An Experimental System Development for Head Posture Estimation Based on 3-D Images Measurement

Although automobile is an indispensable vehicle to modern life, it also serves as a social problem with a big traffic accident. Among the reasons of traffic accidents, careless driving accounts for the largest part. So in order to avoid the careless driving, a system which can measure the posture of a driver and warns driver to drive carefully in the case of looking aside is necessary. Although the image measurement method is used broadly, there is a problem on which measurement accuracy is influenced by environment light, makeup of the driver, etc. in the general method based on the two-dimensional image. Therefore, in this study, we propose an image measurement method to obtain the head posture of driver. First we use three-dimensional measurement method which based on the infrared pattern projection to get 3-D information of head, and then we calculate the angle for faces. In this paper, we explain the composition method of an experiment system, and the results of head posture measurement experiment.

High-accuracy 3-D deformation measurement method with an improved structured-light principle

In this paper,a high-accuracy 3-D deformation measurement(HADM)method with structured light is proposed and applied to wing deformation measurement in wind tunnel experiments.The present method employs an arbitrarily arranged fringe projector and a perpendicularly placed camera.The exact phase-height mapping using the phase differences of the projected sinusoidal fringe patterns,as well as the spatial distribution of the fringe,is accurately derived.It not only presents high feasibility but also reduces systemic uncertainties arising from deviations between the ideal model and the real-world conditions.Meanwhile,a dynamic boundary process algorithm is proposed to reduce the measurement uncertainty caused by fringe fracture near the object boundary.It is calibrated that a high accuracy with the average measurement uncertainty of 0.0237 mm is achieved,which is less than 0.01%of the side length of 25 cm of the field of view.In the wind tunnel experiments,the 3-D deformations of the elastic wing,particularly the key geometric parameters such as wing tip position,angle of attack,and dihedral angle,are well reconstructed to provide an in-depth explanation for the aerodynamic characteristics.

The Intelligent Measuring Sub-system in the Computer Integrated and Flexible Laser Processing System

Based on the computer integrated and flexible laser p rocessing system, we developed an intelligent measuring sub-system. A novel mod el has been built to compensate the deviations of the main frame-structure, and a laser tracker system is applied to calibrate the accuracy of the system. Anal yzing the characteristics of all kind surfaces of automobile outer penal moulds and dies, the surface and border to be measured and processed are classified int o four types. A 2-D adaptive measuring method based on Bzier curve and a 3 -D adaptive measuring method based on Spline curve are developed for different types of surface. During the data processing, a 3-D probe compensation method i s described in details. The control software of the sub-measuring system is des cribed. Some measuring experiments are carried out to testify the methods.

3-D Shape Measurement of Complex Objects by Combining Color-Coded Fringe and Neural Networks

A new approach for three dimensional (3-D) shape measurement was proposed based on colorcoded fringe and neural networks. By applying the phase-shift technique to fringe projection, point clouds were generated with high spatial resolution and limited accuracy. The picture element correspondence problem was solved by using projected color-coded fringes with different orientations. Once the high accurate corresponding points were decided, high precision dense 3-D points cloud was calculated by the well trained net. High spatial resolution can be obtained by the phase-shift technique and high accuracy 3-D object point coordinates are achieved by the well trained net, which is not dependent on the camera model and will work for any type of camera. Some experiments verify the performance of this method.

Three-dimensional finite-time cooperative guidance for multiple missiles without radial velocity measurements

In order to simultaneously attack a target with impact angle constraint in threedimensional(3-D) space, a novel distributed cooperative guidance law for multiple missiles under directed communication topologies is proposed without radial velocity measurements. First, based on missiles-target 3-D relative motion equations, the multiple missiles cooperative guidance model with impact angle constraint is constructed. Then, in Line-of-Sight(LOS) direction, based on multiagent system cooperative control theory, one guidance law with directed topologies is designed with strict proof, which can guarantee finite time consensus of multiple missiles' impact times. Next, in elevation direction and azimuth direction of LOS, based on homogeneous system stability theory and integral sliding mode control theory, two guidance laws are proposed respectively with strict proof, which can guarantee LOS angles converge to desired values and LOS angular rates converge to zero in finite time. Finally, the effectiveness of the designed cooperative guidance law is demonstrated through simulation results.

基于人体三维扫描技术的人体体积回归模型研究

目的基于三维扫描的人体测量技术建立人体体积的回归模型。方法通过三维扫描及后续的修复,使用三维软件获取了160名成年男性的137项人体测量数据,然后使用因子分析法及回归分析对各数据与体积的相关性进行了研究。结果通过因子分析获取影响人体体积的4项主要指标:身高、体重、胸上围与BMI指数,建立了线性、对数、乘幂、指数4个回归模型,并使用额外的16名志愿者进行模型验证,结果部分给出了4个回归模型的预测体积与实际体积的误差绝对值的平均值及误差百分比的平均值。结论在三维扫描获得的大量人体数据基础上建立的人体体积回归模型计算方便,预测可靠,结果精度符合工业设计的阈值范围要求,该方法在传统空气置换体积描记法与水下称重法难以实施的情况下有着良好的预测结果。

弧齿锥齿轮真实齿面的测量及齿面偏差的确定和补偿方法研究(英文)

This paper presents a method for measurement of deviation of the real gear tooth surface from the theoretical one with a coordinate measurement machine and compensation of repeatable parts. By investigation of characteristics of distortion of the gear tooth surface along the circle direction, the deviation is derived from distortion, and the definition of deviation with the geometrical invariability is proposed. Then the approach for determination of the location and orientation of the gear with respect to the coordinate measurement machine and the measurement way are developed. The deviation is represented with a difference surface, and an algorithm for derivation of parameters of global form deviations from the discrete points has been provided. Finally, the compensation approach is discussed.

基于特征参数的青年女性乳房形态分析

为探究青年女性乳房形态区别,提出了乳房边界定义方法以保证乳房形态参数测量的一致性。使用[TC]2三维扫描仪对140名18~25岁在校未婚孕青年女性进行扫描,获取了包括高度、宽度、角度、弧线等28项乳房形态相关参数;通过变异系数和相关性分析筛选出6个影响乳房形态的主要参数作为聚类指标,从乳房立体形态和聚拢程度两方面对乳房形态进行细分;基于乳房形态分类结果,利用Fisher判别函数对样本进行回判验证。结果表明,青年女性乳房形态可分为9类,基于形态判别规则对初始样本数据整体回判的准确率高达97.1%,说明此判别方法具有较高的准确性,为现有的乳房形态研究提供了新思路。

Quality measure of color images based on properties ofvision psychology and color distortion in MPEG-21

In this article, a new way to evaluate the quality of color images is proposed, in which the properties of human vision psychology, objective fidelity, edge information, and color distortion will be combined through utilizing 3-D matrix transform. There exists color redundancy and structural similarity between three different frames of a color image, the definition of vision properties will be measured by 3-D submatrix integration transform （SIT）, in which three color components are integrated into one model and color redundancy can be exploited fully. The simulation results show that the measure index is very effective and objective in accord with vision properties.

Applications of Digital Correlation Method to Structure Inspection

In structure inspections, applications of optical techniques are rare, but the advantages of a noncontact, full field technique using a simple apparatus are attractive. The main requirements for structure inspection are the full-field strain measurement with the required precision and on-site measurement ability. The digital correlation method （DCM）, a new optical deformation measurement tool, can satisfy all of the requirements for structure inspection. A smoothing algorithm which can greatly improve the strain measurement precision, and a 3-D DCM have been developed in this paper. For verifying this improvement, a comparison of strain measurements by computer-simulated speckle images has been carried out. Additionally, three structure inspection examples that cover typical materials and structure styles are presented： the interface shear stress distribution for reinforced concrete piles bedded on rock, the 3-D strain distribution of a composite vessel structure, and stresses in a hookup that connects two steel bridge structures. All the examples show that the new structural inspection tool is exemplary and illustrates the obvious advantages of this optical non-destructive technique.