制动器试验台高精度免拆卸惯量飞轮组的设计

针对传统的制动器试验台试验安装中惯量调整费时、费力且准确度较差的特点,设计开发了一种高精度、免拆卸、可快速任意组合惯量装置,该装置能够为车辆制动器、离合器等研究提供更加接近实际的模拟机械惯量;同时能满足试验台设计范围内的任意惯量要求,大大降低了试验准备时间。     

大型精密测量设备的微振研究

微振对精密测量设备的测量精度有很大的影响。文中针对一种大型精密测量设备进行微振研究。依据惯性测量原理,对运行中的设备进行微振测试。根据微振测试结果得出设备的谐振点、启停的振荡时长、微振的位移振幅以及不同微振源对精度的影响程度等,并给出解决谐振问题的具体措施。微振研究结果对同类产品的设计具有指导意义。     

A method for measuring the inertia properties of rigid bodies

A method for the measurement of the inertia properties of rigid bodies is presented. Given a rigid body and its mass, the method allows to measure (identify) the centre of gravity location and the inertia tensor during a single test. The proposed technique is based on the analysis of the free motion of a multi-cable pendulum to which the body under consideration is connected. The motion of the pendulum and the forces acting on the system are recorded and the inertia properties are identified by means of a proper mathematical procedure based on a least square estimation. After the body is positioned on the test rig, the full identification procedure takes less than 10 min. The natural frequencies of the pendulum and the accelerations involved are quite low, making this method suitable for many practical applications. In this paper, the proposed method is described and two test rigs are presented: the first is developed for bodies up to 3500 kg and the second for bodies up to 400 kg. A validation of the measurement method is performed with satisfactory results. The test rig holds a third part quality certificate according to an ISO 9001 standard and could be scaled up to measure the inertia properties of huge bodies, such as trucks, airplanes or even ships.     

An improved pendulum method for the determination of the center of gravity and inertia tensor for irregular-shaped bodies

An improved Trifilar Torsional Pendulum (TTP) for the experimental determination of the Center of Gravity (C.G.) and inertia tensor (the three moments of inertia and the three products of inertia) for an irregular-shaped body is proposed and developed. In the improved apparatus, a universal joint is adopted to facilitate the adjustments of the C.G. of the body in line with the pendulum axis. To enhance the precision of the measurement, a tri-coordinate measuring machine is employed to measure the coordinates of the predefined points and vectors of axes, which are then used for calculating the C.G. and inertia tensor for an irregular-shaped body. The theoretical fundaments of an improved TTP, the experimental setup, data processing procedures, and error estimation for measuring C.G. and inertia tensor are presented. With the proposed TTP and data processing procedure, the relative error in the determination of the moments of inertia can be estimated within 1%, and the deviation of the measured C.G. to the theoretical C.G. is within 1.5 mm. An example is given to demonstrate the effectiveness of the new approaches.     

On mathematical modelling for the elastic coupler response of a planar four-bar linkage with possible speed perturbation at crank

A procedure to predict the response of the elastic coupler of a four-bar linkage allowing for possible fluctuation in crank speed is presented. The response is described by Mathieu–Hill equations obtained by applying Hamilton’s principle and method of Kantorovitch. These are solved by the RKM-method of numerical integration. The effect of crank inertia on coupler response is studied. It is concluded that crank speed fluctuation gives rise to increased strains and hence should be controlled by suitable crank inertia.     

基于MATLAB的破碎机动力学参数优化设计

破碎机动力学参数设计包含机构平衡重、拉杆弹簧计算载荷、飞轮转动惯量等动力学参数的优化设计,是破碎机设计极其重要的内容.破碎机在运转过程中,其偏心轴、动颚、肘板等运动件都具有一定的加速度,会产生很大的惯性力而且大小、方向呈周期性变化.这些惯性力在运动副中引起附加动载荷,是破碎机零件磨损、机器振动的主要原因.破碎机动力学参数优化设计就是通过优化计算,获得最优的平衡条件,使机构总的惯性力平衡,其根本目的就是减小运动件的惯性力引起的附加动载,消除其有害影响,以确保破碎机运转稳定、可靠,降低机器的振动和噪声,提高设备的寿命和效率.以国内广为生产、使用的PE600×900破碎机为研究对象,利用MATLAB的优化功能,在进行运动学、动力学分析,建立一系列运动方程和力学模型之基础上,采用最优动力平衡法,在MATLAB环境下对破碎机机构平衡重进行优化设计.通过优化计算获得机构平衡重及其方向角的最佳值,使随机构位置而变化的振动力降低到最小.     

汽车防抱死制动系统测试装置研究

目前国家汽车检测设备还无法检测ABS性能。利用物体动能可用转动惯量等效原理，提出并设计了汽车ABS滚筒式惯性检测台架，用惯性式制动试验台模拟道路制动试验工况，用主动滚筒测得汽车车速，用支撑滚筒测定车轮速度，由计算机数据采集并计算出汽车滑移率，进行试验研究。试验结果符合实际情况，装置可进行汽车整车的滑移率和制动力测试。     

基于粒子群算法的车间布局优化应用研究

研究了某机加车间零件生产工艺路线,以典型加工工艺为主要参考,构建车间设备最优布局数学模型。应用基于分工合作的粒子群优化算法,在粒子群搜索的不同阶段给予粒子不同的惯性权值,对模型进行计算求解,提高算法的搜索及收敛效率。通过车间典型加工工艺与设备实例模型,验证了基于粒子群优化算法对车间设备布局优化求解的可行性及有效性。     

某高空高速无人机载电子设备热设计试验研究

文中研究了某高空高速无人机载电子设备的热设计问题。针对某高空高速无人机上冷却资源稀缺的特点,提出了结构热惯性和液氮冷却相结合的冷却方式,并设计了2种冷却单元的结构形式。通过实验研究,得到了不同供液工况下的电子设备温度分布,并分析了液氮消耗量对单元温度分布的影响。结果表明：在极少的载机冷却资源条件下,该热设计方式仍可以保障电子设备工作在允许的温度范围内。该设计方式可以供类似热设计参考。     

基于粒子群算法的车间布局优化应用研究

研究了某机加车间零件生产工艺路线,以典型加工工艺为主要参考,构建车间设备最优布局数学模型。应用基于分工合作的粒子群优化算法,在粒子群搜索的不同阶段给予粒子不同的惯性权值,对模型进行计算求解,提高算法的搜索及收敛效率。通过车间典型加工工艺与设备实例模型,验证了基于粒子群优化算法对车间设备布局优化求解的可行性及有效性。     

机车智能优化操纵向导装置的研制

本文介绍了一种以优化原理与自适应控制为理论基础，利用离线寻优计算，在线自整定参数、预测控制相结合的方法，在单片机测控装置硬件平台上建立的智能优化操纵向导，由于该系统采用了部分参数自整定，预测预报等方法，有效地解决了列车高速运行、惯性大不易优化驾驶的问题，同时又能够减少频繁操作，达到最佳节能效果。     

An advanced excitation technique for measurement of unloaded multidirectional mobilities

This paper describes a technique to determine the mobility matrix (including rotational degrees of freedom) from measurements. The determination is performed without loading from the excitation equipment (lever, force transducers, etc.) and uses only one set-up. The advantages of using only one set-up are that an improved consistency of the mobility matrix is achieved in comparison to traditional techniques, and that it saves set-up time which usually is a large portion of the total time required for the actual measurements.The measurements are performed in two steps. During the first step, the mass- and inertia-loaded mobility matrix is determined by using sequential measurements and a physical model of the excitation equipment. In a second step, the loaded mobility matrix is used to actively compensate for the mass and inertia of the excitation equipment; thereafter the unloaded mobility matrix is obtained. The two steps are explained theoretically and are demonstrated experimentally for a freely suspended beam vibrating in bending motion.     

测量转动惯量的新装置

本文介绍了一种测量转动惯量的新装置.该装置用齿轮将圆周等分,通过提高数据采集密度,来提高测量精度.而对于采集到的大量数据点,用MATLAB软件处理,准确、方便.与目前其他测量转动惯量的方法相比、能达到较高的测量精度.     

装船机行走制动器改造

针对黄骅港2期装船机行走盘式制动器存在的问题进行分析，通过研究采用新型惯性制动器进行改造，提高了设备防风能力和使用安全性。     

数控高速旋转式自动切断锯

这里设计了一种新的钢管定尺切断设备,驱动锯片的高速电机与旋转的圆盘形成三角函数的运动关系,实现锯片对圆盘旋转中心的平动而将钢管切断。该设备克服了飞锯机结构复杂,冲击惯性大的缺点,尤其是连续切短管材更为方便。     

提高海上白天测星能力的方法研究

船载经纬仪是远洋航天测量船导航定位系统专用光学测量设备.该设备以电视跟踪和测量为基础,主要用于测量船执行海上卫星测控任务和校飞时提供精确的航向数据.通过昼夜测量恒星获取脱靶量解算航向角,修正惯性导航系统的航向差是船载经纬仪的主要功能.由于种种原因白天测星一直不很理想,本文从应用角度提出新的白天测星方法,并重点讨论了视频人工判读法.通过海上校飞及码头校飞的检验,可以提高白天测星的数量和星等,测量精度完全可以满足要求.     

高速下摆式光学透镜抛光机的研发

传统光学透镜抛光机存在主轴摆动惯性大,机架易产生振动,整机稳定性差等严重影响产品精度的问题。本文在充分研究传统光学透镜加工设备性能的基础上,利用虚拟样机技术,研发了一套能够克服上述设备缺陷的新型高精度光学透镜抛光机。通过虚拟样机技术,不仅能解决传统研发方法的不足,而且能有效地降低抛光机的研发成本、缩短研发周期。     

盘式制动器的原理与应用

桥式起重机起升机构制动器的摩擦零部件,以一定的作用力压紧机构中某一根轴上的制动轮,产生制动力矩,利用这个制动力矩使物体质量和惯性力等所产生的力矩减小,直至两个力矩平衡,达到调速或制动的要求。盘式制动器由于制动转矩大,性能稳定可靠,外形尺寸小,磨损小,正广泛应用在起重机械设备上。     

基于等效静态载荷原理的高速机构结构拓扑优化方法

IC封装等高速精密设备要求高速执行机构的机械结构在满足一定刚度下尽量降低惯性。基于等效静态载荷方法的优化方法是近来发展起来的柔性多体动力学优化设计的有效方法。针对高速机构的特点,对该优化方法做了一些改造。为了模拟运动关节影响,采用含有运动学自由度的准静态方法,对离散结构响应方程进行求解。为了考虑单元修改对惯性载荷的影响,将单元应变能与动能的比值作为单元修改的灵敏度。提出量纲一单元测度,能够综合反应该单元在所有离散点的重要性。所提方法应用于微电子封装摆杆式焊头摆臂的优化设计中,并将三种方法进行了比较,结果表明,含有运动学自由度的准静态分析能够反映机构运动副的影响,当速度非常高时,惯性比刚度对振动的影响更大。数值结果表明本文方法对高速机构的优化设计是有效的。     

MEASURING THE SIX dof DRIVING POINT IMPEDANCE FUNCTION AND AN APPLICATION TO RB INERTIA PROPERTY ESTIMATION

An accurate driving point measurement is imperative in structural dynamic testing. For example, it is used to derive modal scaling, for experimental correlation of finite element models, impedance modelling and extracting the rigid body (RB) inertia properties of an object. A typical driving point measurement gives the linear force/displacement relationship at a single degree of freedom (dof), but any point on an object actually has rotational dofs as well. For example these rotational dofs must be measured in an impedance model where moments are transmitted at the connection point of two substructures. By ignoring the rotations, an inaccurate model will result. In the past, dynamic sensing technology has been limited to the accurate measurement of translational dofs. While rotational sensors do exist, their accuracy is called into question for certain applications. Rotational dofs have tended to be ignored in the measurement process. Applications, which require their use, such as impedance modelling and RB inertia property estimation, have suffered as a result. A process/sensor is being developed to accurately measure the driving point impedance function in all six dofs. The sensor as well as a calibration procedure will be presented here. In order to verify the validity of the calibration and measurement procedure, a new method for measuring the RB inertia properties of an object will be presented. This new method requires an accurate six dof driving point impedance measurement to provide accurate results. The inertia properties of an automotive brake rotor will be measured and compared with the results of a traditional pendulous swing test.