Digital Control Using Digital Signal Processing

Electronic Design Magazine

It's no secret that traditional analog controls are being superceded by digital ones. As this trend gains momentum, engineers are utilizing digital signal processors (DSPs) as controllers. In fact, with the declining cost of fixed- and floating-point DSPs, and simplification of the programming tools, more designers are using DSP solutions for control systems. Unfortunately, very little information is available about implementing DSPs in these control applications.
To fill that void, Farzad Nekoogar's and Gene Moriarty's textbook, Digital Control Using Digital Signal Processing (Prentice Hall, Upper Saddle River, N.J.), explains the use of DSPs in control applications. Nekoogar; technical manager at Intrinsix Corp., Westboro, Mass., lectures at the University of California Berkeley. Moriarity is a professor of electrical engineering at San Jose State University, Calif.
This book contains information based on material that was compiled for graduate and undergraduate electrical engineering courses on control systems. Yet in also was composed with the practicing engineer in mind. While the book's first half covers the basic analysis and design of control systems, the second part focuses on the fundamentals of DSPs and design techniques. Additionally, a section is devoted to selecting single-chip DSPs for control applications. This discussion is a good starting point, but it isn't sufficient for picking the right single-chip DSP from price and performance standpoints.
Readers who need more information on single-chip DSP selection must get it directly from the manufacturers. Key suppliers like Texas Instruments Inc., Dallas, Texas, and Analog Devices, Norwood, Mass., have optimized DSP chips with the right mix of peripherals, memories, and interfaces to solve a myriad of control problems. They also come with application notes to help users implement these DSP chips in control designs.
Furthermore, this book provides some examples of applying single-chip DSPs in several control-system applications. For instance, it describes an ac-motor-control system using Analog Devices's ADSP-2115 DSP chip and the ADMC200 motion coprocessor: The system comprises a permanent magnet ac servomotor with a shaft-mounted resolver, a three-phase power inverter, and the motor-control circuit using ADSP-2115, the ADMC200 and the AD2S90 resolver-to-digital converter: Similarly, it presents robotics examples, using TI's TMS320C25-based DSP board and software tools from dSPACE, paderborn, Germany-A supplier of DSP development tools.
While the last chapter contains a detailed example of motion control to illustrate modern design techniques like state controllability, observability, and pole placement, it also touches upon the basic ideas of fuzzy-logic control. And, the book includes several appendices to familiarize readers with design analysis software like MATLAB and MATRIXx, table of z and Laplace transforms, and popular motion controller boards available the industry.

Booknews

Begins with a review of digital control systems and their design and basic mathematical concepts including difference equations, the z- transform, and state-variable methods. Then applies the fundamentals of digital signal processors to such control systems, describing such state-space techniques as pole placement, state estimation, and optimal linear quadratic regulation. Also considers advanced topics, among them chaos in nonlinear control systems and fuzzy logic control. For practicing engineers, graduates, and advanced undergraduates with some background in linear systems theory and linear algebra and a familiarity with the CAE, MATLAB, and MATRIX software packages. Has been used in courses. Annotation c. by Book News, Inc., Portland, Or.