Lateral tape displacement in a tape drive is believed to be one of the critical limiting factors in achieving high track density in tape storage media. For improving track density, servo control systems can be designed on the basis of information from a position error signal to improve the track following capabilities in a tape drive. In this paper, we consider the characterization of lateral t...

The paper presents an indirect adaptive regulation algorithm for the attenuation of unknown narrow-band disturbances. The main features of this new scheme are: (i) the use of adaptive Band-stop Filters (BSFs) tuned at the frequencies of the disturbance and (ii) a procedure for direct identification of frequencies contained in the disturbance. The use of adaptive BSFs allows to introduce the des...

A l~ t r~e t -A novel matrix fraction solution to the discretetime LQ stochastic tracking and servo problems is extended to the disturbance rejection problem. Unlike recent contributions, here the resulting control law at time t is given in terms of an expectation conditioned to the accessible disturbance given up to time t + k. If k is positive and large enough, the optimal feedforward input c...

In the resonance ratio control, which we proposed for vibration suppression and disturbance rejection in torsional system, the estimation speed of the disturbance observer should have been much faster than the resonance frequency of the controlled system. However, too fast disturbance observer sometimes causes implementation problem. In this paper, we give the optimal speed of the disturbance o...

In this paper, measurable disturbance compensation techniques are analyzed, focusing the problem on the input-output and disturbance-output time delays. The feedforward compensation method is evaluated for the common structures that appear between the disturbance and process dynamics. Due to the presence of time delays, the study includes causality and instability phenomena that can arise when ...

A tracking control algorithm based on a disturbance estimation scheme is studied. The tracking control problem is formulated as a disturbance rejection problem, with all the system nonlinearities and uncertainties lumped into disturbance. A disturbance estimation scheme is proposed, which is based on a nominal linear plant dynamics plus proportional error feedback corrections. The tracking cont...

Recently, active disturbance rejection control (ADRC) scheme has been widely used for current regulation in ac drive systems owing to its robustness system uncertainties and high disturbance-rejection capability. However, it not considered as an option high-speed drives usually operated at limited switching sampling frequencies. Therefore, this article thoroughly analyzes discusses the effects ...