Papers by Author: Yan Ming Quan

Abstract: In the guiding system for fillet welding of corrugated sheet based on laser line projection, the Laser Lines Projected on the Corrugated Sheet and Plane (abbreviated as LLP_CS_P) are interfered by the irregular width of Assemble Gap to be Welded (abbreviated as AG-W), the Scratches of the Metal Surface (abbreviated as S_MSS), the Laser Line Projected on the Welding Point (abbreviated as LLP_WP) an so on. As a solution of these problems, an algorithm and on-line processing system based on morphology are proposed to stably and accurately locate the endpoints of LLP_CS_P. First, the interferences are separated from the laser line projection. Second, the interferences are eliminated by morphology filter. Third, the locations of laser line projection at AG-W are obtained through connected component labeling and extreme theory. Image acquiring and processing on line indicate that this algorithm and system can perform stably and effectively under the condition of irregular width of fillet welding seam of corrugated sheet, scratches, welding points. The trajectory and width of welding seam are monitored on line to guide the torch to track the AG-W and adjust welding parameters adaptively.

Abstract: To overcome the problems resulting from weldment trimming and assemble errors, thermal deformation, arc blow, etc., a set of new tracking system of fillet seam for automatic corrugated plate welding was put forward based on machine vision technology. The tracking system included two cameras: the precursor was set in front of the welding torch (a corrugation cycle far away), for capturing the linear laser projected on the side plate and the base plate; the another one was installed over the melting pool for capturing the image of welding torch tip and the seam. The processed image information from the precursor camera was used to track the fillet seam three-dimensional trajectory and the seam width, according to the information the welding motion controller and the welding power made preplanning; the processed torch tip and seam image information was sent to the motion controller and the welding power so that they could make real-time motion and welding parameter adjustment. Computer simulation proved that this new tracking system could work efficiently.

Abstract: The drilled surface characteristic of epoxy resin reinforced by multi-directional carbon fibers is investigated based on experiments. With the emphasis on the effect of fiber direction, the mechanism of inhomogeneous surface topography is discussed. Besides, the mechanism of drilling-induced delamination and splitting defects are analyzed, and the drill condition and drilling parameters are also considered. It is indicated that the varied fiber direction is the main cause resulting in the inhomogeneous topography; delamination is easy to occur between two adjacent laminas which have different fiber directions, and it is more serious near the exit of drilled hole.

Abstract: AC algorithm of blind sources has been applied to the identification of engine noise sources. However, the testing platform based on the blind separation theory is difficult to actualize some experiments and obtain data in the real environment, or to obtain these requires high cost. Therefore, this paper proposes a new approach to construct an experimental testing platform-Sinmulink Model so as to identify engine surface noise sources. This model is applied to the test of the experimental data. These experiments demonstrate that Simulink model is efficient to identify engine noise source and the testing data accord with that made by the former platform. It is obvious that Simulink model, to some degree, can be used to replace engine surface noise sources testing platform.

Abstract: The variety of surface emissivity of carbide insert P10 against temperature raise is calibrated with antitheses. The influence of high temperature object near the carbide insert and the open measurement environment of the thermal infrared imager on the calibrated values are investigated. Then the thermal images of turning tool’s rake face are continuously captured by an infrared imager in the designed turning experiment. In the analysis of thermal images, the influence of measurement environment is taken into consideration and varied emissivity values are used to analyze the temperature in different areas of the rake face. A series of measurement results of temperature field in the rake face are achieved and they are consistent with the conventional rules of turning researches.

Abstract: The transferring of electronic signal from rotating work piece or cutter presents a challenge problem. In this paper, a wireless communication method is proposed to transmit signal from rotating bodies. The corresponding device including the signal input & transmission module and the signal receiving and processing module was fabricated. The working principle of the wireless system is introduced, and a series of experiment is set up to calibrate the system accuracy and to measure the cutting temperature of the rotating work piece. The experimental results show that the wireless system has a satisfactory reliability and temperature measurement accuracy.

Abstract: Carbon fiber reinforced plastics (CFRP) are typical difficult-to-cut materials because of their anisotropic mechanical properties and poor heat conductivity. Drilling is the most common process in the manufacturing of CFRP products in which delamination is the most potentially damaging defect. In the present work the delamination damage around drilled hole of multi-directional CFRP is analyzed by means of infiltration inspection method with gold chloride solution, and the effects of drill rotational rate and feed as well as drill geometry on delamination are investigated, the damage degrees in laminas near the hole entrance and the hole exit are compared. The experiment proves the infiltration method is applicable for the investigation. The results show that the nearer the distance to the hole entrance or exit, the larger the remains area of infiltration agent is; the remains mark near the hole exit is larger and more irregular than that near the hole entrance, and it has the largest length in the direction along fiber length; a chisel-free drill, a high drill rotation rate combining with a small feed brings on the decrease of delamination damage.

Abstract: Making holes in glass or ceramic with conventional twist drills is difficult because of the hard and brittle properties of the workpieces, but the drilling-grinding process with diamond core-tools has found application in the field due to its high efficiency and low cost. However, small hole drilling-grinding with the core tools is still a challenge because the small core tools have a limited strength and chip-removal capacity. In this paper, the small hole drilling-grinding in glass and ceramic by diamond core-tools with 4mm diameter is experimentally investigated, the drilling-grinding force and heat are measured and calculated, the performances of two types of electroplating diamond core tools are compared.

Abstract: A novel movable monocular stereo vision measurement system was designed considering the application objectives and on-machine measurement situation. The physical model and mathematical model for measurement accuracy was established. The appropriate structure parameters scope was obtained after simulation analysis. Finally, an application example of the measurement system is introduced.

Abstract: Glass is a kind of difficult-to-machine material due to its hard and brittle properties. Although many special hole machining methods for brittle and hard materials have been developed, the traditional drilling is still widely applied because it is simple and reliable. However, the drilling tool for hard and brittle material is an obstacle, especially for small hole drilling. In this paper, two types of diamond abrasive core-tools which are made by electroplating and sintering process are used to machine small holes in glass plates, their structures are introduced and their machining performances are compared. The experimental result indicates that these diamond abrasive tools are satisfied for small hole machining in glass, and the performance of electroplating tool is better than that of sintering one.