光电红外成像消旋系统测控技术研究

针对某光电红外成像消旋系统检测项目的需求,设计完成了一套基于PCI总线的自动化测控系统。该系统以旋转变压器和RDC组成轴角编码器,通过数据采集卡实时采集角度数据,再经实时滤波算法和信号变换,显示消旋角度。测控系统采用了积分分离的PID控制方法,驱动直流力矩电机完成消旋功能。该测试系统已成功应用于某光电红外成像消旋系统的维修与测试工作。试验结果表明,本系统设计合理,工作可靠,自动化程度高,具有较强的实用性,满足了自动化测控系统结构化、通用化、模块化的设计要求。     

车载两轴转台伺服控制系统的研究

根据车栽两轴转台电气系统的性能指标要求,采用旋转变压器和位置变送器构成转轴的角位置反馈,同时检测陀螺敏感转轴在惯性空间中的速率变化;利用陀螺信号稳定转台的姿态;脉宽调制功放和直流力矩电机构成系统的执行机构;以无刷直流电机作为伺服系统的伺服电机;采用电流环、速率环、位置环三闭环的控制策略,基于TMS320F240DSP芯片设计了全数字PID控制算法,代替了该型号转台原来的模拟控制算法,实现了光电跟踪系统的高频响、超低速、宽调速和高精度。     

旋转变压器的角度误差校正系统设计

针对旋转变压器输出数据存在的角度误差问题,对旋转变压器校正方法进行了研究,设计并实现了旋转变压器角度误差校正系统。该系统充分利用了旋转变压器工作原理,发挥了光电编码器优势,采用了FPGA和ARM的优点,由同一电机带动光电编码器和被测旋转变压器,以FPGA+ARM组成的控制模块读出光电编码器和被测旋转变压器的角度,并进行比较分析,测量旋转变压器的非线性误差,建立误差分析表,提出了一种根据系数进行补偿的方式,对旋转变压器的误差进行了补偿。研究结果表明,该系统能对旋转变压器的输出数据进行校正,校正前旋转变压器的角度误差最大为21.2弧分,通过该系统校正后,测角误差最大为5.3弧分,系统校正速度较快且效果明显。     

基于旋转变压器的电机转子位置检测电路设计

主要研究了基于DSP和旋转变压器的电机转子位置检测方案,很好地结合了DSP的快速数据处理能力和旋转变压器的高可靠性,实现了旋转变压器的轴角数字测量.在给出旋转变压器工作原理基础上,提出了测量原理和系统的电路设计方案,已成功地应用于实际伺服系统的位置检测中,具有经济、简便、实用的特点.     

地平主焦点式大视场望远镜的双电机消旋系统

大口径大视场地平式望远镜长时间曝光时,主焦点探测器会由于地球自转产生像旋,即视场中除中心外其余星体均绕视场中心旋转,进而导致目标不能正确提取与观测。为消除图像旋转的影响,某大口径大视场望远镜的消旋跟踪精度需小于5″。本文根据星体像旋原理对主焦点探测器像旋的位置特性和速度特性进行系统分析及实验验证,提出采用双电机驱动消间隙消旋机构进行消旋,利用复合电流指令控制方法消间隙并进行控制。实验结果表明:像旋特性符合消旋公式,测量误差不超过2%。最终在低速15(″)/s及高速170(″)/s时消旋机构的跟踪精度小于1″,进行高变速切换即7.86°sin(2π×0.5t)时,控制精度仍然小于1″,采用双电机消间隙控制方法可有效提高系统的稳定性和精度。     

基于8051单片机控制带自锁太阳能发电自动跟随系统

从应用角度出发,研制一种单轴跟踪控制系统,实现太阳光照射方向的实时跟踪。该系统以8051单片机为核心,采用光敏电阻,构建一种光电传感器跟踪模式,通过光电传感器检测太阳光位置,由单片机按程序驱动电动机使得电池板绕轴旋转,使其能够始终正对太阳,直到固定平面与太阳光垂直。有效地提高了太阳能利用效率。经检测结果显示,采用跟踪装置后,电池板平均输出能量提高25%以上,有效地提高太阳能利用效率。     

高精度角位移测量系统设计

采用双通道多极旋转变压器和AD2S83构成的测角系统可以实现角位置和角速度的高精度动态测量。该测角系统采用单片机实现角位置的动态监控,使用CPLD完成了AD2S83与DSP通信的接口逻辑设计,并采用DSP实现双通道角位置粗精耦合及测速算法。     

空间光电跟踪系统动量平衡设计与试验

研制了空间光电跟踪系统的输出力矩(角动量)和动量自补偿的平衡轮,用于降低光电跟踪系统运动对卫星平台姿态的影响。根据光电跟踪系统对目标捕获和跟踪成像的指标要求,针对其频繁启动、速度和加速度变化范围大、速度频繁过零等区别于卫星姿态控制用平衡轮的特点,基于角动量平衡原理设计了一种平衡轮。通过有限元法完成了平衡轮的模态分析和结构优化,建立了包含平衡轮的光电跟踪系统的机电动力学数学模型,利用Matlab/Simulink对光电跟踪系统的方位轴系进行了模型的仿真计算。为验证其可行性,研制了一套平衡轮原理样机,提出了基于单轴气浮平台的平衡轮性能测试方法,并完成了模拟方位轴系的残余角动量检测。仿真和试验结果显示,平衡轮的使用将光电跟踪系统对平台的残余角动量输出减小了96%,表明所设计的平衡轮结构和控制系统合理可行,能够满足空间应用的需求。     

变结构PI控制器的设计及其在光电跟踪系统中的应用

为了给光电跟踪系统提供高性能的伺服控制,基于传统的PI控制器原理,结合变结构的思想,设计了一种变结构PI控制器(VSPI)。介绍了该控制器的工作原理并讨论了设计参数的选择。基于某型号光电跟踪系统,分别对采用了VSPI、抗积分饱和PI控制器(AWPI)和积分分离PI控制器(ISPI)作为位置回路控制器的伺服控制系统进行了仿真和实验。实验结果表明,采用了VSPI的光电跟踪系统基本无超调,上升时间为0.378s,稳定时间为0.488s,跟踪精度为1.26″。该系统结构简单,能实现嵌入式实时控制;与其他两种控制器相比综合性能更好,完全满足光电跟踪系统精度高、响应快的要求。     

基于阵列光电传感阳光跟踪系统设计与实现

依据太阳光线变化的缓慢性、间歇性及环境天气的变化,设计了一种光电跟踪和太阳轨道跟踪相结合的实时阳光跟踪系统,采用阵列光电传感与时钟计算组合方法,分析太阳运动轨迹、角度姿态对阳光跟踪与能量转换效率的影响,探讨四元阵光电传感对太阳运动角度与方向变化的阳光跟踪光电控制系统原理,通过光照强弱与时钟计算太阳历史位置进行精确跟踪。实验表明,系统能实现太阳位置的二维实时跟踪和太阳能电池姿态控制,在光强大范围变化条件下也可以精确的跟踪,大大提高了太阳光的利用。     

回转进给轴回转运动误差检测系统开发

对于数控机床回转进给轴动态回转精度目前还缺乏有效检测手段,笔者提出了回转进给轴动态回转精度的评价准则并给出了一种基于激光干涉仪的动态回转精度检测系统。该系统以直驱电机作为反转装置驱动元件,以圆光栅作为反转装置位置闭环反馈及角位置检测元件,以激光干涉仪的同步触发功能实现直驱电机转角和激光干涉仪误差数据的同步采集。对圆光栅的误差进行了标定并给出了基于分段三次样条的误差特性描述模型。该系统也适用于回转进给轴静态回转角度的误差检测。     

Geometric error modeling and compensation for large-scale grinding machine tools with multi-axes

Synthesis modeling of a geometric error-based traditional method for large-scale grinding machine tools with six axes is too complicated to perform in a real-time compensator with a built-in position control system, and it is difficult to obtain all of the error elements corresponding to the model. This paper proposed a novel strategy in which a machine may be considered as translation axes and rotary axes, and geometric errors of the translation axes and rotary axis are modeled and the geometric error models of the machine are very simple for real-time error compensation. The volumetric errors of the translation axes are measured using spatial circular curve ball bar test, and every element of the rotary axis is also obtained by a series of considerate ball bar tests. According to the characteristics of a position controller used in the machine, a synthesis error compensation system based on the NUM numerical control system was developed. Error compensation experiments were carried out, and the results show that the accuracy of the machine is improved significantly.     

数控回转轴回机械原点问题的探讨

文章分析了在数控机床回转轴与电动机之间速比不是整数的情况下，回转轴返回机械原点时，回转轴机械原点位置不唯一的原因与机理，并给出了相应的解决方案，在实际中取得了良好的效果。     

回转窑简体轴线测量方法与系统

回转窑轴线的测量对于合理调整工艺操作规程及托轮摆放位置，避免托轮轴瓦发烧，改善筒体的受力状况，保护筒体等，具有重要的实际意义。论述了大型回转窑运行轴线动态测量的原理和方法，包括轮带和托轮直径的在线测量、轮带与筒体间隙的测量、筒体运行轴线水平直线度和垂直直线度的动态测量。设计研制了一种新型大型回转窑运行轴线动态测量系统，该系统具有结构简单、安装使用方便、测量精度高等特点。实际测量应用表明：所述的方法及仪器具有较高的测量精度和可靠性。     

数控机床转动轴进给系统轮廓误差分析

在五轴联动数控机床中,转动轴进给系统的动态精度对轮廓误差的影响是不可忽视的。采用不同空间位置上的外形轮廓,对五轴联动数控机床转动轴的联动运动产生的轮廓误差进行分析。在建立转动轴进给系统模型的基础上,利用刀具位置系统到加工系统的转换得到转动轴指令,通过进给系统动态误差模型得到仿真输出指令,再将输出指令从加工系统转换回刀具位置系统,比较刀具位置的偏差,从而得到轮廓误差。找出轮廓误差点与外形轮廓空间位置之间的对应关系,利用这种关系可快速通过轮廓误差来考察转动轴进给系统的动态性能,为机床快速调整和维修提供一种手段。     

Simultaneous geometric error identification of rotary axis and tool setting in an ultra-precision 5-axis machine tool using on-machine measurement

This paper presents a method to identify the position independent geometric errors of rotary axis and tool setting simultaneously using on-machine measurement. Reducing geometric errors of an ultra-precision five-axis machine tool is a key to improve machining accuracy. Five-axis machines are more complicated and less rigid than three axis machine tools, which leads to inevitable geometric errors of the rotary axis. Position deviation in the process of installing a tool on the rotary axis magnifies the machining error. Moreover, an ultra-precision machine tool, which is capable of machining part within sub-micrometer accuracy, is relatively more sensitive to the errors than a conventional machine tool. To improve machining performance, the error components must be identified and compensated. While previous approaches have only measured and identified the geometric errors on the rotary axis without considering errors induced in tool setting, this study identifies the geometric errors of the rotary axis and tool setting. The error components are calculated from a geometric error model. The model presents the error components in a function of tool position and angle of the rotary axis. An approach using on-machine measurement is proposed to measure the tool position in the range of 10 s nm. Simulation is conducted to check the sensitivity of the method to noise. The model is validated through experiments. Uncertainty analysis is also presented to validate the confidence of the error identification.     

分度板检测数控机床回转轴定位精度与误差分析

介绍了自制标准分度板配合电感测微仪,替代多面棱镜加自准值平行光管,检测数控机床回转轴定位精度的方法,提高测量效率降低测量成本,并通过误差分析验证了该测量方法的准确度,保证了数控机床回转轴线定位精度的检测要求。     

Measuring probe alignment errors on cylindrical coordinate measuring machines

This note describes a method for measuring probe alignment errors on precision cylindrical coordinate measuring machines. Specifically, this method is used to determine the minimum distance between the line of travel of the center of a spherical probe tip and the axis of rotation of a rotary axis. Within the Timken facility, we refer to this error as intersection error [Bryan JB. Private communication; 7 June 1992]. In addition to intersection error, this method determines the position along the probe line of travel at which the center of the probe tip passes nearest to the axis of rotation. This position is commonly referred to as probe offset error. It is used to adjust the probe location such that its radial position is zero where it intersects (or nearly intersects) the axis of rotation. In this way, the probe tip location is datumed to the axis of rotation.     

NON-CONTACT MEASUREMENT OF SCULPTURED SURFACE OF ROTATION

A method for measuring the sculptured surface of rotation by using coordinate measuring machine (CMM) and rotary table is proposed. The measurement is realized during the continuous rotation of the workpiece mounted on the rotary table while the probe moves along the generatrix of the surface step by step. This method possesses lots of advantages such as simplicity of probe motion, high reliability and efficiency. Some key techniques including calibration of the effective radius of the probing system, determination of the position of axis of rotation, auto-centering of the workpiece, data processing algorithm, are discussed. Approaches for determining the coordinates on measured surface, establishing workpiece coordinate system and surface fitting are presented in detail. The method can be used with contact or non-contact probes. Some fragile ceramic and plaster parts are measured by using the system consisting of a CMM, rotary table, motorized head and non-contact laser triangulation probe. The measurin     

基于Hermite插值的复杂光学曲面车削加工路径规划

为解决复杂光学曲面加工难题,探讨其车削加工路径规划。基于慢刀伺服加工技术对复杂光学曲面的刀位点规划进行设计,分析刀触点等角度离散方案及刀具圆弧半径补偿方案。轨迹插补采用可编程多轴控制器(Programmable multi-axiscontroller,PMAC)提供的位置、速度、时间(Position velocity time,PVT)插补运动模式,分析PVT的数学实质Hermite分段插值模型,并根据此模型提出恒速法、面积法和三点法三种PVT入口参数生成算法。以离轴抛物面、环曲面、正弦面为例进行仿真,加工路径的仿真表明刀位点的设计可以应用于复杂光学曲面加工。同时z轴运动特性的分析表明z轴往复频率和C轴回转频率相仿时,面积法(c=2/3)和三点法均能满足z轴速度光顺要求;z轴往复频率明显大于主轴频率时,采用三点法的加速度变化明显优于面积法。提出的加工路径方法可为复杂光学曲面的实际加工提供指导意义。