Papers by Keyword: Non-Contact Measurement

Abstract: The molten steel level in twin-roll strip casting (TRC) has a significant impact on the heat transfer process between the molten steel and the rolls, as well as the subsequent solidification process of the steel. Therefore, ensuring a specific and stable molten steel level is crucial for the quality of as-casting strips. To achieve this, a precise and real-time molten steel level detection system is required. This paper utilizes machine vision technology to measure the molten steel level. A general mathematical model for the molten steel level in the TRC process is established. An image processing method for measuring the molten steel level using a single camera is proposed, including image segmentation, edge detection, and multiple coordinate transformations of the molten pool contour. The adverse effect of the inlet or nozzle is taken into account. Experimental measurements were conducted, and the results indicate that a single camera can accurately measure the molten steel level. Potential sources of error or limitations that may impact the accuracy of the proposed method is discussed.

Abstract: In this paper, the limitations of the direct contact measurement of yarn tension in domestic and foreign are analyzed by use of yarn balloon theory and digital image processing technology. A new method is established for measuring the dynamic tension of yarn ------non-contact measurement. The mathematical model is established according to the theory that yarn tension is relent to yarn balloon through the research on the dynamics of yarn balloon. In human-computer interaction, image enhancement is realized by using the gray scale linear transformation curve, image segmentation is achieved by using Canny edge detection operator and the edge of the image is extracted by using mathematical morphology and borders tracking algorithm accurately from yarn balloon which is taken by CCD immediately, finally the pattern characteristic parameters of the yarn balloon are extracted and the yarn tension is measured.

Abstract: Hybrid measurement method is proposed to solve the problem that the partial or whole three-dimensional reconstruction accuracy of aviation engine parts is high. The point clouds of the aviation engine part are captured first using contact and non-contact measuring method. Feature-based parametric modeling strategy is adopted to reconstruct the aviation engine part so that it is easy to be modified in the future. Then, the point cloud data obtained by contact measurement and the reconstructed model are registrated to the same coordinate system to detect the deviation. The point cloud registration method is based upon the feature-based registration method and standard Iterative Closest Point (ICP) algorithm, which help to improve the accuracy of registration. According to the result of deviation, the three-dimensional model can be modified. The accuracy of the modified model is controlled within 0.02mm, satisfying the requirement of aviation engine parts. Three-dimensional reconstruction results have verified the feasibility of the method.

Abstract: Standard is the root of the measurement, But a complete set of measurement specifications has not appeared in the applications of non-contact measuring technology at present.This article talks about the study of the two fitting methods of the Polyworks software, and puts forward when the Polyworks software deals with the circle, slot etc. features,we should choose the fitting method of minimal, and verifys the feasibility of the method through the relevant experiments.

Abstract: This study presented a novel non-contact optical measuing method for grape stem diameter in fields. The main algorithm contained 3 steps: saperation of the stem from background, determination of the stem segment, and the computation of stem diameter. The experiments conducted in field not only validated the effectiveness, but also proved the high accuracy of the optical measuring system. And our further experimental results showed that the continuous measurement of grape stem diameter can provide periodic data for the analysis of physiological disorders in grapes.

Abstract: Project Moiré Interferometry system includes fringes projection system,image acquiring system and image processing system. Laser beam is changed to planar optical wave by expanded beam collimation system.The ideal grating is produced when planar optical wave passes through spatial light modulator. The emergence of light waves which include the information of grating are projected on the model surface.The fringes image modulated by the height of model surface is formed. The image is captured by image acquiring system to be processed.After the distortion brought by camera perspective transform is eliminated,the image is added with reference stripes.The Moiré fringes containing information of model surface can be obtained.Quantitative continuous data of model surface shape can be gained after fartherly image processing.

Abstract: The wear of the plastic injection molding machine bore has an effect on the quality of the machine to some extent. In order to pursuit the maximum of comprehensive benefits in plastic molding factory. Its necessary to design economic, efficient, dedicated instrument which measure inner diameter in the machine bore. In this paper, the measurement instrument in the plastic injection molding machine bore uses eddy current sensors non-contact measurement theory and virtual instrument technology, it can measure the degree of wear in the plastic injection molding machine bore easily. The results are processed by Radial Basis Function neural network (RBF) technology and then get the curve by using curve fitting to reduce measurement error. It can show the degree of abrasion in the plastic injection machine bore.

Abstract: The paper deals with the possibilities of using non-contact 3D measurement systems for the digital capture and subsequent dimensional and shape analysis of multi-part forms. The paper illustrates a practical method of the 3D digitization of two-part moulds using a combination of TRITOP and ATOS optical systems. It introduces dimensional control of the cavity of a mould during its real closure and compares this method to traditional methods of measurement. The analyses carried out show the undeniable benefits of these innovative approaches in practice, because the appropriate use of optical methods often enables the detection of the errors of products and tools which would be impossible to detect using traditional approaches.

Abstract: Based on the analysis of the production technology and present status of online glass coating production, a non-contact measurement capacitance sensor, which is adaptive to the high temperature condition and enjoys a novel structure, is proposed in the paper. The online measurement of molten tin surface position in the CVD coating production process under the condition of 700°C can be realized with the sensor. The reliability and feasibility of the dynamic measuring system have been proved by the experiment. The dynamic accuracy is better than 0.1mm within the effective range of 25mm.

Abstract: This system brings forward the CCD measurement method based on oblique laser triangulation , which to resolve the minimal thickness measurement precision problem, in this system use linear array CCD, then used CCD as a photoelectric conversion device, the image on the CCD image point displacement variation to realize planar sheet thickness measurement, design and construction of the contactless thickness measurement system. Finally, the experimental analyze the measurement error of the system, prove the feasibility and validity of the system.