Search results for "digital control"
showing 10 items of 20 documents
FPGA-based concurrent watchdog for real-time control systems
2003
A straightforward and efficient implementation of a custom concurrent watchdog processor for real-time control systems is presented. Emphasis is given to the techniques used for on-line checking the main processor activity without adding overhead, and to the advantages of a field programmable gate array implementation.
A Novel Linear-Non-Linear Digital Control for DC/DC Converter with Fast Transient Response
2006
In this paper, a digitally controlled multimodule DC-DC converter with fast transient response, based on a linear-nonlinear control is presented. The proposed digital control improves the stability of the system, cuts off the effects of limit-cycle and reduces the recovery time, by making the "effective" bandwidth of the system independent of the bandwidth of the linear control loop and limits, at the same time, output voltage variations. The digital control is AVP-compatible and halves the recovery time. Preliminary hardware tests on a single phase step-down converter are reported. The experimental results match simulation ones, obtained by modelling system with Matlab/Aldec mixed environm…
Ein einfacher Impulssummen-Schreiber zur digitalen Registrierung von Prozessabläufen
1972
The coordinate plotter summarizes impulses from digital control mechanisms geometrically in terms of time. It is possible to obtain additional impulses from the plotter by mounting of special switches.
A novel digital control for DC/DC converters to improve steady-state performances
2006
This paper describes an innovative digital PWM control implementation for low voltage, high current DC-DC converters. The proposed technique, based on the use of a low resolution DAC, improves steady-state performances, minimizing limit cycle effects. The novel technique is tested on a FPGA-based single phase buck converter operating at 250 kHz. A detailed description of the proposed architecture is given and test results, simulation and experimental ones, are shown
Architecture of a digital PFM controller for IC implementation
2006
This paper presents a digital controller architecture oriented to IC implementation. The classical digital pulse width modulator (D-PWM), using digital analog converter (DAC), is replaced with a Sigma-Delta (/spl Sigma//spl Delta/) modulator based on pulse frequency modulator (PFM) technique. Results of an investigation from a prototype for DC-DC converter, in terms of simulated and experimental performances, are reported, together with harmonic frequency investigation. The control function design is implemented on a field programmable gate array (FPGA). As a consequence of good agreement between simulated and experimental results, the proposed architecture realizes a digital control loop w…
A novel linear-non-linear digital control for DC/DC converters
2006
In this paper, a digitally controlled multi-module DC-DC converter with fast transient response, based on a linear-non-linear control is presented. The proposed digital control improves the stability of the system, cuts off the effects of limit-cycle and reduces the recovery time, by making the "effective" bandwidth of the system independent of the bandwidth of the linear control loop and limits, at the same time, output voltage variations. The novel digital control is AVP-compatible and halves the recovery time. Preliminary hardware tests on a single phase step-down converter are reported. The experimental results match simulation ones, obtained by modelling system with Matlab/Aldec mixed …
Non-linear digital control improving transient response: Design and test on a multiphase VRM
2010
Multiphase interleaved buck converters are widely used for point of load applications, especially for VRMs. Performance optimization issue often clashes with size and cost requirements thus leading the industrial and academic research to focus on advanced solutions. This paper presents a control technique for multiphase VRMs including two interacting sections: the linear loop implements a PWM peak current mode control and the nonlinear subsystem modifies few linear loop parameters under load transients only. Steady-state performances are affected by the linear control only while dynamic performance optimization is a non-linear algorithm issue. The proposed control system improves the dynami…
Digital power conversion system based on a sigma-delta modulator linear model
2005
This paper presents a new linear model for the sigma-delta (/spl Sigma//spl Delta/) modulator, based on modeling the nonlinear quantizer with a linear factor, and its input-to-output transfer function is given. The use of a 1-bit sigma-delta modulator in DC/DC power converter systems permits to implement a complete digital control. Results of an investigation from a prototype for a DC-DC converter are here reported. Using of a field programmable gate array allows implementing a simple variable control function. The modulator output produces a variable-frequency variable duty-ratio signal to control the switching power transistors.
Energy Based Characterization of Fatigue Behaviour of Cyclically Unstable Materials
2009
The paper presents a definition of a new energy based parameter which allows to better describe fatigue proprieties of materials, especially cyclically unstable materials in comparison with the Lagoda-Macha parameter. The proposed parameter distinguishes positive and negative work of external force and depends on the sign of the stresses in paths of strain in materials. It is used in laboratory tests for control of a fatigue process on hydraulic stand. A close-loop control system has been equipped with computer program based on MATLAB/Simulink module.
Modeling and simulation of a digital control design approach for power supply systems
2006
Electronic designers need to model and simulate system features as close as possible to its effective behaviour. Moreover, today, electronics systems are often composed of mixed analog and digital components. The increasing complexity has led to the use of different simulation softwares, each one specific for a particular level of abstraction: mathematical, circuital, behavioural, etc. In order to simulate the entire system these softwares should work together: co-simulation is necessary for digitally controlled power electronics systems. In this paper, the modeling of a digitally controlled switching power supply system using MATLAB/Simulink, ALDEC Active-HDL and Powersys PSIM is presented…