高精度数字特斯拉计设计

介绍了一种高精度、低成本的数字特斯拉计的系统结构.该仪器设计了高稳定度的恒流源驱动砷化铟霍尔传感器,采用自稳零、低噪声的放大器对信号进行拾取、放大、调理,对采集信号进行自适应调节放大倍数,得到的电压信号经A/D转换后利用曲线拟合技术对数据进行修正,从而保证在整个量程范围内的高精度和高分辨率.经检测和使用证明:该仪器稳定可靠,精度高.     

高精度数字稳定平台控制系统设计与实现

针对高精度数字稳定平台稳定跟踪目标、快速隔离扰动的要求,设计一款基于浮点型DSP控制器TMS320F28335的数字稳定平台系统。选用高精度测量元件提高系统测量精度;引入电流环提高系统控制精度、动态特性及隔离扰动能力;通过调零调漂补偿电路、硬件滤波电路及数字滤波算法设计保证陀螺采样精度。系统测试表明,该稳定平台系统能精确、稳定地跟踪目标并能有效地隔离载体扰动。     

A digital twin-driven approach for the assembly-commissioning of high precision products

High precision products (HPPs) with multidisciplinary coupling are widely used in aerospace, marine, chemical and other fields. Since the internal structure of HPPs is complex and compact, the assembly process requires high precision and involves multidisciplinary coupling. Traditional assembly process of HPPs is based on manual experience, which results in low assembly efficiency and poor-quality consistency. Given the above problems, this research proposes a digital twin-driven assembly-commissioning approach for HPPs. Firstly, this paper introduces the theoretical framework of digital twin-driven assembly-commissioning. Secondly, we introduce the construction method of assembly-commissioning total factor information model based on digital twin technology; the fusion method of twin data and the interoperability method between digital twin models; in addition, the assembliability prediction and assembly-commissioning process optimization methods. Finally, a case study product is used to verify the effectiveness and feasibility of the proposed method.     

一种高精度数字倾角测量系统的设计

详细介绍了利用A/D转换器、温度传感器和单片机实现数字倾角测量系统的硬件和软件设计。该系统具有精度高、运行稳定、性能可靠、带温度补偿等优点,可广泛应用于宽工作温度范围的高精度倾斜角测量中。     

Development of a novel flexure-based microgripper for high precision micro-object manipulation

Micro-scaled parts with dimension below 1 mm need to be manipulated with high precision and consistency in order to guarantee successful microassembly process. Often these requirements are difficult to be achieved particularly due to the problems associated with the structural integrity of the grasping mechanism which will affect the accuracy of the manipulation. Furthermore, the object's texture and fragility imply that small perturbation by the grasping mechanism can result in substantial damage to the object and leads to the degradation of its geometry, shape, and quality. This paper focuses on the unification of two designing approaches to develop a compliant-based microgripper for performing high precision manipulation of micro-objects. A combination of Pseudo Rigid Body Model (PRBM) and Finite Element Analysis (FEA) technique has proven to improve the design efficiency by providing the essential guideline to expedite the prototyping procedure which effectively reduces the cost and modeling time. An Electro Discharge Machining (EDM) technique was utilized for the fabrication of the device. Series of experimental studies were conducted for performance verification and the results are compared with the computational analysis results. A high displacement amplification and maximum stroke of 100 μm can be achieved.     

高精度计量芯片数字系统研究与设计

从Full-chip设计角度出发,分析和提炼高精度计量芯片设计基本准则,研究相关的数字系统核心算法,优化RTL数字设计架构,使芯片不仅具有高精度,而且面积得到有效控制,为设计符合智能电表新标准的计量芯片提供重要参考。通过仿真、FPGA验证,表明芯片设计方法的有效性,该款芯片已成功流片。     

基于FPGA的高精度数字程控直流变换器设计

精密仪器的快速发展对直流变换器品质提出愈来愈高的要求。为了获得稳定高性能直流输出,提出一种以FPGA为核心的数字程控直流变换器。介绍了该变换器的总体方案,给出主要硬件电路和软件设计。实验结果表明,该变换器具有输出精度高、纹波小、稳定性好和可靠性高等特点,能够满足电子测量领域的要求。     

量程自整定高精度频率测量的FPGA实现

数字频率计是一种应用十分广泛的电子测量仪表,针对宽频率范围被测信号频率测量应用需求,提出并实现了一种基于FPGA的自动量程切换高精度数字频率计的设计方法。通过构建测频控制器、闸门同步生成器、量程自动切换等模块,并采用Verilog HDL语言进行描述,运用自顶向下的数字系统设计方法实现了宽频率范围频率测量的量程自动切换。在Xilinx公司的XUPV5-LX110T开发板上进行了测试,给出了系统后仿真波形。结果表明目标系统能根据被测信号频率范围进行自动量程切换,实现高精度频率测量,测量精度不低于10-7,有效提高系统稳定性和抗电磁干扰能力。     

高精度MEMS传感器在弹载测试系统上的应用

针对静态存储器掉电数据易丢失的缺点,提出了一种基于复杂可编程逻辑器件(CPLD)和闪存的弹载测试系统。该控制系统充分利用CPLD功能,采用VHDL语言和图形化编程方式,有效地实现了对A/D、静态存储器及闪存的时序控制,实现了对弹体飞行姿态(三轴加速度、三轴角速度及两路地)的分时采样、存储及数据的显示。     

Markov model of a digital stochastic generator

A stochastic process generator based on a chain of modulo-two adders with asynchronous feedback loops is investigated. The generator dynamics is described by the Erlang equations. A mathematical model of the generated stochastic process is proposed. The implementation of the generator using modern electronic devices is considered.     

数字化波形发生器的设计

介绍一种数字化波形发生器的设计。采用MAX038函数发生器芯片,在单片机的控制下输出正弦波、三角波、矩形波,频率、占空比可通过12位4路输出的数模转换器MAX526进行数控调节。波形的频率和幅值采用LCD显示。8选1多路模拟开关AD7501在单片机的控制下实现频段的选择。MAX038输出的幅值电压放大后送入数字衰减器AT-280进行衰减,以调整放大后的输出幅度。     

Compiler testing using a sentence generator

A system for assisting in the testing phase of compilers is described. The definition of the language to be compiled drives an automatic sentence generator. The language is described by an extended BNF grammar which can be augmented by actions to ensure contextual congruence, e.g. between definition and use of identifiers. For deep control of the structure of the produced sample the grammar can be described by step-wise refinements: the generator is iteratively applied to each level of refinement, producing at last compilable, complete programs. The implementation is described and some experimental results are reported concerning PLZ, MINIPL and some other languages.     

Factoring Gaussian precision matrices for linear dynamic models

The linear dynamic model (LDM), also known as the Kalman filter model, has been the subject of research in the engineering, control, and more recently, machine learning and speech technology communities. The Gaussian noise processes are usually assumed to have diagonal, or occasionally full, covariance matrices. A number of recent papers have considered modelling the precision rather than covariance matrix of a Gaussian distribution, and this work applies such ideas to the LDM. A Gaussian precision matrix P can be factored into the form P = U^TSU where U is a transform and S a diagonal matrix. By varying the form of U, the covariance can be specified as being diagonal or full, or used to model a given set of spatial dependencies. Furthermore, the transform and scaling components can be shared between models, allowing richer distributions with only marginally more parameters than required to specify diagonal covariances.

The method described in this paper allows the construction of models with an appropriate number of parameters for the amount of available training data. We provide illustrative experimental results on synthetic and real speech data in which models with factored precision matrices and automatically-selected numbers of parameters are as good as or better than models with diagonal covariances on small data sets and as good as models with full covariance matrices on larger data sets.     

高精度数字式MEMS陀螺仪驱动闭环控制系统设计

为提高微机械陀螺检测灵敏度,设计了一种数字式微机械陀螺驱动闭环控制系统,该系统利用数字锁相环来实现陀螺驱动谐振频率和相位的跟踪,同时利用数字自动增益控制模块实现驱动幅值的稳定控制.该控制系统先是在MATLAB/Simulink平台上进行仿真验证,之后在基于FPGA的验证平台上进行验证.实验结果表明在该数字系统的控制下陀螺驱动起振时间大约为0.6 s,驱动幅值相对稳定性小于10×106,陀螺零偏稳定性达到10.448 °/hr.     

基于CBR的精密播种机数字化设计研究

绝大多数的工业设计属于变型设计,而基于CBR技术能够有效的解决变型设计中设计重用所面临的难题。对CBR相关理论及技术进行了分析介绍,对基于CBR的精密播种机数字化设计的具体实现进行了设计研究,提出了一种新的检索算法——基于树的最近邻居法,使实例的检索更准确、高效。以铲式玉米精密播种机为例,对设计过程的实现及推理效率和准确性方面进行实验分析,实验结果表明了将CBR应用于设计问题中的可行性及优势。     

基于AVR的直流电机高精度数字控制系统

提出了一种基于微控制器Atmega128、CPLD技术和电机驱动芯片HIP4080的直流电机数字控制系统的实现方法.该系统实现对电机角度和速度的高精度控制,并可在PC机界面上观察电机状态.     

基于FPGA的高精度光子计数检测系统研究

为了实现微弱光信号的高精度检测,设计了一种基于现场可编程门阵列(FPGA)的光子计数检测系统.采用高灵敏度的光电倍增管作为光电转换器件,有效地实现微弱光信号的获取与处理.基于FP-GA,设计了时序控制模块、光子计数模块、串口通信模块、存储模块和键盘扫描控制模块,完成信号的处理与存储.使用该系统对三磷酸腺苷(ATP)样品...     

高斯白噪声发生器的FPGA实现

分析了几种高斯白噪声发生器的实现途径,提出了一个基于Box-Muller算法级联中心极限定理实现高精度高斯白噪声发生器的方法,在FPGA中使用HDL语言实现。与现有的实现方法相比,本设计速度更快、占用的资源更少,且易于FPGA实现,可作为一个快速实用的误码率测试平台的一部分。     

Development of an integrated look-ahead dynamics-based NURBS interpolator for high precision machinery

Methodologies for planning motion trajectory of parametric interpolation such as non-uniform rational B-spline (NURBS) curves have been proposed in the past. However, most of the algorithms were developed based on the constraints of feedrate, acceleration/deceleration (acc/dec), jerk, and chord errors. The errors caused by servo dynamics were rarely included in the design process. This paper proposes an integrated look-ahead dynamics-based (ILD) algorithm which considers geometric and servo errors simultaneously. The ILD consists of three different modules: a sharp corner detection module, a jerk-limited module, and a dynamics module. The sharp corner detection module identifies sharp corners of a curve and then divides the curve into small segments. The jerk-limited module plans the feedrate profile of each segment according to the constraints of feedrate, acc/dec, jerk, and chord errors. To ensure that the contour errors are bounded within the specified value, the dynamics module further modifies the feedrate profile based on the derived contour error equation. Simulations and experiments are performed to validate the ILD algorithm. It is shown that the ILD approach improves tracking and contour accuracies significantly compared to adaptive-feedrate and curvature-feedrate algorithms.