Proc. SPIE. 6177, Health Monitoring and Smart Nondestructive Evaluation of Structural and Biological Systems V
KEYWORDS: MATLAB, Digital signal processing, Detection and tracking algorithms, Sensors, Field programmable gate arrays, Computer simulations, Platinum, Data processing, Structural health monitoring, Algorithm development
To continue with the development of a wireless sensing unit built upon an off-the-shelf FPGA development board presented by the authors at SPIE 2005, this paper outlines a further effort consisting of embedding onboard computations, simulation and validation of the FPGA-based wireless sensing unit that is able to collect, process and transmit data. This research supports the concepts of decentralized wireless sensor networks and local-based damage detection, where individual wireless sensor nodes are capable of performing intricate tasks and can eventually transmit the processed results. An FPGA-based hardware platform is thus looked upon as a major contender for performing this function in a proficient manner. Throughout this research, the principal design complexities, in terms of both hardware and software development, are kept to a minimum. Development cycle and monetary cost of the hardware are other major considerations for this research. Data processing functions including windowing, Fast Fourier Transform (FFT), peak detection, are implemented into the selected FPGA, when limitations of different design options are explored to yield a solution that optimizes the resources of the selected FPGA. Numerical simulations and laboratory validations are carried out to scrutinize the operations and flexibility of the design.
Proc. SPIE. 5765, Smart Structures and Materials 2005: Sensors and Smart Structures Technologies for Civil, Mechanical, and Aerospace Systems
KEYWORDS: Digital signal processing, Logic, Sensors, Field programmable gate arrays, Data processing, Civil engineering, Structural health monitoring, Logic devices, Analog electronics, Data communications
This paper presents the preliminary results of an investigation on the application of Field Programmable Gate Arrays (FPGAs) to civil infrastructure health monitoring. An off-the-shelf FPGA development board available at a comparable price to microprocessor development boards is adopted in this study. Advantages, disadvantages, feasibility and design concerns when using such a reconfigurable hardware architecture for implementing algorithms for structural health monitoring in a wireless sensor unit are studied in a showcase of implementing Fast Fourier Transform (FFT) in a wireless data transmitting setting.
This paper presents the preliminary findings of a study on data and system identification results (derived from collected data) in a wireless sensing environment. The goal of this study is to understand how various hardware design choices and operational conditions affect the quality of the data and accuracy of the identified results; the focus of this paper is packet and data loss. A series of experimental investigations are carried out using a laboratory shaking table instrumented with off-the-shelf Micro-Electro-Mechanical Systems (MEMS) accelerometers. A wireless sensing unit is developed to interface with these wired analog accelerometers to enable wireless data transmission. To reduce the overall design variance and aid convenient application in civil infrastructure health monitoring, this wireless unit is built with off-the-shelf microcontroller and radio development boards. The anti-aliasing filter and analog-to-digital convectors (ADC) are the only customized components in the hardware. By varying critical hardware configurations, including using analog accelerometers of different commercial brands, taking various designs for the anti-aliasing filter, and adopting ADCs with different resolutions, shaking table tests are repeated, the collected data are processed, and the results are compared. Operational conditions such as sampling rate and wireless data transmitting range are also altered separately in the repeated testing. In all of the cases tested, data is also collected using a wire-based data acquisition system to serve as a performance baseline for evaluation of the wireless data transmission performance. Based on this study, the challenges in the hardware design of wireless sensing units and data processing are identified.