一种具有纹波消除技术的10 bit SAR ADC

逐次逼近寄存器模数转换器(SAR ADC)在逐次逼近的过程中,电容的切换会使参考电压上出现参考纹波噪声,该噪声会影响比较器的判定,进而输出错误的比较结果。针对该问题,基于CMOS 0.5μm工艺,设计了一种具有纹波消除技术的10 bit SAR ADC。通过增加纹波至比较器输入端的额外路径,将参考纹波满摆幅输入至比较器中;同时设计了消除数模转换器(DAC)模块,对参考纹波进行采样和输入,通过反转纹波噪声的极性,消除参考纹波对ADC输出的影响。该设计将信噪比(SNR)提高到56.75 dB,将有效位数(ENOB)提升到9.14 bit,将积分非线性(INL)从-1~5 LSB降低到-0.2~0.3 LSB,将微分非线性(DNL)从-3~4 LSB降低到-0.5~0.5 LSB。

一种可支持多种类型电路进行BIT的检测方法

机内测试(Built-in-Test, BIT)技术是机载计算机实现故障检测、故障处理及提高系统可靠性的重要技术。提出了一种可同时支持过压保护电路、频率检测电路、模拟量采集电路、离散量输出电路进行BIT的检测方法。实际应用证明使用该方法后,产品的故障覆盖率与检测正确率明显增长,可有效提高产品的可靠性和可维护性,进而降低产品维护成本。

基于HR-BIT神经网络的图像变化检测

针对现有的遥感图像变化检测方法准确率不高的问题,通过对HRNet网络结构进行优化,提出HR-BIT网络模型。该模型在特征提取的过程中融合多尺度特征信息,提高检测精度。引入连通和邻域的概念,通过对分类结果阈值处理消除孔洞,提高模型的准确率。在LEVIR-CD数据集上的实验结果表明,该模型有效地提高了图像变化检测的准确性。

基于层次模型的雷达BIT显示软件设计

本文针对雷达机内检测(BIT)信息显示需求,研制一个基于层次模型的BIT显示软件。着重阐述了模型管理与协议解析方法,并介绍了软件工作原理。软件具备良好的通用性,亦可应用于其他设备系统。

模拟和混合信号BIT技术

BIT技术在数字电路测试中取得了巨大的成功。而模拟电路的特点决定了BIT技术在其应用存在一定的难度。笔者对模拟和混合扫描总线、模拟BIT。

接枝BIT的有机硅基丙烯酸防污树脂的制备和性能研究

将有机硅材料和防污剂共聚接枝到丙烯酸树脂中,制备了一种接枝BIT(1,2-苯并异噻唑啉-3-酮)的、具有协同防污机制的有机硅基丙烯酸防污树脂。通过红外光谱、凝胶渗透色谱对树脂的结构和相对分子质量进行测定,并对树脂分别进行了接触角、静态海水浸泡质量损失、抑藻性能测试以及实海挂板实验。结果表明:树脂表面接触角随着有机硅含量的增加而增加;在海水中,接枝到树脂上的BIT-W可以缓慢稳定地释放,其质量损失曲线近似呈线性变化,平均质量损失在0.03~0.09 mg之间;树脂对旋链角毛藻和小球藻均具有良好的抑制作用,调整BIT-W含量使得树脂对2种藻类的抑制率分别达到了70.8%和82.7%。此研究中的防污树脂合成方法简单、原料成本低廉,同时引入防污剂和有机硅基材料,赋予防污树脂在静态水和动态水中良好的防污性能。

Micro:bit开发板在高职课程《传感器技术与应用》教学中的实践思考——以“光电传感功能应用”为例

高职课程《传感器技术与应用》既有理论性又有实践性。针对高职学生理论学习能力较弱、实践学习能力较强的学情,可引入Micro:bit开发板用于实践教学。以“光电传感功能应用”教学为研究对象进行教学说明。实践证明,Micro:bit开发板能够实现软硬件的结合,有助于提升学生的学习兴趣,从而提高教学效果。

数字阵列雷达系统的BIT设计

随着现代电子技术的发展,数字阵列雷达已从概念、关键技术研究、实验系统研究转到工程化实用化阶段。同时数字阵列雷达的高集成度给测试和维修带来一定的难度,本文结合某型数字阵列雷达的测试性设计,给出了一个典型的数字阵列雷达BIT设计方案,该方案在实际运用中获得了较好的评价。

Research on Fe-based impregnated diamond drill bits strengthened by Nano-NbC and Nano-WC

In order to improve the matrix performance of impregnated diamond drill bit to better meet the drilling needs,the effects of the addition of nano-WC and nano-NbC particles on the matrix material together with the mechanical properties and microstructure of the diamond-matrix composite material of the Fe-based diamond drill bit were studied by using the method of uniform formula design,regression analysis and solution finding.An indoor drilling test was also carried out using the fabricated impregnated diamond drill bit.The results showed that after the addition of nano-NbC and nano-WC,the hardness and flexural strength of the matrix material got improved,as the flexural strength of the diamond composite material increased to 4.29%,the wear-resistance ratio increased to 8.75%,and the tighter the chemical bonding between the diamond and the matrix.This,indicates that the addition of nanoparticles has a positive significance in improving the performance of the diamond composite.The results of the drilling test showed that the mechanical drilling speed of the impregnated diamond drill bit after nanoparticle strengthening is 25.85%higher than that of the conventional drill bit,and the matrix wear was increased by 17.5%.It proves that nanoparticles can improve the drilling performance and efficiency of drill bit.

BIT技术在运载火箭测试系统中的研究与应用

为了满足运载火箭高密度发射任务及对地面测试设备高可靠性需求,应用BIT技术从设计原则、设计原理和工作模式等方面进行分析测试工作,设计了BIT测试流程并将其应用在运载火箭测试系统中,实现了系统运行状态的实时监测,可以对出现的故障进行快速定位和排查,能够及时处置定位故障,保障测试流程顺利进行;利用大数据降低了BIT系统虚警率,对于运载火箭测试领域提高测试可靠性和故障检测、故障隔离及排除效率,优化了运载火箭测试发射流程,在实际应用中具有良好的工程应用效果。

基于Micro: bit的计量检定用温湿度监控系统设计

环境条件是计量工作的重要一环。根据重复试验的需要,许多规程强调了试验中温湿度变化量的指标。由于检定过程中,常用的两种温湿度表无法实时记录试验时的温湿度变化,因此,无法满足规程中对温湿度变化量的监控需求。本文设计了一种计量专用的温湿度监控系统,使用Micro:bit与DHT22传感器,实时采集试验室的温湿度数据,并实现监控与报警。试验证明:该系统操作简单、误差精度高、便携性强,满足检定员现场试验的需要。

Drill bit wear monitoring and failure prediction for mining automation

This article introduces a novel approach for tricone bit wear condition monitoring and failure prediction for surface mining applications.A successful bit health monitoring system is essential to achieve fully autonomous blasthole drilling.In this research in-situ vibration signals were analyzed in timefrequency domain and signals trend during tricone bit life span were investigated and introduced to support the development of artificial intelligence(AI)models.In addition to the signal statistical features,wavelet packet energy distribution proved to be a powerful indicator for bit wear assessment.Backpropagation artificial neural network(ANN)models were designed,trained and evaluated for bit state classification.Finally,an ANN architecture and feature vector were introduced to classify the bit condition and predict the bit failure.

Hydraulic modeling and optimization of jet mill bit considering the characteristics of depressurization and cuttings cleaning

A jet mill bit(JMB)is proposed to increase the drilling efficiency and safety of horizontal wells,which has the hydraulic characteristics of depressurization and cuttings cleaning.This paper fills the gap in the hydraulic study of the JMB by focusing on the hydraulic modeling and optimization of the JMB and considering these two hydraulic characteristics.First,the hydraulic depressurization model and the hydraulic cuttings cleaning model of the JMB are developed respectively.In the models,the pressure ratio and efficiency are chosen as the evaluation parameters of the depressurization capacity of the JMB,and the jet hydraulic power and jet impact force are chosen as the evaluation parameters of cuttings cleaning capacity of the JMB.Second,based on the hydraulic models,the effects of model parameters[friction loss coefficient,target inclination angle,rate of penetration(ROP),flow ratio,and well depth]on the hydraulic performance of the JMB are investigated.The results show that an increase in the friction loss coefficient and target inclination angle cause a significant reduction in the hydraulic depressurization capacity,and the effect of ROP is negligible.The flow ratio is positively related to the hydraulic cuttings cleaning capacity,and the well depth determines the maximum hydraulic cuttings cleaning capacity.Finally,by combining the hydraulic depressurization model and hydraulic cuttings cleaning model,an optimization method of JMB hydraulics is proposed to simultaneously maximize the jet depressurization capacity and the cuttings cleaning capacity.According to the drilling parameters given,the optimal values of the drilling fluid flow rate,backward nozzle diameter,forward nozzle diameter,and throat diameter can be determined.Moreover,a case study is conducted to verify the effectiveness of the optimization method.

航电产品BIT研制流程设计与应用

如何合理地规划航电产品机内测试(built-in test,BIT)的研制流程,是BIT设计尚需解决的重要问题.首先,分析了当前与BIT相关的研制流程,指出现有BIT设计流程存在的不足;其次,通过对BIT设计相关工作项目的梳理,确定了航电产品研制的方案阶段和初样/试样阶段的BIT设计工作项目;再次,结合航电产品研制工作流程,建立了融入产品整个研制周期的BIT设计工作流程.通过构建针对航电产品BIT研制的工作流程,提高了航电产品BIT设计工作的可操作性,BIT针对性强,节约了时间成本,降低了开发费用,并为航电产品BIT研制工作的流程化设计提供了参考范例.最后,以某综合控制管理系统的研制为案例,对该BIT研制流程进行了应用,验证了工作流程的有效性.

Tooth arrangement design of retractable DTH hammer bit used for drilling while casing

Down-the-hole(DTH)hammer with casing while drilling(CWD)is a technology that has been proven to be able to alleviate many of the problems faced by complex formations.However,the drill bit is suffered from rapid wear,low drilling efficiency,and high energy consumption due to the unreasonable tooth arrangement and impact energy selection in drilling process,which affect the application effect of this technology.ABAQUS software was used for numerical simulation of rock breaking behavior under impact load with the single,three,and five teeth arrangement drill bit respectively,to improve the application effect and solve the aforementioned technical problems.Based on the calculated parameters of tooth arrangement,we designed a novel drill bit for hard rocks and provided a theoretical basis for the tooth arrangement of largediameter drill bits.

Reliability analysis of retractable drill bit with air reverse circulation used for drilling while casing

Casing-while-drilling(CWD)with down the hole(DTH)hammer drilling technology has been widely used in unconsolidated formations,due to its advantages in protecting the borehole wall,excellent rock cuttings capacity,and fast penetration rate in hard rock.As an important component of the CWD system,the structure of the retractable drill bit needs not only to ensure to form stronger reverse circulation,but also to be expandable or retractable as needed,otherwise the drill bit cannot be lift and put down smoothly in the casing,and may lead to drilling accidents.This paper developed a new type of reverse circulation DTH hammer drill bit used for CWD drilling technology.The retractable performance of this type of drill bit is studied using ADAMS software.The results show that it is smoothly expandable and retractable as designed under the conditions of the weight of the bit(WOB)of 0.5–2.0 t and the rotation speed of 30–60 r/min.To investigate the reverse circulation effect of the drill bit,Fluent software was used to simulate the flow characteristic inside it.The simulation results indicated that it can form strong reverse circulation,and the entrainment ratio h can reach 9.5%.

Discussion of reasonable drilling parameters in impregnated diamond bit drilling

The impregnated diamond(ID)bit drilling is one of the main rotary drilling methods in hard rock drilling and it is widely used in mineral exploration,oil and gas exploration,mining,and construction industries.In this study,the quadratic polynomial model in ID bit drilling process was proposed as a function of controllable mechanical operating parameters,such as weight on bit(WOB)and revolutions per minute(RPM).Also,artificial neural networks(ANN)model for predicting the rate of penetration(ROP)was developed using datasets acquired during the drilling operation.The relationships among mechanical operating parameters(WOB and RPM)and ROP in ID bit drilling were analyzed using estimated quadratic polynomial model and trained ANN model.The results show that ROP has an exponential relationship with WOB,whereas ROP has linear relationship with RPM.Finally,the optimal regime of mechanical drilling parameters to achieve high ROP was confirmed using proposed model in combination with rock breaking principal.

基于bit-map算法的DMA数据流仲裁器设计

针对集成电路产业快速发展所需要的复杂通信要求,设计了一种基于bit-map算法的DMA数据流仲裁器。DMA数据流仲裁器由通道优先级bit-map映射模块、通道请求生成模块、通道请求仲裁模块、通道授权标志生成模块和外设请求应答模块组成。在完成逻辑设计后,通过UVM验证方法学对电路的各个功能进行验证。验证结果表明,本设计仅使用一个32位bit-map映射寄存器将8条通道的32种优先级配置映射到对应有效位,便可实现对8条通道DMA请求的仲裁,无需配置优先级比较电路,不会因逐级比较产生优先级配置相互干扰的问题,且在后期生成实际电路的过程中可以减小电路面积、降低电路功耗。

基于系统需求数据库的BIT自动测试技术

根据飞控系统BIT检测系统需求和数据库适合规范及大规模处理的特点,考虑到将来飞控系统综合检测与诊断、综合诊断保障系统、综合诊断专家系统等技术发展需求,提出了基于系统需求数据库的BIT自动检测技术。本技术利用脚本的强大文档处理能力,将需求抽象为规范文档,以此作为为输入,生成测试数据库并将测试流程固化为数据库操作流程,实现了飞控系统BIT的自动化测试功能。目前,这一技术已应用于多个机种项目,为型号的研制和交付节省了宝贵的时间。

电传飞控计算机子系统BIT设计研究

飞控计算机子系统是飞行控制系统的计算和控制核心,影响着飞行安全。采用BIT进行故障检测和定位可以显著提高飞控系统安全性。现阶段的BIT设计研究中,系统级偏向于顶层功能要求的论述,计算设备的BIT研究偏重于通用计算机的软硬件论述,飞控系统向计算机子系统的需求传递和可追溯性不强,也缺乏基于系统工程的飞控计算机子系统BIT设计流程研究。通过对飞控计算机子系统架构的分析得出其通用的组成模块。以此为基础开展BIT设计研究,分析了BIT的分类及特点,提出了BIT设计的通用需求,设计了基于系统工程的飞控计算机子系统BIT设计流程,重点从飞控系统功能需求出发详细论述了飞控计算机子系统BIT的初始化、工作模态转换、测试项目、执行时序及与飞控系统功能高关联度的BIT项目测试的设计方法原理,分析了故障预测及健康管理的设计方法和减少虚警的措施。采用该设计流程和详细设计原理方法的飞控计算机子系统BIT设计通过了地面综合试验的验证。