Applied Mechanics and Materials Vols. 130-134

Abstract: In this paper, four-wheel steering and direct yaw-moment integrated controller is designed. To verify the effectiveness of the integrated controller, a nonlinear three-degree-of-freedom model is employed for computer simulation. Considering the nonlinear effects of tyre, Pacejka tyre model was adopted to set up the nonlinear vehicle dynamic model. The direct yaw-moment controller was designed based on optimal control theory. Simulation on the nonlinear vehicle with integrated controller in Matlab/Simulink software environment was described. The simulations suggest, compared with FWS and 4WS, the integrated controller can make the handling and stability performance on big lateral acceleration and slip angle improved, and make the driver drive the vehicle normally. The conclusion can be useful for the system design of vehicle stability control system.

Abstract: There is much advancement in steering control technology with time. Steering-By-Wire (SBW) system is the most modern and efficient technique. This paper first introduces current status and history of SBW system from concept proposal, prototype design and development of concept car with SBW system. The structure, principle, key components and classification of SBW system are also described systematically. Then several features of SBW system are analyzed in detail in connection with efficient handling, stability, spatial structure, intelligence and security of vehicle. Finally the future issues to be researched are discussed, including system reliability, hardware technology, system control strategy and power supply.

Abstract: Suspension roll characteristics are investigated using multi-body dynamic simulation software to analyze the handling stability of a coach air suspension system. Sensitivity analysis is applied to reveal the relationship between the guide mechanism geometry and roll center height of the suspension. The locations of V-pole mounts are adjusted to obtain a lower roll center position. The results of the steering wheel angle step input and steady-state circular tests are compared. To verify the effectiveness of vehicle model. Results indicate considerable improvement in handling stability, made possible by the low roll center height of the rear suspension.

Abstract: . The control principle of VCU (Vehicle Control Unit) was described in this paper. Both hardware and software based on MC9S12XET256 microcontroller were designed using modular design method. Fuzzy control method was used for the study of recovery of braking energy. Through the design of software and hardware, vehicle control functions are realized, including real-time data acquisition, data communication, braking energy recovery and so on.

Abstract: Three-dimensional simplified model of auto windshield, mold, hot ring and quench ring was built using UG software in this article. Hot bend-forming numerical simulation process of auto windshield was reserched based on Show-implicit sequence solving algorithm. Finite element dynamic display simulation of press and drop forming and rebound deformation work step were finished. Distortion status, stress and strain distribution in forming process could be real-time displayed. It compared measured value and simulated value in two ways (bending depth and rebound rate) in the three groups product samples randomly selected.The comparison result proved the veracity of numerical simulation result. It had certain actual production guiding significance.

Abstract: Control strategy is the most important issue in the Plug-in Hybrid electric vehicles (PHEV) design, which has two modes: charge depleting mode (CD) and charge sustaining mode (CS). The different control strategies in depleting mode will have a great influence on PHEV dynamic performance and fuel economy. The engine optimal torque control strategy was proposed in the paper. The vehicle simulation model in Powertrain Systems Analysis Toolkit (PSAT) was adopted to evaluate the proposed control strategy. The aggressive highway drive cycle Artemis_hwy and a random drive cycle generated by Markov Process were used. The simulation results indicate the proposed control strategy has great improvement in fuel economy.

Abstract: To define the situation of traffic safety about highway passenger transport accurately, and reveal the statistical regularity of braking safe performances on long distance buses, based on large sample braking performance detection of a given type long distance buses, the statistical models about 4 braking performance were established. This research shows that the unqualified rate of front axle braking force balance performance of the given type long distance buses beyond 24%, and the rear one is 7% as well, which could be one serious hidden danger. The models established have very high calculating precision. What makes this conclusion more persuasive is the relative error maximum between model calculating values and real detecting results is 0.428% only. In addition, the practicable direction and way to solve the exposed problem in vehicle braking system are given. The research results can be used to understand the braking performance statistical regularity of typical long distance bus accurately, providing a reliable technical guarantee for improving traffic safety.

Abstract: AC charging point is one of the main equipment of electric vehicle charging system. The design process of a kind of AC charging point, which is controlled by a Cortex-M3-based microprocessor and μC/OS_II-based management software, is discussed in this paper. Hardware structure and the design principle of each module are described in detail, as well as the important aspects of software design, such as the priority arrangement of tasks and interconnection between tasks. The AC charging point features friendly and easy-to-use user interface, accurate measurement and stable operation, and has obtained the certification from authority department.

Abstract: Based on the computer and multifunction data acquisition device, the stiffness test system for car body was developed by using Microsoft Visual Studio.Net 2008, which could manage the test process, test the stiffness automatically according to the test process, manage the template of test report, generate the test report automatically and etc. The high precision displacement transducer and the high accuracy multifunction data acquisition device were used to realize precise test of car body. In order to improve system reliability and test accuracy, the method including opt electric isolating, software and hardware filtering has been used. By practical application, it is proved that this system has some advantages such as high test precision, high test efficiency, and convenient operation.

Abstract: With the small-sized motor power density becomes bigger and bigger, and it carries high electromagnetic loads, causing its thermal load to be higher and higher. So temperature should be considered when small-sized motor is designed. Temperature rise has a bad effect on the motor of the electric automobile, in order to reduce the effect, it lists the reasons causing motor temperature rise and summarize calculation methods, and then make analyses about motor output characteristics influenced by the temperature, what’s more, summarize the monitoring and cooling measures, finally put forward challenges and research direction about the motor of the electric automobile with distributed drive.