MX345芯片及单片机控制

MX345芯片用于产生模拟信令—CTCSS单音.本文在介绍MX345编码/解码器工作原理的基础上,设计出MX345芯片与单片机的接口电路.最后给出控制软件.     

The development of a high-speed spindle measurement system using a laser diode and a quadrants sensor

Reducing the manufacturing time is the trend of precision manufacturing, and the precision of a work-piece is very important for manufacturing industry. High-speed cutting is becoming more widely used and the high-speed spindle is a very important element, whose precision may affect the overall performance of high-speed cutting. Most of the studies on high-speed cutting are focused on the cutting force, the vibration of the spindle and the effects of the spindle's thermal expansion; however, the measurement of the high-speed spindle continues to use the conventional spindle measurement method.As with the measurement of the high-speed spindle, more strict demands are set on the dynamic balance of cutting tools and the bandwidth of the measurement systems when compared with common spindles. The capacitance displacement sensor has been employed for the spindle error test. The precision of the measurement system is limited by the reference (such as a master ball or a master cylinder). Also the capacitance sensor and the reference must be grounded together. This paper presents a simple spindle measurement system using a laser diode and a quadrants sensor, with accuracy up to 1 μm, within 300,000 rpm for various spindles. The system does not need any reference and it is easy to set up. This system can be applied to measure the spindle errors, the spindle speed and the spindle indexing.     

悬锤式小巧光电测角仪

本文给出一种基于微型光电编码器和８９Ｃ２０５１ 单片机的数字显示的小巧测角仪。其创新点在以重锤杆做为转动角度的基准线; 并用磁吸合方式与被测体固定。该仪在一些场合应用特别方便     

WAP网关的研究与实现

WAP网关是WAP应用中的关键部分,是连接移动通信网络和Internet网络的桥梁。本文根据WAP应用大都由Web应用发展而来的现状,设计了一个高性能的WAP网关的架构,对WML编码器进行了设计与实现,并为WAP网关增加了HTML过滤转换器模块,实现了HTML页面到WML页面的翻译转换。     

一种自适应快速视频编码的新方法

在传统的视频编码中,为了保证图像质量,采用标准视频编码器模块实现。但这种方式存在大量的计算量,编码时间长。为有效解决这一问题,本文提出了一种改进视频编码实现的自适应控制方法,并结合快速DCT算法及近似计算进一步提高编码速度。在保证图像质量的前提下,实现视频图像的快速编码。     

绝对码编码器中一种新型的编码方法

提出了码盘式传感器码盘的一种全新的码制——单道码绝对码编码法，即绝对码简码。它是一种单道码编码法，图形简单，制作方便，容易提高精度，将对绝对码编码器的小型化，集成化和绝对式磁编码器的研制提供一种新的思路。     

Fast pixel-matching for video object segmentation

Video object segmentation, aiming to segment the foreground objects given the annotation of the first frame, has been attracting increasing attentions. Many state-of-the-art approaches have achieved great performance by relying on online model updating or mask-propagation techniques. However, most online models require high computational cost due to model fine-tuning during inference. Most mask-propagation based models are faster but with relatively low performance due to failure to adapt to object appearance variation. In this paper, we are aiming to design a new model to make a good balance between speed and performance. We propose a model, called NPMCA-net, which directly localizes foreground objects based on mask-propagation and non-local technique by matching pixels in reference and target frames. Since we bring in information of both first and previous frames, our network is robust to large object appearance variation, and can better adapt to occlusions. Extensive experiments show that our approach can achieve a new state-of-the-art performance with a fast speed at the same time (86.5% IoU on DAVIS-2016 and 72.2% IoU on DAVIS-2017, with speed of 0.11s per frame) under the same level comparison. Source code is available at https://github.com/siyueyu/NPMCA-net.     

A new fault diagnosis algorithm for helical gears rotating at low speed using an optical encoder

Helical gears are widely used in gearboxes due to its low noise and high load carrying capacity, but it is difficult to diagnose their early faults based on the signals produced by condition monitoring systems, particularly when the gears rotate at low speed. In this paper, a new concept of Root Mean Square (RMS) value calculation using angle domain signals within small angular ranges is proposed. With this concept, a new diagnosis algorithm based on the time pulses of an encoder is developed to overcome the difficulty of fault diagnosis for helical gears at low rotational speeds. In this proposed algorithm, both acceleration signals and encoder impulse signal are acquired at the same time. The sampling rate and data length in angular domain are determined based on the rotational speed and size of the gear. The vibration signals in angular domain are obtained by re-sampling the vibration signal of the gear in the time domain according to the encoder pulse signal. The fault features of the helical gear at low rotational speed are then obtained with reference to the RMS values in small angular ranges and the order tracking spectrum following the Angular Domain Synchronous Average processing (ADSA). The new algorithm is not only able to reduce the noise and improves the signal to noise ratio by the ADSA method, but also extracts the features of helical gear fault from the meshing position of the faulty gear teeth, hence overcoming the difficulty of fault diagnosis of helical gears rotating at low speed. The experimental results have shown that the new algorithm is more effective than traditional diagnosis methods. The paper concludes that the proposed helical gear fault diagnosis method based on time pulses of encoder algorithm provides a new means of helical gear fault detection and diagnosis.     

MEMS陀螺与编码器在机器人自主定位中的应用

为提高微机械陀螺仪输出精度及移动机器人定位精度,研究了基于微机械陀螺仪与光电编码器的移动机器人自主定位方法。实时小波滤波法算法去除微机械陀螺仪输出数据噪声;通过微陀螺精度校正平台,用加权最小二乘支持向量回归机算法对微机械的先验数据作回归运算,构造先验回归决策函数,运用回归决策函数补偿微机械陀螺仪输出误差,提高微机械陀螺仪的角速率输出准确度;实验证实了方法能较好提高了MEMS陀螺仪的准确度,可以应用于移动机器人的自主定位之中。     

基于LM628的光谱分析仪波长定位系统

本文介绍了基于LH628的光谱分析仪波长定位系统,详细阐述了其原理及具体实现。