Papers by Author: Shun Ming Li

Abstract: During blade-to-case full annular rub, the frictional thermal response characteristic of blade-to-case was analyzed by the finite element method. A thermal structure coupling finite element model of blade-to-case was established and the transient thermal and structural field was analyzed. The distributions of temperature field and equivalent stress field were obtained on the basis of a certain centrifugal force, friction coefficient and rotate speed of the blade. The numerical simulations have been conducted to show that the heat affected zone (HAZ) locates in a very thin layer of blade-to-case, and the thermal stress is very high in this layer. The thermal effect in the blade-to-case friction process is more obvious as the rotate speed of blade and centrifugal pressure are increased. In practice, it is suggested that the friction thermal effect in the process of rotor-stator rub-impact should not be ignored.

Abstract: This paper presents a fast pedestrian detection algorithm for intelligent vehicle based on FPGA architecture, using AdaBoost algorithm and Haar features. We describe the hardware design including image scaling, integral image generation, pipelined processing as well as classifier, and parallel processing multiple classifiers to accelerate the computational speed of the pedestrian detection system. The proposed architecture for pedestrian detection has been tested using Verilog HDL and implemented in Xilinx Virtex-5 FPGA. Its performance has been measured about 38 times than the equivalent software implementation.

Abstract: For weak vibration signal with strong noise, a new kind of weak vibration signal detection method was proposed in this paper. Based on the redundancy reducing capability and the uncertain amplitude of independent component analysis, virtual noise was introduced to extend the dimension of original observed signal after we analyzed the prior features of noises in observed signal. Then extended signals were processed to get the independent source signals by applying to blind source separation (BSS). Thus, the noise embedded in observed signal was removed and characteristics of weak vibration signal were obtained successfully. Through the theoretical analysis and the simulation, the introduced method of this paper was checked to be available and then it was applied to faults analysis of rotor misalignment successfully. Finally, we made a conclusion that this method had great application value for the extraction of weak vibration signal.

Abstract: As the most energy-saving hybrid system in the world, the full hybrid system has high research value. On the basis of the mechanical structural analysis of one new full hybrid system, studied its control strategy and analyzed the control algorithm for its power balance in the five working modes by means of simulated equivalent lever. It is hoped that this could provide technical support for the development of domestic full hybrid cars.

Abstract: Design and develop a new type of parallel hybrid electric vehicle with ISG motor, super capacitor and electric dual-clutch, based on the former automobile chassis. Look profoundly into the structure and the control strategy of the hybrid power system. The driving mode of the vehicle has been divided strictly into five modes and the torque of engine and ISG motor has been distributed rationally. The control model of the system has been built by Simulink, and the control parameters for each driving mode have been optimized through a lot of experiments. At last, the validity of control strategy has been proved and verified by the simulation platform of Matlab/Simulink and hub experiments.

Abstract: Based on compute analysis engineering (CAE), the performances of acoustic and fluent for muffler comprehensively were analyzed and optimized in the paper. First, aiming at the heavy exhaust noise of diesel engine, bench experiments of measuring independently were designed and carried out, the frequency spectrum of exhaust noise was achieved, combining with simulation analysis of the finite element, acoustic and fluid performances of the original muffler and respective muffling cavities were analyzed, whose shortage such as transmission loss, pressure loss and flow regeneration noise were achieved, the muffler would be re-designed by CAE. Simulation shows the performances of improved mufflers were better than the original one. Eventually, insertion loss of experiment for new muffler is more 10dB(A) above than the original one, and power loss met requirement.

Abstract: In order to know about the damping characteristics of leaf spring in the actual working conditions, the finite element model was build with large deformation, interleaf friction and contact considered simultaneously. In the single sinusoidal excitation, the effects of different friction coefficient, amplitude and excitation frequency on the hysteresis and damping characteristics of leaf spring were studied. Many results were reached in the paper. It provided the references for researching the vibration characteristics of leaf spring further in the nonlinear states.

Abstract: With regard to the problem of abnormal vibration for power assembly of diesel engine of the Sport Utility Vehicle in working rotation speed conditions, the method of test mode combined finite element simulation analysis was adopted, the dynamic characteristics of the power assembly were studied in all conditions. First vibration modal testing of the power assembly was carried out in whole vehicle condition and in test bed, the cause of abnormal vibration of the power assembly was found out, the bending stiffness was low, then a kind of actual finite element simulation model of the power assembly was set up, the constraint mode was calculated. The rationality of finite element simulation model of the power assembly was validated. Integrated modal testing and simulation analysis showed that the low stiffness of flywheel shell led to the low first modal frequency of power assembly which was easily in the excitation frequency range of diesel engine working rotational speed, and resulted in system resonance of the power assembly