With the rapid advance of digital control hardware, it is time to take the simple but effective proportional-integral-derivative (PID) control technology to the next level of performance and robustness. For this purpose, a nonlinear PID and active disturbance rejection framework are introduced in this paper. It complements the existing theory in that (1) it actively and systematically explores the use of nonlinear control mechanisms for better performance, even for linear plants; (2) it represents a control strategy that is rather independent of mathematical models of the plants, thus achieving inherent robustness and reducing design complexity. Stability analysis, as well as software/hardware test results, are presented. It is evident that the proposed framework lends itself well in seeking innovative solutions to practical problems while maintaining the simplicity and the intuitiveness of the existing technology.
Gao, Zhiqiang, "From Linear to Nonlinear Control Means: A Practical Progression" (2002). Electrical Engineering & Computer Science Faculty Publications. 61.
Gao, Z. (2002). From linear to nonlinear control means: A practical progression. ISA Transactions, 41(2), 177-189. doi:10.1016/S0019-0578(07)60077-9
NOTICE: this is the author’s version of a work that was accepted for publication in ISA Transactions. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in ISA Transactions, 41, 2, (04-01-2002); 10.1016/S0019-0578(07)60077-9