tailieunhanh - Multisensor thiết bị đo đạc thiết kế 6o (P7)

MEASUREMENT AND CONTROL INSTRUMENTATION ERROR ANALYSIS Systems engineering considerations increasingly require that real-time I/O systems fully achieve necessary data accuracy without overdesign and its associated costs. In pursuit of those goals, this chapter assembles the error models derived in previous chapters for computer interfacing system functions into a unified instrumentation analysis suite, including the capability for evaluating alternate designs in overall system optimization. This is especially of value in high-performance applications for appraising alternative I/O products. . | Multisensor Instrumentation 6a Design. By Patrick H. Garrett Copyright 2002 by John Wiley Sons Inc. ISBNs 0-471-20506-0 Print 0-471-22155-4 Electronic 7 MEASUREMENT AND CONTROL INSTRUMENTATION ERROR ANALYSIS 7-0 INTRODUCTION Systems engineering considerations increasingly require that real-time I O systems fully achieve necessary data accuracy without overdesign and its associated costs. In pursuit of those goals this chapter assembles the error models derived in previous chapters for computer interfacing system functions into a unified instrumentation analysis suite including the capability for evaluating alternate designs in overall system optimization. This is especially of value in high-performance applications for appraising alternative I O products. The following sections describe a low data rate system for a digital controller whose evaluation includes the influence of closed-loop bandwidth on intersample error and on total instrumentation error. Video acquisition is then presented for a high data rate system example showing the relationship between data bandwidth conversion rate and display time constant on system performance. Finally a high-end I O system example combines premium performance signal conditioning with wide-range data converter devices to demonstrate the end-to-end optimization goal for any system element of not exceeding FS error contribution to the total instrumentation error budget. 7-1 LOW-DATA-RATE DIGITAL CONTROL INSTRUMENTATION International competitiveness has prompted a renewed emphasis on the development of advanced manufacturing processes and associated control systems whose complexity challenge human abilities in their design. It is of interest that conventional PID controllers are beneficially employed in a majority of these systems at 147 148 MEASUREMENT AND CONTROL INSTRUMENTATION ERROR ANALYSIS the process interface level to obtain industry standard functions useful for integrating process operations such as control tuning