Can Zhao

The Research of Data Points Quality Assessment Method in Reverse Engineering

In the field of reverse engineering, data quality assessment is a very important work in the detection, the result of data quality assessment will directly or indirectly affect the detection and the following manufacturing process quality. Data quality assessment can be used in the camera calibration, the model and model reconstruction comparison, and so on. In this paper, on the basis of the existing method of calculating each point error, and multipurpose use of average and standard error and some other concepts of mathematical statistics, and then improve a novel and simple calculating error method. This method is applicable to many groups of one-to-one ideal data and the measured data comparison, and it can be more intuitive to reflect the error of overall data, as well as the error distribution, and it can be more efficient to determine the measured data is reasonable or not. In this paper, the data point quality which is collected in the reverse engineering is assessed, and it can see that the method which is proposed in this article has some advantages in the data point quality assessment field.

The Research on Cutting Force in High-Speed Milling Process of Aluminum Alloy Impeller

High-speed cutting process of cutting force influence variables and variation and ordinary speed cutting are obviously different, in order to study the high-speed cutting process of different parameters on the effect of cutting force, based on five axis high-speed NC machining center, using multi-factor orthogonal test method for high speed milling of aluminum alloy impeller conducted experiments. It was analyzed that cutting force influence factors of 5-axises blade machining process. A private clamp was designed and produced, to measure the cutting force of machining process. It was observe that distribution of 3-dimension cutting forces in cutting path. It was found that the distribution rule of cutting force. With the experiment study on cutting force when high speed cutting aluminum cuprum, the influence disciplinarian of each cutting parameter on cutting force was obtained.

Research on Force and Temperature in Milling Ti6Al4V Titanium Alloy Based on Tool Geometry

First, quadratic regression general rotary combination experimental design is adopted in this paper. The cutting force prediction model based on tool rake angle and helix angle is established using regression analysis. And the proper cutter for milling Ti6Al4V is selected, rake angle = 12.5 °, helix angle = 34.5 °.Secondly, milling temperature during different milling process is simulated by the use of finite element simulation software. And the variation rule of milling temperature along with the rake angle and helix angle is obtained which provided the basis for the selecting tool.

Influence of Cutting Parameters and Tool Geometric Angles on TC4 Titanium Alloy Chip Shape

To select reasonable cutting parameters, improve the processing surface quality, and extend the tool life, this paper uses four solid carbide end milling tools to process TC4 titanium alloy, and analyses the influence of the difference cutting parameters and the geometric angles to chip shape. The experiment results indicate that the degree of serrated chip shape is increased by increasing the feed rate under the condition of certain spindle speed. But the degree of serrated chip shape may be decreased by the adoption of small axial and radial depth, or bigger rake angle and smaller helix angle. Select larger rake angle, cutting edge is sharp, the metal deformation of cutting layer is small, which can reduce the friction force when chip flowing through the tool rake face, so that the cutting force and cutting temperature decreases accordingly.The greater the helix angle is, the worse the chip removal conditions is, and the degree of serrated chip becomes larger, the blade is more sharp, easily crack, and the tool life decreases. So relatively small helix angle is better. The choice of angles is interrelated with each other, the selection of some angle separately cannot get the desired reasonable value.

Application of High Speed Machining in Impeller Process

For improving previous compressor impellers machining efficiency, the new process routine and tool parameters were adjusted by using high speed machining(HSM), which can decrease machining time and the types of tools. The high efficient machining process was proved by tests, and it had been shown that the time of machining was shorter. Improvement measures were taken to deal with the problems of vibration ripples which occurs in the improvement process.

Experimental Research on Aluminum Alloy Blade’s Surface Roughness of Integrate Rotor Based on Four-Axis High Speed Milling

It was carried out that a HSM test for aluminum alloy (2A70) rotor with carbide cutter. It was investigated and analyzed that the influence of different cutting speed and feed speed on the roughness of blade’s finished surface. The experiment showed that high quality surface was easy to obtain by increasing the cutting speed and decreasing the feed. But when the cutting speed crossed the critical value, increase in the cutting speed caused slight decrease in the surface roughness. The feed decreased to a very small value, the roughness increased a little. It was expected that best surface roughness and machining efficiency could be obtained by selecting the appropriate cutting speed and feed.

Correction of the Asymmetrical Projection for Accurate Camera Calibration Using Co-Planar Circular Feature

Circular features are one of the most widely used shapes for camera calibration, due to several advantages: easy to make and recognize, not sensitive to image noise, symmetry, analytic formulation is simple. However, perspective projection is generally not a shape preserving transformation. A circle often mapped as an ellipse on the image plane when the feature and the image plane are not parallel to each other, as a result, the center of the circle shift from the center of the ellipse. In this paper we present a simple and robust algorithm to compensate this bias before camera calibration. Experimental results show the algorithm is important and convenient.

Parameters Optimization about Precision Milling Titanium Alloy TC4 Used for Aviation

To improve the production efficiency and product quality of titanium alloy TC4, with the minimum of cutting force F, surface roughness Ra, and surface peak valley height Pv as the optimized goal, using orthogonal rotating combination design method of three factors quadratic regression, the influence of cutting speed vc, feed per tooth fz and cutting width ae to cutting force (Fx, Fy) surface peak valley height Pv and surface roughness Ra are mainly studied, and the best cutting amount combination is chosen. Experiment results indicate that the best cutting parameters of titanium alloy are vc=28.588 m/min、fz=0.043 3 mm/z、ae=0.1 mm, the optimal values are =3.346 N、 =47.01 N、 =673.89 nm and =201.78 nm. This research is of theoretical significance for improving the processing efficiency and machining quality and reducing the production cost.

Stability Research on High Speed Milling of Aviation Aluminum Alloy

The stability of cutting system is an important research in high-speed machining area. It is widely used in engineering practice. First, this paper studies the milling forces and their change law when milling aluminum alloy through orthogonal experiment. And it solves the milling coefficients. Second, it modal parameters of milling system such as natural frequency, modal mass and equivalent stiffness by hammer experiment. On this basis, it draws the stability lobe about the spindle speed and radial depth of cut and verifies the accuracy of the stability lobe.

Comparative Study on 2A70 Aluminum Alloy High-Speed Milling Cutting Force Model

The mechanical properties of flat end mill is analyzed the high-speed milling, the linear model for milling force is established. And the 2A70 aluminum alloy four-factor four-level orthogonal milling tests are carried out, the nonlinear model of milling is set up by using regression analysis method. The comparative analysis is made between the linear model and nonlinear model, whose results show that the two models have good agreement on the value and trend of change, which is the basis of the follow-up tool path optimization, fault diagnosis and so on.