Papers by Keyword: Three-Dimensional

Abstract: Laser Doppler Velocimetry is an important flow diagnostic methodology used in modern day fluid flow investigations. The present paper describes the design and manufacturing aspects of a novel fibre optic LASER Doppler probe head intended for three dimensional measurements in a complex flow field. The paper particularly concentrates on the tight tolerances required of the various components associated with the probe head to achieve the desired measurement volume. Keywords: Fibre Optic, Laser Doppler, Velocimetry, three-dimensional, complex flow field

Abstract: With the development of the 3D technology, the construction of a 3D substation monitoring system becomes feasible. The Unity3D is a professional and comprehensive engine for providing advantages in fast deployment, architectural visualization, and 3D animation. It can support multiple platforms and make the development much easy with an expansive architecture involved. In the normal use, we build 3D model with tools such as the 3DMax, and import the models to Unity3D. By the means, we can finish making scenes and cartoons as well as integrating business data. We can also design multive functions such as the roaming in first person view, camera switching, real-time monitoring data displaying, real-time alarming, and so on. We write custom Shader to achieve some special effects. For example, we can write vertex and fragment shader to receive the data from the scripts and parse the data to get the information of temperature points. The distance between each UV point and the given temperature points is also computed and mapped to the values of temperature and color.

Abstract: A three-dimensional finite element model for die spinning of a cylindrical workpiece is established and a practical spinning process of 5A06 alloy tube is simulated with the model and Marc software. The rotation of the workpiece driven by the die and the passive rotations of spinning wheels due to the friction between the spinning wheels and the workpiece are considered in this model. The distributions of stress and strain of deformation region are analyzed. The phenomena during tube spinning are simulated, such as build-up, shape distortion, diametric reduction and increment. From the simulated results, it is concluded: Consideration of the quality and efficiency of production, spinning speed should not be too large. In this study, the simulation process should not exceed 0.8mm/s the traction speed. Spinning force is direct proportional to the traction speed and inverse proportion to the tip radius. This model reprents the spinning deformation behaviors completely. Simulation results correspond with the experiments very well.

Abstract: On the basis of a study of measuring inclination angle with a two-dimensional accelerometer, a principle method using a three-dimensional accelerometer to measure attitude angle is analysed on the condition of micro-rotating. The method can reduce random systematic errors caused by uniaxial or biaxial output of the two-dimensional accelerometer. It can simultaneously measure both inclination angle and roll angle. So hardware selection, hardware circuit design and experiments are done: simulate the roll and tilt movement of the special objects and compare the solver results with the actual results. The principle method achieves preferable results, and provides a theoretical support for attitude determination of a particular industry as well.

Abstract: In this paper a new three-dimensional large-size optical measurement system by laser radar has been proposed in combination of double-optic circuit measuring technology, ultra-high frequency modulation technology and laser intellectual tracing and location technology. The system can measure 3d shape unconnectedly for lager-size object, which has the advantages of high accuracy, automatic measurement and freedom from being influenced by material and light ray.

Abstract: Classical coaxial plasticity constitutive models implicate an inevitable limitation that directions for principal stress and that for principal plastic strain increment are always coaxial. They are not capable of simulating non-coaxial phenomena during the rotation of principal stress axis. In this paper, a three-dimensional, non-coaxial plasticity constitutive model for sands with a modification of Lade angle dependent shape function is introduced to describe the non-coaxial behavior under principal axes rotation. A series of numerical simulations of hollow cylindrical torsional shear tests are performed. The results show that the proposed constitutive model can predict the variations of principal plastic strain increment directions with principal stress directions reasonably.

Abstract: Wireless energy transmitting technology provides MEMS inside body with a new power supplying approach. At present, the efficiency and stability of a single- dimensional wireless energy transmitting system are still handicaps in practical applications and need improving. In present paper, two structures of multi-dimensional wireless power are presented and compared each other. Single dimensional primary-three dimensional secondary structure is applied in further research. At last System efficiency is expressed after deduction.

Abstract: Recently, three-dimensional (3D) measurement technology has achieved a high level of satisfaction in various fields such as medical and engineering fields. However, most of three-dimensional measurement systems have some disadvantages. Once the geometric configuration of the system has been determined, the configuration must be maintained until the measurements have been completed. Another disadvantage is the existence of immeasurable area that inherently exists in a single image taken from a fixed angle. In this paper, a handheld three-dimensional thermo-sensing measurement system is presented. This system is composed of a three-dimensional measurement device and a thermographic device. To realize the handy scanning measurement, 3D magnetic sensor is attached on the image capturing devices. Since the movement of the image capturing devices is detected in real-time by the magnetic sensor, the immeasurable area can be reduced by free movement of the image capturing devices. On the basis of the presented mathematical model, this system is possible to detect not only the three-dimensional shape but also the temperature distribution of an object. Experimental results show the feasibility of the measurement system.

Abstract: Three-dimensional geological model of open-pit is an information platform in the construction of digital mine, which plays a significant role in the engineering design and manufacturing management of open-pit. In the AutoCAD platform, take an open-pit for example, it is required to construct a geological database, to construct fault wire-frame model according to the ore body lines, to construct a terrain model according to the present situation map of stope and topographic contour map, to construct coal solid model according to the borehole data and interpolation points, and realize a visible display of a three-dimensional geological model for the open-pit; to construct a block model according to the coal & rock solid model, and add the attribute and assign to it, and then apply it to the calculation of stripping and mining quantities of open-pit. Compared with traditional calculation method, this method is simple in operation, which enhances its calculation speed and precision.

Abstract: This paper presents an investigation of the geometric quality of three-dimensional data obtained by a thermal-sensing system. On the basis of the presented mathematical model, it is possible to detect not only the three-dimensional shape but also the temperature distribution of an object. Here, the whole 3D shape of the object is reconstructed using the ICP (Iterative Closest Point) algorithm. The measurement system is established using a three-dimensional measurement sensor (Kinect) and thermographic device. Since the three-dimensional surface shape of the object can be measured using the 3D sensor, and the corresponding temperature data obtained by thermography can be allocated to the reconstructed surface of the object on a computer, the data can be used for a quantitative analysis of heat radiation by considering the area and the roughness of the heat source object. Experimental results show the feasibility of the measurement system.