| Oil Film Bearing SUBCO, Taiyuan Heavy Industry CO., LTD. has imported one CNC grinding machine of high precision from Italy at a cost of several hundred millions RMB with the capacity to manufacture oil film bearing of super large-scale. But the method to detect Form and Position errors is only bow-shape ruler with micrometer gauge. It has the following defections: low measurement precision, manual operation and extraordinary complex calculation, and low reliability. At abroad roundness measurement instrument equipped with measuring software or 3d coordinate measuring machine are still adopted in Form and Position errors detection. But because of the expensive price, the high detection cost, incapability of real-time detection and the largest detection diameter smaller than 500mm, they are not applied broadly in domestic companies. The imported on-line detection instrument costs 4000000-6000000 RMB per set and has the following defections: 1.) being unable to support non-contact detection; 2.) being to abrade probe in the long run and create influence on precision; 3.) being with the possibility to scratch the surface of work piece. For all of these, Taiyuan Heavy Industry CO., LTD. consigns Jilin University to develop this research issue-the technique of non-contact, on-line, and intelligent detection of Form and Position errors of cylindrical work piece.The main works of this paper are as follows:1. Developing the system of non-contact, on-line, and intelligent detection of Form and Position errors of cylindrical work piece (both software and hardware)The hardware is composed of CCD Laser Displacement Sensor, controller, and computer. The software adopts multithreading technology, database technology and various algorithm models providing support for user's different kinds of functional needs mainly including set of system parameters, data acquisition, data process, display and memory. The main functions are as follows: 1.) through one friendly interaction interface, users can use the intelligent detection instrument with ease and convenience. 2.) Users can control CCD Laser to implement conveniently data acquisition through USB port. 3.) System ensures the process of data acquisition real-time and visible through the program control to detection. 4.) System has the function to take real-time process and calculation of the acquisitive data, display detection results, save the original data and detection results. To prove the reliability and detection precision of our system, we hold the on-the-spot experiments in several companies separately and make the comparative detection with our detection system, roundness instrument, and Coordinate Measuring Instrument to the same work piece. The practice, at last, proves that our developed detection system lives up to the requirements of the actual production.2. Research on the multilevel error separation theory and method of cylindrical work pieceThis paper presents an intelligent algorithm for multilevel error separating. The first level is to use successive approximation limiting filter and a sub-band filter; the second is 53H filter and multipoint smoothing arithmetic; the third is wavelet analysis of the frequency of error separation algorithm or the principal component error separating algorithm. According to the practical experiments, if the surface finish, roundness and the rotary precision of the cylindrical work piece is high, it is rather effective to use the three levels above. These error separation algorithms can be used in various combinations as well as alone with the characters of flexibility and convenience and have a common application value.3. Building up one mathematical model of Form and Position errors based on artificial immune optimization algorithmAlthough there are many kinds of methods to evaluate Form and Position errors, ultimately it is a process of optimization for accurate calculation. Based on the research of the artificial immune algorithm and evaluation methods of Form and Position errors, we build up one new intelligent mathematical model for Form and Position errors evaluation (roundness, cylindricity and coaxality). Aiming at the measuring data of oil film bearing (diameter 1065mm), it shows that the new algorithm based on artificial immune optimization improves the precision by 2.18% compared with the traditional Least Squares method.4. Presenting one new algorithm of chaos and immune and applying in the detection of Form and Position errorsOn the foundation of the research on the chaos theory and immune optimization algorithm, this paper mainly studies the important features of Logistic chaos model. Integrated organically the chaos theory with immune optimization algorithm, we present one new method to measure the Form and Position errors-chaos_immune algorithm. It is such an algorithm with the character of better global optimization and convergence. The practical measuring data comparison shows that chaos_immune algorithm improves the precision by 4.45% compared with the traditional Least Squares method and by 2.31% compared with the artificial immune algorithm.5. Discovering one new method of CCD Laser Non-contact Measuring Rotating SpeedDuring the detection process of form and position errors, we find one new method of measuring rotating speed-the extraction of circular signals from detection data. CCD Laser Displacement Sensor can distinguish accurately the surface roughness of the rotating objects and the harmonic frequency with the largest amplitude is equal to the rotating frequency. We can get the rotating frequency of the rotating objects accurately so as to get the rotating speed from the signals filtered by the multilevel error separation algorithm. We adopt CCD Laser Displacement Sensor (model: LK-G150H) to accomplish data acquisition and measure separately the speed of Stepper Motor of high accuracy (model: A16K-569), spindle speed of CNC grinding machine of high precision made by Italy, and spindle speed of the lathe. In the experiments the diameters of the measured objects range form 10mm to 2000mm, the rotating speeds range from 5rad/m to 1500rad/m. The relative error of the measuring result is 0.01% and the accuracy is 100%. We have found no relevant reports by document retrieval at home and abroad. This method goes well without the restriction of the measuring diameter theoretically, increasing the load of the measured object. Furthermore, it has the advantage of high precision, good stability and a wide range of application especially with a good practical value in the realm of highly accurate speed measurement.6. Researching on the non-contact, off-line detection instrument of the scale of cylindrical workpiece.We designed and manufactured a non-contact, off-line detector measuring the outward scale of cylindrical work piece. On the foundation of many experiments in the laboratory, we held an on-the spot experiment in Taiyuan Heavy Industry CO., LTD. in July, 2005. The experiment proves that the principle of the equipment is feasible, but the detection precision is still waiting for the further research.These research findings of the paper fill the gap of this domain and have the common application value. The price of the developed detection system is equal to ten percents of like products abroad and the precision is up to micron-grade. So the highly precious, non-contacted and on-line detection system for cylindrical work piece can replace completely the imported instrument. The application of our research findings will improve the manufacturing ability of our country's major equipment and detection standards and create huge economic and social benefits.
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