Papers by Author: Ping Wang

Abstract: The streak tube imaging lidar (STIL) system is a new 3D imaging technology that can obtain a complete frame image of the target with only one laser pulse and it has many advantages such as high frame rate, big field of view and so on over the scanning-mechanism system. The principle of the experiment will be introduced firstly and the pre-process of the data will be simply discussed, such as correction of image distortion, the noise filter and image enhancement, data segmentation and so on. All the methods to the above data pre-process are specially adopted for the STIL system. The range of the target, the time of the photoelectron flight and the range of the target image on the phosphor screen have a linear relationship and it will be proved; according this, a mathematical model to reconstruct the 3D image is put forward and the algorithm to calculate the relative range of the target is confirmed. Based on the model and the algorithm, a program in the VC++ and matlab environment to analyze the lidar data, reconstruct and display the 3D image of the target is compiled. The result verifies the model and the algorithm effective.

Abstract: The structure of chemical sensor has great influence on the performance of the sensor. This article studies on the relationship between the structure parameter and the mechanical characteristics of the sensor. The original resonance frequency and modes shape of the structure are obtained by the finite element analysis. Then a series of simulation comparison analyses are carried out to verify that the performance of modified sensor structure for food safety detection is improved greatly, which provides a good guide for the design of MEMS chemical sensor further.

Abstract: Uncooled infrared bolometer arrays have become mainstream low-cost thermal detector used in applications such as firefighting, security and surveillance, and environment temperature control for food operation. In order to resolve the pixel structure’s stress problem of microbolometer, this paper adopts finite element analysis method to model and analyze the mechanical properties of pixel structure. Several results of the stress and displacement are presented and the influence of structure optimization on the stress is also analyzed quantitatively. The research provides a good foundation and mechanics reference for mechanical design of uncooled microbolometer.

Abstract: The structure of chemical sensor has great influence on the performance of the sensor. This article presents an optimum design method to improve dynamic stiffness of the sensor structure. The original resonance frequency and modes shape of the structure are obtained by the finite element analysis. Then a series of reasonable parameters are determined by optimum calculation. In the end, the result of the random vibration analysis verifies that the performance of chemical sensor structure for food hazard detection is improved greatly by the presented method here.

Abstract: With the three-dimensional computational fluid dynamics method, the airflow effects over the huge telescope assemble is investigated in this article. The distributing of velocity field and natural convection are studied by modeling and simulating the turbulent airflow of the huge telescope. Numerical simulations show the best observation direction is the 90o angle between the main optics axis and the horizontal line in which the air velocity distribution is the least. And the air temperature distribution and uniformity around the telescope are also provided by simulation.

Abstract: This paper focuses on the structural optimization of chemical sensor support for food safety detection. The mechanical characteristic of chemical sensor support is influenced greatly by its structural parameters. Aiming at improving dynamic stiffness of the support, the modal analysis is implemented with the dynamic theory and the finite element analysis. And a group of rational structure parameters are determined through the optimum calculation. The validity simulation of the optimization is verified by the analyses of the random vibration and harmonic response. The results demonstrate that the performance of the support of the chemical sensor applied for the food detection is enhanced greatly by the presented optimization method here.