25位绝对式编码器

介绍了在高位数、高精度光电绝对式轴有编码器小型化研制中,采用特殊的绝对编码技术和多读数头模拟量相加获得高质量的光栅信号,并用单片机实现高倍的电插补细分,成功地研制出了小尺寸的２５位高精度绝对式编码器。     

编码器分度误差检测中自准直仪读数的处理方法

自准直仪与棱体或多齿分度台等角度计量器具配合使用对编码器分度误差进行检测时,自准直仪读数的处理直接影响测量结果的准确性.通过分析,提出了应用《光电轴角编码器校准规范》中分度误差计算公式时自准直仪读数的处理方法.     

超小型准绝对式编码器的研制

针对编码器日趋小型化的技术要求,本文提出一种全新的编码方式和独特的读数头设计结构,成功研制出了超小型准绝对式编码器.该新型编码器采用准绝对式编码方式,即距离编码与增量式编码进行组合编码,只用两圈码道进行编码,极大减少码道数量,整周设多个绝对参考位置,可迅速获得绝对位置信息.采用单读数头结构和相位补偿技术,缩小结构尺寸,直径Ф25 mm,经过电子学细分后可到达16位的分辨力,从而实现高精度编码器小型化.     

等分多读数头位置偏差对测角误差的影响研究

提出了一种针对等分多读数头系统中读数头位置偏差对抑制测角误差作用机理的分析方法。介绍了读数头在非理想位置引入测角误差的理论分析和仿真实验方法,利用频谱分析法分离谐波误差,获得各阶误差幅值的衰减率用以计算测角误差。将该方法应用于等分双读数头编码器误差分析,结果表明读数头在0.5°位置偏差时,引入的测角误差在±0.09″范围内。     

对径模拟量相加的增量式光电轴角编码器

一、前言本编码器是一种整装式增量编码器。采用对径模拟量相加的信息叠加方式,运用电子学插补技术和全增量可逆计数器。外形尺寸为φ180×120毫米,光栅盘大小为φ150毫米。全部电路元件均用半导体固     

SDS系列电子水平仪常见故障及排除

若水平仪调零范围偏向一侧或调不出零位，可将水平仪置于已调好水平的平板上，量程开关置于Ⅱ档位置。顺时针旋转调零旋钮，直至数值不变记下该读数；然后逆时针旋转调零旋钮，直至数值不变记下该读数：将两次记录的数值的绝对值相加．即为该水平仪的调零范围。     

浅谈圆光栅编码器的检测——圆光栅编码器与数显表的匹配

一、检测方法根据JJG900-1995《光电轴角编码传感器》检定规程,检测圆光栅编码器的准确度是用正多面棱体和自准直仪或分度头、精密转台、精密测角仪进行直接检测的。二、测角准确度光电轴角编码传感器的测角准确度A类分为7级,B类分为5级,其要求见表1,准确度的检定结果以测角误差的峰值P与谷值V之差a(即最大间距误差P-V)表示,也可以用数值a的1/2冠以±号表示。三、数显表的分辨力和圆光栅编码器的准确度等级应相匹配当圆光栅编码器和数显表直接连接时,如果以正多面棱体和自准直仪产生一个标准角,读数显表的方波的脉冲数时,可能会出现数显…     

钟罩式气体流量标准装置的自动化改造以及需要注意的问题

针对目前国产钟罩存在人工读数误差大的问题,通过加装旋转编码器、光电传感器和温度传感器,并与计算机相连,对其进行了自动化改造.同时,针对一些国产钟罩在设计上存在的问题提出了一些改进意见.     

燃油加油机自动检定系统存在问题及如何提高其检测准确性

正一、测量原理现在比较主流的加油机自动检定装置安装于改装过的中型客车后座空间,该装置主要由标准金属量器、浮子连杆、感应头、检测传感器、导沫管、微型伺服电机、编码器及安装在上位机内的检测软件组成。自动检定装置的标准金属量器在上级单位量值传递之后,都要对读数装置进行不同油品、不同罐号的零位容积标定,以确定读数装置在标准量器的计量颈范围内零位容积所对应的刻度位置,读数装置再根据这个零位容积对应的"零位值",确定计量颈内不同的液位高度     

给DT—830数字万用表增设读数保持功能

ＤＴ－８３０数字万用表是三位半液晶显示仪表,其本身不具备读数保持功能,本文介绍一种简单的方法,就能给其增加读数保持功能。一、显示器驱动信号分析ＤＴ－８３０数字万用表采用的是ＬＤ－Ｂ７０１５Ａ型三位半液晶显示器,此显示器采用交流电压驱动,七段字码显示,...     

Reconsidering natural binary encoding for absolute positionmeasurement application

It is well known that absolute encoders using natural binary codes are prone to reading errors because more bits can change between adjacent scale sectors. Some solutions, such as V-scan, were proposed to solve this problem, but they required too many additional reading heads and decoding circuits to be competitive with the reduced complexity obtained when using the Gray code. The author describes a novel natural binary absolute encoder using an original scanning technique that solves more efficiently the problem of the inherent code reading errors. It is shown that for the same nominal resolution, the complexity of the encoder is similar to, if not better than, that of the Gray-type encoder     

Autofocus laser rotary encoder

A laser incremental encoder with autofocus operation isproposed. In the encoder, an optical read head focuses three laserbeams upon a disk with a scaling grating. The scaling grating is areflection grating for which the height difference between adjacentpixels is one quarter of the wavelength of the laser. Each of thetwo laser beams is focused onto one of the two sections of thereflective grating, whereby the pitch of the grating can be detected byinterferometric reflection. The third beam acts to provideautofocus and is reflected from a smooth part between the two sectionsof the reflective grating. Therefore the encoder is less sensitiveto the gap between the optical read head and the scaling grating, andno precision adjustment is required. Also, the reading data arefree from the vibration and waviness of the grating surface. In theexperiments an encoder disk was fabricated from a wafer by lithographictechniques. The encoder with an 18-mm radius of the disk can reacha resolution of 2(16) = 65,536 pulses per revolution withoutelectronic interpolation.     

Integrated magnetic recording heads

A new type of integrated magnetic recording head has been developed. The head is made completely from thin films by vacuum deposition through a mask. This technology enables us to make many heads in one vacuum cycle. A special study has been carried out on the geometrical forms and on the anisotropic magnetic material. The demagnetizing fields require that we make magnetostatic coupling layers for each magnetic leg of the head. Also, the results indicate that the heads can be used for writing and reading.     

An investigation of separation losses in high-speed, high-density recording tapes

The trend in digital tape recording is toward larger storage capacity and faster accessing, which necessitate packing information at greater densities on tapes moving at higher speeds. The losses that inevitably arise from the finite separation between the head and the moving tape become much more serious as the length of the magnetized regions in the tape is reduced and as the relative velocity of head and tape is increased. The purpose of this paper was to investigate experimentally the dependence of separation losses on bit density and head gap length, and to distinguish from the reading losses those losses introduced during the writing process. Briefly, results showed that, for the heads and tapes used in the experiment, virtually all the losses could be attributed to the reading process. Furthermore, writing with a wide gap head and reading back with the four heads established that the percentage reading losses as a function of separation were apparently the same whatever reading head was used.     

基于椭圆假设的单对磁编码器误差补偿方法

研究了一种单对磁极磁编码器的误差补偿方法。针对单对磁极磁编码器中存在的零位误差、灵敏度误差、正交误差和铁磁干扰等每一种误差进行分析,得出各自的误差表达式。为了便于误差补偿,总结出描述这种误差共性的表达式,此式将误差的形成过程假设为圆到椭圆的变化过程,其逆过程就是误差补偿的过程。实验结果表明,利用此种方法的磁编码器精度达到了0.02°,误差补偿效果明显。根据此方法研究的磁编码器具有成本低、精度高、使用方便的特点。     

High-resolution optical position encoder with large mounting tolerances

A high-resolution optical position encoder is described that consists of a scale as encountered in a standard moiré-based system, a simple imaging system with stabilized magnification and a novel segmented phase detector integrated circuit. Compared with encoder systems of comparable resolution and accuracy, the encoder presented offers large mechanical tolerances in the alignment of the reading head to the scale, while an interpolation accuracy of better than 0.1 mum is preserved. The system is especially well suited for high-resolution linear encoders as well as for the cost-effective fabrication of compact high-resolution rotary encoders.     

A track locating servo system utilizing the data heads as absolute position transducers

Magnetic transitions may be compactly written in the normally unused deadspace between the data sectors on each data surface of a moving head disc drive, which may be read by ordinary data heads to obtain absolute position information for use by the track locating servo. A track following system which complements the track locating system is briefly described. Implementation of these techniques eliminates both the need for a servo surface or external encoder, and troublesome reference surface to data surface mechanical tolerance problems.     

HLR-Net: A Hybrid Lip-Reading Model Based on Deep Convolutional Neural Networks

Lip reading is typically regarded as visually interpreting the speaker’s lip movements during the speaking. This is a task of decoding the text from the speaker’s mouth movement. This paper proposes a lip-reading model that helps deaf people and persons with hearing problems to understand a speaker by capturing a video of the speaker and inputting it into the proposed model to obtain the corresponding subtitles. Using deep learning technologies makes it easier for users to extract a large number of different features, which can then be converted to probabilities of letters to obtain accurate results. Recently proposed methods for lip reading are based on sequence-to-sequence architectures that are designed for natural machine translation and audio speech recognition. However, in this paper, a deep convolutional neural network model called the hybrid lip-reading (HLR-Net) model is developed for lip reading from a video. The proposed model includes three stages, namely, pre-processing, encoder, and decoder stages, which produce the output subtitle. The inception, gradient, and bidirectional GRU layers are used to build the encoder, and the attention, fully-connected, activation function layers are used to build the decoder, which performs the connectionist temporal classification (CTC). In comparison with the three recent models, namely, the LipNet model, the lip-reading model with cascaded attention (LCANet), and attention-CTC (A-ACA) model, on the GRID corpus dataset, the proposed HLR-Net model can achieve significant improvements, achieving the CER of 4.9%, WER of 9.7%, and Bleu score of 92% in the case of unseen speakers, and the CER of 1.4%, WER of 3.3%, and Bleu score of 99% in the case of overlapped speakers.