一种基于PVDF的车辆动态称重系统设计

针对高速公路车辆超载问题,设计了一种基于PVDF的车辆动态称重系统。首先介绍了动态称重系统的硬件系统,然后比较了三类压电传感器优缺点,简述了PVDF传感器的安装,给出了电荷放大器以及信号采集器等硬件的选择,并对软件系统的设计流程进行了分析。最后设计了动态称重系统试验,对系统进行了验证。     

基于单片机的高精度数字万用表

设计了基于单片机的具有电压、电流、相位以及电阻等电参量的测量功能的数字万用表。介绍了主要的硬件电路设计和软件设计主要原理及流程,实验结果表明该仪表具有测量精度高的优点。     

基于DSP的车床主轴回转误差的动态测量系统

数据采集及传送方案的制定是主轴回转误差动态测量装置硬件系统设计的关键.区别于基于单片机的数据采集及传送方案,提出了基于DSP的数据采集及传送硬件系统接口电路,同时讨论了基于DSP对电涡流传感器输出的电压信号实现A/D转换的软件程序设计流程.该系统较传统测量系统具有测量精度高、数据处理能力强等特点,有较高的可靠性和应用价值,可广泛应用于生产实际中.     

激光路面测量控制系统

介绍HS5010激光路面测量控制系统的基本工作原理、硬件组成，软件流程及设计思想。     

基于ATmega8的舵机测试装置的研制

设计了基于ATmega8单片机和LCD 162A屏幕的多功能舵机测试装置,介绍了其体系结构、硬件接口电路、软件工作流程.该测试装置具有控制舵机、测量控制信号、测量舵机电流和速度等基本参数的功能,体积小巧,硬件简洁.实验结果表明该测试装置能满足试验要求,测量精度高,使用方便快捷,性能稳定.     

自动包装生产线控制系统设计

针对能实现颗粒、粉末物料自动化动态称量、包装和输送的包装生产线设计控制系统。通过分析包装线工艺流程和控制要求,设计了气动控制系统,并对电气控制系统的硬件组成、软件流程及人机界面的设计给予了详细阐述。     

滚动直线导轨副摩擦力动态测量系统设计

介绍了滚动直线导轨副摩擦力动态测量系统的设计,包括系统方案、硬件系统、数据采集与分析等,并给出了HJG-D系列滚动直线导轨副动态摩擦力的测试结果.本系统测量可靠,实用性强,已在汉江机床厂稳定运行近一年.     

基于PLC控制的轨道螺栓作业机研究与设计

介绍了适合铁路螺栓拧紧的测量方法,并简要说明了能实现该测量的基于PLC控制的轨道螺栓作业机的硬件结构及相关软件的设计流程.     

基于CC2420的机车蓄电池在线检测系统设计

设计一种由显示通信主机、测量节点组成的蓄电池电压温度检测系统,可实时检测电池的电压及温度变化,具有较高的测量精度和可靠性,并可将存储的24h数据通过U盘转储提供给PC机.文章给出了系统的设计原理、硬件结构、软件设计流程.     

滚珠丝杠副摩擦力矩动态测量系统设计

介绍了滚珠丝杠副摩擦力矩动态测量系统的设计,包括系统方案,测量原理,软件流程和数据处理与分析等,并给出了HJG-S系列滚珠丝杠副动态摩擦力矩的测试结果。该系统测量可靠,实用性强,已在陕西汉江机床有限公司稳定运行。     

A re-configurable cross-sectional imaging system for reverse engineering based on a CNC milling machine

This paper presents a novel reverse engineering digitizing system for full part geometry, which is based on a cross-sectional imaging device built in a NC milling machine. The system successively captures a picture for each planar cross-section contour of the part by end-milling and CCD imaging, and builds the geometry for both external and internal surfaces of the complex 3D part based on a set of the vectored cross-sectional contours. The system mainly consists of three components: a NC milling machine, a cross-sectional imaging device and a computer control unit. Some issues involving the principle and process flow of the system, encasing materials, cross-sectional imaging and NC code generation, etc. are described in detail. Built on an existing NC milling machine, a portable device for capturing the cross-sectional images is designed, which includes an isolated light source, a digital camera, a protective case, a rigid arm and a robust tripod. The device, connected to a computer control unit, serves as a highly flexible accessory for the NC milling machine, constructing the cross-sectional imaging system for reverse engineering. Furthermore, the error analysis and accuracy assessment of the system are also addressed. A typical case is discussed in detail to illustrate the applications of the system. Such a re-configurable digitizing system for reverse engineering offers a number of advantages, such as the functional extension of an existing NC milling machine, low costs, and rapid construction. As a result, this system provides a feasible and useful scheme for many enterprises to construct their own reverse measuring system based on existing equipment to aid in rapid product development and extend the function of existing equipment.     

Robust scene recognition using a GA and real-world raw-image

This paper presents a new concept of scene recognition by a genetic algorithm (GA), using the 2-D gray-scale image of a working space, termed here as raw-image, and a model shaping the 2-D top-surface of a target object. In fact here, the problem of object recognition in the raw-image is changed into an optimization problem of a model-based evaluation function. We make use in this research of a GA, as a search and optimization method. This GA employs a model-based fitness function as its objective function to perform the search of a target in the raw-image. In this research, three object models, namely a frame model, a surface model, and a surface-strips model are investigated in order to determine which one is the best for scene recognition in a noisy environment. Also, in order to appraise the recognition performance of each model, a comparative study is performed by analyzing the answers to the following criteria questions: sensitivity, reliability, and speed. The effectiveness of the method has been verified through experiments using real-world raw-images, and the method has shown its robustness of object recognition with the surface-strips model, in spite of the noises in the scene.     

Automated fixture configuration using projective geometry approach

The geometric and topological specification of a workpiece boundary is usually represented in a specific data format in a CAD database. To retrieve a set of workpiece data, to analyse its shape in addition to the machining requirements, and to determine the proper fixture configuration accordingly, are not trivial tasks when a part has a complicated shape. The real challenge is to recognise and synthesise the shape of a workpiece from its data representation. Consequently, the decision for fixturing can be made when the shape of a workpiece and the relationship of the shape and the fixturing configuration can be derived by a systematic methodology. In this paper, a projective spatial occupancy enumeration (PSOE) approach is applied as a representational and manipulating scheme for developing algorithms in automatic fixture configuration. The workpiece is projected onto the working plane of the fixture baseplate. A 2D projection is defined as a matrix of cells which can represent a workpiece with an arbitrary shape. Using a discrete search based upon the matrix of cells, the fixture types and their locations are generated according to a set of heuristic algorithms. This work is a generalisation and extension of previous works for prismatic parts. The same methodology is equally applicable in general robot grasping.     

智能气体识别仪的研究

智能气体识别仪用以识别气体种类,它具有学习识别多种气体的功能。本文介绍了仪器的工作原理、特点及仪器的硬件和软件构成。     

Plate tearing by a cone

The present paper is concerned with steady-state plate tearing by a cone. This is a scenario where a cone is forced through a ductile metal plate with a constant lateral tip penetration in a motion in the plane of the plate. The considered process could be an idealisation of the damage, which develops in a ship bottom raking accident or a collision with a floating object. The deformation involves a complex mixture of large plastic deformations, fracture and friction. The observed mode of deformation is idealised by a simplified, kinematically admissible deformation mode, and the rate of internal energy dissipation in plasticity, fracture and friction is quantified accordingly by analytical expressions. The idealised mode has two free parameters which are determined from the postulate that they adjust to give the least rate of energy dissipation. The theory is compared to a series of measurements. The coefficient of friction was not measured, so the calculations are presented for different realistic values and it is shown that, for a coefficient of friction of about 0.2, there is a reasonably good agreement between theory and measurements for the in-plane resistance force as well as for the out-of-plane reaction force.     

Massless links with external forces and bushing effect for multibody dynamic analysis

When the contribution of lightweight components to the total energy of a system is small, the inertia effects are sometimes ignored by replacing them to massless links. For example, a revolute-spherical massless link generates two kinematic constraint equations between adjacent bodies and allows four relative degrees of freedom. In this paper, to implement a massless link systematically in a computer program using the velocity transformation technique, the velocity transformation matrix of massless links is derived and numerically implemented. The velocity transformation matrix for a revolute-spherical massless link and a revolute-universal massless link are appeared as a 6X4 matrix and a 6X3 matrix, respectively. A massless link model in a suspension composite joint transmitting external forces is also developed and the numerical efficiency of the proposed model is compared to a conventional multibody model. For a massless link transmitting external forces, forces acting on links are resolved and transmitted to the attached points with a quasi-static assumption. Numerical examples are presented to verify the formulation.     

基于柔性解耦梁和显微视觉的精密同轴定位系统

针对偶件装配对同轴度的要求,提出了一种基于柔性解耦梁和显微视觉技术的同轴定位调整系统.为满足同轴度在线调整和轴套的位姿保持,设计了一种“田”字型两自由度柔性解耦梁机构,并结合微动平台和夹具来实现同轴度调整时零件轴的精确定位.根据力学原理,建立了柔性梁的刚度模型,结合有限元法进行仿真分析,确定出梁的结构参数尺寸.对同轴定...     

连续热镀锌生产线的简化与数学建模

为研究气刀处的带钢大幅抖动原因,试对带钢连续热镀锌系统进行动力学建模。整个镀锌生产线是一个复杂的大系统,动力学建模时必须对其进行适当简化,以得到一个仅包含热张紧辊、退火段带钢、沉没辊、出锌锅上行段带钢、塔顶辊、下行段带钢、转向辊和八个弹簧支承的比较简单的混杂系统力学模型。先将简化后的混杂系统分成多个子模型,用带钢张力和附加惯性载荷代替边界条件,然后基于牛顿第二定律对这些子模型进行建模,以期得到整个系统的控制方程。此项研究可为混杂系统建模提供一种新参考。     

Method of determining temperature fields in rubbing solid contacts

The aim of this study has been to develop a new method of recording temperature fields over friction surfaces and within thin surface layers of friction pair elements. In this, the materials tested include steel, titanium, aluminium, silica glass, and sapphire. When studying the temperature distribution in the surface layers of mated bodies a pin‐on‐disc geometry is used. The friction regimes are as follows: the sliding velocity is varied within the range 10–80 m/s and the nominal pressure is 0.06–0.5 MPa. Experiments have been performed using a set‐up involving an optoelectronic scanning technique and comprising a high‐speed friction machine and a temperature field recording system. The latter consists of an optoelectronic transducer, a monitor, a video tape recorder, an amplifier, a device to form oscillograms of image brightness, and a digital storage oscillograph.     

计算机辅助设计凸轮及其数控加工

介绍了如何利用计算机对于形状复杂和高精度的凸轮进行辅助设计,以及将设计结果直接在数控机床上加工的方法,分析了图解法设计的局限性和计算机辅助设计的优越性,指出了利用计算机辅助解析法设计是实现数控加工的基础,也是未来机械设计的发展方向。