Control of DC-DC converters is a complex task due to the inherent nonlinearity. There is intensive research in developing newer control strategies which should ensures stability of output voltage under varying load, input voltage and parameters variations. The paper is aimed to present possibilities of use fuzzy logic controller to control output voltage of a phase-shifted PWM (PS-PWM) soft-switching DC-DC converter. The converter is a full bridge DC-DC converter with a controlled output rectifier and an active snubber on the secondary side. Despite proven advantages of use of a fuzzy logic control for DC-DC converters, one of the main drawback can be considered computational demand, which could negatively affects the response of a converter on sudden changes of load and raise up the price of the converter, due that there is needed a microcontroller with higher computational capacity. To suppress the high computational demand of a FLC controller there is presented a look-up table controller, which is derived from the original FLC controller. In the paper are described two different suitable interpolation methods for look up table controller composition, and assessment of advantages and disadvantages of both methods.

The paper presents the study of an anti-lock braking system (ABS) that has been complemented by a fuzzy controller. The fuzzy controller was used to improve the braking performance of the vehicle, particularly in critical situations, for example, when braking a vehicle on wet road. The controller for the ABS was designed in the MATLAB/Simulink program. The designed controller was simulated on a medium-size vehicle model. During testing, three braking systems were simulated on the vehicle model. We compared the performance of a braking system without an ABS, a system with a threshold-based conventional ABS, and a braking system with the proposed ABS with a fuzzy controller. These three braking systems were simulation tested during braking the vehicle on a dry straight road and on a road with combined road adhesion. A maneuverability test was conducted, where the vehicle had to avoid an obstacle while braking. The results of each test are provided at the end of the paper.

The paper presents a novel control technique for a phase-shifted PWM (PS-PWM) soft-switching dc-dc converter. The converter is a full bridge dc-dc converter with controlled output rectifier and an active snubber on the secondary side. To solve the problems with nonlinear nature of the dc-dc converter a fuzzy logic control is used. The fuzzy logic controller design and simulation is presented. The performance of the designed fuzzy logic controller is compared to classical PI controller.DOI: http://dx.doi.org/10.5755/j01.eie.22.5.16334