Modern data analysis techniques has been successfully applied in many technical disciplines to understand the complexity of the system. The growing volume of theoretical knowledge about systems dynamic's offered researchers the opportunity to look for non-linear dynamics in data whose evolution linear models are unable to explain in a satisfactory manner. One of the most recent approach in this respect is Recurrence Analysis - RA. It is a graphical method designed to locate hidden recurring patterns, nonstationarity and structural changes. RA approach have first been applied in natural sciences like physics and biology. Quickly, was adopted in economics and engineering. Meanwhile, the fast development of computer resources has provided powerful tools to perform this new and complex model. One free software which we used to perform the analysis is Visual Recurrence Analysis - VRA developed by Eugene Kononov. As is presented in this paper, the recurrence plot investigation for the analyzing of the gasoline engine shows some of the its capabilities in this domain. We chose two specific engine parameters measured in two different tests to perform the RPA. These parameters are ignition angle and engine angular speed. There were computed graphs for each of them. Graphs were analyzed and compared to obtain a conclusion. This work is an incipient research, being one of the first attempt of using recurrence plot for analyzing automotive dynamics. It opens a wide field of action for future research programs.
Flow corrections established based on Lambda control system of spark ignition engines, determines in a decisively way the quality of air-fuel mixture. Faults in the operation of the control system generates deviations of the mixture composition from stoichiometric report, in this way affecting the entire combustion process in engine cylinders. This phenomenon leads, among others, to changes regarding the density of pollutant emissions from exhaust gases. In this context, this paper presents experimental researches made using the simulation of faults that may occur in the control system to highlight their influence on the concentration of engine emissions.
Abstract:The paper proposes a theoretical analysis of kinematic and dynamic performances of several elements in the composition of a combat vehicle shutter's hydraulic system, using LMS AMESim, specialized CAE software.
System descriptionThe project refers to a controlled opening system for a combat vehicle shutters. These shutters are disposed on the ceiling housing armor. Their opening is done with hydraulic cylinders, one for each one.Hydraulic installation scheme was carried out in order to meet the requirements imposed in the development operational project. These requirements are: The maximum opening/closing time to not exceed 15 second; The system must be provided with a hydraulic discharge element, for manual manipulating in case of damage; Hydraulic pump powered at 24 V. The mass of a shutter to not exceed 150 kg The designed actuating system of shutters is a hydraulic system with electrical command. The electricity used to power the system's pump is obtained from additional installed electric generator inside of vehicle or from vehicle batteries.The system's command is realized from an electrical panel. In case of damage, this system allows manual operation of the shutters.The hydraulic system diagram of shutter's actuating (shown in figure 1) has the following components:
The paper aims at issuing of a virtual simulation model that would be able to assess the actual working modes of a torque converter, both hydraulically and mechanically. To estimating the dynamic behavior we used the assessing equations of the converter’s performance coefficients. The rotational inertial phenomena due to the transient regimes during the getaway phase are also considered. The modeling process assumed the use of the pre-defined structures of the Simulink-Matlab and Simscape-Matlab modules. The virtual model of the torque converter was fed with the experimentally determined, performance parameters as input. The input also consisted of the inertia moments of the converter’s components. Eventually, by interrogating the simulation model, we’ve got and plotted the time histories of the converter’s impeller and turbine angular velocities during the vehicle’s getaway process.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.