加减速运动条件下6-UPS型并联机床刚体动力学模型简化研究

为解决刚体动力学模型的复杂性与控制系统的实时性之间的矛盾,对加减速运动条件下6-UPS型并联机床刚体动力学模型的简化进行了研究。首先采用Newton-Euler法建立了并联机床的刚体动力学模型,将模型分解为18项,并通过仿真分析了并联机床的刚体动力学特性。在此基础上,提出和检验了刚体动力学模型的简化策略。检验结果表明,提出的简化策略具有计算效率高、简化误差小的特点,为并联机床的精确实时控制奠定了基础。     

高架桥式高速五坐标龙门加工中心动态仿真与结构优化

在大型高架桥式、高速、高精度五坐标龙门加工中心的动态设计中,通过动态测试的方法获得导轨结合面的特性参数,并将其应用到数字仿真模型中,提高模型的精度。在结构动态分析中采用刚体与柔性体结合的仿真方法,对加工中心的关键部件进行柔性化,分析其对系统相应的影响,并在此基础上对这些主要部件进行结构优化设计,提高系统的动态特性。     

混联虚拟轴研抛机床的多柔体动力学研究

为了在自由曲面的弹性研抛中 ,获得稳定的动力学特性和加工效果 ,开发了一种由“3轴并联 + 2轴串联”构成的新型 5自由度混联虚拟轴研抛机床。采用柔性多体系统动力学方法 ,建立了基于Lagrange方程的空间刚 柔耦合动力学模型 ;考虑研抛机床整体的刚性运动与各支链弹性变形间的相互作用及耦合 ,将机床的各个支链和平台看作独立子结构 ,建立各自的动力学方程 ,根据子结构之间的约束关系建立了系统约束动力学方程 ;通过动力学仿真分析 ,获得了较稳定的动力学特性     

Modelling thermomechanical behaviour of multi-axis machine tools

This paper describes a method to measure and model the thermally induced positioning errors of multi-axis machines. These errors result from changes in temperature distribution of such a machine. To achieve a reduction of the machine's tool positioning errors a generally applicable model has been developed. First the temperature distribution of a machine tool is computed from a limited number of sensors. Using this calculated temperature distribution and a deformation model based on the machine's structural loop and rigid body kinematics the tool positioning error is computed. To validate the developed thermomechanical model a new measuring method based on three-dimensional length measurements has been used.     

基于刚柔耦合与联合仿真的AUV发动机动力学研究

结合多刚体动力学和多柔体动力学理论,建立自主式水下航行器发动机中相关柔性体的刚柔耦合运动学、动力学数学模型;在ADAMS中生成虚拟样机,在Matlab／Simulink中建立发动机控制模型,然后基于ADAMS／Control模块与Matlab／Simulink接口得到发动机多刚体联合仿真模型,并利用相关实车数据对其进行了验证;在ANSYS软件中生成柔性体有限元模态中性文件,导入多刚体联合仿真模型,得到刚柔耦舍的联合仿真模型。     

BP网络在进给系统定位误差预测中的运用

针对机床进给伺服系统定位精度预测的难点,分析了进给伺服系统机械传动系统定位误差增长的原因,提出了一种定位误差预测的方法。在Adams中建立进给伺服系统动力学仿真模型,得到不同初始状态下的定位误差值,基于BP神经网络建立工作台与螺母座间隙、滚珠丝杠倾斜度、工件负载与定位误差之间的映射模型,根据映射模型提出对定位误差预测的方法。利用所建立的精密运动可靠性试验平台进行验证,证明了该方法的正确性和有效性。     

Volumetric error modeling and sensitivity analysis for designing a five-axis ultra-precision machine tool

The five-axis machine tools are increasingly popular for meeting the demand of machining the workpiece with growing geometric complexity and high accuracy. This paper studies the volumetric error modeling and its sensitivity analysis for the purpose of machine design. The volumetric error model of a five-axis machine tool with the configuration of RTTTR is established based on rigid body kinematics and homogeneous transformation matrix, in which 37 error components are involved. The sensitivity analysis of volumetric error regarding 37 error components is carried out respectively. The analysis results are successfully used for the accuracy design and manufacture of a five-axis ultra-precision machine tool. The preliminary experiment of machining sine grid surface testifies the high accuracy and effectiveness of the designed five-axis machine tool.     

五轴数控机床万能主轴头空间误差建模研究

五轴机床万能主轴头空间误差建模的传统方法采用齐次变换矩阵(HTM)进行运算,计算过程复杂,物理意义很难理解。提出了一种主轴头空间误差的简化建模方法。综合考虑了主轴头两个旋转轴的运动误差和刀具热误差对主轴头空间精度造成的影响。优化了机床运动坐标系设置,从而降低了空间误差模型的复杂性。基于刚体运动学原理,描述了主轴头的运动误差传递关系。结合实例,推导出了主轴头空间误差的数学表达式,其建模过程简单,物理意义明确。     

耦合振动对传动系统影响的仿真研究

基于MSC.ADAMS软件,初步探讨了系统动力学模型的建立及仿真问题。主要利用三维实体造型工具UG和多体动力学仿真工具MSC.ADAMS建立了750 kW风力机组系统多刚体模型,对故障率较高的齿轮进行啮合力仿真分析,对齿轮箱故障进行了预测。     

基于损失模型的三轴小型超精密铣床结构设计参数优化分析

将基于损失模型的稳健性参数分析法应用于小型超精密铣床的结构优化设计过程中。首先,建立了系统的刚体运动学空间误差模型;然后以空间误差为稳健设计的目标函数,通过对可控因素及噪音因素的水平选择,安排正交试验方案并进行仿真;最后,运用试验方案的统计分析结果评判各设计参数对机床空间误差及稳健性的影响。     

五轴数控机床综合误差补偿解耦研究

五轴数控机床具有3个移动副和2个转动副,能对复杂曲面实现高精度加工,然而其误差补偿运动却比较复杂,因为其各运动副的误差补偿运动量与刀具和工件间的误差值(位置及方向误差)间存在一定的耦合关系。通过分析五轴机床的运动特点,用齐次坐标变换的方法建立了各运动副坐标系间的变换矩阵。基于小误差补偿运动假设,分析了误差运动和补偿运动间的相互关系,对五轴机床各运动副的位置及方向误差补偿运动进行了解耦,建立了可以进行空间五个误差补偿量计算的数学模型,为五轴机床的误差实时补偿提供了理论基础。     

基于综合评价体系的五轴数控机床加工性能评价和误差溯源方法

五轴数控机床的加工性能在制造行业一直是研究的热点,基于检验试件切削是常见的测评方法,然而试件和机床之间的映射关系难以确定,出现误差后如何调整精度成为难点。为了科学对其评价,通过仿真平台建立了机床控制系统参数与五轴机床检验试件——S试件加工误差之间的映射关系,引入机床各轴分类评价的隶属度,此基础上开发了误差溯源的综合评价体系,由三坐标测量机得到的S件轮廓误差数据反求出机床的加工性能等级和较差的轴类控制参数,并制订了基于S试件的机床加工精度测评规范,最后通过某五轴AB摆数控机床的切削试验,验证了方法的有效性。该成果有助于解决我国高端制造业长期缺乏机床性能测评的共性技术问题,具有重要的应用前景和经济价值。     

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.     

基于刚-柔耦合的机床虚拟样机建模技术

针对机床系统建模的复杂性,提出基于多种软件集成的刚-柔耦合建模技术,以一桥式加工中心为例,介绍了Pro／E、ANSYS与ADAMS的仿真环境的相互集成的步骤,得到了机床的多柔体仿真模型,并进行了试验验证,试验结果证明虚拟样机在产品开发中的有效性、准确性。     

五轴联动旋风铣削机床设计与仿真分析

应用虚拟制造技术拟订了五轴旋风机床的创新设计方案,建立了三维数字分析模型.首先在数字模型上进行了多体运动仿真,验证机构原理;其次在数字样机上进行了机构运动仿真,检查机构碰撞和干涉情况,验证机床运动功能;设计了电主轴,再进行了主轴的动态特性仿真,验证了主轴的刚度.通过仿真分析得知机床性能与设计质量能满足旋风加工要求,验证了方案的可行性.     

Motor current prediction of a machine tool feed drive using a component-based simulation model

In recent times, simulation techniques have been rapidly accepted by the machine tool industry. However, most existing simulation studies have focused on a particular machine tool and described an entire machine tool feed drive as a single combined system. This paper presents a method to accurately predict motor current (torque) behavior and acquire a more generalized and accurate dynamic simulation model for a machine tool feed drive. To improve the generality, a component-based approach is introduced. In this approach, the feed drive model is composed of subcomponent models, and each component mechanism is then independently modeled. In the developed model structure, the parameters of the subcomponent model can easily be determined by using product datasheets or simple parameter identification based on motor current measurements. To enhance the model accuracy in predicting the motor current, an improved friction model including time-dependent frictional characteristics and rolling contact conditions was introduced to the simulation. The performance of the developed dynamic simulation model is demonstrated through a comparison with real machine tool behavior.     

基于硬件在环的滚齿机数控系统的开发

运用硬件在环技术在沈阳机床厂开发的i5数控系统平台上进行了滚齿机数控系统的开发。采用SolidWorks软件建立了滚齿机的三维模型,并利用Virtuos建立了滚齿机控制系统模型,从而构建了硬件在环仿真系统。经过数控加工程序仿真验证,结果表明,可大大提高数控系统的开发效率,降低开发风险。     

盾构模拟试验台液压监控系统的实现

介绍盾构模拟试验台中盾构机的结构及组成。利用基于CC-Link现场总线的PIE控制实现了盾构液压系统的控制功能，同时对盾构液压系统PIE控制策略进行了分析。采用组态王软件对盾构液压监控系统进行了组态开发，详细介绍了人机界面的开发以及监控系统的数据存储与显示。     

基于VERICUT的虚拟机床建模与复杂曲面加工的研究

VERICUT是一款既能完成加工仿真又能进行程序优化的三维软件,可实现加工轨迹仿真和机床仿真,本文介绍了虚拟机床技术及其常用的建模方法和加工轨迹仿真。同时对机床建模,并应用此虚拟机床对一零件进行了仿真加工。通过仿真可以消除试切中的撞刀干涉等现象,免去试切试验的烦琐过程,有效预测加工结果;并且能降低成本、提高程序编制的效率、缩短制造周期。该技术在现代制造业中具有广阔的应用前景。     

ENERGY-SAVING TYPE OF HYDRAULIC WORKOVER RIG AND SIMULATION FOR LOWERING PIPESTRING

0 INTRODUCTIONThe workover rig is often used in oilfields, and the ordinaryworkover rig has an unreasonably large energy waste. Thereforethe Shengli oilfield in China developed the energy-saving type ofhydraulic workover rig. This rig received the inventi…