Approach to Interference Riveting Process Control of Aircraft Automatic Drilling and Riveting

Interference fit riveting is an effective way to improve the fatigue life of aircraft.The accurate control of riveting interference of aircraft automatic drilling and riveting equipment is achieved by process parameters including upsetting force and upset head height.It is valuable for aircraft manufacturing engineering.An approach to interference riveting process control based on the analysis of interference riveting stress field is proposed.According to assembly structure,the upsetting force is calculated by the material property and interference fit level,and the upset head height is deduced by the upsetting force.The experimental result shows that the interference fit level can be controlled accurately by the upsetting force and upset head height,and then,the quality of aircraft automatic riveting can be improved.The proposed approach is verified by the good match between the predicted result and the experimental result.

A Laser Line Scanner Based Hole Position Correction Mechanism for Automatic Drilling and Riveting in Aircraft Assembly

The low-stiffness of aircraft skins may results in the differences between aircraft actual parts and their theoretical models,which will consequently affect the accuracy of automatic drilling and riveting in aircraft assembly.In this paper,a novel approach of hole position correction using laser line scanner(LLS)is proposed to assign a single row of holes on the parts’surfaces.First,we adopt a space circle fitting method and the random sample consensus(RANSAC)to obtain the precise coordinates of center of the datum holes’coordinates.Second,LLS is calibrated by the laser tracker,and the relations between the LLS coordinate system and the tool coordinate system(TCS)can be calculated.Third,the kinematics model of the automatic riveting machine is established based on a two-point referencing strategy proposed in this paper.Thus,the positions of the holes to be drilled can be adjusted.Finally,the experimental results show that in TCS the measurement error of LLS is less than 0.1 mm,and the correction error of the hole position is less than 0.5 mm,which demonstrates the reliability of our method.

Design of Drilling and Riveting Multi-functional End Effector for CFRP and Aluminum Components in Robotic Aircraft Assembly

To fulfill the demands for higher quality,efficiency and flexibility in aviation industry,a multi-functional end effector is designed to automate the drilling and riveting processes in assembling carbon fiber reinforced polymer(CFRP)and aluminum components for a robotic aircraft assembly system.To meet the specific functional requirements for blind rivet installation on CFRP and aluminum materials,additional modules are incorporated on the end effector aside of the basic processing modules for drilling.And all of these processing modules allow for a onestep-drilling-countersinking process,hole inspection,automatic rivet feed,rivet geometry check,sealant application,rivet insertion and installation.Besides,to guarantee the better quality of the hole drilled and joints riveted,several online detection and adjustment measures are applied to this end effector,including the reference detection and perpendicular calibration,which could effectively ensure the positioning precision and perpendicular accuracy as demanded.Finally,the test result shows that this end effector is capable of producing each hole to a positioning precision within ±0.5 mm,aperpendicular accuracy within 0.3°,a diameter tolerance of H8,and a countersink depth tolerance of±0.01 mm.Moreover,it could drill and rivet up to three joints per minute,with acceptable shearing and tensile strength.

Automatic Modification of Local Drilling Holes via Double Pre-Assembly Holes

Manufacturing accuracy, especially position accuracy of fastener holes, directly affects service life and security of aircraft. The traditional modification has poor robustness, while the modification based on laser tracker costs too much. To improve the relative position accuracy of aircraft assembly drilling, and ensure the hole-edge distance requirement, a method was presented to modify the coordinates of drilling holes. Based on online inspecting two positions of pre-assembly holes and their theoretical coordinates, the spatial coordinate transformation matrix of modification could be calculated. Thus the straight drilling holes could be modified. The method improves relative position accuracy of drilling on simple structure effectively. And it reduces the requirement of absolute position accuracy and the cost of position modification. And the process technician also can use this method to decide the position accuracy of different pre-assembly holes based on the accuracy requirement of assembly holes.

Automatic de-noising and recognition algorithm for drilling fluid pulse signal

Wavelet forced de-noising algorithm is suitable for denoising of unsteady drilling fluid pulse signal, including baseline drift rectification and two-stage de-noising processing of frame synchronization signal and instruction signal. Two-stage de-noising processing can reduce the impact of baseline drift and determine automatic peak detection threshold range for signal recognition by distinguishing different features of frame synchronization pulse and instruction pulse. Rising and falling edge relative protruding threshold is defined for peak detection in signal recognition, which can make full use of the degree of the signal peak change and detect peaks flexibly with rising and falling edge relative protruding threshold combination. A synchronous decoding method was designed to reduce position uncertainty of the frame synchronization pulse and eliminate the accumulative error of time base drift, which determines the first instruction pulse position according to position of the frame synchronization pulse and decodes subsequent instruction pulse by taking current instruction pulse as new bit synchronization pulse. Special tool software was developed to tune algorithm parameters, which has a decoding success rate of about 95% for the universal coded signals. For the special coded signals with check byte, decoding success rate using the automatic threshold adjustment algorithm is as high as 99%.

Mtuli-objective Optimization Method for Automatic Drilling and Riveting Sequence Planning

There are numerous riveting points on the large-sized aircraft panel, irregular row of riveting points on delta wing. It is essential to plan the riveting sequence reasonably to improve the efficiency and accuracy of automatic drilling and riveting. Therefore, this article presents a new multi-objective optimization method based on ant colony optimization （ACO）. Multi-objective optimization model of automatic drilling and riveting sequence planning is built by expressing the efficiency and accuracy of riveting as functions of the points＇ coordinates. In order to search the sequences efficiently and improve the quality of the sequences, a new local pheromone updating rule is applied when the ants search sequences. Pareto dominance is incorporated into the proposed ACO to find out the non-dominated sequences. This method is tested on a hyperbolicity panel model of ARJ21 and the result shows its feasibility and superiority compared with particle swarm optimization （PSO） and genetic algorithm （GA）.

Hole surface strengthening mechanism and riveting fatigue life of CFRP/aluminum stacks in robotic rotary ultrasonic drilling

Carbon fiber reinforced plastic(CFRP)and aluminum stacks are widely used in aviation industry due to light weight and high performance.Millions of rivet holes need to be drilled on body materials,and more than 80%of fatigue cracks occur at the connection holes,so the damage and residual stress of hole surface have crucial effect on the riveting fatigue life of CFRP/aluminum stacks and the flight performance.Recently,robotic rotary ultrasonic drilling(RRUD)technology is a promising method to machine the stacks.However,the hole surface strengthening mechanism in RRUD and the service performance of the riveting joint are not verified.Thus,in this paper,the hole surface strengthening mechanism of RRUD for CFRP/aluminum stacks is investigated,a theoretical residual stress model is established,and the fatigue life experiment of riveted joints is conducted.Firstly,analysis on residual stress in RRUD is carried out with consideration of strengthening force and cutting temperature.Residual stress model is established based on the calculation of elastic stress,plastic stress and stress release.Validation experiment results show that ultrasonic vibration changes residual stress from tensile stress to compressive stress.At the same time,comparative damage analysis of CFRP hole exit and hole surface in robotic conventional drilling(RCD)and RRUD is presented.Finally,fatigue strength experiments of riveted joints are conducted for performance verification.Experimental results indicate that fatigue life of single-hole riveted joints is increased by 68%with ultrasonic vibration,and four-hole riveted joint arranged according to aerospace design standards is increased by more than 86%.

89钻杆自动排放机械手设计与研究

为了解决目前人工辅助完成陆地钻台立柱存取存在排放工作劳动强度大、安全性低等问题,以KV3000钻井平台为大环境、89钻杆组成的立柱为研究对象,设计了钻杆自动排杆机械手。首先,对钻井过程中存取立柱的动作及时序过程进行分析;其次,采用动力学仿真分析方法对自动排放机械手进行干涉检查和行程检验,并针对核心零部件进行有限元分析。结果表明:研究装置可顺利完成钻杆存取工作,实现立柱在立柱盒与井口之间的位置转换,加速度均为线性,变化比较平稳,整体无较大波动;核心零部件最大变形为0.15167 mm,最大应力为59.875 MPa,均在允许范围。设备结构合理、运动轨迹规划合理、核心受力部件满足使用要求,提高了钻井作业过程中的自动化程度和安全性,为钻井作业钻杆自动排放提供了解决方案。

钻井液漏斗黏度和密度自动检测仪的研制与应用

近年来,国内外对钻井液性能自动检测技术的研究取得了长足进步。针对现有钻井液自动检测仪器成本高、结构复杂和工作环境受限等问题,研制了钻井液漏斗黏度和密度自动在线检测仪。使用可编程逻辑控制器、物联网模组、压力传感器、超声传感器、蠕动泥浆泵、电动球阀和隔膜泵等,搭建取浆模块、检测模块、清洗模块和控制模块,实现了对钻井液漏斗黏度和密度的自动检测、移动端设备数据查看和操作等功能。采用传感器数据融合和滤波算法等方法提高仪器精度和稳定性,对不同钻井液体系性能测试验证,漏斗黏度误差控制在±1 s,密度误差控制在±0.01 g/cm^(3),且可连续地对钻井液性能进行自动测试。室内测试和现场试验结果表明,该仪器具有操作方便、测试结果准确、可重复性高、人为测量误差小和节约人工等优点,能满足实际钻井施工过程中对钻井液性能检测的要求,具有较强的普适性和广泛的应用前景。

基于单目视觉的散堆铆钉识别与定位技术

针对自动送钉过程中散堆铆钉识别与定位困难的问题,提出一种基于单目视觉的识别与定位方法。通过研究铆钉的反射光强获得钉杆的灰度分布规律,以参数化的方式构造了铆钉模板,并提出基于灰度匹配的铆钉识别算法。将单目视觉与激光位移传感器结合获取铆钉的空间位置,同时为解决单目视觉在测量不同深度下的铆钉位置存在原理性误差的问题,研究了一种重复定位拍照的测量方法,使真空吸嘴与钉杆中心的最大位置偏差由7.86 mm降低到0.87 mm。实验表明,灰度匹配算法的铆钉识别准确率在85%以上,并能适应30%~70%的照明亮度变化。使用该方法的机器人抓钉节拍最长为3.32 s,可留有充足的时间将铆钉输送至自动钻铆设备,满足自动钻铆设备的需求。

煤矿井下三段式自动封孔器结构设计

针对传统封孔器自动化程度低和现有自动封孔器安全性低、封孔器下放与注料不连续等问题,分析了自动封孔器的功能需求与安全需求,提出三段式自动封孔器方案。设计了封孔器同轴接扣机构、钻孔封堵机构、自动注料流道和动密封机构等关键机构。制作样机并开展了室内封孔实验。实验显示,钻孔封堵机构可自动封堵模拟钻孔,封孔料可自动注入模拟钻孔中完成封孔,三段式自动封孔器方案合理,具有可行性。

煤矿井下自动钻机集控系统设计

针对煤矿井下多台自动钻机工作状态,实现一控多模式,提出了一种自动钻机集控系统。通过从硬件搭建、控制方法、网络连接三方面对煤矿井下自动钻机集中控制系统进行设计研究,最终采用井下控制站对多自动钻机进行集中控制。现场试验表明,该方案可达到减人提效的安全生产目标。

高柔性弹夹式流钻螺钉铆接系统研究

流钻螺钉工艺主要应用于空间狭小、封闭管腔等只能单边可达的铝型材、铝铸件部位。汽车行业主要采用的吹钉式流钻螺钉铆接设备受送钉管限制,存在可达性差、节拍慢等不足。传统弹夹式流钻螺钉铆接设备一套只能使用一种规格的螺钉,每增加一种规格螺钉,需要额外增加一台机器人和一套设备,设备利用率低,投资成本高。对此,提出兼容多规格螺钉的高柔性弹夹式流钻螺钉铆接系统,解决了吹钉式流钻螺钉铆接设备和传统弹夹式流钻螺钉铆接设备存在的问题,满足柔性、高效的生产需求。介绍了高柔性弹夹式流钻螺钉铆接系统的组成、原理和特点,分析了系统中的拧紧枪和充钉站。

自动定向钻机双摩擦力胶体卡瓦仿真研究

煤矿井下钻孔封孔技术自动化程度不足,采用自动定向钻机协助封孔可提高封孔自动化程度。设计了一种自动定向钻机用双摩擦力胶体卡瓦,以解决自动定向钻机夹持器夹坏封孔器的问题;提出了2种胶体结构,实现了主动钻杆接扣与退扣2个过程摩擦力差异化,确保钻机顺利加接封孔器。采用非线性有限元法,选用Mooney-Rivlin应变能函数表征胶体力学性能,开展了胶体夹持封孔器仿真,得到了不同材料胶体的工作摩擦力,验证了2种结构胶体的合理性,研究了胶体表面胶条压缩量对封孔器应力的影响,探究了胶体表面胶条数量对胶体轴向摩擦力的影响。结果表明:天然橡胶与聚氨酯橡胶作为胶体材料是合理的,胶条压缩量宜为0.9 mm、胶条数量宜为3条。

煤矿用钻机钻杆自动更换机构分析

煤矿用钻机在钻进过程中,钻杆的上杆与下杆都需要人工进行操作。在操作过程中劳动强度大、效率低且存在很大的安全隐患。针对此问题,提出一种自动换杆机构的思路,并对换杆机构的运动学进行可行性分析。

TGQ-200RC型多工艺自动化钻机的研制与应用

新一轮找矿突破战略行动对钻探技术提出更高要求,利用浅钻技术在浅覆盖区进行快速查证是重要的技术手段。多工艺钻探可以为复杂地层钻探施工提供绿色高效的钻探技术支撑。围绕这一需求研制了TGQ-200RC型多工艺自动化钻机,制定了钻机的总体方案,研制了多工艺动力头、夹持拧卸装置、6自由度移摆管机构、车装集成式液压储杆库、电液控制及参数监测系统等钻机主要部件,规划了自动加减钻杆过程中多机构协同动作控制流程。实钻试验表明,TGQ-200RC型钻机钻进效率高,取样质量好,具有多工艺、机动化、自动化、数字化等特点,单次自动加减钻杆平均用时约90 s,配合无线遥控可实现孔口无人操作,有效降低劳动强度,提高施工安全性。TGQ-200RC型多工艺自动化钻机可以为构建绿色、高效、经济的快速查证钻探技术体系提供坚实支撑,为推动国内浅层钻探装备自动化升级提供有益借鉴。

煤矿用钻杆自动化生产线方案设计

针对传统煤矿用钻杆加工生产线劳动强度大、生产成本高的问题,根据企业生产场地与工艺流程,规划设计一条连续流自动化生产线。该生产线基于机器人自动上下料技术,集成了长度检测、同轴度检测、激光打标、摩擦焊接、回火、铣外焊疤、车内焊疤以及打磨内外焊疤等工序。通过定尺摩擦焊接、物料码追溯管理、关键工艺参数实时采集、智能在线检测以及异常报警等手段,确保产品的高可靠性。根据实际生产,该自动线性能可靠、运行稳定,达到了降低成本、减轻劳动强度的目的。

自动垂直钻井工具纠斜液压系统的研究

对一种用于石油自动垂直钻井工具的纠斜液压系统展开研究,以实现钻具的纠斜力稳定、可变及钻具矢量纠斜效果。针对油缸压力无法调节及液压泵引起油缸压力不易稳定的问题,研究一种新型纠斜液压系统。在建立纠斜液压系统数学模型的基础上,进行了系统和油缸压力的动态响应分析。仿真结果表明,新型纠斜液压系统提供的导向推力较传统系统稳定性更高,压力波动幅度更低;调节比例溢流阀的输入电流55~85 mA,并保持比例溢流阀输入电流增量不变,钻杆转速越大,油缸压力在单位时间内的开环调节精度就越高。

多规格转台轴承组件的自动紧钉装置

在装配转台轴承组件时,需要按照十字交叉顺序分三步拧紧固定螺钉,现有的装紧钉方式存在效率低和紧钉质量低等问题。文章设计了一种多规格转台轴承组件的自动紧钉装置,实现了多规格转台轴承组件的自动定位夹紧、装钉、按照十字交叉顺序分三步加扭力和加胶功能。实际使用表明,该设备工作可靠、效率高,紧钉质量得到很大提高。

基于激光测距的标贯自动记录系统研究

随着现代工程技术的发展,地质勘探和钻探作业在土木工程、矿业开采等领域中扮演着至关重要的角色。然而,传统的地质钻探作业存在着效率低下、安全隐患较多、数据采集不准确等问题,亟待解决。为了提高地质钻探作业的效率和安全性,笔者旨在探讨基于激光测距技术的标贯自动记录系统的设计与应用,以期为地质勘探行业的现代化和智能化发展提供有益的借鉴。