Tracking Of Periodic Reference Signals Research Articles

Roll Damping Using Voith Schneider Propeller: a Repetitive Control Approach

Abstract: Voith Schneider propellers are potential propulsion systems for dynamic positioning in offshore applications because of their fast and accurate thrust generation. An overlaid roll damping control by the same propulsion system is possible to reduce the influence of external disturbances. The paper at hand presents simulation results of roll damping control using a repetitive control approach. Repetitive control is a highly effective control technique for the compensation of periodic disturbances, or for exact tracking of periodic reference signals. Simulation results of repetitive control in roll damping will be compared with those from a classical approach. The simulation models as well as the disturbance signals are based on theoretical considerations as well as on verifying experiments in a towing tank. The robustness of the method has been investigated according to deviations from a purely periodic excitation as well as to the influence of propulsion saturation.

Low-order continuous-time robust repetitive control: Application in nanopositioning

A low-order repetitive control (RC) design in continuous-time for nanopositioning applications is presented. It focuses on achieving high performance and sufficient robustness to uncertainties. The design is mainly applicable to analog implementation, but due to the exceptionally low order, it also results in a fast and efficient digital implementation. Experimental results for an analog implementation using a bucket brigade device (BBD), as well as a digital implementation, is presented. RC can provide fast and accurate tracking of periodic reference signals, which is useful in many scanning probe microscopy and nanofabrication applications.

Analog Circuits to Implement Repetitive Controllers With Feedforward for Harmonic Compensation

A feedforward modification for both positive- and negative-feedback schemes of repetitive control is described. It was shown that repetitive controllers can be a useful tool for tracking of periodic reference signals and compensation of periodic disturbances, in other words, for harmonic compensation. It was shown that the feedforward modification considerably improves the frequency response and performance, providing higher gains with enhanced selectivity. Simple analog circuits are presented to implement both positive- and negative-feedback repetitive schemes. A description of the circuits and their corresponding experimental frequency responses are also given

Output regulation of periodic signals for DPS: an infinite-dimensional signal Generator

In this note, we consider output regulation and disturbance rejection of periodic signals via state feedback in the setting of exponentially stabilizable linear infinite-dimensional systems. We show that if an infinite-dimensional exogenous system is generating periodic reference signals, solvability of the state feedback regulation problem is equivalent to solvability of the so called equations. This result allows us to consider asymptotic tracking of periodic reference signals which only have absolutely summable Fourier coefficients, while in related existing work the reference signals are confined to be infinitely smooth. We also discuss solution of the regulator equations and construct the actual feedback law to achieve output regulation in the single-input-single-output (SISO) case: The output regulation problem is solvable if the transfer function of the stabilized plant does not have zeros at the frequencies i/spl omega//sub n/ of the periodic reference signals and if the sequence ([CR(i/spl omega//sub n/, A+BK)B]/sup -1/ /spl times/(Q/spl phi//sub n/-CR(i/spl omega//sub n/, A+BK)P/spl phi//sub n/)) /sub n/spl isin/z//spl isin/l/sup n2/. A one-dimensional heat equation is used as an illustrative example.

Analog circuits to implement repetitive controllers for tracking and disturbance rejection of periodic signals

In this paper, simple analog circuits to implement a repetitive control scheme are discussed. The repetitive control has shown to be a useful tool for tracking of periodic reference signals and for compensation of periodic disturbances. The main advantages of the proposed circuitry are: 1) no digital conversion required; 2) easy tuning to the corresponding frequency; and 3) cost effectiveness. A description of the circuits and corresponding experimental frequency responses are given.

A repetitive-based controller for the boost converter to compensate the harmonic distortion of the output Voltage

A novel repetitive based-control strategy is proposed for the pulsewidth modulated (PWM) boost converter to compensate the output voltage ripple due to the harmonic distortion present in the input voltage. Repetitive control has shown to be a useful tool for tracking of periodic reference signals and for compensation of periodic disturbances, in other words, for harmonic compensation. The structure of the proposed controller is preserved as close as possible to the conventional one, which includes outer and inner control loops. Thus, in the proposed controller, the repetitive strategy appears as a refinement term added to the inner control loop. We show that the repetitive strategy can be built using a single analog delay integrated circuit, thus, simplifying enormously the implementation. The repetitive strategy is able to cancel almost every remaining harmonic distortion component while maintaining an acceptable dynamical performance and without inclusion of additional hardware in the power stage. Experimental results on a boost converter board, using a poorly regulated voltage source, are presented to assess the performance of our approach.