衍射型绝对式轴角编码技术研究

发布时间：2018-04-05 10:03

本文选题：绝对式轴角编码器　切入点：光栅　出处：《浙江大学》2015年硕士论文

【摘要】：光电轴角编码器是一种采用光电技术将轴的角位置、角位移和角速度等物理量转换成相应的电脉冲信号或数字量的精密角位移传感器,被广泛应用于工业控制、精密测量、航空航天、机器人等多个领域。随着工业技术的发展,人们不断地对轴角编码器的工作性能提出更高的要求,一方面要求编码器具有更高的分辨率和测量精度,另一方面又要求编码器保持小尺寸。而传统光度型的绝对式轴角编码器很难兼具高分辨率和小尺寸。为了解决轴角编码器尺寸与分辨率之间的矛盾,本文提出了一种衍射型绝对式编码技术,该技术利用光栅衍射信号位置进行绝对编码,利用衍射信号光强进行精码细分。码盘基元由四个不同方向的光栅组成,光栅周期在一周内按照五进制格雷码变化,与激光相互作用产生光衍射现象,面阵探测器接收衍射信号后实时传送至计算机,计算机对数据进行译码处理获得角度信息。首先,根据编码原理建立了理论模型,并对编码细分信号进行了理论仿真,初步验证了方案的可行性。在此基础上,考虑已有的硬件条件,完成码盘的设计与加工,并确定了信号的处理方法。最后,搭建了绝对式衍射型编码器实验样机,其中光源为658 nm半导体激光器,码盘直径为40mm,探测器为面阵CMOS,分辨率为2048×1536,通过对衍射信号质量进行评估得到编码系统的分辨率为20.63"。在实验中,引入了激光光束偏转法对编码系统进行精度测试,得到测角精度78.00",标准差为16.86"。
[Abstract]:The photoelectric shaft encoder is a kind of precise angular displacement sensor which uses photoelectric technology to convert the angle position, angular displacement and angular velocity of the shaft into the corresponding electrical pulse signal or digital quantity. It is widely used in industrial control and precision measurement.Aerospace, robotics and other fields.With the development of industrial technology, more and more demands have been put forward to the performance of the axial encoder. On the one hand, the encoder is required to have higher resolution and measurement accuracy, on the other hand, the encoder is required to keep small size.However, it is difficult for the traditional absolute shaft angle encoder to have high resolution and small size.In order to solve the contradiction between the size and resolution of the axial encoder, a diffractive absolute coding technique is proposed in this paper, in which the position of the grating diffraction signal is used for absolute coding and the light intensity of the diffraction signal is used for fine code subdivision.The code disk element is composed of four gratings in different directions. The grating cycle changes within a week according to the quaternary graycode, and the interaction with the laser produces the phenomenon of optical diffraction. The array detector receives the diffraction signal and transmits it to the computer in real time.The computer decodes the data to obtain angle information.Firstly, the theoretical model is established according to the coding principle, and the theoretical simulation of the coded subdivision signal is carried out, which preliminarily verifies the feasibility of the scheme.On this basis, considering the existing hardware conditions, complete the design and processing of the code disk, and determine the signal processing method.At last, an experimental prototype of absolute diffractive encoder is built, in which the light source is 658nm semiconductor laser, the code disk diameter is 40mm, the detector is a plane array CMOS, the resolution is 2048 脳 1536, and the resolution of the coding system is 20.63 "by evaluating the diffraction signal quality.In the experiment, the laser beam deflection method is introduced to test the accuracy of the coding system. The accuracy of angle measurement is 78.00 "and the standard deviation is 16.86".
【学位授予单位】：浙江大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN762

【相似文献】