摘要：
The partial eigenvalue (or natural frequency) assignment or placement, only by the stiffness matrix perturbation, of an undamped vibrating system is addressed in this paper. A novel and explicit formula of determining the perturbating stiffness matrix is deduced from the eigenvalues perturbation theorem for a low-rank perturbed matrix. This formula is then utilized to solve the partial eigenvalue (or natural frequency) assignment via the static output feedback. The control matrix, output matrix and feedback gain matrix can be explicitly expressed and easily constructed.
摘要：
A novel method for partial eigenstructure assignment of undamped vibration systems using acceleration and displacement output feedback is presented in this paper. It is based on modifications of mass and stiffness that preserve partial eigenstructure. A numerical algorithm for determining the required control gain matrices of acceleration and displacement output feedback, which assign the desired eigenstructure, is developed. This algorithm is easy to implement, and works directly on the second-order system model. More importantly, the algorithm allows the output matrix and the input matrix to be specified beforehand and also leads naturally to a small norm solution of the gain matrices. Finally, some numerical results are presented to demonstrate the effectiveness and accuracy of the proposed algorithm. (C) 2015 Elsevier Ltd. All rights reserved.
关键词：
acceleration and velocity feedback;partial quadratic eigenvalue assignment;vibrating system;minimum norm;70J50;65F18;93B52
摘要：
The partial quadratic eigenvalue assignment problem (PQEVAP) is to shift a few undesired eigenvalues of a damped vibrating system to suitably chosen locations, while leaving the remaining eigenvalues and corresponding eigenvectors unchanged. In this paper, an algorithm for solving PQEVAPs and the minimum norm PQEVAP (MNPQEVAP) using acceleration and velocity feedback is proposed. It is shown that solving the PQEVAP here is transformed into solving an eigenvalue assignment of a linear system of a much lower order. Furthermore, the MNPQEVAP here can be efficiently solved by a gradient-based unconstrained optimization method with the derived gradient formula. This algorithm works directly on the second-order system model, and requires the knowledge of only the open-loop eigenvalues to be replaced and their corresponding eigenvectors. Lastly, through two numerical examples, the results of solving the MNPQEVAP under two different combined feedback signals, velocity and displacement signals, and acceleration and velocity signals, are compared from two points of view, i.e. the F-norms of their feedback matrices and the active control energy required from the actuators.
期刊：
Applied Mechanics and Materials,2013年274:299-302 ISSN：1660-9336
通讯作者：
Xiao, Yuan
作者机构：
[Xiao, Yuan; Chen, Ruomeng; Qian, Jianjun] China Special Equipment Inspect & Res Inst, Beijing, Peoples R China.;[Ye, Jianping] Wuhan Polytech Univ, Sch Mech Engn, Wuhan, Peoples R China.
通讯机构：
[Xiao, Yuan] C;China Special Equipment Inspect & Res Inst, Beijing, Peoples R China.
会议名称：
International Conference on Mechanical Engineering, Materials Science and Civil Engineering (ICMEMSCE 2012)
会议时间：
AUG 18-20, 2012
会议地点：
Harbin, PEOPLES R CHINA
会议主办单位：
[Xiao, Yuan;Chen, Ruomeng;Qian, Jianjun] China Special Equipment Inspect & Res Inst, Beijing, Peoples R China.^[Ye, Jianping] Wuhan Polytech Univ, Sch Mech Engn, Wuhan, Peoples R China.
会议论文集名称：
Applied Mechanics and Materials
关键词：
Amusement ride;Risk assessment;Risk matrix
摘要：
The probability of hazard of amusement rides is divided into 5 categories according to characteristics, and the degree of risk hazard is divided into 5 categories. The risk matrix of amusement ride was created according to risk matrix model. The risk categories were created according to the values of matrix elements. The risk knowledge table was created according to all links of life of amusement ride.
摘要：
According to the physical characteristics and safety requirements, the evaluation levels of special electromechanical equipment were created. The five-layer neural network model was created according to the multi-layer neural network model. The first layer is input layer, the last layer is output layer, and the others are hidden layers. The software structure of evaluation system was designed, and the main class diagram was designed with UML. The relations among views, data model and dispatch controller were designed with MVC pattern. The factory method was used to instantiate view objects according to the object creation pattern. The ITERATOR pattern of structural pattern was used to find out view objects in the view object aggregation. The strategy pattern of behavior pattern was used to encapsulate different neural network algorithms.
摘要：
The heat-transfer tubes and tube-sheets are the most complicated pressure parts in PWR steam generator. For analyzing the stress of heat-transfer tubes and tube-sheets, the geometry model of heat-transfer tubes and tube-sheet was constructed. The finite element grids were generated by ANSYS. According to operating temperature, the temperature field and temperature stress were calculated with ANSYS. The results show that the maximum stress is located on the inner wall of juncture of heat-transfer tubes and tube-sheet. According to the operating conditions of heat-transfer tubes and tube-sheet, the operating stress was calculated with ANSYS. The results show that stress changes on the juncture of heat-transfer tubes and tube-sheet.
摘要：
Based on the power spectral density (PSD) function of stochastic irregularities of the standard grade road and by means of inverse fast Fouerier transform (IFFT) based on discretized PSD sampling, an equivalent sample of stochastic road surface model in time domain was built. A one-dimensional model of stochastic road was developed into a 2D model of stochastic road surface. Through computer simulation practice based on the MATlab, a 2D sample of stochastic road surface in time domain was regenerated. Furthermore, given the sample data, the PSD was estimated and then compared with the theoretical 2D PSD Equation deduced from the one-dimensional PSD expreesion so as to prove the effectiveness and accuracy of the time-domain model regeneration of 2D stochastic road surface by means of IFFT method. The 2D stochastic road surface model directly provided basic road excitation input data for virtual prototyping (VP) and virtual proving ground (VPG) technology.
会议名称：
International Conference on Computational Materials Science (CMS 2011)
会议时间：
APR 17-18, 2011
会议地点：
Guangzhou, PEOPLES R CHINA
会议主办单位：
[Ye Jianping] Wuhan Polytech Univ, Dept Machine Engn, Wuhan, Peoples R China.^[Shi Linxiang] Shanghai Second Polytech Univ, Sch Comp & Informat, Shanghai, Peoples R China.
会议论文集名称：
Advanced Materials Research
关键词：
Dijkstra;Mobile robot;Path planning;Quantitative model
摘要：
According to free configuration space, the skeleton graph of working environment of mobile robots was constructed. The length of link of skeleton graph was quantified according the actual length of pathway and presented with quantitative length matrix. The width of link of skeleton graph was quantified by the width rate of pathway and robot body, and presented with quantitative width matrix. For a pathway with width changing, the width was quantified according to the minimum width of the pathway. For multiply pathways between two vertexes, the pathways were merged into one pathway. In dynamic environment, the matrix value of link was set to -1 for a pathway with obstacles. In Dijkstra algorithm, the coordination path planning of multiply robots was implemented by comparing the remaining capacity of pathway width and the robot body.
关键词：
data acquisition instrument;embedded system;ARM;Ping-Pang mechanism
摘要：
Based on ARM9 RSIC CPU AT91SAM9260 and WinCE, the wireless data acquisition instrument for amusement ride was designed and developed. According to Ping-Pang mechanism, two buffers are created to save real-time sampling data in turns and the full buffer is saved to SD card between sampling timeslot. When data acquisition instrument begins to sample, the sampling start time is saved to a start time index file, and at the same time a directory coded by sampling start time is created to hold sampling data files. To avoid high bit error rate (BER), the length of data transporting frame is not over 100 bytes. The shell and system commands were used to delete and copy data files at the end of instrument, and the system command was used to merge data files at the end of supervisory controller. The implementations of data file operating were described in detail. The data acquisition instruments were used to collect running data of amusement rides in many amusement parks.
