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Viewpoint Planning for Freeform Surface Inspection Using Plane Structured Light Scanners

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International Journal of automation and computing 2016年第1期13卷 42-52页

作者： Qian Wu Wei Zou De Xu research Center of Precision Sensing and Control Institute of Automation Chinese Academy of Sciences

This paper proposes an automatic model-based viewpoint planning method, which can achieve high precision and high efficiency for freeform surfaces inspection using plane structured light scanners. The surface model is utilized in stereolithography format, which is widely used as an industrial standard. The proposed method consists of 4 steps： topology reconstruction, mesh refinement, scan direction determination and viewpoint generation. In the first step, the topology structure of the surface model is reconstructed according to a designed data structure, based on which a neighborhood search algorithm is developed. In the second step, big facets in the surface model are segmented into several small ones, which are suitable for viewpoint planning. In the third step, an initial scan region of a viewpoint is grouped by the neighborhood search algorithm combining with total area and normal vector restrictions. Accordingly, the scan direction is determined by the normal vectors of facets in the initial scan region. In the fourth step, the position, the orientation, and the final scan region of the viewpoint are determined by 4 scan constraints, i.e., field of view, working distance range, view angle and overlap. Experimental results verify the effectiveness and advantages of the proposed method.

关键词： Freeform surface 3D measurement structured light scanner stereolithography (STL) viewpoint planning.

Calculation of eigenvalues and their distribution for linear systems

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Science China(Technological Sciences) 1998年第4期41卷 443-448页

作者：冯纯伯 1. research inst.tute of automation Southeast University 210096 Nanjing China

Two methods for calculating eigenvalues of linear systems are proposed. One is to use the root locus method to calculate the eigenvalues step by step from low order systems to high order systems. The other is to use the property of Schwartz matrix to determine the factors of the characteristic equation by the searching method. A method for determining the number of eigenvalues in each half complex plane is also presented.

关键词： eigenvalue distribution of eigenvalue stability analysis Schwartz matrix.

A TV-l_1 Based Nonrigid Image Registration by Coupling Parametric and Non-parametric Transformation

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International Journal of automation and computing 2015年第5期12卷 467-481页

作者： Wen-Rui Hu Yuan Xie Lin Li Wen-Sheng Zhang research Center of Precision Sensing and Control Institute of Automation Chinese Academy of Sciences

To overcome the conflict between the global robustness and the local accuracy in the dense nonrigid image registration,we propose a union registration approach using a l1-norm based term to couple the parametric transformation and the non-parametric transformation. On one hand, we take the parametric deformation field as a constraint for the non-parametric registration, which is a strong constraint that guarantees the robustness of the non-parametric registration result. On the other hand, the non-parametric deformation field is taken as a force to improve the accuracy of the parametric registration. Then, an alternating optimization scheme is carried out to improve the accuracy of both the parametric registration and the non-parametric registration. Moreover, accounting for the effect of spatially-varying intensity distortions and the sparse gradient prior of the deformation field, we adopt the residual complexity(RC) as the similarity metric and the total variation(TV) as the regularization. Because of the TV-l1-l2 composite property of the objective function in our union image registration, we resort to the split Bregman iteration for the complex problem solving. Experiments with both synthetic and real images in different domains illustrate that this approach outperforms the separately performed parametric registration or non-parametric registration.

关键词： Nonrigid registration free-form deformation non-pa

Rail Detection Based on LSD and the Least Square Curve Fitting

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International Journal of automation and computing 2021年第1期18卷 85-95页

作者： Yun-Shui Zheng Yan-Wei Jin Yu Dong College of automation and Electrical Engineering Lanzhou Jiaotong UniversityLanzhou 730070China automation research inst.tute Lanzhou Jiaotong UniversityLanzhou 730070China

It is necessary to rely on the rail gauge to determine whether the object beside the track will affect train operation safety or not.A convenient and fast method based on line segment detector(LSD)and the least square curve fitting to identify the rail in the image is proposed in this *** image in front of the train can be obtained through the camera *** preprocessing,it will be divided equally along the longitudinal *** the characteristics of the LSD algorithm,the edges are approximated into multiple line *** screening the terminals of the line segments,it can generate the mathematical model of the rail in the image based on the least *** show that the algorithm in this paper can fit the rail curve accurately and has good applicability and robustness.

关键词： Rail inspection line segment detector(LSD)algorithm the least square curve fitting foreign object detection

Substrate bias effects in p-channel GaN-on-Si transistors

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Science China(Information Sciences) 2025年第1期 404-405页

作者： Mengyao ZHAO Jie MA Lanlan YANG Chuanqi PAN Denggui WANG Jianjun ZHOU Sheng LI Jiaxing WEI Long ZHANG Siyang LIU Weifeng SUN National ASIC System Engineering research Center School of Integrated Circuits Southeast University National Center of Technology Innovation for Electronic Design automation Southeast University National Key Laboratory of Solid-State Microwave Devices and Circuits

The drain current （ID） of the n-channel GaN field-effecttransistor （n-FET） is influenced by the substrate-to-source bias voltage (VBS)（substrate bias effect）[1].Actually,nonzero VBSis also likely to occur in p-FET in real application,because the source electrode of p-FET is usually connected to high *** study reports the dependency between IDand VBSin p-FET for the first time,and analyzes the underlying mechanisms from the perspective of vertical electric field （EF） distribution.

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Iterative learning control of SOFC based on ARX identification model

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2007年第12期8卷 1921-1927页

作者： HUO Hai-bo ZHU Xin-jian TU Heng-yong Fuel Cell research lnstitute Department of Automation Shanghai Jiao Tong University Shanghai 200240 China

This paper presents an application of iterative learning control (ILC) technique to the voltage control of solid oxide fuel cell (SOFC) stack. To meet the demands of the control system design, an autoregressive model with exogenous input (ARX) is established. Firstly, by regulating the variation of the hydrogen flow rate proportional to that of the current, the fuel utilization of the SOFC is kept within its admissible range. Then, based on the ARX model, three kinds of ILC controllers, i.e. P-, PI- and PD-type are designed to keep the voltage at a desired level. Simulation results demonstrate the potential of the ARX model applied to the control of the SOFC, and prove the excellence of the ILC controllers for the voltage control of the SOFC.

关键词： Autoregressive model with exogenous input (ARX) lterative learning control (ILC) Solid oxide fuel cell (SOFC) Identification

Study on Distributed Motion of Self-Reconfigurable Robot Based on Local Rules

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Journal of Shanghai Jiaotong university(Science) 2007年第2期12卷 164-171页

作者：吴秋轩曹广益田华英费燕琼 inst.of automation Hangzhou Dianzi Univ. research inst.of Fuelcell Shanghai Jiaotong Univ. inst.of Robot Shanghai Jiaotong Univ.

The eigenvector of a module with six adjacent module's state was constructed according to self-reconfigurable robot M-Cubes and the configuration of system was expressed with the eigenvectors of all *** to the configuration and motion characteristics of the modules,a 3-dimension motion rule set was *** rule sets of each module was run according to eigenvector of the module after the motion direction of system decided and motion rules were *** last,the rapid and effective motion and metamorphosis were realized in *** rule sets are operated on three systems and the distributed motion of system is fully *** result of simulation shows that the 3-dimension motion rule sets has perfect applicability and *** motion steps and communication load of the modules increase with the module number in linear.

关键词： modular self-reconfigurable robot (MSRR) cellular automata local rules distributed control

Group consensus of multi-agent systems with additive noises

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Science China(Information Sciences) 2022年第10期65卷 242-255页

作者： Chuanjian LI Xiaofeng ZONG School of automation China University of Geosciences Hubei Key Laboratory of Advanced Control and Intelligent automation for Complex Systems Engineering research Center of Intelligent Technology for Geo-Exploration Ministry of Education

This paper is concerned with group consensus of multi-agent systems(MASs) that consist of two groups in additive noise environments. First, a control protocol is proposed based on the state information of each agent’s neighbors corrupted by additive noises. Second, some sufficient conditions and necessary conditions are obtained for the following two types of group consensus behaviors.(1) Pure group consensus:agents in both groups have the same behavior(weak consensus or strong consensus);(2) hybrid group consensus: agents in different groups achieve different consensus behaviors. It is revealed that the influence between the two groups should be attenuated such that the MASs can achieve group consensus in additive noise environments, i.e., the affected group must fight against.the influence that comes from another ***, some simulation examples are given to illustrate the feasibility of the theoretical results.

关键词： group consensus multi-agent systems additive noises pure group consensus hybrid group consensus

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Leader-following coordination of multiple UUVs formation under two independent topologies and time-varying delays

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Journal of Central South University 2017年第2期24卷 382-393页

作者：严浙平刘一博于长斌周佳加 College of automation Harbin Engineering University research School of Information Science and Engineering Australian National University

The new method which uses the consensus algorithm to solve the coordinate control problems of multiple unmanned underwater vehicles （multi-UUVs） formation in the case of leader-following is adapted. As the communication between the UUVs is difficult and it is easy to be interfered under the water, time delay is assumed to be time-varying during the members communicate with each other. Meanwhile, the state feedback linearization method is used to transfer the nonlinear and coupling model of UUV into double-integrator dynamic. With this simplified double-integrator math model, the UUV formation coordinate control is regarded as consensus problem with time-varying communication delays. In addition, the position and velocity topologies are adapted to reduce the data volume in each data packet which is sent between members in formation. With two independent topologies designed, two cases of communication delay which are same and different are considered and the sufficient conditions are proposed and analyzed. The stability of the multi-UUVs formation is proven by using Lyapunov-Razumilkhin theorem. Finally, the simulation results are presented to confirm and illustrate the theoretical results.

关键词： multiple unmanned underwater vehicles formation consensus algorithm Lyapunov-Razumikhin theory time-varying delay state feedback linearization method