【作者】 郭雨梅；

【导师】 杨理践；

【作者基本信息】 沈阳工业大学 ， 测试计量技术及仪器， 2009， 博士

【摘要】 莫尔条纹信号细分技术是光栅计量技术的核心,采用先进的莫尔条纹细分方法来获得不满一个栅距内的位移变化量是提高光栅测量系统分辨率的关键。目前常用的细分方法在实际应用中存在不足之处,因此,对光栅莫尔条纹信号细分方法进行研究,探寻最佳的细分方案具有十分重要的意义。本文主要研究新型莫尔条纹信号细分理论及其在光栅位移测量系统和磨床测控系统中的应用。基于数字集成化设计思想,提出了新型锁相位移式光栅莫尔条纹信号细分理论,并用数学的方法论证了其细分及辨向的可行性与正确性。该方法将光栅传感器的输出信号进行相位调制,经带通滤波后再送入锁相倍频器细分。通过相位调制,把光栅传感器输出的空间位移信号转变为与之成正比的时间信号,使原来对空间位移量的测量转化为对时间信号相位角的测量,解决了原模拟细分中存在的、随细分数增加位移跟踪速度显著下降以及细分数受温度、电源、元器件参数变化影响严重等主要矛盾。通过采用引入一个恒频、引入一个相位量、引入一个细分基准信号等主要措施,解决了三个关键技术问题,使得该方法具有细分的同时即可完成辨向、可避免绝大多数细分方法所采用的大小数分别计数而产生的不协调、既适合完整周期测量又适合不完整周期测量、细分数高且调整方便、不仅能进行动态测量也能进行静态测量等优点。同时,还提出了利用乘法倍频技术对光栅原始信号进行修正,以降低对原始信号正交性、等幅性等方面要求,进一步增强该细分方法实用性的设计思想。以新型锁相式莫尔条纹信号细分理论为基础,研制了光栅位移测量系统,改变原来利用分立数字逻辑电路进行系统设计的思路,提出集成化设计的思想。将细分模块及系统的数字逻辑电路集成在一片可编程逻辑器件中,大大提高了系统的集成度。通过实验验证了该系统具有分辨率高、跟踪速度快、可靠性及抗干扰能力强等特点。对基于神经网络的莫尔条纹信号细分方法进行了研究,提出采用整周期硬件计数、辨向和周期内神经网络软件细分相结合的方法,并提出两种提高细分精度的措施。利用少量学习样本让神经网络学习后,对于任意输入值,经过神经网络的泛化,都可以产生高精度的输出。由于训练时采用光栅输出的正、余弦信号比作为网络的输入,消除了幅值波动对细分精度带来的影响。该细分方法硬件电路简单,分辨率、可靠性较高,具有一定的实用价值。在研究分析磨床测控系统国内外现状及发展趋势的基础上,提出了采用专用微小型光栅传感器取代原来电感线圈,测量磨加工过程中工件尺寸变化的设计思想,改变了我国近30年来一直使用的电感测量的传统方法,有效克服了电感线圈的非线性误差和测控精度受周围环境温湿度变化影响严重的弊端。基于本文提出的新型数字化锁相细分理论,利用在系统可编程技术,对磨床测控系统进行了全数字集成化设计。采用微处理器与现场可编程门阵列相结合的并行处理方式,把FPGA作为单片机的一个嵌入式芯片,专门用于对光栅莫尔条纹信号的细分、辨向、计数处理及系统数字逻辑电路的集成化设计,提高了处理速度,保证了系统对被加工工件磨削量的实时测量与控制。系统设计过程中提出了基于FPGA的部分串行结构FIR滤波器设计思想,与完全串行结构相比,成倍提高了运算速度,减少了运算延迟;与完全并行结构相比,减少了逻辑单元的消耗。此外,还提出一种基于FPGA的新型数字锁相倍频方法,利用整数分频组合实现了小数分频。通过仿真分析,证明了该方法具有细分精度高、锁相速度快等优点。论述了智能磨床测控系统的软件设计思想及部分功能实现方法,增设了在线补偿、快速驱动、自校等功能,使系统具有更加优良的性能。通过磨削实验及测试,证实了该系统具有良好的重复性,满足国家标准要求,同时验证了系统具有测控精度高、功能齐全、操作方便、实用性强等特点,为实现我国磨床行业高端产品的国产化奠定了坚实的基础。更多还原

【Abstract】 The Moire fringe signal subdivision technology is the core of the grating measurement technology. To obtain the displacement variation less than one grating distance with advaced Moire fringe signal subdivision method is a key in enhancing the resolution of grating measurement system. However, the commonly used subdivision methods exhibit some disadvantages in practical application. Obviously, it is of very important significance to perform the research on the Moire fringe signal subdivision method and to search the optimal subdivision scheme. In the present investigation, new Moire fringe signal subdivision theory and its application in both grating displacement measure system and grinder measure and control system have been discussed.Based on the digital integrated design idea, new phase-locking displacement grating Moire fringe signal subdivision theory was proposed. And both feasibility and validity of the proposed theory in subdivision and direction seeking were demonstrated with the mathematical method. In the present method, the phase modulation for the output signal of the grating sensor is conducted, and then the modulated signal is subdivided in phase-locking frequency multiplier after band-pass filtrating. The spatial displacement signal outputted by grating sensor is transferred into the directly proportional time signal through phase modulation. Thus, the original measurement for the spatial displacement is transformed into the measurement for the phase angle of time signal. Farthermore, the significant decrease of displacement tracing velocity with subdivision number as well as the serious influence of the variation in temperature, power and component parameters on the subdivision number can be avoided. Through introducing a constant frequency, a phase mass and a subdivision reference signal, three key problems get solved. And thus, the proposed method can synchronously finish both subdivision and direction seeking, avoid the uncoordination from individual counting in most subdivision methods, and is available for both complete period measurement and incomplete period measurement. In addition, the proposed method has such advantages as high subdivision number and convenient adjustment, and can be used for conducting the static and dynamic measurement. At the same time, the design idea that the original grating signal is modified with the frequency multiplication technology in order to reduce the requirement in the orthogonality and equal-amplitude as well as enhance further the practicality of the present subdivision method has been proposed.On the basis of new phase-locking Moire fringe signal subdivision theory, the grating displacement measuring system was developed. The original system design scheme adopting the discrete digital logic circuit was replaced, and the integrated design idea was proposed. Because the subdivision module and digital logic circuit are integrated in one programmable logic device, the integration degree of the system is considerably enhanced. It has been experimentally proved that the present system has such characteristics as high resolution, rapid tracing ability, good reliability and strong disturbance resistance.Through investigating the Moire fringe signal subdivision based on neural network, the method to combine the complete period hardware counting and direction seeking with the period inside neural network softeware subdivision was proposed. Two measures to enhance the subdivision precision were presented. With allowing neural network to learn a few learning samples and by the generalization of neural network for discretional input value, very precise output can be attained. Because the sine-cosine signal ratio of grating output is taken as the input of network during training, the influence of the amplitude fluctuation on the subdivision precision gets eliminated. The proposed subdivision method has such advantages as the simple hardware circuit as well as the higher resolution and reliability, and is of some practical application value.By analyzing the present status and development tendence of grinder measure and control system, the design idea to replace inductance coil with special mini grating sensor and to measure the dimensional variation in grinding process was proposed. The traditional inductance measuring method used for 30 years in our country is changed, and the nonlinear error from inductance coil as well as the serious influence of environmental temperature and humidity on measure and control precision get effectively avoided. Based on the proposed digital phase-locking subdivision theory and with utilizing the programable technology, the full digital integrated design was carried out for grinder measure and control system. With the parallel processing mode combining micro processor and field programable gate array, the FPGA was taken as a embedded chip of microcontroller and specially applied in the subdivision, direction seeking and count processing of grating Moire fringe signal as well as the integrated design of digital logic circuit. Thus, the processing speed of the system gets increased, and the real-time measure and control of the system for the grinding quantity of processed parts can be ensured.The partial serial FIR filter based on FPGA was adoped in the design of the system. Compared with the complete serial structure, the partial serial structure can considerably increase the operation velocity and reduce the operation delay. On the other hand, the partial serial structure can decrease the consumption of logic uint, compared with the complete parallel structure. In addition, a digital phase-locking frequency multiplication method based on FPGA was proposed, where the decimal frequency-division was realized using the integral frequency-division assemble. The simulation analysis proves that the proposed method has such advantages as high subdivision precision and large phase-locking velocity.The software design idea of intelligent grinder measure and control system as well as the realization method of partial functions were introduced. Such functions as on-line compensation, rapid drive and self-check were added, which can ensure the excellent performance of the system. The grinding tests prove that the system exhibits good repeatability and can meet the requirement of national standard. In addition, it has been demonstrated that the system has such characteristics as high measure and control precision, integrated function, easy operation and obvious practicability, which settles good foundation for home manufacturing of top-end products in Chinese grinding machine industry.更多还原