摘要：
A new approach for the partial eigenvalue and eigenstructure assignment of undamped vibrating systems is developed. This approach deals with the constant output feedback control with the collocated actuator and sensor configuration, and the output matrix is also considered as a design parameter. It only needs those few eigenpairs to be assigned as well as mass and stiffness matrices of the open-loop vibration system and is easy to implement. In addition, this approach preserves symmetry of the systems. Numerical example demonstrates the effectiveness and accuracy of the proposed approach.
作者机构：
[陈喜娣; 尹荔松] Department of Electromechanical Engineering, Wuyi University, Guangdong, 529030, China;[蔡启舟] State Key Laboratory of Material Processing and Die & Mould Technology, Huazhong University of Science and Technology, Wuhan, 430074, China;[罗强] Mechanical Engineering Institute, Wuhan Polytechnic University, Wuhan, 430023, China
通讯机构：
[Cai, Q.] S;State Key Laboratory of Material Processing and Die & Mould Technology, Huazhong University of Science and Technology, Wuhan, China
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.
作者机构：
[Gartner, Hunter; Almenar, Eva] Michigan State Univ, Sch Packaging, E Lansing, MI 48824 USA.;[Li, Yana] Wuhan Polytech Univ, Mech Engn Coll, Wuhan, Peoples R China.;[Almenar, Eva] Michigan State Univ, 448 Wilson Rd,Room 130,Packaging Bldg, E Lansing, MI 48824 USA.
通讯机构：
[Almenar, Eva] M;Michigan State Univ, 448 Wilson Rd,Room 130,Packaging Bldg, E Lansing, MI 48824 USA.
摘要：
Aiming at the shortage of the traditional teaching mode in mechanical engineering subject, the three-dimensional teaching reform was put forward based on the cultivation of innovative ability. The principles of construction of three-dimensional teaching resources were considered and the system structure was brought according to the three-dimensional teaching objectives. Then the three-dimensional teaching methods were discussed in detail from four aspects, including teaching content, teaching mode, learning mode and teaching evaluation. Using this teaching reform, the teaching instruction function of the teachers and activeness of the students can be increased greatly, which helps to cultivate students' innovation ability.
摘要：
Considering the requirements of climbing obstacle and stairs for Explosive Ordnance Disposal (EOD) robot, a method about step feature extraction based on two-dimensional (2D) laser radar is in great demand. In this paper, we research the three-dimensional (3D) environment feature extraction (EFE) method including the 3D point clouds map construction, the line feature extraction and the plane feature extraction. The EFE method can be applied to feature extraction of the step vertical plane. Based on the method, we construct a 3D feature recognition system (FRS) using 2D laser radar. FRS can help us extract quickly the step vertical planes from 3D laser radar line map, thus can provide necessary environment information for the decision and action of EOD robot. We demonstrate the ability of FRS by applying it to some typical step environment.
摘要：
The traditional screw press has many disadvantages,such as the lower level of automation,the existing unstable control system and the longer response time.Through the research on the principle of pres
摘要：
By collecting different grade road images, standard sample library was established. Using fuzzy approach degree algorithm, the approach degree of reconstructed road surface and criterion of road was determined. Then power spectrum of road roughness was built. According to the parameters of power spectrum, we can obtain a 3d figure of road surface by improved harmonic superposition method.
