Papers by Author: Jun Jie Guo

Abstract: Combined with sewage disposal characteristics and content networking technology, Constructing the relatively flexible structure, the price is relatively cheap,reliable performance of sewage treatment monitoring system. Improve the sewage disposal automation and informationization level and the ability of the key sources of pollution monitoring and environmental incident coping,The environmental protection,energy saving and emission reduction is of great significance.

Abstract: Gear Measuring Center(GMC) is a kind of instrument for measuring the accuracy of the tooth surface. For the gears whose modulus is not small, the contact measuring method is commonly used. 3D scanning probe is the key component. Because it can reflect the trend of 3D error of the tooth surface, and has the advantages of high-speed and high-precision, it is generally used in the measurement of complex and large gear. However, due to the anisotropy of the mechanical structure of the probe itself and the influence of the external environment factors, it will result in mutual influence among the three deformation directions of the probe, that is coupling phenomenon, therefore it must be calibrated before measurement. In the paper, on the basis of the structure of 3D scanning probe and measurement principle, the varying coefficients linear calibration matrix was innovatively proposed. Through measuring the points planned on the standard ball, based on the spherical equation, the overdetermined nonlinear equations were established. The equations were iteratively solved with the least squares method and genetic algorithm. The calibration matrix was finally experimental verified. The experimental results show that the linear calibration matrix has higher calibration precision than traditional constant coefficient calibration matrix, the calibration method has the advantages of high-efficiency and high-precision, it has a certain reference meaning for the research of the calibration of the probe.

Abstract: Gear Measuring Center(GMC) is commonly used to test error of the tooth surface of the gear, whose geometric accuracy directly impacts on the accuracy of measurement. How to quickly and accurately detect space geometric error of the measuring machine and compensate becomes the essential means of high-precision measurements. According to the problem above, in the paper, three-beams laser detection technology is proposed. The detection of the geometric errors of the linear axis was achieved. The accurate measurement for the position and attitude of the plane mirror on measurement seat was achieved based on laser telemetry principle. The positioning error, the pitching angle errors, the deflection angle errors and the straightness errors were separated. And then based on multi-body system theory, by using of homogeneous coordinate transformation, the error compensation model of 4-axis measuring machine which includes three shifting pairs and one revolute pair was established, and the algorithm was given in the paper. The theoretical foundation for real-time compensation of 4-axis GMC was established. The geometric errors of GMC can be improved by the method of the error detection and compensation. The method plays a very important role in high-precision measurements.

Abstract: Error compensation is an effective method to improve the machining accuracy of NC machine tool. A laser tracker is used to rapidly and accurately detect the geometric error of NC machine tool in the paper. The machine tool is controlled to move on the preset path in the space, and a laser tracker is used to measure the motion trajectory of the machine tool. Each geometric error can be identified by error separation. Based on the error model of 3-axis machine tool, error compensation can be carried out by modifying the machining process (G code). Results of experiment show that, this measurement method is feasible, and modifying the G code for error compensation is also effective.

Abstract: Traditional one-dimensional, two-dimensional probe can only measure the micro displacement in one or two directions of space, therefore highly-efficient and highly-precise measurement requirements of the surface of the complex gear can’t be satisfied. Because 3D scanning probe can measure the micro-displacement in three mutually perpendicular directions of space, with it, continuous scanning motion measurement can be achieved and a large number of data points in three directions of space can be measured in a very short time, it is widely used in gear measurement industry at home and abroad. However, because of the limitations of mechanical structure of 3D scanning probe, installation errors and environmental factors, the measured three directions can’t always be strictly vertical, and in the measurement, there will be the interference and the coupling phenomenon among the three directions. The study about how to ensure the highly precise characteristics of 3D scanning probe using a reasonable calibration method has become hot and difficult. In the paper, a new calibration method is proposed, the different regions on the standard ball were continuously contacted by 3D scanning probe, and let the probe step 10 times on the each contact point of standard ball, 10 group of points data were read out. The point of subsection was determined based on the deformation of the probe in the experiment, the data of the probe collected in each segment were fitted by using of the least squares method. Several calibration matrices were so obtained, the precise calibration of 3D scanning probe can be achieved. This method is finally verified by experiment. The experimental results show that the method of calibration is feasible, and has the advantages of high-speed and high-precision, which lays a solid foundation for high-precision measurement of 3D scanning probe.

Abstract: In the measurement process of the large, complex surface, due to the errors of the installation, the errors of the machine bed itself and other factors, the probe can be over pressed. The situation of measuring interruption can be occurred. In the paper, take the measurement of the spiral bevel gear for example, by using of the gear meshing theory and differential geometry, through a series of coordinate transformations, the coordinates of the tooth surface grid nodes are calculated. Through measuring the tooth surface of the spiral bevel gear by using of Gear Measuring Center(GMC) and 3D scanning probe system, the follow-up control strategy of continuous scanning measurement based on the constant measuring force was proposed. The measurement and evaluation of the tooth surface were achieved through continuous scanning motion along the measurement path planned. In the measurement process, the measurement path was planned according to the theoretical models. The offset values of the probe were real-time detected, the constant deformation of the probe was ensured through controlling the motion of X,Y,Z axes. The mathematical model of the relationship between the velocity of each axis and the deformation vector of the probe was established. The continuous scanning measurement along the path planned based on the constant measuring force can be implemented. The requirement of the steady-state errors and real-time were meted by using of PID control strategy of subsection variable parameters. The method was finally simulated and experimented. The results showed that the occurrence of unexpected interruption in the measuring process can be effectively solved. It plays an important role for the highly-efficient and highly-precise measurements of the tooth surface.

Abstract: How to quickly and accurately detect the error of NC machine has become a hot issue for domestic and foreign scholars. Based on GPS principle, a laser tracker is adopted the multi-station and time-sharing measurement to rapidly and accurately detect the geometric accuracy of NC machine. The machine is controlled to move in the preset path, and a laser tracker is used to measure the same motion trajectory of the machine successively at different base stations. The position of base station and the space coordinates of measuring points can be determined based on large amount of measured data. The algorithms of multi-station and time-sharing measurement are given, and the influencing factors of measurement results are discussed in the paper. Meanwhile, a detection system of machine error is developed based on the platform of Matlab, which can quickly process the measured data and shows each error of machine intuitively.

Abstract: The paper presents the principle and algorithm of multi-point and time-sharing measurement method to detect the machine geometric accuracy.Its basic principle is based on laser tracker and the multilateral method,moreover,only one laser tracker is used in the measurement.Its cost is lower than multi-point and simultaneous measurement.Then the application of the method is introduced on a glass measuring instrument.The geometric error of the machine is separated in x and y direction.

Abstract: This paper presents a measurement method of NC machine geometric accuracy. The principle is that a laser tracker is used to collect a lot of target point coordinates on four different locations around the machine during the machine spindle moving. A redundant equations could be established through target point coordinates,then the exact location of each target point coordinates could be determined by the principles of GPS positioning.Through the target point coordinates,the geometric error of machine could be separated. The method has fast measuring speed and low cost.Moreover the measurement precision is higher than direct measurement only using one laser tracker because the GPS positioning principle is used to avoid the angle measurment of laser tracker.

Abstract: Aiming at the problem that the traditional plunged-bar method is difficult to meet the measurement requirement of spatial location of thin and small through-hole, in this paper, the digital image processing technique combined with sub-pixel detection technique is employed, and a new method is proposed to detect the tiny through-holes. The evaluating function method based on the “roundness” of the image of hole is presented to find out the posture parameters of CCD where the optical axis of CCD is parallel to the centerline of hole. Therefore, the spatial location of hole can be easily obtained by these posture parameters. Meanwhile, the diameter of hole can be achieved by means of image measuring technology at calculated posture of CCD. Owing to the non-contact measurement, this method is particularly suitable for those small through-holes drilled on the soft and easy-deformed object. The experiment results on the experimental platform illustrate the feasibility and validity of this method.