Search Results

The price of fossil fuels and the increasing inexorable energy crisis have become vital issues for everyone. Tongji University EconoPower Racing Team was established to participate in the “Honda EconoPower Cup” annually. Every contestant in the competition must finish a certain distance in the fixed time, with the gasoline supplied by the committee. After that the committee will measure the fuel consumption of every team and calculate the distance per liter fuel (the farther the better) to determine the champion. In order to enhance the EP vehicle's achievement we've made some improvements, such as framework, body, engine's optimization and so on. In this passage we mainly state some details of our research approaches in framework, steering, transmission, shape and driving strategy. The main technologies were: friction reduction, lightweight, enhancement of power train efficiency, tire selection and driving strategy.

In this paper an estimation method on location of peak pressure (LPP) employing flame ionization measurement, with the spark plug as a sensor, was discussed to achieve combustion parameters estimation at quick start of HEV engines. Through the cycle-based ion signal analysis, the location of peak pressure can be extracted in individual cylinder for the optimization of engine quick start control of HEV engine. A series of quick start processes with different cranking speed and engine coolant temperature are tested for establishing the relationship between the ion signals and the combustion parameters. An Artificial Neural Network (ANN) algorithm is used in this study for estimating these two combustion parameters. The experiment results show that the location of peak pressure can be well established by this method.

This paper describes a methodology to estimate longitudinal velocity of a 4-wheel-drive electric vehicle, in which wheel driven torque can be independently controlled by electric motor. Without non-driven wheels it would be difficult to estimate the vehicle longitudinal velocity precisely, especially when all of four wheels have large slip ratio. Therefore, an estimation methodology based on fuzzy logic is put forward, which uses four wheel speed and longitudinal acceleration as input signals. However, this method works not very well when two or more wheels have large slip ratio. In order to improve estimation effect, a state variable filter is designed to calculate wheel acceleration signals, which are used as additional signals to the fuzzy logic observer. Furthermore, the possibility of using four wheel driving torque signals to improve the estimation precision is also discussed.

A Controllable Active Thermo-Atmosphere (CATA) Combustor enables the investigation of stabilization mechanisms in an environment that decouples the turbulent chemical kinetics from the complex recirculating flow. Previous studies on combustion of the low-pressure fuel jets in the Controllable Active Thermo-Atmosphere (CATA) showed non-linear effect of coflow temperature on autoignition delay and the randomness of autoignition sites. In this work, a diesel spray is injected into the CATA with the injection pressure at 20MPa from a single-hole injector and the autoignition and combustion process of the spray is recorded by a high-speed camera video. The multipoint autoignition of diesel spray is observed in the CATA and the subsequent combustion process is analyzed. The results show that autoignition phenomenon plays an important role in the stabilization of the lifted flames of diesel spray under low coflow temperature.

The prevention and control of brake judder and its various negative effects has been a key target of vehicle production. One of the effects is the steering wheel vibration during vehicle braking. Experimental and theoretical investigation into “steering wheel vibration due to brake judder” is extensively presented in this paper. The vehicle road test is carried out under controlled braking conditions. During the test, the accelerations of brake caliper assembly, suspension low and upper control arm, steering arm, tie rod and steering wheel, left and right wheel rotary speed, are measured by a multi-channel data acquisition system. The data processing focuses on order tracking analysis and transfer path analysis to work out the related resonant components. A disc brake assembly, with deliberately designed disc thickness variation and surface run-out combinations, is tested on a brake dynamometer.