Applications of a Nonlinear Controller Design Approach based on Quasilinear System Models

A new software tool for design of linear compensators

“…Alternatively, one could add es n terms (n = 1, 2) to the denominator until the order of the denominator equals that of the numerator. This is a standard practice in realizing such improper transfer functions as a pure derivative [2]. The numerical value of e must be selected such that this does not require unreasonably small integration step size, and it also must not be so large that it alters the behavior of the original transfer function.…”

“…The software is also of interest to graduate students participating in such courses as adaptive control and nonlinear systems when designing self-tuning compensators or designing a preliminary linear compensator before a fully nonlinear compensator is designed [1,2].…”

197 An approach to modeling and identification of systems with signal-dependent parameters

“…The so-called sinusoidal-input describing function models are input amplitude dependent [59][60][61]. Such a modeling approach is based on an assumption that the system nonlinearities can be lumped into an input-dependent function such as those of Hammerstein systems.…”

Fuzzy-logic controller synthesis based on sinusoidal-input describing functions and optimization

“…The SIDF basis of this work has been established previously: Taylor [2] outlined the motivation for using a modern' SIDF approach for control system design and established a systematic plan of attack, and both Taylor and Strobe1 [5,61 and Taylor and O'Donnell [7] presented several implementations of these concepts. More specifically, this modern SIDF approach was first applied in [5], where a linear PID (proportional-integralderivative) compensator in series with a single static nonlinearity was designed, and it was subsequently extended to the design of a fully nonlinear PID compensator, i.e., a PID controller with a nonlinearity in each of the three channels [6].…”

“…More specifically, this modern SIDF approach was first applied in [5], where a linear PID (proportional-integralderivative) compensator in series with a single static nonlinearity was designed, and it was subsequently extended to the design of a fully nonlinear PID compensator, i.e., a PID controller with a nonlinearity in each of the three channels [6]. Then the extension to independent rate-feedback and PI forward-path compensation was realized [7], and finally the use of the SIDF approach for control of nonlinear electro-mechanical systems with flexible members was accomplished [8], by combining an sm?-based inner-loop controller (to take care of drive-train nonlinearities) with an outer-loop linear controller (to deal with the flexible modes).…”