Theoretical And Experimental Research On The Dynamic Parameter Test Technology Of The Remote Motion Object

The research work of the dissertation is the pre-research item of the project"The theoretical and experimental research on dynamic parameter test technology of missile falling to the ground", cooperated with PLA Second Artillery Forces. An electro-optical measurement system has been developed. Using the imaging technology of the binocular vision, the proposed electro-optical measurement system can measure the attitude and velocity of remote motion object easily. In the measurement system two CCDs are fixed toward the space which the remote moving object will go through, and the working principles of the photoelectric theodolite and the ballistic camera are used in the analytic photogrammetry. It is of the advantages such as low requirement to hardware, easy to implementation, low cost, high accuracy, and extensive applied fields. The research work of the dissertation mainly includes four aspects as follows:1. The simplified binocular stereo vision measurement systems are studied. On the basis of the analysis on general binocular stereo vision measurement system, two kinds of novel simplified binocular stereo vision measurement systems, namely one system in which two cameras'(CCD ) ray axes are parallel and the other in which two cameras'(CCD) ray axes are vertical, is proposed and the corresponding mathematic model is established. The relation of the camera location and its inner parameters is researched and discussed. Based on the above relation, how to select the parameters of the high speed camera employed in the measurement system is analyzed. Through the experiment, the relation of the camera location and its inner parameters is given and some available camera parameters are obtained when the moving object fall to different site on the ground.2. The CCD calibration method of the two simplified binocular stereo vision measurement systems is researched. Starting with perspective theory, the camera imaging model without thinking of distortion is derived and established. The camera imaging model with radial and tangential distortion is given, and the outer and inner parameters of CCD are obtained with the penalty function algorithms. The parallel condition and vertical condition of CCDs'ray axes is studied and performed separately. Experiments give the calibration results such as inner and outer parameter, radial and tangentialdistortion coefficients of the CCD, and calibration figures. The calibration error is also analyzed. The results show that the calibration method is of high precision: the error of X direction is no more than±0.05pixel, and the error of Y direction is no more than±0.07pixel.3. The methods of edge feature extracting and stereo matching on images of the remote moving object are researched and the corresponding settle schemes are given. On the basis of studying three general feature extracting methods, we realize the edge feature extracting as follows: Firstly, the images collected are pre-processed with grey compress method; Secondly, the images are extracted with the mask method; Lastly, the edge information of the images are obtained with the Sobel operator. The stereo matching on images are proceeded as follows: Firstly, The span of right points matching with left points is obtained with the search method of level line; Secondly, the grey correlation method and model matching model are employed to obtain the coordinates of right points from the span; Lastly, the related window method is used to realize the stereo matching of the points which is not edge points, and then the 3-D profile of the moving object can be recovered. With the level sequence matching strategy, the error of disparity image is detected and corrected. A lot of experiments have been done and the results such as the edge information, disparity image, corrected disparity image and recovered 3-D profile of different measured object at different angle, are obtained.4. The implement methods of the attitude and velocity of missile in the two simplified binocular vision measurement system are discussed. When the measurement system in which two CCDs'ray axes are parallel, is employed, starting with the principle of equal interval between the measured object's surface points and its axis, the axis vector of the object is obtained with the least-square fitting method. When the measurement system in which two CCDs'ray axes are vertical, is adopted, there are two methods to get the axis vector of measured object. One method is to derive the linear equation of the object axis'projection line in CCD image plane with the axle wire method, and then to get the axis vector of the object using the transmission principle. The other method is to adopt the vertical principle of two CCDs'optical axes to obtain the axis vector of measured object. Starting with the axis vector, the attitude angle is derived. The 3-D interpolation method is improved to interpolate the 3-D coordinates of measured model in different times which are obtained by stereo matching. The moving distance of object is gotten by the3-D interpolation, and then the mean velocity is obtained. The experiment to get the motion parameters of missile model such as moving trace, attitude, interval and velocity has been done. The experiment results show that the measurement methods are of high accuracy, and can satisfy the measurement require of remote moving object.