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Sampling points in one cycle of 400 Hz inverter are 8 times less than that of 50 Hz inverter, resulting in lower control accuracy and larger static error in 400 Hz power supply system. This paper set up a mathematical model for single-phase solid-static power supply system. The transformer leakage inductance and load can be regarded as uncertainties. A robust controller based on the principle of mixed...
The linear motion of the Corner Cube Mechanism developed for the infrared sounder of the third generations of Meteosat weather satellites requires a high level of accuracy. The system is subject to external micro-vibration perturbations from surrounding instruments, which cannot be rejected with the current PID controllers with notch filters. A data-driven H∞ robust controller design method is proposed...
A general framework for the design of multivariable control systems subject to hard constraints on each control channel is developed. The design procedure is an extension of the well-known H∞ Loop Shaping Design Procedure and is based on the calculation of the maximum possible control amplitude for a certain class of reference signals. Special attention is given to the adaption of the design weights...
This paper presents a novel robust 2-degrees-of-freedom (2-DOF) positioning controller design methodology against frequency perturbations in mechanical vibration modes. The authors have already proposed an LMI (linear matrix inequality)-based feedforward (FF) compensator design to provide robust properties in positioning against the perturbations, where a feedback (FB) controller has been independently...
This paper presents a user-friendly loop-shaping method employing the Robust Bode (RBode) plot for optimizating the head-positioning system in a hard disk drive. The RBode plot represents the robust performance criterion as allowable and forbidden regions on the open-loop Bode plot. Using the RBode plot, control engineers can easily design controllers that suppress disturbances and account for perturbations...
Being an inherently unstable system, active magnetic bearing, with its envisaged widespread applications, is a potential research area in today's scenario. So far many controllers including the H- Infinity controller has been developed but a generalized design is lacking. In this paper a generalized design of H-infinity controllers for Magnetic bearings is proposed along with a novel automatic weight...
Since digital implementation of repetitive controllers is simpler than analog in many industrial applications, some design criteria for a discrete-time repetitive controller to suppress periodic disturbances within a specified frequency range are presented. The small gain theorem is applied to perform the controller design for system stability. Upper and lower bounds of the discrete-time repetitive...
A delay-locked loop of multi-band selector with wide-locking range and low power dissipation is presented. The architecture of the proposed delay-locked loop consists of phase frequency detector, charge pump, band selector, multi-control delay line, and start-up circuit. The multi-band selector is used to extend operation frequency of delay-locked loop by switching the multi-control delay line. The...
A high bandwidth critical path monitor (1 sample/ cycle at 4-5 GHz) capable of providing real-time timing margin information to a variable voltage/frequency scaling control loop is described. The critical path monitor tracks the critical path delay to within 1 FO2 inverter delay with a standard deviation less than 3 FO2 delays over process, voltage, temperature, and workload. The CPM is sensitive...
Traditional infrared detection system has small viewing field and low scanning speed, a new all-directional IRST system with high scanning speed is designed, which quickly images the whole spherical airspace on the infrared sensors by the reflector circumrotating in pitching and azimuth with high speed. The real-time processing system for high speed input images is constructed based on the processor...
In conventional hard disk drives, a control system compensates for the vibration in which frequency is higher than the Nyquist frequency by using a multi-rate filter that can decrease the gain above the Nyquist frequency. However, such a control system can only avoid instability that results from mechanical vibrations and cannot suppress the vibrations. In response to these problems, we proposed a...
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