整体叶盘机器人自动化抛光技术

根据整体叶盘结构,在对整体叶盘造型方法分析的基础上,对应用机器人抛光过程中的刀轨生成和干涉检测进行了研究,提出了适合于整体叶盘机器人抛光的刀轨生成算法,并对机器人控制数据的确定进行了分析.该技术对于提高抛光加工质量和效率具有重大的实际意义.     

窄流道整体叶盘定轨迹数控抛光技术研究

为了实现对窄流道整体叶盘的数控抛光,在采用复杂母线超硬磨料柔性抛光轮的基础上,开展了针对叶盘型面、流道及叶根的抛光轮形状与尺寸设计研究,确定了用于整体叶盘高效率抛光的鼓型抛光轮和球头抛光轮尺寸设计原则,实现了大尺寸鼓形半径的优选.随后,针对型面、流道、叶根圆弧不同区域的抛光需求,利用选定工具对某型号整体叶盘全型面进行定...     

航空发动机整体叶盘刀具性能灰色综合评价

以某型航空发动机钛合金整体叶盘的数控铣削为研究对象,提出了一种面向航空发动机整体叶盘的数控铣削刀具性能灰色综合评价方法。首先设计涵盖航空发动机整体叶盘难加工特征的基准件模型,然后基于灰色关联度分别构建了粗精加工刀具性能灰色综合评价模型,最后进行基准件的切削试验并应用所建立的灰色综合评价模型对刀具性能进行综合评价。研究结果表明,所构建的基准件模型和灰色综合评价模型可以快捷、有效地评价刀具性能。     

整体叶盘数控铣削优化技术探讨

针对整体叶盘数控铣削过程中存在的难题,从最优化的角度出发,结合近年来国内外文献研究,从铣削工艺方案优化和工艺参数优化两方面进行介绍,重点对刀具可达性、加工效率、颤振变形、刀具磨损以及优化模型、优化算法等相关优化技术的研究现状进行综述。通过分析现有研究中存在的一些难题,探讨了整体叶盘数控铣削优化技术的研究方法,对后期开展整体叶盘制造技术研究具有一定的参考意义。     

整体叶盘铣削参数的优化

针对刀具的磨损和加工效率的问题,通过使用硬质合金刀具对整体叶盘(TC4)切削加工获取参数,根据试验数据建立数学模型,运用遗传算法对目标函数进行优化来解决。以Visual Studio 2010为开发工具,MATLAB为算法工具,SQL Server 2008为数据库系统管理软件,建立了铣削参数优化模块,提高了加工效率,降低了刀具磨损。     

整体叶盘无干涉五坐标数控抛光轨迹生成算法研究

整体叶盘是典型的薄壁、难加工材料和复杂结构零件,其叶型表面的抛光质量和抛光精度会显著影响其使用性能和寿命。根据整体叶盘的结构特点以及抛光的特殊性,围绕所开发的专用五坐标数控抛光机的编程需要,提出了相应的抛光轨迹生成算法,并对可能存在的干涉进行检查,最终生成了光顺的抛光轨迹。经初步试验证明,该抛光轨迹算法既能有效进行干涉检测,又能生成适合整体叶盘型面的最佳抛光轨迹。     

整体叶盘结构叶片弹性特征分析

以某三级风扇为例,通过数值计算及试验数据分析,对比研究了整体叶盘结构及盘榫结构的不同弹性特征;分析了整体叶盘结构叶片弹性变形角变化量随叶片叶高、相对换算转速变化的特点;阐述了整体叶盘结构叶片径向变形量的特点。研究结果表明,整体叶盘结构的弹性变形量小于盘榫结构叶片,弹性变形角随叶高及转速呈非线性变化。     

整体叶盘型面电解加工阴极进给方向优化及试验研究

电解加工技术是航空发动机整体叶盘零件主流加工技术之一。电解加工中阴极进给方向与阳极型面法线方向夹角的均匀性是影响加工精度的重要因素。为进一步提升整体叶盘型面电解加工精度,针对工具阴极进给方向优化设计问题开展研究。通过研究阴极进给方向与阳极型面法线方向夹角变化对电解加工极间间隙的影响,在分析传统进给方向存在的不足基础上,提出一种叶盘电解加工阴极进给方向优化方法。该方法以阴极进给方向与叶片型面法线方向夹角集合中的最大夹角值为评判指标,以评判指标值最小为判优准则。为验证优化方法的有效性,开展整体叶盘电解加工中阴极进给方向优化设计,采用黄金分割法获得了优化进给方向的最优解。与传统进给方向相比,优化后的进给方向显著提升了夹角分布的均匀性。开展传统进给方向与优化进给方向的加工比较试验以及多叶片扇段加工试验,试验结果表明采用优化进给方向可显著提高加工精度。     

整体叶盘数控加工技术研究

无需榫头与榫槽就可以把整体叶盘旋转的工作叶片与转子盘毂连接在一起,这种结构形式减少了零件的数量与质量,也避免了榫头的气流损失,大大提高了发动机的性能,所以在航空发动机中整体叶盘的应用越来越广泛。本文采用五坐标数控系统,针对整体叶盘的数控加工技术展开研究。     

闭式整体叶盘电火花加工电极运动轨迹搜索与优化方法

针对闭式整体叶盘电火花成形加工时电极造型复杂、无干涉运动轨迹难以搜索等问题,研究了闭式整体叶盘的电火花加工电极设计方案,提出了一种电极结构及其运动轨迹设计方法。建立了成形电极减厚拆分原则,构造了直纹曲面的成形电极分型面;基于随机方向法进行了电极运动轨迹的搜索求解,得到了每个节点处电极上端面中心点的无干涉运动轨迹坐标;基于NURBS曲线对电极运动轨迹坐标点做出了拟合优化;进行了电极运动轨迹验证实验研究,实验结果表明叶片型面误差为±0.08 mm,满足了闭式整体叶盘的技术指标要求。研究表明,提出的电极结构及运动轨迹搜索优化方法适用于闭式整体叶盘的电火花加工,可作为此类问题的一种有效解决方案。     

An adaptive flexible polishing path programming method of the blisk blade using elastic grinding tools

Journal of Mechanical Science and Technology - As for blisk blade profile polishing, the “five-axis numerical control + flexible grinding head + elastic grinding tool” polishing process...     

Posture adaptive control of the flexible grinding head for blisk manufacturing

In order to improve the machining quality, stability, consistency, and other mechanical properties of the blisk surface, a novel pneumatic flexible grinding head is designed, and working principle, accessible region, and real-time position of the grinding head are analyzed. Considering the influence of nonlinear dead-zone, unknown system function, and uncertain disturbance on the performance of pneumatic servo system, an adaptive sliding mode control (ASMC) based on extended state observer (ESO) is proposed. ESO is employed to estimate the system state variables and an adaptive law is adopted to compensate the input dead-zone. Finally, stability of the closed-loop system is guaranteed by Lyapunov theory. Experimental results illustrate the perfect estimation of ESO, and the proposed ASMC has much stronger anti-interference and robustness compared with the traditional PID control, which can achieve the control precision within submicron. Grinding experiments show that this method can reduce waviness and roughness of the blade surface by nearly 50 %, and decrease the form error by about 22.93 %.     

PLC在机器人柔性抛光机床中的应用

介绍了机器人柔性抛光机床的机械设计原理及控制要求，阐述了抛光轮的轮径检测原理和力控制原理。详细介绍了该控制系统的组成和工作原理，确定了以S7-300PLC为核心的机器人柔性抛光机床控制系统。说明了其硬件组成、软件设计和控制系统的抗干扰措施。     

大型曲面自适应研抛机器人运动学仿真

为了提高加工效率,提出了一种安装盘状工具在大型曲面上进行自适应研抛加工的机器人,可以在行进中进行作业.在分析了大型曲面的特征,针对盘状工具多点切触加工的特点,确定了机器人的技术构成.通过Pro/Engineer软件建立了研抛机器人的虚拟模型,研究了自适应研抛机器人和加工系统的运动学并建立了数学模型,应用Adams和Matlab软件对研抛机器人的自适应性和整机运动性能进行了联合仿真.仿真结果表明研抛机器人及其工具系统具有良好的动态性能,为研抛机器人系统的设计、制造和控制提供参考依据.     

Composite adaptive control of belt polishing force for aero-engine blade

The existing methods for blade polishing mainly focus on robot polishing and manual grinding.Due to the difficulty in high-precision control of the polishing force,the blade surface precision is very low in robot polishing,in particular,quality of the inlet and exhaust edges can not satisfy the processing requirements.Manual grinding has low efficiency,high labor intensity and unstable processing quality,moreover,the polished surface is vulnerable to burn,and the surface precision and integrity are difficult to ensure.In order to further improve the profile accuracy and surface quality,a pneumatic flexible polishing force-exerting mechanism is designed and a dual-mode switching composite adaptive control(DSCAC) strategy is proposed,which combines Bang-Bang control and model reference adaptive control based on fuzzy neural network(MRACFNN) together.By the mode decision-making mechanism,Bang-Bang control is used to track the control command signal quickly when the actual polishing force is far away from the target value,and MRACFNN is utilized in smaller error ranges to improve the system robustness and control precision.Based on the mathematical model of the force-exerting mechanism,simulation analysis is implemented on DSCAC.Simulation results show that the output polishing force can better track the given signal.Finally,the blade polishing experiments are carried out on the designed polishing equipment.Experimental results show that DSCAC can effectively mitigate the influence of gas compressibility,valve dead-time effect,valve nonlinear flow,cylinder friction,measurement noise and other interference on the control precision of polishing force,which has high control precision,strong robustness,strong anti-interference ability and other advantages compared with MRACFNN.The proposed research achieves high-precision control of the polishing force,effectively improves the blade machining precision and surface consistency,and significantly reduces the surface roughness.     

电化学机械复合抛光薄膜太阳能电池柔性不锈钢衬底

设计了针对薄膜太阳能电池柔性不锈钢衬底的电化学机械复合抛光法以满足其对表面粗糙度、光反射率和有害物质扩散的要求。首先,设计并制造了一种用于平面加工的复合阴极刀具,理论分析了它的材料去除机理。然后,结合法拉第原理和黏着摩擦理论分析了电化学腐蚀行为和摩擦力作用行为,解决了电化学腐蚀和机械去除钝化膜的匹配一致性问题。最后,以50mm×50mm×0.3mm规格的304不锈钢为阳极工件,对提出的方法进行了实验验证。结果显示:对衬底加工20min后,其表面粗糙度Ra从124nm降到10nm;表面反射率从加工前的56.8%提高到62.4%;表面金属氧化层的形成(氧化铁和氧化铬),有效阻挡了Fe和Cr离子的扩散。实验显示,提出的方法是处理柔性不锈钢表面的有效方法,成本低、效率高。     

Model reference adaptive control of a flexible structure

In this paper, the model reference adaptive control (MRAC) of a flexible structure is investigated. Any mechanically flexible structure is inherently distributed parameter in nature, so that its dynamics are described by a partial, rather than ordinary, differential equation. The MRAC problem is formulated as an initial value problem of coupled partial and ordinary differential equations in weak form. The well-posedness of the initial value problem is proved. The control law is derived by using the Lyapunov redesign method on an infinite dimensional Hilbert space. Uniform asymptotic stability of the closed loop system is established, and asymptotic tracking, i.e., convergence of the state-error to zero, is obtained. With an additional persistence of excitation condition for the reference model, parameter-error convergence to zero is also shown. Numerical simulations are provided.     

Robust adaptive vibration control of a flexible structure

Different types of L1 adaptive control systems show that using robust theories with adaptive control approaches has produced high performance controllers. In this study, a model reference adaptive control scheme considering robust theories is used to propose a practical control system for vibration suppression of a flexible launch vehicle (FLV). In this method, control input of the system is shaped from the dynamic model of the vehicle and components of the control input are adaptively constructed by estimating the undesirable vibration frequencies. Robust stability of the adaptive vibration control system is guaranteed by using the L1 small gain theorem. Simulation results of the robust adaptive vibration control strategy confirm that the effects of vibration on the vehicle performance considerably decrease without the loss of the phase margin of the system.