Laurentiu Racila

Mathematical Algorithm for Calculating the Total Traffic Lights Cycle in Junctions

Because the current development of cities and increased motorization, mobility in the city/metropolis suffers greatly. In these conditions the development of new traffic control methods in junctions is important. Conditioned by the current technical development, control methods are developed more in the area of mathematical algorithms which can be used to control the traffic equipment’s with a new efficiency. So the new intelligent traffic control modes involve the use of even more efficient and faster mathematical algorithms.

Characterization of Sunflower Oil Biodiesel as Alternative for Diesel Fuel

Methyl esters from various vegetable oils have been increasingly used in diesel engines to partially substitute or replace petroleum fuels. In this present study biodiesel was produced from sunflower oil by base-catalyzed transesterification process. A 30 L per batch experimental installation was used to produce biodiesel using a molar ratio of alcohol to oil 6:1, a reaction temperature of 65 °C and a reaction time of 2 h. A characterization and quality evaluation were done by measuring viscosity, flash point, density, fatty acid compositions, elementary and thermal analysis of sunflower oil, sunflower oil biodiesel and petroleum fuel. The results show poor atomization due to the high viscosity with the increase of combustion chamber deposits. Biodiesel has less carbon and hydrogen content than diesel fuel. The process of volatilization for sunflower oil biodiesel initiates and finishes in temperatures that are much higher than diesel.

Smart Signalization and Public Transport Priority, a First Step to Smart Mobility in a Smart City

Smarty city is a current topic, growing very fast in the last years. This concept is linked as a winning strategy to solve some major problems of big cities, like pollution, traffic jams, energy consumption, etc. Smart city is the next level, a more complex concept of the much restrictive green city, being an extension of this one, involving a better urban zone, a smaller environmental footprint, a higher penetration of ICT in the city life. A very important component of a smart city is the urban mobility, a smart mobility in a smart city. The aim of the paper is the presentation of the first step in this direction, because a smart mobility involve a smart signalization first. To reduce the traffic jam in an cross junction, an adaptive signal master plan of the intersection are used, with the help of a dedicated software.

Mathematical method for studying passenger flows in Craiova Municipality public transport system

Public transport in general contributes to cleaner air and better quality of life in cities and reduces greenhouse gas (GHG) emissions. For this is important that the public transport system to be very well analysed in regards to displacement of daily trips. The aim of the paper is to get a new introspection into the measurements and mathematical equations that were used in calculating the displacement volume of trips in Craiova Municipality public transport system. The calculation method was developed in order to compensate the short time that was allocated to the real data collection from the public transport system and to better understand the random phenomena related to the variation in the volume of daily trip movements of passenger in Craiova public transport system.

Public transport traffic management systems simulation in Craiova city

Abstract Urban transport is a comprehensive and dynamic mechanism. Therefore, all the problems for improving and reorganization of the system can be examined only in the light of a systemic approach. Currently, public passenger transport is one of the most important branches of the urban development in cities and metropolis. Public passenger transport activity and all the steps taken to improve that activity are considered to be of great social importance. In the current stage of city development, one of the main tasks is to create a public passenger transportation system that is safe, affordable, economical, reliable and environmentally friendly. The important role of passenger transport in the citys economy and achieving important social services to the population, dictates the need to introduce measures in the system that are harmonious, balanced and effective. This can only be done, in the context of current development, only after the system as a whole is tested extensively through special traffic and management software.

Design of a Wheelchair Intended to Humans with Locomotors Disabilities

The purpose of this research is to develop a motorized wheelchair, to meet the special requirements of indoor use. A wheelchair prototype is developed, which uses two motors, controlled by a PWM controller. The PWM controller is based on a L298N Dual H-Bridge Motor Controller module with an Arduino board. The prototype has the ability to perform forward/backward motion and steering. These functions are controlled by a joystick mechanism, operated by disabled human. As a drive train from motors to wheels are used chain transmissions. Drive trains convert high motor speed to lower speeds but with increased torque. The proposed design solution allows wheelchair folding for transportation. Experimental tests carried out gives us a kinematic and dynamic characterization of the wheelchair.

Car Jack Based on 6R Overconstrained Mechanism

The paper presents a possible practical application based on two 6R overconstrained mechanism, more precisely 6R Wohlhart overconstrained mechanism. Two of these mechanisms are put in a mirror position, in order to obtain a car jack. The mechanisms are disposed in other position than the original one, three non-adjacent joints being constrained to remain in a fixed plane.

Design of a Transmission for Wheelchairs Intended to Humans with Locomotors Disabilities

In this paper is presented the development of a wheelchair intended to be use by the people with locomotors disabilities. They are presented various solutions of kinematics schemes proposed to be implemented as a mechanical transmission for the wheelchair. The developed wheelchair integrates a mechanical transmission which allows the movement in a straight line, and also in cornering. The mechanical transmission implemented contains a bevel gearbox. The purpose of the bevel gearbox is to multiply the moment transmitted to the motor wheels for movement on uneven terrain. They are presented aspects concerning the design of the wheelchair frame an of implemented bevel gearboxes.

One 6R Overconstrained Mechanism, Many Applications

The aim of the paper is to present many possible applications based on a very special 6R overconstrained mechanism. This mechanism is based on 6R Wohlhart overconstrained mechanism, but not in its original disposition, that is with one fixed element. A new spatial disposition is used, with three non-adjacent joints that are constrained to remain in a fixed plane. This disposition allows the conception of many possible devices. The input–output equations, special characteristics, the advantages and disadvantages of each device are presented.