基于多波长协作的切削液残留表面激光位移测量误差补偿方法

在加工测量一体化过程中,工件表面切削液残留形成的油膜会严重影响光学在机测量的精度。 现有的误差补偿方法通 常需要获取油膜介质的先验信息,如成分、厚度等。 而这些信息受加工形质、切削液随机分布等因素的影响难以实时获取。 为 此,本文提出一种基于多波长协作的切削液残留表面激光位移测量误差补偿方法。 首先设计并搭建了基于激光三角位移测量 的多波长激光测量系统,可利用多波长激光测量同一被测点位移。 通过引入柯西色散规律,建立光学系统与激光波长的解析关 系,并基于此推导出多波长激光测量内在的差分特性,最终实现误差补偿。 本文依此方法进行了实验。 结果表明补偿后测量误 差绝对值小于 0. 01 mm,与未补偿的测量数据对比,误差降低了至少 92% 。     

Precision compensation method for tooth flank measurement error of hypoid gear

When measuring the tooth flank of hypoid gear, the measurement datum surface (the large end surface of the gear) does not always coincide with the design bases (the theoretical mounting distance), and this non-coincidence error would affect the tooth flank measurement results. Based on the measurement theory of the hypoid gear tooth flank, a precision matching method of the theoretical tooth surface and the measured tooth surface is designed, the objective function of the tooth flank matching method is established, and the search iterative method was used to calculate the compensation value of the measurement error of the tooth flank, when the two gear tooth surface is most accurately matched. As the mounting distance of the hypoid gear changes, two experiments are done to verify the proposed method. The experiment results show that, for different tooth flank of the measured gear, the measuring error of the tooth flank along Z-axis dropped significantly after compensated by this method, more than 80% of the error along Z-axis are compensated. It is obvious that this method could improve the measurement accuracy of the tooth flank form of hypoid gear.     

影响待测物面测量误差的因素及补偿

分析被测物面对激光三角法测量技术的影响,从原理、位移传感器的非线性补偿、被测表面倾角、被测表面特征(颜色、粗糙度、光泽)几方面分析误差产生的原因。探讨各因素的误差补偿方法,对传感器进行非线性误差标定,测量出其非线性误差曲线图;使用标注件标定激光头本身倾角误差,对绘制倾角误差测量结果做曲线拟合;对被测件表面的颜色处理;在非特定条件下,可以忽略表面光泽度和粗糙度;最后综合上述过程,得出测量结果。该方法提高了测量精度。对于小型机电,电子产品外形反求测量,提高其生产过程中的测量精度,具有一定指导作用。     

采煤机截割高度测量模型与测量误差分析

采煤机截割高度的测量及其误差分析是实现综采工作面自动化的一项重要研究内容.本文针对机身姿态传感器和摇臂摆角传感器测量方案、机身姿态传感器和调高油缸位移传感器测量方案,分别建立了采煤机截割高度测量模型.利用函数误差公式,推导了测量误差模型.以MG1000/2660-WD型采煤机为例,分析了截割高度测量误差分别随俯仰角、摇...     

Thermal error compensation method for machine center

High-speed machining (HSM) technology has become the most important application in metal cutting industries. However, overcome the positioning error is one of a great concern. The position error happens due to poor machine structure design and thermal expansion comes from cutting, especially when HSM is applied. In this paper, a new technique is developed to compensate for these errors. The thermal images are used to confirm dispersion of all the affect positions. PT-100 thermo-measuring sensors are applied to detect the thermal expansion. And a mathematical model is built by multi-variable regression analysis, which is based on the sensed temperature variation and the thermal expansion. Finally, these errors are reduced significantly by sending a feedback to the microprocessor. Meanwhile, the thermal deformation can be compensated by the mathematical model, under the condition when the machine is equipped with linear encoder. Moreover, based on the simulation, it is possible to reduce the number of sensors from ten to six, which save the memory capacity and great benefit for calculating and speeding the process of algorithm. The model improves the accuracy of machining which meets the precision requirement of HSM technology. As the result of various machining tests, the axial positioning error can be reduced from 20 μm to be 3 μm, which is a significantly improvement than existing methods.     

An integrated error compensation method based on on-machine measurement for thin web parts machining

Thin webs are widely used in the aerospace industry for the advantages of compact structure, light weight and high strength-to-weight ratio. Due to its low rigidity, serious machining error may occur, therefore, Finite Element method and mechanism analysis are usually utilized to modeling its deformation. However, they are very time-consuming and only suitable for elastic deformation error. In this study, an integrated error compensation method is proposed based on on-machine measurement (OMM) inspection and error compensation. The OMM inspection is firstly applied to measure the comprehensive machining errors. The Hampel filtering is then used to eliminate outliers, followed by the triangulation-based cubic interpolation as well as a machine learning algorithm which are used to establish the compensation model. At last, the real time compensation of high-density cutting points is realized by developing the compensation system based on External Machine Zero Point Shift (EMZPS) function of machine tool. Three sets of machining experiment of a typical thin web part are conducted to validate the feasibility and efficiency of the proposed method. Experiment results revealed that after compensation, the comprehensive machining errors were controlled under different machining conditions and 58.1%, 68.4% and 62.6% of the machining error ranges were decreased, respectively. This method demonstrates immense potential for further applications in efficiency and accuracy improvement of thin-walled surface parts.     

非调制双色红外测温误差实时补偿方法研究

针对环境温度变化对双色红外测温准确度的影响,基于双色比色红外测温原理,分析了非调制双色红外测温的误差来源,提出一种新的快门式非调制双色红外测温方法。在光路中增加快门及其控制模块,控制快门闭合,将测得系统偏移作为补偿项,补偿实际测温时因温度变化给测量带来的误差。仿真结果表明,在600～1 100℃的测温范围内,长时间使用的无快门非调制红外双色测温的精度严重劣化,而快门式非调制双色红外测温的准确度大幅提高,可达到±0.5%。     

Progressive development of an absolute sensorless compensation system for cutting force-induced error

Cutting forces in traditional machining processes solely originates from the contact points on the cutting tool and workpiece. Therefore comprehensive mechanistic modeling of the machining process offers a means for realizing a sensorless cutting force monitoring system. This paper presents the progressive development of a sensorless compensation system for cutting force-induced error, whereby a learning and intelligent computer system is established, based on machining mechanics modeling and a reference compensation system. Experiences from normal machining sessions of new cutting tools and workpieces are modeled progressively and incorporated into the system. Finally with ample experience available, a full-fledged sensorless system is developed as a stand-alone solution. The sensorless system is economical, convenient, reliable and efficient. Administered on a CNC face milling machine, the model demonstrated exceptional performance and robustness.     

风速风向测量误差补偿算法的研究

为了提高风帆助力船舶中风速风向的测量精度,提出一种基于空间模型的风速风向测量误差补偿算法.首先建立了船舶运动状态下风速风向矢量的空间模型.在应用超声波风速风向测量技术的基础上,通过空间测量的方法确定测量误差与空间倾角的对应关系,并对测量误差进行单向拟合补偿计算和空间拟合补偿计算.最后,经过大量的实验和测量数据的对比,验证了基于空间模型误差补偿算法的有效性和可行性.从而解决了一类风帆助力船舶辅助推进控制系统的风速风向空间测量的误差补偿问题,使得风速风向测量精度满足风帆辅助推进控制系统的要求.     

数控切绘机的平面误差自动补偿方法研究

为了解决数控切绘机的大幅面切割台调平人工耗费大、加工的深度精度不能满足一些行业标准的问题。通过软件设计以正方形分割机床幅面,结合传感器测试切割台平面误差,在加工过程中进行实时补偿的方法实现平面误差的自动补偿。     

光学自由曲面研抛机床的综合误差建模与补偿

为提高光学自由曲面的加工精度,本文基于多体系统理论建立了五轴数控研抛机床综合误差模型。采用直接测量方式对各轴的移动误差和转角误差进行重复测量与分析,发现不同进给速度和测量间距对移动误差和转角误差没有显著影响。把误差数据代入综合误差模型中,得出研抛机床综合误差在x轴、y轴和z轴轴向上的移动误差和转角误差分量的变化规律,进而获知线性位移误差是影响综合误差最主要的因素。依据综合误差模型进行补偿实验,补偿后x轴、y轴和z轴的线性位移误差分别下降88%、89%和84%,补偿效果显著。实验结果证明本文所提出的综合误差建模及补偿方法具有较高的精度和较好的鲁棒性。     

实用的蠕变与滞后误差的补偿方法

传感器的称重信号是由粘贴在用弹性材料做成的弹性体上的应变计给出的,由于温度、湿度以及弹性材料特性、结构等等许多变化会产生误差信号。在各种误差中,滞后和蠕变是典型的、由于材料和结构的弹性特性引起的。如不锈钢因有很好的耐候性而常常被作为弹性体材料,但其蠕变和滞后较大。相比之下应用更广泛的弹性材料是铝合金。     

面向相对导航的UWB测距误差估计与补偿方法

基于无人飞行器和智能机器人等载体构成的智能集群是当前的研究热点,相邻或相近集群成员之间精确的相对距离是密集集群实现协同控制的关键信息。超宽带(UWB)无线传输技术能传输信息,同时具有厘米级的理论测距精度,在集群的协同导航与控制中具有广阔的应用前景。面向集群成员间相对导航的厘米级测距需求,阐述了UWB的测距方案,分析了实际环境中UWB天线的时钟偏移、节点之间有相对速度和非视距环境引起的测距误差的特性,研究了UWB距离测量的状态检测和误差补偿、估计的方法,采用DW1000超宽带模块构建了实验环境,对所研究的方法进行实验验证。结果表明,所研究的方法可显著提高UWB在实际应用中的测距精度,与传统的测距算法相比,在空旷环境(LOS)状态下误差降低了70%,在非视距环境(NLOS)状态下误差降低了50%。     

基于共路光线漂移补偿的直线度测量

针对影响激光测量直线度误差的主要因素之一激光光线漂移,提出了一种基于共路光线漂移补偿的直线度误差测量方法,给出了具体的测量原理和系统构成。从产生激光光线漂移的几个因素出发,理论分析了所产生的光线漂移对直线度误差测量的影响,建立了相对应的光线漂移补偿模型。结果表明,进行补偿后激光器出射光线引起的光线漂移在X方向的最大漂移量由28.4μm减少为5.6μm,Y方向的最大漂移量由21.6μm减少到5μm;由温度梯度引起的光线漂移经补偿后最大漂移量由65.7μm减少为8.9μm。实验结果与理论分析均表明,该方法能有效减少各种因素引起的光线漂移对直线度测量结果的影响,提高测量直线度误差的准确性。     

数控机床切削负荷误差补偿装置的设计

以开放式数控系统-华中I型为平台研制了数控机床切削负荷误差补偿装置,介绍了这套基于电流检测和处理技术的负荷误差补偿装置的基本构架和设计方法,这套装置被用于数控铣削粗加工中,被证明是成功、有效的,它显著提高了机床加工效率和加工精度。     

Comprehensive thermal growth compensation method of spindle and servo axis error on a vertical drilling center

This paper deals with the modeling of comprehensive thermal growth of spindle and servo axis. Thermal errors of a vertical drilling center TC500 were measured using a spindle error analyzer and a laser interferometer, thermal error of servo axis was decomposed, and each term analyzed. Spindle thermal growth model based on temperature variation including an identification method for the parameters of the suggested model was presented. Similarly, the servo axis models for thermal expansion error (TEE) in the stroke range and the thermal drift error (TDE) of origin were derived based on heat-transfer mechanism, and the parameter identification method was presented. The experimental results indicate that by applying the proposed model, high accuracy stability can be achieved, even when the moving state changes randomly. A specific machining process of the upper surface of a rectangular workpiece was designed to verify the effects of error compensation to the unaided eye. The machining results indicate that the proposed model has high accuracy and strong robustness in compensating the comprehensive thermal error.     

A comprehensive error compensation system for correcting geometric, thermal, and cutting force-induced errors

A comprehensive error compensation system has been developed to correct geometric, thermal, and cutting force-induced errors on a turning centre. The basic approach to error compensation is proposed in this paper. The implementation of error compensation control and of hardware configuration of the system are also presented. A total of 11 geometric and thermal error components and 10 cutting force-induced error components can be compensated for using this system. Performance evaluations have been carried out using actual cutting tests. Experimental results show that the diameter accuracy of the part has been improved more than 5 times and taper accuracy of the part has been improved about 5 times.     

谐波电能计量的比差与角差校正方法

分压电路、电流互感器(TA)的比例误差和电流互感器的相角误差是谐波电能计量装置误差的主要来源.本文在分析谐波电能计量的电压、电流信号采集与调理等效电路基础上,建立了谐波条件下的电能计量比差、角差的误差模型,提出了谐波电能计量的比差与角差修正方法;针对宽量程仪用电流互感器的非线性误差,通过多项式曲线拟合得到了修正模型,据此提出了选取曲线拐点作为电能计量校准点的比差、角差分段线性化校正方法,提高了全测量范围内的谐波电压、谐波电流和谐波电能计量准确度.在本文算法基础上研制的三相多功能谐波电能表的基波有功误差≤0.2%,基波无功误差≤1%,2～21次谐波电压测量误差≤2%、谐波电流测量误差≤5%、谐波相位测量误差≤5°,满足GB/T-14549-93的A类谐波测量仪器要求.     

凸轮机构的等效四杆机构误差分析方法研究

凸轮机构是机械中的一种常用机构,在自动化和半自动化机械中应用非常广泛。以盘形凸轮机构的机械误差分析为例介绍一种新的误差分析方法——等效四杆机构法。根据凸轮轮廓的向量参数式及等效连杆的特点,由凸轮机构各个设计参数的尺寸偏差引起的从动件运动误差都可以用解析式表示。通过推导得到了凸轮机构各设计参数的尺寸偏差所导致的从动件的运动误差函数,分析了凸轮轮廓的法线方向误差与径向尺寸误差之间的关系,从而确定凸轮轮廓的尺寸公差的容许值,以保证凸轮轮廓有足够的精确度来满足机器的性能需求。     

地磁测量误差矢量补偿方法研究

精确补偿磁测误差是确保地磁导航精度的一项关键技术。针对磁干扰补偿问题,提出了一种改进的基于模糊自适应卡尔曼滤波的矢量补偿方法。该方法对卡尔曼滤波中的观测矩阵进行修改,有效地解决了某些参数收敛过慢的问题;通过监视实时得到的量测新息的实际方差与理论方差的比值,应用模糊控制理论对卡尔曼滤波的量测噪声协方差进行递推修正,使其逐渐逼近真实噪声水平,进而得到最优估计参数。仿真结果表明,该方法对于时变的量测噪声具有较强的自适应性,总场补偿误差从175.8 nT降低到6.7nT,X、Y、Z方向的补偿误差分别由59.2、110.2、122.2 nT降低到6.0、1.7、1.5 nT,总量和分量补偿精度显著提高。最后通过构建矢量测量系统实验验证了改进方法具有较快的收敛速度且具有更高的补偿精度,为磁场测量误差矢量补偿提供了良好的借鉴。