Shenyang Institute of Automation,Chinese Academy Of Sciences
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Design and control of semi-physical simulation device for tether dragging system
No full text为有效清除太空垃圾，模拟空间中对废弃卫星的回收过程，采用半物理实验技术对绳系收放装置进行地面试验考核，验证绳系收放控制系统的性能。半物理仿真是一种通过实物或物理模型与数学模型相结合进行仿真的技术，通过地面半物理仿真实验对空间任务进行先验，大大减少了空间实验的成本，可有效指导空间任务的设计与控制。首先，对绳系卫星拖拽过程进行动力学建模，明确了拖拽过程的任务目标，确立了绳系拖拽半物理系统的机械组成。其次，设计了全物理仿真单元为被动加载单元，卫星质量采用等效惯量转台模拟。然后，为模拟目标在绳系拖拽作用下的动力学状态，仿真加载单元由半物理仿真方式设计。最后，针对实际试验过程中存在的张力测量误差扰动，设计了基于模型预测控制的控制策略，为了对拖拽过程的张力和绳长精确控制，实验使用双闭环电机联合控制，通过模型预测控制的方式联合张力位置双电机仿真。结果表明，基于模型预测控制的张力误差精度为5%，从而验证了绳系收放控制系统对拖拽过程的控制有效性。</p
Nonconvex Nonlocal Tucker Decomposition for 3D Medical Image Super-Resolution
No full textLimited by hardware conditions, imaging devices, transmission efficiency, and other factors, high-resolution (HR) images cannot be obtained directly in clinical settings. It is expected to obtain HR images from low-resolution (LR) images for more detailed information. In this article, we propose a novel super-resolution model for single 3D medical images. In our model, nonlocal low-rank tensor Tucker decomposition is applied to exploit the nonlocal self-similarity prior knowledge of data. Different from the existing methods that use a convex optimization for tensor Tucker decomposition, we use a tensor folded-concave penalty to approximate a nonlocal low-rank tensor. Weighted 3D total variation (TV) is used to maintain the local smoothness across different dimensions. Extensive experiments show that our method outperforms some state-of-the-art (SOTA) methods on different kinds of medical images, including MRI data of the brain and prostate and CT data of the abdominal and dental.</p
All Weather Robot Vision
No full textComplex illumination and meteorological conditions can significantly limit the robustness of robotic vision systems. This book focuses on image pre-processing for robot vision in complex illumination and dynamic weather conditions. It systematically covers cutting-edge models and algorithms, approaching them from a novel viewpoint based on studying the atmospheric physics and imaging mechanism. It provides valuable insights and practical methods such as illumination calculations, scattering modeling, shadow/highlight detection and removal, intrinsic image derivation, and rain/snow/fog removal technologies that will enable robots to be effective in diverse lighting and weather conditions, i.e., ensure their all-weather operating capacity. As such, the book offers a valuable resource for researchers, graduate students and engineers in the fields of robot engineering and computer science
电推力器推进剂管道大变形弯曲特性仿真研究
No full text根据电推力器指向机构的实际机械结构,建立了推进剂管道仿真模型。利用Abaqus有限元仿真软件分析对比了推进剂直管道和螺旋管道大变形弯曲应力,随后又分析了不同中径、内径、有效圈数三个变量对螺旋管道应力的影响。仿真分析结果表明,直管道在大变形弯曲情况下应力远远超过屈服强度,螺旋管道在同样条件下,应力未超过屈服强度;控制上述变量中两个变量不变时,随着中径变大,应力越来越小;随着内径变小,应力越来越小;随着有效圈数增多,应力越来越小。该研究可用于电推力器推进剂管道方案的设计和参数优化。</p
Review on Endogenous Information Security Technology of Industrial Measurement and Control Equipment
No full text工业测控设备是工业控制系统的神经中枢，其信息安全问题直接关系到工业控制系统的安全。传统信息安全防护技术手段具有局限性，网络无法阻断物理介质传输数据和物理设备的接入，即使是物理隔离的工业测控设备，亦可以成为攻击目标，迫切需要增强工业测控设备自身的内生安全防护能力。本文结合相关国际标准和国家标准，将工业测控设备内生信息安全防护技术分为静态加固技术和动态防护技术，对涉及的七类信息安全防护技术进行了逻辑分类，给出了工业测控设备的内生信息安全的术语定义，并具体分析、评价了已有相关理论研究和关键技术的优势和不足之处。最后，对工业测控设备的内生信息安全防护技术的发展趋势进行了展望。</p
Motion Parameters Estimation of Underwater Moving Target Based on Iterative Optimization Algorithm for an AUV
No full text为了解决自主水下机器人（autonomous underwater vehicle,AUV）对水下运动目标进行实时动态追踪的技术难题，本文将渐消记忆递推最小二乘算法与平方根算法相结合，提出一种迭代优化算法．该算法充分利用渐消记忆递推最小二乘算法的快速收敛性能，利用平方根算法解决迭代过程中的数值不稳定问题．迭代优化算法能够快速解算出运动目标的初始距离、航向角及运动方向，数值收敛时间约为3 min，目标运动速度信息也能够在5 min左右收敛．该算法的收敛时间短、计算速度快，甚至AUV无需进行任何形式的机动即可令其保持悬停，这些优点使本算法适用于AUV水下运动目标追踪的工程实际问题．</p
A review of soft manipulator research, applications, and opportunities
No full textSoft manipulator is a kind of special manipulator that uses soft material or flexible structure to perform manipulation task under the specific drive mode inspired by the soft tissue. It is developing gradually as an important component of the soft robot. In this paper, the typical design cases of the soft manipulators as well as the related research teams are firstly investigated. The characteristics of different drive modes are compared and analyzed. Based on these investigations, the enabling technologies are systematically summarized in five aspects, such as kinematic and dynamic modeling, motion control, shape detection, dynamic tactile perception, and stiffening method. Currently, the research on soft manipulator has initially formed a technical system, although it is still in the primary stage. With the development of the soft manipulator, its overall technology maturity will be gradually improved. Currently, the applications of the soft manipulator lie mainly in the fields of the ground rescue, the underwater grabbing, the medical operation, the assist maintenance, the man-machine interaction, the space manipulation and so on. The application fields, such as origami soft manipulator, biomimetic soft microrobots, self-healing soft robot, space soft manipulator and so on, emerge new opportunities and challenges for the soft manipulators.</p
Reducing self-absorption effect by double-pulse combination in laser-induced breakdown spectroscopy
No full textThe method of double-pulse laser-induced breakdown spectroscopy is usually employed to enhance the spectral signal intensity. However, in this study, double-pulse laser-induced breakdown spectroscopy is adopted to investigate the effect of the self-absorption reduction of the spectrum. This research explored that the influence of the change of the gas environment generated by the first laser beam on the self-absorption effect of the plasma spectrum by the second laser beam. Especially despite the different combinations of laser energy, for the three elements of Cu, Mn and Ni, the weakest spectral self-absorption effect can be obtained when the double-pulse delays are around 80 mu s, 100 mu s, and 110 mu s, respectively. In addition, this paper also found that when the energy of the first laser beam is unchanged, the spectral self-absorption effect has a strong correlation with the double-pulse delay, and has a weak correlation with the change of the second laser energy
Design, modeling, and control of morphing aircraft: A review
No full textA morphing aircraft can adapt its configuration to suit different types of tasks, which is also an important requirement of Unmanned Aerial Vehicles (UAV). The successful development of an unmanned morphing aircraft involves three steps that determine its ability and intelligent: configuration design, dynamic modeling and flight control. This study conducts a comprehensive survey of morphing aircraft. First, the methods to design the configuration of a morphing aircraft are presented and analyzed. Then, the nonlinear dynamic characteristics and aerodynamic interference caused by a morphing wing are described. Subsequently, the dynamic modeling and flight control methods for solving the flight control problems are summarized with respect to these features. Finally, the general as well as special challenges ahead of the development of intelligent morphing aircraft are discussed. The findings can provide a theoretical and technical reference for designing future morphing aircraft or morphing-wing UAVs.</p
Evolving Metric Learning for Incremental and Decremental Features
No full textOnline metric learning has been widely exploited for large-scale data classification due to the low computational cost. However, amongst online practical scenarios where the features are evolving (e.g., some features are vanished and some new features are augmented), most metric learning models cannot be successfully applied to these scenarios, although they can tackle the evolving instances efficiently. To address the challenge, we develop a new online Evolving Metric Learning (EML) model for incremental and decremental features, which can handle the instance and feature evolutions simultaneously by incorporating with a smoothed Wasserstein metric distance. Specifically, our model contains two essential stages: a Transforming stage (T-stage) and a Inheriting stage (I-stage). For the T-stage, we propose to extract important information from vanished features while neglecting non-informative knowledge, and forward it into survived features by transforming them into a low-rank discriminative metric space. It further explores the intrinsic low-rank structure of heterogeneous samples to reduce the computation and memory burden especially for highly-dimensional large-scale data. For the I-stage, we inherit the metric performance of survived features from the T-stage and then expand to include the new augmented features. Moreover, a smoothed Wasserstein distance is utilized to characterize the similarity relationships among the heterogeneous and complex samples, since the evolving features are not strictly aligned in the different stages. In addition to tackling the challenges in one-shot case, we also extend our model into multi-shot scenario. After deriving an efficient optimization strategy for both T-stage and I-stage, extensive experiments on several datasets verify the superior performance of our EML model. IEEE</p