Shenyang Institute of Automation,Chinese Academy Of Sciences
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Experiment Analysis on Robot Automatic Grinding of Welding Seam
No full text为了实现机器人自动打磨焊缝且余高0.2 mm的加工要求，进行了机器人自动打磨焊缝试验平台的搭建和实验研究。分析了可控焊缝余高的打磨理论，采用力控去除和定尺结构相结合的方法，完成了试验平台的搭建和焊缝打磨头的设计，选取多组工艺参数进行实验验证和结果测量。实验结果表明，采用力控去除和定尺结构相结合的机器人自动打磨平台可以良好地实现余高可控的焊缝自动打磨加工要求，焊缝打磨后余高一致性良好，表面粗糙度均匀稳定，能够代替人工打磨作业要求，为焊缝自动打磨提供了参考依据。</p
Actuator fault modeling and fault-tolerant tracking control of multi-vectored propeller aerostat
No full textFor a multi-vectored propeller aerostat with actuator faults, this study presents a fault-tolerant tracking control strategy, which includes fault modeling, observer, force estimation and tracking controller. Fault modeling considers the four types of faults of vectored propellers, namely, thrust offset, thrust efficiency loss, vectored angle offset and vectored angle stuck. Actuator faults can be determined from the fault observer, which identifies the thrust offset from the acceleration difference of the faulty aerostat with the ideal model. For tracking positions, a traditional PID controller is constructed with virtual control, compensated with the estimated fault force. The control allocation scheme is proposed to redistribute the available actuators in case faults occur. Simulation results of position tracking prove the effectiveness of the proposed strategy.</p
AFM下的淋巴瘤患者血浆外泌体的物理特征(英文)
No full textObjective The exosome, a type of extracellular vesicle, is considered a kind of information carrier and biomarker and has a significant role in extracellular physiologic activities and disease progression. Research into the characteristics of exosomes is key to addressing numerous fundamental issues in pathologic processes. Exosomes are secreted by tumor cells into the tumor microenvironment through exocytosis. Exosome vesicles carry a large amount of genetic information related to the tumor cells from which they are derived, which plays an important role in the tumor microenvironment, such as information transmission, immune regulation, promotion of tumor invasion and metastasis, and regulation of tumor response to drugs. At present, most exosomes research focuses on the bioinformatics exploration of protein expression, mRNA, lncRNA and other aspects of exosomes, and there is still a lot of space to explore the microscopic morphology and physical characteristics of exosomes. This study investigated the physical characteristics of plasma exosomes from patients with lymphoma through atomic force microscopys. Methods The exosome has been extracted from clinical cancer patients’ peripheral blood samples. The samples contain diffuse large B cell lymphoma and follicular lymphoma. At first, the electrostatic adsorption method has been utilized to fix the isolated exosomes onto the mica substrates, the discrete living exosomes have been scanned with AFM method. The multi-parameter exosome images at nano/micro scale can be obtained in situ. Results The multi-parameter mechanical properties of isolated living exosomes have been visualized and quantitatively measured. The significant fringe effect at the edge of the exosome has been revealed in the AFM adhesion image, which means more energy dissipation can be produced there. The young's modulus of plasma exosomes was different in patients with lymphoma from different pathological subtypes. Conclusion Plasma exosomes from patients with hematological tumors can be successfully extracted. Due to the convenient and less invasive characteristics of peripheral blood, plasma exosomes can be used as biomarkers for dynamic monitoring and analysis of tumor diagnosis and treatment, and the extracted exosomes can be captured by AFM probes through treatment and fixation. In this study, the morphological details and mechanical properties of exosomes at nano and micro scales were revealed. The physical properties of exosomes may be related to their biological properties. The multi-dimensional understanding of exosome performance opens up a new perspective for the future application and in-depth study of exosomes.</p
A supervised independent component analysis algorithm for motion imagery-based brain computer interface
No full textRecognizing the corresponding neural activities of independent components(ICs) obtained by independent component analysis(ICA) is of prime importance to take use of ICA in EEG analysis. There are many methods trying to solve this problem. But most of them combining ICA, a unsupervised method, and recognition of ICs in a separate way. In this paper, we propose a supervised method to extract the independent components corresponding to different motion imagery(MI) activities in the brain. By designing a new optimization objective and solving it, we combine the idea of ICA with principle of MI in an individual algorithm. From the perspective of event-related desynchronization and synchronization (ERD/ERS), specific frequency band power of the motion related component should be enhanced or suppressed when executing or imaging movement of body. Therefore, the new optimization function extract the components that satisfy both independence and band power maximization for specific motions. Then, we solve this optimization problem based on the fixed-point iteration scheme. In the experimental stages, we show that our methods can extract motion-related independent components without losing independence. Experimental results show that, although basing on the principle of ERD/ ERS, our methods' effectiveness can be verified in the perspective of movement-related potential (MRP). Additionally, by identifying features in the extracted motion-related independent components, we can achieve better motion recognition accuracy. When using the proposed algorithms with different schema, the results yielded significant accuracy imporvements of 6.9%(p < 0.001) and 7.9%(p < 0.01)
Medical image fusion via discrete stationary wavelet transform and an enhanced radial basis function neural network
No full textMedical image fusion of images obtained via different modes can expand the inherent information of original images, whereby the fused image has a superior ability to display details than the original sub images, to facilitate diagnosis and treatment selection. In medical image fusion, an inherent challenge is to effectively combine the most useful information and image details without information loss. Despite the many methods that have been proposed, the effective retention and presentation of information proves challenging. Therefore, we proposed and evaluated a novel image fusion method based on the discrete stationary wavelet transform (DSWT) and radial basis function neural network (RBFNN). First, we analyze the details or feature information of two images to be processed by DSWT by using two-level decomposition to separate each image into seven parts, comprising both high-frequency and low-frequency sub-bands. Considering the gradient and energy attributes of the target, we substituted the pending parts in the same position in the two images by using the proposed enhanced RBFNN. The input, hidden, and output layers of the neural network comprised 8, 40, and 1 neuron(s), respectively. From the seven neural networks, we obtained seven fused parts. Finally, through inverse wavelet transform, we obtained the final fused image. For the neural network training method, the hybrid adaptive gradient descent algorithm (AGDA) and gravitational search algorithm (GSA) were implemented. The final experimental results revealed that the novel method has significantly better performance than the current state-of-the-art methods. (C) 2022 Elsevier B.V. All rights reserved
Conceptual design of a long-range autonomous underwater vehicle based on multidisciplinary optimization framework
No full textThe endurance of a deep-sea AUV is closely related to its sailing resistance, the amount of carrying batteries and equipment load, which involves interactions among multiple disciplines. In this paper, in order to develop the conceptual design of a long-range AUV in the early stage, a multidisciplinary optimization design framework is presented for decision-makers to explore the given design space, which takes into account the coupling between the disciplines of hull form, structural design and energy use. A Self-adaptive Surrogate Ensemble (SASE) method is proposed to replace the expensive process of hydrodynamic analysis, a recommended approach by the China Classification Society (CCS) specification is applied to carry out the design of metallic pressure hulls, and the classical lamination theory and Tsai-Wu criteria are adopted in the design of composite pressure hulls. Finally, the evaluation model of AUV endurance is created from the perspective of energy capacity and consumption. The conceptual design of a 200 kg-class AUV is executed to maximize the endurance based on the proposed multidisciplinary optimization design framework. The results show that the most important factors that affect AUV endurance are the velocity and diameter, and the optimum velocity of the AUV increases with the load power. The Sea-Whale 2000 AUV was developed based on the optimal result and the excellent endurance performance in the sea trial validated the effectiveness of the proposed design method in the preliminary design process
一种考虑记忆效应的水动力相互作用力预报方法
No full text本发明涉及一种考虑记忆效应的水动力相互作用力预报方法。本发明所提预报方法主要分为三步。第一，通过考虑流体记忆效应实现对传统水动力模型的修正。第二，基于修正后的水动力模型，通过多水下机器人在水中近距离运动时某一个体所受水动力与该个体独立运动所受水动力做差的方法来构建水动力相互作用力预报模型。第三，利用参数等价代换方法，将多水下机器人的间距作为水动力相互作用力预报模型的自变量，以实现水动力相互作用力与间距关系的连续表示。本发明具有机理明确清晰、预报精度高等特点，可广泛应用于多水下机器人近距离运动时的水动力相互作用力预报工作
一种基于知识库推理的通用视点规划方法
No full text本发明涉及主动感知领域，具体的说是涉及一种基于知识库推理的通用视点规划方法。基于知识库推理的通用视点规划方法包括：视觉任务与先验信息的描述方法，对视觉任务的任务状态，被测物体的候选状态、感知状态与先验信息进行形式化表达，依据这些形式化表达对主动感知系统进行输入；各状态的更新方法与模型空间未知区域的预测方法，根据探测信息对各个状态实时更新，并利用物体先验信息预测目标的未知区域；基于形式化描述的下一视点确定方法，使用条件熵度量各个特征的权重，用一种加权信息增益的视点评价方法确定下一最佳视点。本发明能够应用于目标建模与目标识别任务，使视点规划方法脱离了具体视觉任务，应用范围更广
一种船用直流混合电力系统的能量管理方法
No full text本发明涉及能量管理技术领域，尤其是针对船用直流混合电力系统的能量管理技术，具体的说是一种针对由多组燃料电池、多组锂电池及超级电容构成的船用直流混合电力系统的能量管理方法。本发明通过监测母线电压、各电源剩余电量等信息，对船用直流混合电力系统中各电源DC/DC变换器进行控制，使得混合电力系统在11种工作模式之间切换，适时调配能量在混合电源中的流动，在保证直流母线稳定的同时，使混合电源系统快速跟踪负载变化，实现整个直流混合电力系统的稳定可靠运行
面向固定翼无人机海上回收的拦阻钩测试系统
No full text本实用新型涉及一种面向固定翼无人机海上回收的拦阻钩测试系统，其中模拟测试车可移动地设于导向架体中，缓冲架体两侧均设有带升降滑块的回收绳高度调节组件，所述滑块上设有回收绳转向组件，所述回收绳转向组件设有张力传感器，每个回收绳高度调节组件底端均设有回收绳收放组件，且回收绳两端分别绕过对应侧回收绳转向组件上的张力传感器后绕置于对应侧的回收绳收放组件中，所述模拟测试车下侧设有拦阻钩与所述回收绳配合，所述模拟测试车上设有参数捕捉模块，任一回收绳高度调节组件上设有云台摄像机。本实用新型测试成本低且能对拦阻钩动作时的瞬间进行深入分析，并通过试验测试可分析估算出回收绳的最优拉力以及拦阻钩最佳参数