢量量化方法识别正确率提升20%，高于竞赛第一名；并且计算速度快，模型训练及测试时间分别为基于仿射不变度量的同类型算法的1%和10%。在BCI III IIIa和图像数据集ETH-80上也取得了较好的结果。</p

一种基于感知信息的无人航行器目标定方位等距跟踪方法

本发明涉及目标跟踪领域，具体说是一种基于感知信息的无人航行器目标定方位等距跟踪方法，包括以下步骤：1)航行器获取目标的感知信息和航行器的航行器信息；2)对感知信息进行数据处理，获取经滤波平滑处理后的感知信息；3)设定目标相对于航行器的方位，设定距离数值D，建立虚拟目标运动坐标系，通过坐标系变化矩阵，得到航行器在虚拟目标运动坐标系下的位置；4)航行器通过速度调节策略对期望速度进行调节；5)根据目标航向，航行器解算航行器的期望航向；6)将期望速度和期望航向输出形成闭环，重复步骤1)～5)。本发明安全稳定，可靠性高。能够根据感知信息实时调节航行速度、航向，即使在较差海况下，亦能够安全稳定的完成任务

一种基于脑电和视觉的水下机械手控制系统及方法

本发明涉及水下机器人人机交互技术领域，尤其涉及一种基于脑电和视觉的水下机械手控制系统及方法。包括：脑电采集装置、视觉采集装置、刺激诱发模块、脑电处理模块、视觉处理模块、脑电视觉融合模块、机械手驱动模块以及多个液压机械手；脑电采集装置，用于采集脑电信号；视觉采集装置，用于实时捕捉瞳孔图像；脑电处理模块，用于处理脑电数据，判断出当前操作人员注视的色块图像；视觉处理模块，用于判断出当前操作人员视线焦点对应的色块图像；脑电视觉融合模块，用于将脑电处理模块与视觉处理模块的判断结果对比，得到机械手操作指令；本发明使用脑电和视觉信息完成命令选择及命令确认和撤销，提高了控制结果的正确率，保证可靠性

一种太赫兹精确聚焦透镜设计方法

本发明涉及一种太赫兹精确聚焦透镜设计方法，包括以下步骤：太赫兹透镜工作频率和材料选取；太赫兹透镜材料折射率准确标定；太赫兹透镜通光孔径、焦距、边缘厚度和面型选取；太赫兹透镜聚焦焦移效应补偿；太赫兹透镜表面非球面优化。使用本发明而设计出的太赫兹透镜为非球面折射聚焦透镜，其真实焦距与理论焦距的偏差绝对值可控制在1％之内。本发明主要解决了目前商用太赫兹折射透镜在对太赫兹波进行聚焦时，因焦移效应导致实际焦距小于理论焦距，进而导致焦平面位置偏差较大的问题

一种高机动大潜深自主水下机器人形体结构

Disclosed is an autonomous underwater robot with high mobility and a great submerging depth, the robot comprising a submarine body (1), a channel propeller (3) and rudder-propeller coupling mechanisms. The submarine body (1) is of a vertically flat structure, the channel propeller (3) is horizontally arranged at the bow of the submarine body (1), and the rudder-propeller coupling mechanisms are arranged on two sides of the submarine body (1); and the channel propeller (3) and the rudder-propeller coupling mechanisms cooperatively control the six degrees of freedom of the submarine body. Each rudder-propeller coupling mechanism comprises a front horizontal rudder plate (5), an auxiliary propeller (6), a rear horizontal rudder plate (11) and a main propeller(12). Each of the two front horizontal rudder plates (5) is provided with one auxiliary propeller (6), and each of the two rear horizontal rudder plates (11) is provided with one main propeller (12). The underwater robot can be used in a sea area with a great depth and complex terrain, has complex environment perception and high-mobility autonomous collision avoidance capabilities, and realizes high-efficiency environment perception and high-mobility autonomous collision avoidance detection capabilities in a sea area with complex terrain

Incremental Learning and Fault-tolerant Classifier for Myoelectric Pattern Recognition against Multiple Bursting Interferences

Bursting interference that causes a sudden and significant change in surface electromyography (sEMG) characteristics, can reduce the stability and security of myoelectric assistive robots. Current adaptation strategies for progressive-generated interference are incapable of dealing with bursting interference. To address this problem, an incremental learning and fault-tolerant classifier (ILFTC) was proposed by combining a Gaussian mixture model (GMM) ensemble and linear discriminant analysis (LDA), in conjunction with online update and marginalization schemes. Subsequently, an ILFTC-based myoelectric pattern recognition (MPR) strategy was developed to improve the robustness of MPR against multiple interferences, including outlier motion and missing/fault data owing to electrode loosening. Experiments on hand/wrist motions were conducted to validate the anti-interference performance of the ILFTC. Experimental results showed that the ILFTC could effectively resist the two types of bursting interference and produce a significant improvement in the recognition performance over traditional classifiers, as well as the methods presented in previous studies. The results show that the proposed method has the potential to enhance the robustness of myoelectric assistive robots.</p

一种用于深海摄像机圆顶视窗的密封装置

本发明属于水下机器人领域，具体地说是一种用于深海摄像机圆顶视窗的密封装置，包括玻璃球罩、球罩压盖、球罩隔垫、密封环、矩形补偿环及镜片组基座，其中球罩压盖套设于所述玻璃球罩的后端，并与所述镜片组基座的前端螺纹连接，所述镜片组基座的后端与摄像机舱体密封螺纹连接；所述球罩压盖与玻璃球罩之间装有密封环，所述密封环的后端延伸至球罩压盖与镜片组基座前端之间，所述球罩压盖与密封环之间安装有矩形补偿环；所述玻璃球罩的底部与镜片组基座之间设有球罩隔垫。本发明具有结构紧凑、可靠性高、易于实现等优点

Application of Machine Learning in Forest Fire Prediction

森林火灾的发生对社会经济和自然环境造成了威胁，因此及时预测森林火灾的发生具有重要意义。目前，机器学习被广泛用于各个行业，基于此本文应用神经网络、随机森林、逻辑回归3种机器学习算法，建立森林火灾预测模型，并用此模型对阿尔及利亚Bejaia地区和Sidi Bel-abbesl地区采集到的数据进行预测。实验结果证明，3种机器学习算法对森林火灾风险预测均有较好表现，综合准确率可达95.9%，其中随机森林算法在准确度方面表现最好，逻辑回归算法在运算效率方面表现最好，利用该森林火灾预测模型在防范森林火灾方面具有一定的可行性。</p