Showing 12 results for Tehrani
M. M. Tehrani, M. R. Hairi-Yazdi, Ba. Haghpanah-Jahromi, V. Esfahanian, M. Amiri, A. R. Jafari,
Volume 1, Issue 2 (6-2011)
Abstract
In this paper, an adaptive rule based controller for an anti-lock regenerative braking system (ARBS) of a series hybrid electric bus (SHEB) has been proposed. The proposed controller integrates the regenerative braking and wheel anti-lock functions by controlling the electric motor of the hybrid vehicle, without using any conventional mechanical anti-lock braking system. The performance of the proposed system is evaluated by a comprehensive vehicle dynamics model in MATLAB/Simulink. Using the designed ARBS, the braking and regenerative performances of SHEB have significantly improved in slippery roads while the slip ratios are kept between 0.15 and 0.20.
P. Hosseini-Tehrani, S. Pirmohammad,
Volume 1, Issue 4 (12-2011)
Abstract
P. Hosseini Tehrani, M. Talebi,
Volume 2, Issue 3 (7-2012)
Abstract
In this paper, finite element elastic contact analysis of a functionally graded (FG) hollow brake disk in
contact with pad, subjected to rotation, contact pressure and frictional heat is presented. The material
properties vary through the thickness according to a power-law characterised by a grading index, n. The
material property is purely steel at the core part and gradually moves and approaches to the ceramic
properties at the surfaces of the FGM disk. In this task, thermal analyses are performed on two ventilated
disk brake one of them is constructed of functionally graded composite material and the other is a
homogeny disk brake which is constructed of steel alloy. In this study three-dimensional finite element
model and ABAQUS software is used. Through comparison of temperature and displacement fields the
benefits of using functionally graded material is investigated. It is shown that temperature variation in
FGM disk is much lower than steel disks, it may be concluded that FGMs disk restrain the growth of
thermal perturbation and delay the contact separation..
M. Esfahanian, A. Mahmoodian, M. Amiri, M. Masih Tehrani, H. Nehzati, M. Hejabi, A. Manteghi,
Volume 3, Issue 4 (12-2013)
Abstract
In the present study, a model of a large Lithium Polymer (Li-Po) battery for use in the simulation of Hybrid
Electric Vehicles (HEVs) is developed. To attain this goal, an Equivalent Circuit (EC) consisting of a series
resistor and two RC parallel networks is considered. The accuracy and the response time of the model for
use in an HEV simulator are studied. The battery parameters identification and model validation tests are
performed in low current with a good accuracy. Similar test process is implemented in high current for
another cell and the simulation is verified with experimental results. The validation tests confirm the
accuracy of the model for use in HEV simulator. Finally, the battery model is used to model a Vehicle, Fuel
and Environment Research Institute (VFERI) hybrid electric city bus using ADVISOR software and its
compatibility with other components of the vehicle simulator are demonstrated in a drive cycle test.
M. Masih-Tehrani , M.r. Hairi-Yazdi , V. Esfahanian,
Volume 4, Issue 2 (6-2014)
Abstract
In this paper, the development and optimization of Power Distribution Control Strategy (PDCS) have been
performed for a Hybrid Energy Storage Systems (HESS) of a Series Hybrid Electric Bus (SHEB). A
common PDCS is based on the use of Ultra-Capacitor (UC) pack. A new simple PDCS is developed as a
battery based one. For the battery based PDCS, four parameters are introduced for tuning the PDCS
performance. The Design of Experiment (DoE) method is utilized to optimize the parameters of the battery
based PDCS for the driving cycles and the vehicle controllers. The results show the optimized battery based
PDCS performance for some cases are better than the UC based PDCS performance. Vice versa, for some
cases the performance of the UC based PDCS is better than the battery based PDCS. Finally, the costs
rising from the HESS (about 66%) is reasonable when considering the over double increase in the battery
life-time when using an appropriate PDCS.
M. Masih-Tehrani, V. Esfahanian, M. Esfahanian, H. Nehzati, M.j. Esfandiary,
Volume 5, Issue 2 (6-2015)
Abstract
The Energy Storage System (ESS) is an expensive component of an E-bike. The idea of Hybrid Energy Storage System (HESS), a combination between battery and Ultra-Capacitor (UC), can moderate the cost of E-bike ESS. In this paper, a cost function is developed to use for optimal sizing of a HESS. This cost function is consisted of the HESS (battery, UC and DC/DC converter) cost and the cost of battery replacements during 10 years. The battery lifetime and riding pattern limit the life span of ESS. The “Portuguese standard NP EN 1986-1” riding pattern is used in this research. The Genetic Algorithm (GA) is used to solve the optimization problem. The results show that the cost and weight of HESS are clearly better than optimally sized battery ESS.
A. Otadi, M. Masih-Tehrani , S.m. Boluhari , A. Darvish-Damavandi ,
Volume 7, Issue 3 (9-2017)
Abstract
In this paper, a three-axle bus rollover threshold and the effective parameters are studied. The rollover threshold is a speed that automotive is passing without occurring rollover. The objective is a determination of the heavy vehicle rollover critical speed while turning. For this purpose, a three-axle bus is studied. The dynamic equations related to rollover is extracted, and then rollover criterion, which is LTR (Load Transfer Ratio) in this paper, is obtained. The governing equations are simulated in MATLAB software and then the effect of the parameters such as steering rate, road curvature radius, road bank slope and automotive effective parameters on the rollover critical speed is studied. Prior to the investigation of these parameters, due to validation of the simulation model in MATLAB, a three-axle bus with specific parameters values is placed under various maneuvers with different conditions in TruckSim software then results are recorded. In order to validate, these results are compared with the results which are achieved from MATLAB. After validation, the relation between effective parameters in rollover stability and vehicle speed for desire maneuvers is obtained and it is illustrated in form of function. The results of this research work can be used in road threshold speed without huge computation costs and expensive tests.
Prof. M.h. Shojaefard, Mr. M. Maleki, Dr. M. Masih-Tehrani, Mr. A.r. Sang-Sefidi, Mr. M.m. Niroobakhsh,
Volume 8, Issue 2 (6-2018)
Abstract
A combined hydraulic engine mount and buffer is proposed in this study for use in the mid-priced vehicle. In some vehicle design projects, an engine is selected to use in a new car design. To achieve the desired vibration conditions, the mount can be redesigned with exorbitant costs and long-term research. The idea of using a buffer in the combination of the conventional engine mount is to suggest a solution with affordable price which can improve mount vibration specifications. As a case study, the engine of Renault L90 (Dacia Logan), which name is K4M engine, is selected to use in the national B class automotive platform design. This automotive platform is designed at Automotive Engineering Research Center of Iran University of Science and Technology. The hydraulic engine mount is modeled in CATIA. Some tests are done to validate the simulation results. The conventional and buffer-equipped mount characteristics, which are determined by CATIA, is imported to Adams/Vibration software to evaluate the vibration behavior of the engine mounts. The results show that the use of buffer reduces the stiffness of mount, which should be 2 to 3 times lower than engine's frequency excitation. In some directions, the buffer-equipped mount has a better modal energy and isolation characteristics.
Mr Pouriya Rahimirad, Dr. Masoud Masih-Tehrani, Dr. Masoud Dahmardeh,
Volume 9, Issue 2 (6-2019)
Abstract
This paper investigates the effect of temperature on a hybrid energy storage system with various energy management systems. The hybrid energy storage system consists of a fuel cell, ultracapacitor and battery with associated DC/DC and DC/AC converters. The energy management strategies employed are the state machine control strategy, fuzzy frequency/logic decoupling strategy, minimization strategy of equivalent consumption (ECMS) and external energy maximization strategy (EEMS). Initially, a module of 3.3v 2.3Ah LiPo4 batteries consisting of 15 cells in series and 15 rows in parallel are studied without considering the temperature effect. In the next step, the studies are repeated considering the temperature variation effects. The current and SOC associated with the battery, the hydrogen consumption, and battery life are studied for each strategy. The results suggest that the errors associated with the battery life estimation, as well as the battery current are significant with and without considering the temperature effects with the values of 30% and 20%, respectively.
Mahdi Ajami, Hossein Jannat, Masoud Masih-Tehrani,
Volume 10, Issue 4 (12-2020)
Abstract
Braking test is one of the most important tests of a mechanized technical inspection line. In this study, the effect of tire pressure changes on the accuracy of the braking test results is investigated at technical inspection centers. This study is conducted in three stages. In the first step, the braking efficiency at different tire pressures is examined using a roller brake tester. In the second step, the tests at different pressures and velocities on the road are done. These tests are carried out in terms of stopping distance, to ensure the accuracy and reliability of the first step test results. The results of the first and second steps showed that the effect of tire pressure changes on the braking efficiency is significant. In the third step, the braking test results of a thousand vehicles that received technical inspection certificate are studied. Analysis of these results, considering the results of the first and second steps cleared that about 16% of vehicles that received technical inspection certificate have lower braking efficiency than the minimum acceptable efficiency. The obtained results specified the necessity of adjusting the pressure of tires before the braking test at vehicle technical inspection centers in Iran.
Mr Mohamadreza Satvati, Dr Abdolah Amirkhani, Dr Masoud Masih-Tehrani, Mr Vahid Nourbakhsh,
Volume 11, Issue 4 (12-2021)
Abstract
This paper experimentally investigates the trafficability of a small tracked vehicle on a slope. An increase in the angle of slope inclination may divert the vehicle from its path. In other words, the deviation of the vehicle is due to a sudden increase in the yaw angle. Also, the tip-over occurs at a specific slope angle. The locomotion of the small tracked vehicle on soils with different terramechanics (such as cohesion, internal friction angle, cohesive modulus, and friction modulus) is also simulated to evaluate its slope-traversing performance. Moreover, the impact of velocity and soil type on traversing a slope is measured. The proposed yaw angle control system is modeled for controlling the yaw angle of the tracked vehicle. This controller is designed through co-simulation. It keeps the tracked vehicle at zero yaw angle to achieve straight locomotion on slopes. It is compared to the PI, PID, and fuzzy controllers. The response of this controller is faster than PI and PID controllers. A Comparison between fuzzy and proposed yaw angle controller yields almost similar responses. The mechanism of the proposed yaw angle controller is also easier to understand. The precision of the controller's performance is measured by simulating over different terrains.
Mr Arash Darvish Damavandi, Dr Behrooz Mashhdi, Dr Masoud Masih-Tehrani,
Volume 13, Issue 3 (9-2023)
Abstract
This paper investigates the performance of the hydraulically interconnected suspension system with the full vehicle model of ride and handling. A sensitivity analysis has been performed by changing the coefficients of the cylinder and accumulator valves and the initial conditions of the accumulators in the default hydraulic circuits to determine the effect on the frequency and damping of the system response such as roll, pitch, and bounce. This study highlights the importance of the influence of all system parameters to investigate vehicle vibration characteristics. The results provide valuable insights for designers and engineers working on improving automotive suspension system performance. Damping and frequency of modes change up to 179% with the change of cylinder valves and 141% with the change of accumulator valves and 74% for the initial pressure of accumulators change in mentioned range.
