共查询到19条相似文献,搜索用时 171 毫秒
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超精密车床进给系统普遍存在大行程与高精度之间的矛盾,研制出动、静态特性好、行程大、精度高的进给系统是当前超精密加工亟需解决的关键技术之一。本文提出了一种新原理及实现方法,即综合利用计算机、动态检测、信号处理、控制理论、传感器、微位移技术等,将精确进给量分解成主进给量和补偿进给量两部分,分别进行协调连续控制。从而解决大行程与高精度之间的矛盾。利用该技术,能使普通进给系统定位精度提高十多倍,同时又大大扩大了进给微系统的行程。 相似文献
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对HCM-Ⅰ型超精密车床的防振措施进行了综合论述,尤其对空气弹簧隔振系统和空气静压轴承主轴进行了较详细的理论分析,并且通过实验验证,HCM-Ⅰ型超精密车床的振动极小。 相似文献
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本文展示了这样一种可能性,即综合计算机,动态检测、信号处理、控制理论、微位移技术等,开发一种主轴回转运动误差补偿技术,来提高超精密车削工件的圆度在国产S1-235超精密车床上进行切削试验表明:工件圆度可改善50%以上,圆度值优于0.05μm。 相似文献
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在分析影响超精密金刚石车床伺服进给机构运动精度的误差源的基础上,不采取提高机床部件制造精度的办法,而从伺服进给机构的机械结构上提出消除这些误差的措施.这些措施主要包括:利用闭合的复合节流方式的气体静压导轨结构与在丝杠与工作台联接之间安装浮动单元.经过实践证明这些措施是有效的,使自研的超精密车床的伺服进给机构运动精度完全达到超精密加工的需求. 相似文献
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考虑摩擦影响的重型车床横向进给伺服系统建模与分析 总被引:4,自引:0,他引:4
进给伺服系统的性能对数控(Computer numerical control,CNC)机床的跟踪及定位精度、零件加工表面质量等有着重要的影响。摩擦的非线性还会导致系统产生爬行行为。结合Karnopp摩擦模型的建模思想,对导轨接触面建立一种改进的Stribeck摩擦模型,针对闭环控制的某重型车床的横向进给系统,建立综合考虑轴的扭转刚度、齿轮的啮合刚度、丝杠螺母副接触刚度、丝杠轴和轴承轴向刚度、导轨接触面摩擦的进给伺服系统的多自由度力学模型和数学模型,研究低速进给下各个刚度变化对工作台输出的影响,找出机械传动系统中的刚度薄弱环节。现场试验测试工作台不同进给位置下的临界爬行速度,得出临界爬行速度与丝杠的轴向刚度的关系,理论分析与试验结果相吻合。所得结论可为该重型车床横向进给伺服系统的优化设计和性能预测提供理论支持。 相似文献
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为提高切削内圆弧曲面类工件的加工精度、加工效率及加工稳定性,设计了一种加工内圆弧曲面类工件专用数控车床。该机床主要有电主轴机构、进给伺服驱动机构和床身机架等。针对加工对象的特点和设计目的,其创新部件有高刚性、高转速的电主轴和进给伺服驱动机构的排刀架部件。其中排刀架部件特点表现为:所有刀具装于工作台上直接选用,改变了传统的换刀方式,缩短了换刀行程,从而节约了加工时间。使用结果表明,该机床加工效果达到了高效、高精度、高稳定性,并具有良好的通用性。该机床的设计是一种工艺装备的创新,使内圆弧曲面类工件加工工艺上了新台阶,创造了良好的社会效益。 相似文献
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在CNC机床伺服进给系统中,控制对象的位置、速度具有不确定性和非线性,很难去建立精确的数学模型,而常规PID控制器的参数无法随着被控对象参数的变化而及时调整。模糊控制降低了对被控对象数学模型的要求,只需把经验知识转化为控制策略,进而使模型难以确定的复杂系统得以有效的控制,模糊PID控制器结合了常规PID控制和模糊控制的优点,将其应用于CNC机床伺服进给系统中,在MATLAB环境下进行仿真分析,结果表明,模糊自整定PID控制器具有更好鲁棒性,改善了伺服进给系统的动态性能。 相似文献
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A nano positioning control is developed using the ultra-precision positioning apparatus such as actuator, sensor, guide, power
transmission element with an appropriate control method. Using established procedures, a single plane X-Y stage with ultra-precision
positioning is manufactured. A global stage for materialization with robust system is combined by using an AC servo motor
with a ball screw and rolling guide. An ultra-precision positioning system is developed using a micro stage with an elastic
hinge and piezo element. Global and micro servos for positioning with nanometer accuracy are controlled simultaneously using
an incremental encoder and a laser interferometer to measure displacement. Using established procedures, an ultra-precision
positioning system (100 mm stroke and ±10 nm positioning accuracy) with a single plane X-Y stage is fabricated. Its performance
is evaluated through simulation using Matlab. After analyzing previous control algorithms and adapting modern control theory,
a dual servo algorithm is developed for a minimum order observer to secure the stability and priority on the controller. The
simulations and experiments on the ultra precision positioning and the stability of the ultra-precision positioning system
with single plane X-Y stage and the priority of the control algorithm are secured by using Matlab with Simulink and ControlDesk
made in dSPACE. 相似文献
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针对普通立式车床的不足之处,在保留右刀架机械结构和操作功能不变的基础上对C5225立式车床的左刀架进给系统进行了数控化改造。左刀架采用滚珠丝杠、伺服电机和一级齿轮减速,并利用SINUMERIK 802D数控系统的半闭环控制实现左刀架的X轴和Z轴联动控制,机床改造后,扩大了加工范围,提高了生产效率和加工精度。 相似文献
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This paper proposes a friction compensator and a design method for control systems to improve the response characteristics of linear motor feed drive systems. The proposed friction compensator cancels the real nonlinear friction of feed drive systems by using the nonlinear friction model proposed in this study and introduces virtual linear friction to facilitate the control system design. The proposed design method enables the determination of servo gains and friction compensator parameters that lead to desirable tracking performance and disturbance rejection without many trial-and-error tuning processes. In addition, the proposed method facilitates the design of the velocity feedforward compensator by using the inverse transfer function of the velocity control loop to correct the position tracking errors for various position commands. The effectiveness of the proposed method with the friction compensator and the velocity feedforward compensator was verified in simulations and experiments using a one-axis feed drive system consisting of a rod-type linear motor and linear roller guides. The results confirmed that the proposed method enables desirable overshoot-free responses and corrects motion trajectory errors due to nonlinear friction characteristics, and the proposed velocity feedforward compensator can correct tracking errors in both constant velocity motion and circular motion. 相似文献