Shenyang Institute of Automation,Chinese Academy Of Sciences
Not a member yet
23582 research outputs found
Sort by
基于自适应阈值图像二值化的AUV水下对接导引灯光信号提取与识别方法
No full text基于自适应阈值图像二值化的AUV水下对接导引灯光信号提取与识别方法，能够从导引图像中提取出导引灯，并识别导引灯编号。所述方法包括：通过分析导引图像的特征，提出导引图像二值化的自适应阈值计算方法；基于Retinex算法提取导引图像R和G分量的反射图像，将二者反射图像和B分量叠加后的均值作为新的图像，进行自适应阈值二值化处理，利用形态学处理提取出导引灯；基于导引灯空间位置关系制定了导引灯编号识别规则，识别出了导引灯编号。本发明可以应用于AUV水下对接导引领域，为基于图像的AUV水下对接控制提供了感知手段
Cascaded effect in a high-peak-power terahertz-wave parametric generator
No full textWe demonstrate megawatt-level terahertz (THz)-wave generation via a Stokes-seed-injected THz-wave parametric generator and study the cascaded effect. The optical-toTHz conversion efficiency was 1.72x10(-3), and the peak power was conservatively estimated to be 1.09 MW using the pulse width of the pump. More than 80% of the THz-wave energy came from primary parametric generation, with the rest coming from high-order parametric amplification. Clear cascaded Stokes spots of second to fourth order were observed, and the factors affecting the high-order parametric process are discussed. The cascaded parametric effect is beneficial for achieving a higher optical-to-THz conversion efficiency, thereby improving the performance of high-peak-power THz-wave parametric sources. (C) 2021 Optical Society of Americ
Static and dynamic performances of sandwich plates with magnetorheological elastomer core: Theoretical and experimental studies
No full textThis paper investigates the static and dynamic performances of sandwich plates with magnetorheological elastomer (MRE) core, in which the MRE core includes two copper wire layers, two inner metal layers, and one MRE layer. First, based on the complex modulus method, the Jolly theory and the pre-defined magnetic coefficients, the dynamic moduli, and loss factors of MRE are assumed as a function of magnetic induction intensity. Furthermore, a theoretical model of the MRE sandwich plates (MRESPs) is proposed, which considers the internal magnetic field excitation and four types of panel materials, namely fiber-reinforced polymer (FRP), fiber-reinforced polymer with carbon nanotubes (CNT-FRP), metal and fiber-metal hybrid (FMH) panels. After the deformation and energy equations are derived to solve the static bearing stiffness, dynamic stiffness, and damping parameters, some literature results are employed to provide the initial validation of the model developed. Subsequently, four MRESP specimens with the FRP, CNT-FRP, metal, and FMH panels are fabricated and measured to further verify the model as well as to evaluate the mechanical performance. The influence of critical geometric and material parameters related to MRE on static and dynamic properties is also discussed to summarize some practical conclusions for engineering applications
Surface topography by water jet-guided laser texturing on wettability of monocrystalline silicon
No full textAt present, the use of microstructure to change the optical properties and wetting properties of the material itself has become the main means to improve the utilization rate of materials in the manufacturing industry. Due to the hydrophilicity of the material surface can achieve underwater self-cleaning, directional transportation function, it becomes an indispensable part of surface modification. Water jet-guide laser processing can significantly reduce the formation of the heat-affected zone and crack, and can clearly ablate the material, with higher precision and resolution. In this experiment, the effects of scan spacing, laser output power and channel aspect ratio are examined and processing conditions for achieving near superhydrophilicity are provided. Owing to the anaerobic processing environment, the surface chemical composition of the material does not change, and the hydrophilicity is increased by 8% to 43% compared with that before. Increasing the aspect ratio can increase the wettability, when the aspect ratio is more than 1.63, the wettability begins to rebound, and the wettability becomes worse. Using small laser power and multiple scanning processing scheme can make the surface covered with tiny small pillars of micro-nano particles layer beneficial to increase the droplet adhesion, and the minimum contact angle can reach 37.2°</p
Optogenetically engineered cell-based graphene transistor for pharmacodynamic evaluation of anticancer drugs
No full textRapid and effective cell-based pharmacodynamic evaluation in vitro is crucial for providing an experimental basis for the effectiveness and safety of drugs, and the existing cell-based methods for pharmacodynamics evaluation are usually invasive, dependent on chemical reagents, and/or unable to monitor the process in real time. Here, an optogenetically engineered cell-based graphene transistor is presented as a biosensor for the pharmacodynamic evaluation of anticancer drugs. The biosensor consists of a bare graphene transistor and optogenetically engineered cells as the gate terminal. The photoresponse of engineered cells regulates the output of the transistor and the increment pattern in the transistor output current upon drug action can be used to evaluate the drug efficacy. The results show that the optogenetic engineering of cancer cells does not affect the killing effect of drugs on the cells, and validate the effectiveness of the biosensor. The patterns of photoinduced increments exhibit significant variation with drug action time within 4 h or drug concentration in a range of 1 nM to 1 mM, and can qualitatively characterize the drug efficacy. Furthermore, the drug efficacy can be quantitatively evaluated with an indicator by logarithmically fitting the photoinduced increment patterns. The result also shows that the drain–source voltage significantly affects the evaluation performance and it is necessary to calibrate the voltage value to enhance the performance of the biosensor. The proposed biosensor affords simple, non-destructive, and time-efficient pharmacodynamic evaluation in vitro and is significant to understand the effect and mechanism of drugs in its early development stage.</p
A multiagent deep deterministic policy gradient-based distributed protection method for distribution network
No full textRelay protection system plays an important role in the safe and stable operation of distribution network (DN), and the traditional model-based relay protection algorithms are difficult to solve the impact of the increasing uncertainty caused by distributed generation (DG) access on the security of DN. To solve this issue, first, the relay protection characteristics of DN under DG access are analyzed; second, the DN relay protection problem is transformed into multiagent reinforcement learning (RL) problem; third, a DN distributed protection method based on multiagent deep deterministic policy gradient (MADDPG) is proposed. The advantage of this method is that there is no need to build a DN security model in advance; therefore, it can effectively overcome the impact of uncertainty caused by DG access on DN security . Extensive experiments show the effectiveness of the proposed algorithm
Industrial process control method based on local policy interaction exploration-based deep deterministic policy gradient
No full text为了实现对非线性、滞后性和强耦合的工业过程稳定精确控制，提出了一种基于局部策略交互探索的深度确定性策略梯度（LPIE-DDPG）的控制方法，用于深度强化学习的连续控制。首先，使用深度确定性策略梯度（DDPG）算法作为控制策略，极大减小控制过程中的超调和振荡现象；同时，使用原控制器的控制策略作为局部策略进行搜索，以交互探索规则进行学习，提高了学习效率和学习稳定性；最后，在Gym框架下搭建青霉素发酵过程仿真平台并进行实验。仿真结果表明，相较于比例-积分-微分（PID）和DQN,LPIE-DDPG在学习效率上提升了27.3%；在控制效果上有更小的超调和震荡；在产量上青霉素浓度提高了3.8%。所提方法能有效提升训练效率，同时提高工业过程控制的稳定性。</p
Research on prefabricated component production line mold platform combination method
No full textAbstract
In traditional prefabricated component manufacturing enterprises, there are often problems such as low utilization rate of the platform surface due to poor production plans of the enterprise, resulting in waste of production resources and low production capacity of the enterprise. In order to solve the problem of mold platform combination allocation in the production process of prefabricated component manufacturers, a mold platform combination allocation method based on the combination of machine learning and backtracking is proposed. The backtracking method is used to search for the theoretical best fit combination result, and the improved BL is used. The positioning algorithm simulates the placement process of the mold on the platform, and uses the Apriori algorithm to train the obtained data set to obtain the association rules contained in the frequent item set. When the enterprise re-produces, the prefabricated components are combined according to the association rules for production, and the utilization rate of the platform is improved. The simulation test is carried out with the example data of the prefabricated component manufacturing enterprise, which verifies the effectiveness of the combination allocation method of mold and platform combined with the backtracking method and the Apriori algorithm to solve the problem
A Unified Framework for Large-scale Occupancy Mapping and Terrain Modeling using RMM
No full textBuilding suitable representations for diversified environments to enable robot autonomous navigation is a complicated task, especially for large-scale environments, where the captured vast amount of data will give rise to computation and storage bottlenecks. In this letter, we first propose the random mapping method (RMM), which can efficiently project the irregular points in the low-dimensional data set into the high-dimensional one, where the points are approximately linearly separable or distributed. In the mapped space, we then propose a unified environment modeling framework in the form of linear parametric model, which can represent the occupancy maps and terrain models consistently. Adopting the idea of parallel computing, we then apply our method to the large-scale environment modeling to reduce the wall-clock time of calculation without losing much accuracy. Experiments were fully conducted to evaluate the proposed random mapping method and the proposed environmental modeling method, showing their better comprehensive performance compared to the typical methods and state-of-the-art methods.</p
