Automotive Science and Engineering
Volume:4 Issue: 4, Autumn 2014

In recent years, need to increase the convenience of trips in railway vehicles causes that train operators and manufacturers focus on reducing the noise level which is sensed by passengers. In this paper, first the state of modeling acoustic noise in cab train is discussed and natural frequencies and acoustic mode shapes are derived and then formulation of acoustic pressure in the cab will be obtained. By utilizing field testing, the noise produced by diesel engine in the cabin of Pardistranset train (source of undesirable noise), has been measured and is used in simulating. In order to reduce the acoustic pressure, a secondary noise source is used which its Stimulation signal is obtained by phased PID controller. Then, active noise control will be investigated in two cases of single-channel and multi-channel. The result of actuating the controller shows that in central frequencies of one octave band, there is a reduction in the sound pressure level, loudness, and sound loudness level.

Robust control design of vehicles addresses the effect of uncertainties on the vehicle’s performance. In present study, the robust optimal multi-objective controller design on a non-linear full vehicle dynamic model with 8-degrees of freedom having parameter with probabilistic uncertainty considering two simultaneous conflicting objective functions has been made to prevent the rollover. The objective functions that have been simultaneously considered in this work are, namely, mean of control effort (MCE) and variance of control effort (VCE).The nonlinear control scheme based on sliding mode has been investigated so that applied braking torques on the four wheels are adopted as actuators. It is tried to achieve optimum and robust design against uncertainties existing in reality with including probabilistic analysis through a Monte Carlo simulation (MCS) approach in multi-objective optimization using the genetic algorithms. Finally, the comparison between the results of deterministic and probabilistic design has been presented. The comparison of the obtained robust results with those of deterministic approach shows the superiority robustness of probabilistic method.

Induction motors are the most commonly used in the traction industries and electric vehicles, due to their low primary cost, low maintenance costs, and good performance. Speed identification is needed for the induction motor drives. However, using of speed sensors in the induction motor drives is associated with problems such as, extra cost, reduced reliability, added mounting space, etc.. Therefore, many of the recent researches had been dedicated to sensor less induction motor drives. In the induction motor, the rotor speed is estimated using measured stator voltages and currents of the induction motor, as the sensor less drive. The rotor speed for sensor less induction motor drives can be estimated by various techniques, which is designed with respect to required accuracy and sensitivity against induction motor parameter variation. In this paper, comprehensive review of different induction motor speed estimation techniques for traction applications, their special features and advantages is presented.

Nowadays, the use of small vehicles is spreading among urban areas and one sort of these vehicles are three-wheeled vehicles (TWVs) which can be competitive with four-wheeled urban vehicles (FWVs) in aspects such as smallness, simple manufacturing, and low tire rolling resistance, fuel consumption and so on. The most critical instability associated with TWVs is the roll over. In this paper a tilt control mechanism has been modeled which can reduce the danger of roll over by leaning the vehicle towards the turning center in order to decrease the amount of lateral load transfer (LLT), and by doing so, system combines the dynamical abilities of a passenger car with a motorcycle. A 3 degree of freedom vehicle model is simulated at constant speed in MATLAB-Simulink environment and a fuzzy algorithm is developed to control such a non-linear system with appropriate tilting torque. Results are interpreted in presence and absence of controller with different longitudinal speeds and steering inputs the results are also compared to behavior of a similar FWV and this is concluded that the tilt control system could countervail deficiencies of the TWV compared to the FWV.

Many studies have been done on hybrid vehicles in the past few years. The full hybrid vehicles need a large number of batteries creating up to 300 (V) to meet the required voltage of electric motor. The size and weight of the batteries cause some problems. This research investigates the mild hybrid vehicle. This vehicle includes a small electric motor and a high power internal combustion engine. In most cases the car’s driving force is created by an internal combustion part. A small electric motor, which can operate as engine starter, generator and traction motor, is located between the engine and an automatically shifted multi-gear transmission (gearbox). The clutch is used to disconnect the gearbox from the engine when needed such as during gear shifting and low vehicle speed. The power rating of the electric motor may be in the range of about 15% of the IC engine power rating. The electric motor can be smoothly controlled to operate at any speed and torque, thus, isolation between the electric motor and transmission is not necessary. The present study evaluates the properties of the mild hybrid vehicle, its structure and performance and proposes an energy control model for its optimum operation.

Vehicular ad-hoc network (VANET) is an important component of intelligent transportation systems, in which vehicles are equipped with on-board computing and communication devices which enable vehicle-to-vehicle communication. Consequently, with regard to larger communication due to the greater number of vehicles, stability of connectivity would be a challenging problem. Clustering technique as one of the most important data mining techniques is a possible method that can improve the stability of connectivity in VANET. Stable communication within a VANET leads to enhanced driver safety and better traffic management. Therefore, this paper presented a novel clustering algorithm based on ant system-based algorithm called IASC in order to provide a fast clustering algorithm with high accuracy and improve the stability of VANET topology. A comparative study was proposed to analogize the results of the proposed algorithm with six VANET clustering algorithms in the literature which were taken as benchmarks. Results revealed improvement in stability and overhead on VANET.

If an air flow is injected into a liquid fluid, many ambulant air bubbles are formed inside the fluid. Air bubbles move inside the liquid fluid because of the buoyancy force, and the mobility of these air bubbles makes sizable commixture and turbulence inside the fluid. This mechanism was employed to enhance the heat transfer rate of a horizontal double pipe heat exchanger in this paper. However it can be used in any other type of heat exchanger. Especially, this method can be expanded as a promising heat transfer improvement technique in automotive cooling system, for instance in radiator which contains of water or other liquid fluid. Bubbles were injected via a special method. Present type of air bubbles injection and also the use of this mechanism for double tube heat exchanger have not been investigated before. Results are reported for varying bubble inlet parameters. The main scope of the present work is to experimentally clarify the effect of air bubble injection on the heat transfer rate and effectiveness through a horizontal double pipe heat exchanger.