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OPC, the data integration middleware in the industrial control field, defined an industry standard for exchanging data between field devices, control systems and other applications. XML, as a W3C standard, was open and platform independent and gave another way to describe and exchange structure data between applications. The combination of OPC and XML, provides vertical integration from floor layer...
As a distributed open system in manufacturing and process control environment, fieldbus aims to provide an international standard in this field. In order to satisfy the requirement of data transfer in industrial control, the interface between fieldbus and the program also need to pursue a standard. OPC technology is introduced to satisfy the requirement of efficient data transfer. It develops an open...
The adaptive synchronization of unified chaotic system is studied when the parameter of drive system is unknown and the parameter of response system is adjustable. Based on Lyapunov stability theory and combining driving method, two new adaptive control methods for the synchronization of unified chaotic system are presented by employing multiple controllers and only a single controller. The analytical...
A distributed real-time production supervisory designing conception based on OPC and Web technique is presented. The OPC technique and its application in the DCS of cement enterprise are introduced, the seamless connection between the application and plant, and the Web distribution of production data are realized.
Low velocity servo system needs precision velocity estimation. An observer for low velocity estimation was proposed in this paper. First, the source of low velocity estimation errors and the shortcomings of the single period difference were analyzed. The relationship between the estimation accuracy and estimator's frequency characteristics was concluded. Then, the structure of the observer was proposed...
Digital control of continuous time processes is usually designed on the basis of a constant sampling rate. In some digital flight control designs it is difficult to preserve this simplification, so it is necessary to design irregular sampling patterns. The problem could be much more complex if there were various subprocesses with different performances either in time or frequency domains. A new way...
This paper presents a FPGA-based auto focusing system for object ranging. It overcomes the disadvantage of manual focusing wise in traditional method of objects ranging. In our system, the distance of objects can be measured automatically by the auto focusing algorithm. We have experimentally demonstrated the effectiveness of this method. The best performance of our system is about 3% relative errors...
This paper presents algorithms for vision-based detection, tracking and trajectory generation of vehicles in simple video sequences of traffic scenes which are registered by a stationary camera. Processing is done by three steps: improved vehicle detection method, faster tracking algorithm and new vehicle trajectory generation technique. Vehicles are viewed as rectangular blocks with certain active...
Image quality assessment is a complex problem due to subjective nature of human visual perception. In this paper, a novel image quality assessment is proposed based on the discrete 2-D wavelet transform and the correlation coefficient. Firstly, the reference image and the distorted images are decomposed into several levels by means of the wavelet transform respectively. Secondly, the approximation...
For overcoming some existing problems of traditional Coordinate Measuring Machine (CMM), a novel robot 3D laser measurement system which is representative in reverse engineering is designed in this paper, and its composition and working principle are introduced in detail. For the purpose of measuring the workpiece accurately, the system model must be built, namely, the CCD parameters must be calibrated...
In image sequence, target's features has two components: the spatial features which include the local background and nearby targets, and the temporal features which include all appearances of the targets seen previously. In this paper, we develop a multi-target visual tracking method based on mixed spatio-temporal features learning model which is a probabilistic inference model considering the above...
Contrast enhancement is a necessary pre-processing step in many image processing algorithms. This paper introduces a new contract enhancement algorithm designed specifically for segmentation applications in which an image contains multiple objects of different sizes. The underlying assumption of our algorithm is that an object can be best segmented if it is locally enhanced at a scale that corresponds...
A novel real-time image target tracking algorithm which is based on Mean Shift and improved Kalman filtering algorithm is studied. In the cases of known initial information(position and velocity), measuring point is integrated in tracking window by applying the method of maximum fuzzy entropy Gaussian clustering. The point which has been integrated is inputted to the Kalman filter, and Kalman filter...
Image registration is kernel algorithm of many system applications such as three-dimensional reconstruction in computer vision area. This paper proposes a registration method that combines mutual information and template matching, firstly carries out template matching with similarity criteria based on mutual information, then gets candidates of sub-images, according to spatial relationship between...
Intelligent empty bottle inspection system is an important inspection equipment of empty bottle before filling beer, it is a blend of machine vision, precision machine and realtime control. They need to cooperate perfectly to achieve the desired effect. In the design of the empty bottle inspection system, one of the key technologies is the location of the bottle mouth and bottom which affect the speed...
This paper describes a machine vision system with back lighting illumination and friendly man-machine interface. Subtraction is used to segment target holes quickly and accurately. The oval obtained after tracing boundary is processed by Generalized Hough Transform to acquire the target's center. Marked-hole's area, perimeter and moment invariants are extracted as cluster features. The auto-scoring...
A face detection method for the color image with complex background is presented, which is a mixed skin-color segmentation model in both YCbCr and HIS color space constructed; The mixed skin-color segmentation model can be used to segment of possible skin regions in the original image. After skin-color segmentation, the geometrical shape information of face and the maximum of the complexity of eyes...
The Hausdorff distance template matching algorithm is one of the most popular algorithms recently for its robustness to the noise and the occlusion. But if the binary image that has lots of edge pixel points, this algorithm needs a long time to calculate the distance one by one, so we propose the small region filtration method to reduce the computing time. The experiment results show that the algorithm...
Recent advances in wireless communication, semiconductor, embedded system and sensor technology have made it possible to build low cost, low power consumption, reconfigurable wireless vision sensor nodes. Wireless vision sensor networks, which consist of wirelessly connected embedded systems with vision capabilities, provide wide a variety of applications that are impossible to be realized with the...
According to the shortcoming of hiding capacity is low in the traditional reversible image hiding algorithm, a reversible data hiding algorithm based on pixels difference is proposed. It utilizes the relevance of two adjacent pixels to hide data by modifying pixel grayscale values. Plenty of experimental results show that it can hide more data than many of the existing reversible data hiding algorithms...
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