Lian Xiaomin

Urban pickup and delivery problem considering time-dependent fuzzy velocity

Article history: Received 17 June 2010 Received in revised form 29 December 2010 Accepted 29 January 2011 Available online 23 February 2011

IEED system: A new kind of Automotive electrical system

A new kind of automotive electrical system is proposed, which named IEED system. It is a completely distributed system with only intelligent electrical & electronic device (IEED) in it. The systempsila features is described and key IEEDs in system are also presented. The system prototype was developed and experimented. Results showed that IEED system is feasible and cost effective.

A hybrid acoustic holography technique for moving sound source identification based on wave superposition algorithm

To solve the ghost sources problem which occurs in the noise source identification, a hybrid acoustic holography technique based on wave superposition method is developed in our current work. This research extended the wave superposition method to the measurement of the moving sound sources and solves the ghost sources problem in moving sound source identification without adding extra microphones. Short-time wave superposition equations for moving sound sources are established employing the Doppler frequency shift, and the equivalent sound sources are calculated according to the pre-estimation results by the beam-forming method. Then the major sound sources are identified through far field acoustic holography based on these equivalent sound sources. Simulation results and validation experiments with known sound pressure generated by loud speakers have proven that our developed method can not only provide better identification results for locating sound sources accurately but also reduce the side lobe significantly and solve the ghost sources problem successfully, suggesting our method�s potential in noise identification work

The adaptive filtering of engine transient rotating speed signals

The calculation of engine transient rotating speed is an important method to identify the working state of the engine and the crankshaft torsion vibration. In the actual working state, the measured engine rotating speed signals contains interference signals, which will reduce the accuracy of the calculation. A new adaptive filtering method of the engine rotating speed is proposed. A narrow band-pass filter with the intermediate frequency changed under the rotating speed variation is designed for the pretreatment of original signals, and the transient rotating speed is calculated with filtered signals. This method is used for the analysis of actual signals of an engine when it is accelerating. The result shows, after preprocessing, interference signals are eliminated, and the accuracy of the calculation of the transient rotating speed fluctuation is increased.

Sound absorption structure optimization based on material absorption models and noise rating curves

The sound absorption materials are more and more widely used in vehicles. An novel optimal design method is proposed in this paper, which mainly includes two steps: (i) the determination of expected absorbing curve based on noise reduction goal and noise rating curve; (ii) choice of absorption materials and optimization of the material thickness based on the sound absorption model. The method has been applied to the absorption performance improvement of some vehicles engine cabin and the results prove to be satisfactory. The absorption coefficients have been improved by 0.2 in the frequency range of 0–1200Hz.

Analytical algorithm for nurbs surface-plane intersections

For general problem of Nurbs surface-plane intersections, an analytical intersection algorithm based on matrix representations for B-Splines is presented. This analytical algorithm firstly gets a set of theoretically precise intersection points between Nurbs surface and plane, then sorts the set of points into a sequence, finally interpolates the sequence into a smooth and precise curve, with this Algorithm we got precise and fairing incisions in machine part design. And in solution procedure, computational complexity and data amount are both decreased compared traditional method. Application examples show that this analytical algorithm has stable performance, high precision as well as high precision, can be widely applied to solve a variety of Nurbs surface-plane intersection problems.

An acoustic holography method with random sparse microphone array to locate moving sound sources

To locate the moving sound sources with microphone arrays, with the random sparse arrays we could get equal results but much less microphones than the complete arrays; then the measuring system could be inexpensive and less complicated. The traditional technique to identify sound source with random sparse array is usually based on the beamforming principle, its resolution at low frequencies is not very good. An acoustic holography method with random sparse microphone array is proposed; an incomplete holography plane is constructed with the sound pressure data collected by the sparse array, then the sound pressure distribution of the radiating plane is computed with the acoustic holography method based on the principle of phase-conjugate waves focusing. The simulation indicates that the results of random sparse array have lower side lobes and better identifying performance than those of regular array with equal microphones. The experiment result shows that the sound sources in a moving car can be located correctly with this method.

Multi-branch model of intersection for vehicle navigation

Model of intersection, as a part of road network model, which is the basis of In-Vehicle Navigation System, provides an abstract description of urban traffic intersection. This paper proposes a Multi-branch model, which abstracts branch based on physical structure of intersection for describing structural features of different types of intersections. And on this basis it describes accurate navigation attributes for vehicle navigation. Experiment shows that the model can be conveniently applied to ln-Vehicle Navigation System, with accurate and abundant driving information. The model is proved practical for In-Vehicle Navigation System.