Papers by Keyword: CCD Camera

Abstract: When using the laser displacement sensor to measure distance, there is a deflection angle which exites between the direction of the laser beam and the direction of axis, this deflection angle has an impact on the final measurement result. This paper presented a calibration method of the laser beam’s direction, designed calibration device and ceramic calibration plate. In the process of calibrating, laser displacement sensor moves along Z-axis and Y-axis of machine, CCD camera takes the image of the spot projected by laser beam on the calibration plate, then calculate the laser beam’s direction based on the movement distance of laser displacement sensor and the spot’s position on calibration plate. Depend on the Mikron five-axis CNC machine tools, this paper describes the whole calibration process in details, the feasibility and accuracy of the method has been verified by experiment. Experimental results show that when the machine tool’s accuracy is within 0.002mm, the calibration error of laser beam’s direction can be controlled within the range of 0.05°.

Abstract: Positioning accuracy of light spot locating algorithms and the stability of the spot are two key factors affect the accuracy in the multi-degree of freedom measurement system based on CCD. Two algorithms of sub-pixel measurement are present. They are threshold gray barycenter algorithm and circle fitting algorithm. The theoretical analysis was carried out with the two algorithms, and the experimental verification was also taken under the laboratory conditions. Experimental results show that the threshold gray barycenter algorithm has a higher locating precision than circle fitting algorithm that the standard deviation in 30 minutes can be under 0.04 pixels. According to CCD pixel size it can be calculated that the light spot locating standard deviation is 0.186μm.

Abstract: CCD aerial camera is one of the important means of obtaining the image information on the ground, it is through the collection, archiving, and reading to achieved the images acquisition. As the very large amounts of data of the images, it takes a lot of time far more than analysis and processing when archiving and reading, so that not only difficult achieve real-time detection and processing, but also causing a waste of storage space. Therefore, the research of image compression and other processing technology has become important particularly.This paper use the wavelet coding to get images compression for the problem, and design the image processing system of aerial camera manipulator. This system designed by embedded modular, and ARINC 429 bus to achieve communications between the camera and the aircraft systems, make compression to the images which captured by the camera, and deal with the compressed image as stored, local zoom in and out, etc.

Abstract: The design of control system is composed of scheme, components, hardware equipment and software structure in continuous grinding machine for working stone slabs based on PLC, CCD camera and touch screen in the paper. Switch between manual control and autocontrol of grinding machine is realized through information acquisition from CCD camera, communication between PLC and touch screen. The electrical control measure of PLC is designed to substitue the traditional control circuit in order to realize non-contacting control. Control system of continuous grinding machine for working stone slabs is composed of the signal acquisition system, PLC and touch screen. The control system of grinding machine is more advanced and reliable, meanwhile production efficiency will be improved greatly.

Abstract: Aiming at the phenomenon that the production line of the strip steel’s detection is fast speed and detection quantity of data is large, which are difficult for worker to detect on line, we put forward a detecting system on defect area of the strip steel’s surface. Using CCD camera regularly to collect the images of the strip steel’s surface and to reflect it back to the detecting device on defect of the strip steel’s surface, and adopting specific arithmetic to analyze and handle images, what can accurately sound a warning while it detects the defected image. It is convenient for worker to take corresponding measures right away. This system has simple structure, low cost, and high defect detection rate, which has the great promotional value.

Abstract: As images of the burden surface are directly related to working status of the blast furnace, monitoring system of the burden surface is essential for blast furnace. Images of burden surface are captured by CCD camera, and then transmitted by video line through anti-interference devices and video capture card from top monitoring device located in furnace roof to the main monitoring room. The three environment parameters including nitrogen pressure, water pressure and working temperature of CCD camera are very important to ensure CCD camera working in good conditions. Pressure gauges for nitrogen and water are installed near top monitoring device; temperature sensor for CCD camera is installed in the top monitoring device. All environment parameters are transmitted by RS485 transmission lines and modbus protocol to be dealt with in the main monitoring room.

Abstract: A hand-shape image acquisition system based on DSP was designed for solving the problem of hand-shape recognition. Acquisition configuration was designed, and the key parts (encoder, decoder, memory chip etc.) were selected. Finally, development of image capture driver was put forward. The imaging information were transferred into analog video signal by CCD camera, and analog video signal decoded was transferred to video port of DSP, after that one frame processed image was transferred to display after being encoded. Consequently, the final output image can be observed in displayer. System performance was evaluated by classification accuracy rate and real-time of recognition, and the results shows that the method proposed is reliable and effective.

Abstract: Due to the impact of the lens optical system and the different manufacturing processes, there could be causing the vignetting when using a CCD camera to take pictures. This paper analyzes the causes of the lens vignetting and put forward a method for reducing this error to improve the accuracy of the intensity of illumination detection. Firstly, according to the analysis of the existing research on the camera lens, concluded that there are two factors that cause vignetting. Secondly, based on the conclusion, do large amounts of test in each case. Analyze for the influence of illumination test in each case. Finally, the article put forward a set of vignetting correction method to correct the image be collected in a fixed aperture. The result shows that the method can effectively reduce vignetting measuring error and has a good stability.

Abstract: A system for orientation the best imaging location of aerial cameras is designed, and the working principle, hardware components of the system are described. The orientation information is produced by collimator. The best imaging location is determined by size of the collecting image with area CCD camera and the data is processed by least square method. The converter controls the translation of the camera in axial direction precisely. Off-focus or not is judged based on the distance between the real image location and the best image location. Through the tests of multiple aerial cameras, the estimation of off-focus or not is similar with test flight result with the system.

Abstract: The principium of measuring focus of aerial camera and the location of the actual image plane with CCD camera are introduced, and the methods to improve survey precision are described. The image is received by area CCD camera. The accuracy of orientation of the imaging central line is improved by means of fit the curve method or by center of gravity method. Therefore, the distance between imaging central lines is refinedly calculated. The experimented turn out that the two methods on measuring focus of aerial camera have high precision, and the survey errors are in accordance with the theoretical ones (0.12%). The two methods on deterministic result of the location of the actual image plane are identical, with their precision reaching 100%.