Research Of Intelligent CNC Internal Grinder Measurement And Control Technology Based On FPGA

With industry 4.0 standard being put forward by the German and concept of Internet of things being promoted by the United States, a world-class industrial technology revolution with an unstoppable trend sweep the world. For this country put forward the development strategy of 2025, the grand development of the manufacturing industry has been rised up to the position of the national strategy. Grinding technology as an important part of industrial processes has become a national focus on the development of technology. So intelligent grinding in measurement and control technology in modern countries under the condition of industrial development appear very important.This paper studies and analyzes the drawbacks and deficiencies of current common inner circle grinding measuring sensor during the measurement process, and determines the grating as the inner circle grinding measuring sensor design scheme, this paper also compares a variety of segmentation techniques based on the grating, and clear the characteristics and the usable range of various methods. The subdivision method of coarse displacement measurement combined with fine displacement measurement put forward with the combination of carrier modulation principle, the grating output displacement signal has high accuracy measurement. The method through the coarse displacement measurement module measure the displacement which is longer than grating spacing. When the displacement measurement shorter than a grating spacing, the measurement is completed by fine displacement measurement module. The realization of each module based on FPGA, peripheral circuit and the corresponding algorithm are given in this paper.For the question about non-sinusoidal property of grating sensor output signal affect the accuracy of measurement seriously, this paper presents a method that can correct the grating sensor moiré fringe signal’s non-sinusoidal property. This method can reduce the error which is caused by non-sinusoidal property. Through Taylor series expansion, trigonometric functions product to sum equation and particle swarm optimization solve the corresponding equation, the grating signal correction is achieved. With fine displacement measurement module accurate values of instantaneous phase can be get by instantaneous phase measurement.For the question about long capture time of traditional phase-locked frequency multiplication method, this paper puts forward a kind of method combining phase segmentation and frequency doubling segmentation. This method extract instantaneous phase values from the carrier signal through phase discriminator, and compare target grinding value corresponding to the phase, change the difference value to the corresponding measurement system’s count value. When measuring system clock complete the counting, the grinding is in place. At the same time through correcting grating sensor moiré fringe signal’s non-sinusoidal property, intelligent inner circle grinding measurement and control system’s accuracy is improved, and the system adaptive ability of environment temperature and humidity influence and reliability is also improved.