Integration of VXI data acquisition into matlab

Engineering Information Abstracts (Part II) Corporate Source: Tennessee Technological Univ, Cookeville, TN, USA Conference Title: Proceedings of the 1998 16th International Modal Analysis Conference. Part 2 Žof 2. Conference Location: Santa Barbara, CA, USA Conference Date: 1998020219980205 Source: Proceedings of the International Modal Analysis Conference - IMAC v 2 1998. SEM, Bethel, CT, USA. p 1560-1565 CODEN: PMCNEW ISSN: 1046-6770 Publication Year: 1998 EI Order Number: EIP98044165538 Abstract: A ruggedized field measurement system for determining wood pile lengths of existing bridges is presented. The development of the measuring system was the goal of a two year funded research project sponsored by the Tennessee Department of Transportation. The measurement technique is based on longitudinal vibration theory. Determination of the wave speed in the wood and the resonant frequencies of a pile will yield the length estimation. The equipment package uses piezoelectric actuators, random excitation, and force and accelerometer transducer responses to generate the required data for length assessment. The data acquisition and processing occur in the field and are controlled by a LabWindowsrCVI custom program. An electronic pulse and special signal conditioning are used for determining accurate delay time between accelerometer locations for the wave speed calculation. Random excitation is used to generate the power spectral densities and frequency response functions of the transducers attached to the pile. Typical field data will be discussed along with the results from preliminary field tests. ŽAuthor abstract . 4 Refs. In English Keywords: Piles; Wooden construction; Bridges; Vibrations Žmechanical .; Structural analysis; Actuators; Piezoelectric devices; Transducers; Computer software; Data acquisition

Title: INTEGRATION OF VXI DATA ACQUISITION INTO MATLAB Author(s): Fladung, William A.; Phillips, Allyn W.; Brown, David L.; Olsen, Norm; Lurie, Roy Corporate Source: Univ of Cincinnati, Cincinnati, OH, USA Conference Title: Proceedings of the 1998 16th International Modal Analysis Conference. Part 2 Žof 2. Conference Location: Santa Barbara, CA, USA Conference Date: 1998020219980205 Source: Proceedings of the International Modal Analysis Conference - IMAC v 2 1998. SEM, Bethel, CT, USA. p 1089-1093 CODEN: PMCNEW ISSN: 1046-6770 Publication Year: 1998 Abstract: This paper describes the integration of VXI data acquisition into MATLAB, which has applications in education, research and industry. VXI is a non-proprietary standard for instrumentation quality data acquisition hardware and MATLAB is a high-level programming environment. MATLAB is linked to the VXI hardware through a plug& play library, and data is read directly into MATLAB for numerical computations. With the MATLABrVXI interface, a multichannel dynamic signal analyzer or application specific measurement software can be developed. The proof of concept is

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demonstrated with a multiple reference impact testing application. ŽAuthor abstract . 4 Refs. In English EI Order Number: EIP98044165467 Keywords: Data acquisition; Data reduction; Computer software; Standards; Computer hardware; Software engineering; Computational methods; Interfaces Žcomputer.; Impact testing; Signal processing

Title: MODULAR, WIRELESS NETWORK PLATFORM FOR MONITORING STRUCTURES Author(s): Straser, E.G.; Kiremidjian, A.S.; Meng, T.H.; Redlefsen, L. Corporate Source: Stanford Univ, Stanford, CA, USA Conference Title: Proceedings of the 1998 16th International Modal Analysis Conference, IMAC. Part 1 Žof 2. Conference Location: Santa Barbara, CA, USA Conference Date: 19980202-19980205 Source: Proceedings of the International Modal Analysis Conference - IMAC v 1 1998. SEM, Bethel, CT, USA. p 450-456 CODEN: PMCNEW ISSN: 1046-6770 Publication Year: 1998 Abstract: Continuous monitoring of structures has recently become an area of great activity in both the research community and commercial sector. The vast majority of published work has focused on developing algorithms to advance the detection and diagnosis of structures. An equally important task is the establishment of a flexible hardware platform capable of real-time data acquisition. Many of the existing monitoring strategies assume a sophisticated hardware infrastructure. Such an assumption ignores the issues of up-front cost, relative total costrinformation benefit, system installation, and life-time maintenance. A multidisciplinary research program at Stanford University, between the Electrical, Mechanical, and Civil Engineering Departments, has developed a hardware platform based on embedded systems and wireless networks to realize the needs of the monitoring community. Our approach has been to determine the desired qualities of a structural monitoring system and design both the hardware to acquire and manage such data and the software to facilitate damage detection diagnosis. A monitoring platform based on embedded systems and wireless packet-switching networks allows for a relatively low-cost, unobtrusive, and maintainable network of ’sensor units.’ The embedded system approach pushes intelligence forward in the monitoring system, relieving the data acquisition and computational burden of a central computer and enabling local decision analysis and data processing. A wireless packet-switched network eliminates cabling installation, cable maintenance, and signal degradation over long distances. A functional network of ’sensor units’ is demonstrated. The hardware and software co-design issues are addressed. The implications for practical deployment using such a network of modular units are discussed. ŽAuthor abstract. 5 Refs. In English EI Order Number: EIP98044165205 Keywords: Structures Žbuilt objects.; Monitoring; Data acquisition; Computer hardware; Packet networks; Design; Computer software; Defects