Showing 6 results for Kazemi
M. Abbasi, R. Kazemi, A. Ghafari Nazari,
Volume 1, Issue 3 (5-2011)
Abstract
Parametric design optimization of an automotive body crashworthiness improvement is presented. The thicknesses of parts are employed as design variables for optimization whose objective is to increase the maximum deceleration value of the vehicle center of gravity during an impact. Using the Taguchi method, this study analyzes the optimum conditions for design objectives and the impact factors and their optimal levels are obtained by a range analysis of the experiment results. A full frontal impact is implemented for the crashworthiness simulation in the nonlinear dynamic code, LS-DYNA. The controllable factors used in this study consist of the six inside foreheads structural parts, while design parameters are relevant thicknesses. The most interestingly the maximum deceleration of the vehicle center of gravity is reduced by 20% during a full frontal impact while several parts experience mass reduction.
M. A. Saeedi, R. Kazemi, M. Rafat, A. H. Pasdar,
Volume 2, Issue 2 (4-2012)
Abstract
In this paper, a complete model of an electro hydraulic driven dry clutch along with its
performance evaluation has elucidated. Through precision modeling, a complete nonlinear
physical and full order sketch of clutch has drawn. Ultimate nonlinearities existent in the
system prohibits it from being controlled by conventional linear control algorithms and to
compensate the behavior of the system mainly during gearshift procedure, a nonlinear control
program has been developed and tested. A unique approach to estimating clamp force has been
adopted which makes the system comparable to a real world and full-physical one. Based on
this type of modeling, the control approach is a true and feasible, ready-to-implement program
which is based only on reality. The clutch model has been validated against experiments and
great agreement has been attained since, every fine point has been taken into account and
nothing is out of representation unless it is not crucial to system performance. The nonlinear
control program does the control task very well and administrates the system in the desired
trajectory.
M. Kazemi, M. Jooshani,
Volume 2, Issue 4 (10-2012)
Abstract
The suspension system of a vehicle is one of the most important parts which is involved in the process of
vehicle designing. When a vehicle suspension system is designed, the evaluation of its performance against
the road disturbances such as shocks and bumps are very important. The most commonly used systems
consist of four hydraulic Jacks with mobility in vertical line with low speed and low exactitude. This paper
offers a new mechanism for inspecting the suspension system of a vehicle using a parallel robot called
Stewart. This robot is a special kind of parallel robots with capability of movements in different directions
with high speed, accuracy and repeatability. In this paper the suspension system is evaluated on a quarter
model of a simulated vehicle with control and guidance of Stewart robot using PID controller. The Stewart
robot simulates the isolated and uneven bumps on a flat road in order to evaluate the given suspension
system, and to investigate some criteria such as comforting of the passengers and remaining of the vehicle
on the road. The results of the simulations show that the proposed method has a high accuracy, applicability
and flexibility as well as simplicity, compared to currently used mechanisms.
M. A. Saeedi, R. Kazemi,
Volume 3, Issue 1 (3-2013)
Abstract
In this study, stability control of a three-wheeled vehicle with two wheels on the front axle, a three-wheeled
vehicle with two wheels on the rear axle, and a standard four-wheeled vehicle are compared. For vehicle
dynamics control systems, the direct yaw moment control is considered as a suitable way of controlling the
lateral motion of a vehicle during a severe driving maneuver. In accordance to the present available
technology, the performance of vehicle dynamics control actuation systems is based on the individual
control of each wheel braking force known as the differential braking. Also, in order to design the vehicle
dynamics control system the linear optimal control theory is used. Then, to investigate the effectiveness of
the proposed linear optimal control system, computer simulations are carried out by using nonlinear twelvedegree-
of-freedom models for three-wheeled cars and a fourteen-degree-of-freedom model for a fourwheeled
car. Simulation results of lane change and J-turn maneuvers are shown with and without control
system. It is shown that for lateral stability, the three wheeled vehicle with single front wheel is more stable
than the four wheeled vehicle, which is in turn more stable than the three wheeled vehicle with single rear
wheel. Considering turning radius which is a kinematic property shows that the front single three-wheeled
car is more under steer than the other cars.
S. H. Tabatabaei Oreh, R. Kazemi, N. Esmaeili,
Volume 4, Issue 3 (9-2014)
Abstract
Direct Yaw moment Control systems (DYC) can maintain the vehicle in the driver’s desired path by
distributing the asymmetric longitudinal forces and the generation of the Control Yaw Moment (CYM). In
order to achieve the superior control performance, intelligent usage of lateral forces is also required. The
lateral wheel forces have an indirect effect on the CYM and based upon their directions, increase or
decrease the amount of CYM magnitude. In this paper, a systematic and applicable algorithm is proposed to
use the lateral force in the process of Yaw controlling optimally. The control systems are designed based on
the proposed algorithm. This system includes Yaw rate controller and wheel slip controllers which are
installed separately for each wheel. Both of the mentioned control systems are designed on the basis of the
Fuzzy logic. Finally, the capabilities of the proposed control systems are evaluated in a four wheel drive
vehicle, for which, the traction of each wheel can be controlled individually. It is shown that considering
the lateral force effect offers significant improvement of the desired yaw rate tracking
R. Kazemi, M. Abdollahzade,
Volume 5, Issue 1 (3-2015)
Abstract
Car following process is time-varying in essence, due to the involvement of human actions. This paper develops an adaptive technique for car following modeling in a traffic flow. The proposed technique includes an online fuzzy neural network (OFNN) which is able to adapt its rule-consequent parameters to the time-varying processes. The proposed OFNN is first trained by an growing binary tree learning algorithm in offline mode, which produces favorable extrapolation performance, and then, is adapted to the stream of car following data, e.g. velocity and acceleration of the target vehicle, using an adaptive least squares estimation. The proposed approach is validated by means of real-world car following data sets. Simulation results confirm the satisfactory performance of the OFNN for adaptive car following modeling application.
