Automotive Science and Engineering

Power Distribution Development and Optimization of Hybrid Energy Storage System

M. Masih-Tehrani

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.

Modeling and Fuzzy Control Strategy Design for the Hydraulic Hybrid Refuse Truck

Gh.H Payeganeh

In the present paper, the idea of braking energy regeneration and reusing that energy during acceleration for a refuse truck is comprehended. According to their driving cycle, the refuse trucks have a good potential for braking energy regeneration. On the other hand, hydraulic hybrid is a powertrain with high power density which is appropriate for energy regeneration. In the primary stage of this issue, the hydraulic hybrid propulsion system is designed with intention of regenerating the maximum possible kinetic energy during the refuse truck braking mode. At this stage, a non-fuzzy rule-based control strategy is applied to manage the energy flow in the hybrid powertrain. After that, the powertrain of the Axor 1828 truck and the elements of the hydraulic powertrain are modeled in MATLAB/Simulink. The modeling is performed considering the efficiencies of the powertrain elements. In the last part of the paper, a fuzzy control strategy is designed and modeled to improve the fuel consumption of the truck with hybrid powertrain. In order to see the usefulness of the designed hybrid powertrain, several simulations are organized on the vehicle model in Simulink. The driving cycle for refuse truck in Tehran is used for performing the simulations. The results state indicated that using the hydraulic hybrid powertrain decreased the fuel consumption of the refuse truck by 7 percent. In addition, this amount of reduction was improved by implementing the fuzzy control strategy. The decrease in fuel consumption was due to the regenerating of the braking energy up to 50 percent.

Design of Continuously Variable Transmission (CVT) with Metal Pushing Belt and Variable Pulleys

E. Maleki Pour

Nowadays, automakers have invested in new technologies in order to improve the efficiency of their products. Giant automakers have taken an important step toward achieving this objective by designing continuously variable transmission systems (CVT) to continuously adapt the power of the engine with the external load according to the optimum efficiency curve of engine and reducing fuel consumption beside, making smooth start up and removing the shock caused by changing the gear ratio and making more pleasurable driving. Considering the specifications of one of Iranian automaker products (the Saipa Pride 131), a CVT with a metal pushing belt and variable pulleys have been designed to replace its current manual transmission system. The necessary parts and components for the CVT have been determined and considering the necessary constraints, its mechanism and components have been designed.

Fuzzy Sliding Mode Control System Design for Car- Following Behavior in Real Traffic Flow

A. Ghaffari

In this paper a control system has been designed to improve traffic conditions in car following maneuver. There are different methods to design a control system. In this paper design approach is based on the Fuzzy sliding mode control (FSMC) system. The aim of designing FSMC system is to achieve safe and desire longitudinal distance and less lateral displacement. In order to control and obtain desired longitudinal and lateral movements, suitable values of composite torque and steering angle is generated. At first to design of FSMC system, a nonlinear dynamics model of vehicle with three degrees of freedom is presented and validated with real traffic data. Then, the performance of the FSMC system has been evaluated by real car following data. At the end, the simulation results of FSMC are compared with the first and second order sliding mode control. Simulation result shows that performance of FSMC is better than sliding mode control. Also by comparing between FSMC and real driver, it is shown that FSMC is much safer than a real human driver in keeping the longitudinal distance and also the FSMC produces less lateral displacement in the lateral movement too.

Strategic Model and Structure Management of Chines Independence Automotive Companies (Case Study)

H. Shojaeefard

Having a full understanding of the world’s social-economic situation is the success key for industries automotive manufacturing industry is an extremely competitive one usually there is no clear guideline among automotive companies about technological causes behind their success and failure. This research provides an investigation about the world’s economic situation and the environmental situation surrounded the automotive industry, than will focus on chines auto industry. Automotive manufacturers and suppliers view China as the largest combination of automotive market and low-cost manufacturing and supply base to appear in decades. Companies are deluged with information about the potential opportunities in China, but typically know very little about what the Chinese think about their automotive future. The steady influx of automotive manufacturers and suppliers over the past ten years has provided the Chinese with firsthand experience of what the impact of a world-class, high-volume automotive industry can mean to a country.

Traction and Efficiency Performance of Ball Type CVTs

H. Ghariblu

This paper concerns the design and analysis, of a ball type continuously variable transmission, (B-CVT). This B-CVT has a simple kinematic structure, and same as a toroidal CVT, transmits power by friction on the contact points between input and output discs, that are connected to each other by balls. After, a brief introduction of our B-CVT structure, the performance and traction efficiency of B-CVT is analyzed. The geometry and speed ratio of the proposed CVT is obtained. Then, by finding the contact areas between rotating elements and stress distribution through them, the torque capacity of B-CVT is computed. Next, the power loss of the system caused by various parameters such as relative arrangement of rotating elements as well as relative velocity at contact areas is found. Finally, after presenting the influence of the different geometrical and assembly conditions at efficiency of the system, the efficiency of the system compared with the efficiency of a Toroidal CVT.

Optimization of Crush Initiators on Steel Front Rail of Vehicle

J. Marzbanrad

This paper focuses on the optimization of initiating dimensions of groove bearing in association with de- sired design of vehicle’s front structure which is made up of low carbon steels in the case of frontal collision. Axial bearing analysis is done numerically using nonlinear finite element code LS-DYNA. In this analysis, changes of two main parameters including measure of energy absorption of structure and maximum force of structure collision are being considered. Square structure profile is being chosen and the groves are placed on two opposite sides. Tests of collision simulation are performed for steel samples and then a mathematical equation is derived next, the initiating dimensions are optimized using Genetic Algorithm. Desired case for design of this structure part is the one which provides maximum energy absorption measure and minimum collision force in this paper, the most optimal case is an initiator with groove depth of 4.5 mm and radius of 10 mm.