Continuous time controller based on SMC and disturbance observer for piezoelectric actuators

Abstract – In this work, analog application for the Sliding Mode Control (SMC) to piezoelectric actuators (PEA) is presented. DSP application of the algorithm suffers from ADC and DAC conversions and mainly faces limitations in sampling time interval. Moreover piezoelectric actuators are known to have very large bandwidth close to the DSP operation frequency. Therefore, with the direct analog application, improvement of the performance and high frequency operation are expected. Design of an appropriate SMC together with a disturbance observer is suggested to have continuous control output and related experimental results for position tracking are presented with comparison of DSP and analog control application

Modeling Piezoelectric Stack Actuators for Control of Micromanipulation

A nonlinear lumped-parameter model of a piezoelectric stack actuator has been developed to describe actuator behavior for purposes of control system analysis and design, and, in particular, for microrobotic applications requiring accurate position and/or force control. In formulating this model, the authors propose a generalized Maxwell resistive capacitor as a lumped-parameter causal representation of rate-independent hysteresis. Model formulation is validated by comparing results of numerical simulations to experimental data. Validation is followed by a discussion of model implications for purposes of actuator control

Piezoelektrik aktüatörler için analog kayan kipli denetleyici

Bu çalışmada Kayan Kipli Denetim (KKD) metodunun analog elektronikle uygulanması ve geliştirilen denetleyicinin piezoelektrik aktüatörlere uygulanması incelenmiştir. Sayısal uygulamalar öncelikle ADC ve DAC çeviricilerin yavaşlığı nedeniyle sınırlı hızlara erişebilirler. Öte yandan piezoelektrik aktüatörler neredeyse sayısal işlemcilerin çalışma frekansına yaklaşan yüksek rezonans frekansları ve sahip oldukları histerezis nedeniyle kontrolü güç, doğrusal olmayan sistemlerdir. Direk analog uygulama ile çalışma frekansında sınırlama olmadan performansın iyileştirilmesi beklenmektedir

Analysis and control of monolithic piezoelectric nano-actuator

The study of the monolithic piezoelectric actuator, the dominant type of micropositioner is an attractive and challenging area, where realtime control theory and digital signal processing are effectively applied. The actuator can be applied in precision instruments and precision control, such as microscopes, medical and optics instruments because of the piezoelectric ceramic\u27s high resolution, fast transient response, and potential low cost. However, hysteresis nonlinearity and lightly damped vibration exist in the system, which limit the actuator applications. This work focuses on the hysteresis characteristics in time and frequency domains along with experimental and simulated results to verify the effectiveness of the model in describing the hysteresis phenomena. The analytic expressions of the hysteresis harmonics are further applied in hysteresis parameter estimation. A reduced order nonlinear hysteresis observer compensator is proposed, and the stability of the compensated system is discussed. The compensator reduces the hysteresis effect significantly under simulated and experimental conditions. Furthermore, an adaptive hysteresis observer compensator is further presented to compensate the slowly changed hysteresis parameters. Time division multi-control strategy is proposed to implement fast transient response, low vibration and high resolution. Extensive numerical simulation and real-time experiment are carried out to verify the control strategies. GUI is developed to implement the communication between the code in DSP memory and Labview, which improves the efficiency in system test