Automotive Science and Engineering

---

---

Kinematic synthesis of a trailing six-member mechanism has been carried out to achieve five precision points of an automotive steering mechanism. The inner wheel can be rotated up to forty five degrees with fair accuracy. Results show that the divergent end behavior of Ackermann Steering Mechanism has been overcome by the present mechanism. The work is similar to earlier work by the present author. But the present mechanism is a trailing mechanism instead of a leading one. This helps to eliminate the spur gears used earlier to bring the mechanism on the rear side of the front axle.

---

This paper presents a force field concept for guiding a vehicle at a high speed maneuver. This method is 
similar to potential field method. In this paper, motion constrains like vehicles velocity, distance to obstacle
and tire conditions and such lane change conditions as zero slop condition and zero lateral acceleration are
discussed. After that, possible equations as vehicles path are investigated. Comparing advantages and
disadvantages of 7th, 11th degree and a few other equations, followed by single mass and bicycle models
lead to an improved method, which is presented in this paper. 

---

Erosive wear damage is common damage in the bearing shell of engines which causes a change in bearing profile and affects the oil film pressure and durability of bearing shell. The objective of the present paper is to present an appropriate algorithm for prediction and failure analysis of wear in BE bearing of engines using the Elasto-HydroDynamic (EHD) model. The mentioned model incorporating a mass-conserving algorithm is utilized to compute the lubrication characteristics of bearing, such as minimum oil film thickness and maximum oil film pressure. In EHD analysis, bearing housing is modeled by the finite element method to consider the bearing deformation. To estimate the wear volume, a code was written in MATLAB^Ò software which modifies the bearing profile and surface roughness during the analysis. A modified Archard model is used to model the lubricated sliding wear of rough contacting surface. Change in bearing surface roughness due to wear is modeled by the Abbot curve. Finally wear damage progression of BE bearing during engine operation is calculated and the results are thoroughly discussed. The numerical simulation results confirm that the wear rate at the initial stage of engine running is significant. It is concluded that wear adapts the bearing geometry in proper condition and improves the contact problem at the edges of bearing.

---

In this paper, an adaptive cruise control system is designed that is controlled by a neural network model. This neural network model is trained with data resulting from the simulation of a multi-objective nonlinear predictive adaptive cruise control system. For this purpose, first, an adaptive cruise control system was designed using the concept of model predictive control based on a nonlinear model to maintain the desired speed of the driver, maintain a safe distance with the car in front, reducing fuel consumption and increasing ride comfort. Due to the time-consuming computations in predictive control systems and the consequent need for powerful and expensive hardware, it was decided to use the extracted data from the simulation of this designed cruise control system to train a neural network model and use this model to achieve control objectives instead of the predictive controller. Using the neural network model in the cruise control system, despite a significant reduction in computation time, the control objectives were well achieved, and in fact a combination of model predictive controller accuracy and neural network controller speed was used.