Chang Hou Lu

Fuzzy clustering analysis of the grinding burn damage level of a workpiece surface layer

Abstract A method for use in evaluating grinding burn damage level by using the burn color spot on the specimen side surface is proposed. The proposed mathematical model of fuzzy clustering analysis can be used for resolving some common problems and is especially suitable for classifying a great number of samples with the characteristic of continuously changing value. This mathematical model has been used successfully in the performance evaluation of cutting fluids.

Investigation of Laser Parameters Influence of Direct-Part Marking Data Matrix Symbols on Aluminum Alloy

This paper studies of laser parameters for direct-part marking Data Matrix symbols on aluminum alloy by using Nd:YAG laser. Different laser parameters and the resultant can affect the barcode grade profoundly. The experiment focuses on all interval values of the vector step, inter-step time, laser Q frequency and laser Q release time. From the experiment results, the relationship between laser parameters and barcodes grade was found, and thus determined the optimal laser parameters. By analyzing the higher and the lower power density processing module SEM images and EDS data, it was found that the microstructure and micro-components of formations that created by the interaction between the laser and the aluminum alloy can affect the barcodes grade level significantly. We also found that the interaction between the laser and the aluminum alloy can be divided into four stages.

Design of Automatic Detection Device for Steel Bar Surface Defects

To inspect the surface quality of steel bar, we designed an automatic system including linear camera and laser. Through the comparison among kinds of cameras, we select linear CCD to our system. The laser is also chosen by us with its high luminance and performance. Through a series of computation, we select the appropriate camera lens to our device. At last, we draw the whole detection system. This device has been used well and provides a good foundation for prospective image processing.

Review of Vision Real-Time Inspection Algorithm for Rolling Steel Surface Defects

Rolling steel surface defect inspection technology based on machine vision is more and more widely used. The latest progress of vision-based real-time inspection algorithm for rolling steel surface defect at home and abroad is introduced, and several key issues are analyzed. Finally, the current domestic research emphases and development trends are proposed.

A New Rate-Dependent Prandtl-Ishlinskii Model for Piezoelectric Actuators

This paper presents a new rate-dependent model for piezoelectric actuators. The proposed method directly utilizes a modified rate-dependent Prandtl-Ishlinskii hysteresis model to characterize the hysteresis and frequency effect of piezoelectric Actuators quickly and efficiently. To identify the model parameters, the least square method is adopted. Based on the identified model parameters, the rate-dependent model for Piezoelectric Actuators is established. By comparing the rate-dependent model with the real output of the Piezoelectric Actuators, the result shows that the new rate-dependent model could characterizes the hysteresis and frequency effect of Piezoelectric Actuator, which clearly demonstrates the effectiveness of the proposed Rate-Dependent Prandtl-Ishlinskii Model.

Design of Energy-Saving Piezoelectric Actuator Drive for High Frequency Servo Valve

The paper presents a circuit topology favorable to drive piezoelectric actuators for high frequency servo valve. It begins with a short overview of different energy-saving PZA drive types and their tradeoff between efficiency and circuit complexity. Then the mechanical structure and equivalent model of the piezoelectric servo valve are described. And the circuit topology including an energy-saving oscillator, an efficient DC bias power and a repetitive controller especially for tracking reciprocating motion, is proposed. The efficiency-improved PZA drive is then derived from the above design. Finally, the drive together with the servo valve is tested in the simulation experiments.

A Gabor Filter Based Image Acquisition Method for Raised Characters

This paper presents a novel image acquisition technology for raised characters. First, laser stripes modulated with height information of raised character are captured using the 3D vision technique; then, laser stripes are combined into a grating image, in which are complete character images with grating background; Finally, a rational design Gabor kernel is applied to filter the grating image. Through this way, the background was removed and the grayscale images of the raised characters are reserved. Experiments show that the proposed method can get the well-separated character images. Also, it is more simple and efficient than the existing methods.

Analysis of Steel Bar Surface Defects Based on Machine Vision

In order to guarantee the steel bar quality, we describe the category of steel bar surface defects in details. Generally, there are about two main categories of steel bar surface defects which include linear and area-like defects. Secondly, the characteristics of the steel bar surface image are analyzed at large. Both of them support a foundation for the future inspection of steel bar surface quality.

Investigation of Laser Current Influence on Two-Dimensional Bar Code Contrast

Laser current is a key parameter in laser direct-part marking symbols on a substrate. Different laser current can create enormous impact on bar code contrast, but the influencing regularities are unclear. In this paper, a new significance test method based on the multivariate nonlinear model was proposed to investigate the influencing regularities. First, the multi-element nonlinear stepwise regression model between the laser current, the laser line spacing and symbol contrast was established, and then the model significance test was employed to evaluate the influence between the two factors and symbol contrast. Finally, the influencing regularities were found by comparing the influence between the laser current and the laser line spacing. These regularities are that along with the laser current value increasing the influence of laser current on symbol contrast decreases and that the effect is much smaller and can even be neglected when the laser current reaches or exceeds a certain value. This certain value is 15 A in the Nd:YAG laser Direct-part marking symbols on the aluminum alloy experiments.

Research of Inspection System Based on Machine Vision for Steel Rod Surface Defects

A new algorithm based on local gradient is proposed to inspect steel rod surface defects. The local gradient method can weaken the effect of noise in steel rod surface image. Then the open operation of morphology theory is employed to remove the retaining noise. Experiments show that this algorithm is effective to inspect steel rod surface defects and is time-saving.