Characteristic And Discriminant Method Of Signal Online Laser Measurement

Tool needs to be calibrated for the accuracy of processing in the modern machining centers and high-precision CNC tools when it is changed and used for a time. Its diameter and eccentricity are sure to meet the requirements. After a long time of high-speed rotation and intense friction, it inevitably occurs that tool wears or is broken. The traditional manual method of inspection is no longer appropriate; research of new laser calibration method is an effective means to meet this demand. The system platform is established from analysis of the tool movement model, process of photoelectric signal, research of discriminant method and so on. The theoretical and experimental research is made for laser calibration techniques of tools calibration in machining center. Main tasks of the issue are as follows:1. Eccentric rotating system is modeled and analyzed. In the CNC machine tools and machining centers, the tools mainly work under rotating. At first the status of tools is analyzed. With Matlab the different moving statuses are simulated and the characteristic of signal curve are gained.2. Analysis of signal characteristic and discriminant algorithm. Edge features of laser online signal are mainly analyzed. Discriminant Method of Signal and testing feasibility are discussed. The edge of signal implies a variety of information of measured object. When the rotating object passes through a laser beam, optical signal is modulated by the object edge in the process, so more information can be attained under binarization algorithm provided.3. Laser online measurement system of calibration is designed. The system is composed of laser transmitter module, optical module, receiver module and data processing unit. Laser source provides a rule for measuring objects. Photoelectric signal is received by the receiver. While the high speed rotating object moves through a fixed laser beam, the changing flux reflects the geometric characteristic of the tool. The electric signal converted from optical signal is processed by MCU and computer system. The geometric information is obtained, such as diameter, length and eccentricity.4. The impact of system accuracy and the main factors of system error are analyzed. Based on gross error analysis theory, the signal processing method is improved.Through theoretical analysis and experimental verification, characteristic and discriminant method of signal online laser measurement are valuable to how to efficiently deal with such signals, useful to improve the application level of the modern industrial calibration technology.