履带式爬壁机器人力学分析及磁吸附结构优化设计

为了解决履带式爬壁机器人吸附性与机动性存在矛盾的问题,设计了一种履带行走与永磁轮吸附相结合的爬壁机器人。为防止机器人在工作壁面上发生滑移和倾覆的失稳状况,对机器人进行静力学分析,得到机器人安全吸附在壁面时永磁轮应满足的最小磁吸附力。对永磁轮进行结构参数设计,并应用COMSOL仿真软件对永磁轮进行磁场分析和结构优化。研究结果表明,优化前永磁轮的吸附力可使机器人在壁面安全吸附;优化后永磁轮的吸附力增大,质量显著减小,吸附效率提高了16.87%。     

一种轮足复合式爬壁机器人动力学建模与分析

针对爬壁机器人不同状态下吸附力合理值的求解问题开展研究.首先分析了一种包含闭链约束的轮足复合型移动机构,基于运动等效原则将其拆成开链机构.利用牛顿-欧拉算法对分拆后的开链机构进行动力学建模.基于动力学模型,以运动失效的临界条件为约束函数,构建爬壁机器人在不同倾角壁面上的吸附力学模型,从而获得不同状态下吸附力的合理值.仿真和实验表明基于该模型获得的吸附力参数能够保证机器人的安全吸附.因此所构建的模型是合理的,可以为爬壁机器人在不同状态下合理控制吸附力大小提供理论依据.     

具有壁面自适应能力的磁吸附爬壁机器人设计

为解决爬壁机器人在船舶货舱清洗过程中多壁面过渡的问题,该文设计了一种具有壁面自适应能力的磁吸附爬壁机器人,其包括磁吸附机构、自适应清洗机构和行走机构。该文首先通过建立机器人壁面过渡时的力学模型,得到机器人磁吸附力的分布特点,并据此设计出一种弧形磁吸附机构。然后利用 ANSYS Maxwell 3D 软件对该机构磁吸附力的分布进行优化,以满足壁面过渡的需要;此外,还在机器人前端设计了一种自适应清洗机构,通过对该机构的结构原理进行分析和实验,验证了清洗机构也具有壁面过渡能力。最后通过模拟船舶货舱壁面的实际特点,对机器人样机进行壁面过渡综合实验,完成了机器人舱底过渡行走实验和舱顶过渡行走实验,验证了该机器人的壁面自适应和舱内行走的能力。     

基于Netvlad神经网络的变磁力吸附爬壁机器人控制系统设计

变磁力吸附爬壁机器人是一种具有快速、灵活移动方式的爬行机器人,但其吸附力难以控制,越障稳定性较差,难以保证机器人的平稳爬行;为实现爬壁机器人在大型建筑结构外表面的自主避障,提升机器人与运动平面之间的吸附紧密性,设计基于Netvlad神经网络的变磁力吸附爬壁机器人控制系统;按照PCB控制要求,连接外置SRAM设备与传感器模块,借助驱动I/O口电路提供的电力驱动作用,控制气动阀门的闭合情况,完成变磁力吸附爬壁机器人控制系统硬件结构设计;建立Netvlad神经网络体系,通过划分控制指令程序任务的方式,确定移植参数取值范围,实现对控制协议的移植处理,联合相关硬件应用结构,完成基于Netvlad神经网络的变磁力吸附爬壁机器人控制系统设计;实验结果表明,在所设计系统作用下,障碍物所在位置与爬壁机器人所在位置之间的实测距离未大于30cm,能够有效实现自主避障,保证机器人与运动平面之间的紧密吸附。     

电磁微马达驱动全方位永磁轮式爬壁微机器人

介绍了一种全方位微型轮式爬壁机器人.将轴向磁通电磁微马达与永磁轮集成在一起,实现驱动吸附一体化设计.采用一套转向齿轮和三个永磁轮,设计了全方位的爬壁机构.通过动力学分析,导出微机器人爬壁所需的力矩和磁力,并结合永磁轮自身的设计约束,采用ANSOFT和Pro/Engineer仿真对其尺寸进行了优化,从而在相司负载的情况下...     

湿吸附机理及其在仿生爬壁机器人中的应用

提出一种新的基于湿吸附机理的仿生爬壁机器人．首先讨论湿吸附模型及吸附力的控制方法,对一种 基于硫化硅橡胶（聚合物）的仿生足垫的湿吸附力进行测试,由此验证足垫与壁面间的液体薄膜对吸附力的积极影 响．然后设计一种实验研究用的轮爪式仿生爬壁机器人,并对其进行静力学分析．最后对所设计的机器人进行爬壁 试验．结果表明,液体薄膜可以有效提高足垫吸附力,所研制的湿吸附机器人可吸附于约85度的壁面,可成功爬行 于坡度约65度的玻璃壁面,一定程度上验证了湿吸附机理爬壁机器人的可行性．     

两端吸附式焊缝修形爬壁机器人研制

针对大型钢结构件曲面补焊焊缝自动化修形需求,研制了一种特殊结构的爬壁机器人.该机器人的末端修形单元和移动平台均以永磁间隙吸附方式吸附于工件表面,通过含主被动关节的多自由度机械臂相连接.采用数学模型分析了新机构相对于传统单端吸附、串联悬臂式爬壁机器人的优点,计算了末端修形单元的吸附力条件.对试制的机器人样机进行的性能参数测试证明:两端吸附方式不仅大幅度降低对机械臂的刚度要求,同时,机械臂的被动关节使得爬壁机器人具有曲面自适应能力.     

焊接机器人运动学分析

为了研究焊缝轨迹跟踪的方法,以实验室专用HP-6焊接机器人系统为对象,对该机器人焊接系统进行了运动学分析.通过建立机器人焊接系统坐标系,导出机器人本体运动学方程和焊丝端头工具矢量齐次变换矩阵.接着,分析了焊接系统闭环运动学,求出机器人本体运动学逆解,从而得到机器人末端空间位姿.最后,通过试验分析,给出了机器人焊接系统整体运动方程.该方程为后续的焊缝轨迹规划提供可依据的数学模型,也为开展更深层次的机器人焊接系统智能化研究提供了可靠的运动学依据.     

一种基于行星履带轮越障与混合双吸附补偿的爬壁机器人的设计与研究

针对爬壁机器人在复杂壁面工作时越障能力弱、移动迟缓和吸附力不足等问题,设计了一种基于行星履带轮越障与混合双吸附补偿的爬壁机器人,并对壁面移动和越障的性能进行研究。首先根据机器人在壁面上的运动原理,建立其力学模型,计算出沿壁面移动和越障所需的吸附力;进一步结合其受力情况,对越障过程中爬升阶段和跨越阶段的吸附力补偿模型和行...     

磁吸式传感器永磁体的仿真设计

文章设计了一种磁吸式传感器永磁体,并且运用COMSOL软件仿真分析了磁吸式传感器永磁体的磁场分布情况.利用几何的对称性和磁场的反对称性,建立了四分之一钕铁硼圆柱永磁体磁场模型,得出了圆柱型永磁体磁通密度模的空间分布图、吸附钢板的磁力值,分析了永磁体磁场强度和吸附钢板厚度对磁力的影响关系,确定了磁吸式传感器永磁体的大小和...     

基于宏微机器人的焊缝跟踪研究

提出了一种基于宏微运动机器人的焊缝跟踪方法．首先,通过若干点的简单示教获得焊缝位置信息,并通过拟合建立焊缝模型．在该模型的基础上,对机器人的宏动进行运动规划．采用激光结构光视觉测量焊缝坐标,并根据焊缝图像偏差控制机器人的微动．结合机器人的宏动规划运动和微动自动调整,实现大范围、高精度的焊缝跟踪．利用宏微运动平台进行了焊缝跟踪实验,实验结果验证了所提出方法的有效性．     

Acquisition of Weld Seam Dimensional Position Information for Arc Welding Robot Based on Vision Computing

Recognition and identification of weld environment and seam dimensional position by computer vision is a key technology for developing advanced autonomous welding robot. Aiming at requirements for recognition of weld seam image characteristics, this paper first presents an improved algorithm of subpixel edge detection based on Zernike moments. Comparing with the Ghosal’s original algorithm, the improved algorithm deals with mask effect and first derivative model on edge gradient direction so that it has the strong robust to noise, self-thinning ability and higher locating precision. An algorithm based on ZMs to extract line is also proposed, the comparative results with SHT and RHT show the method has the highest calculation speed and accuracy. The stereovision technology is developed to identify dimensional position of weld seam by computing dimensional coordinates of the weld seam. According to characteristics of weld seam, view field scope model and stereovision model based on baseline are studied and a stereo matching method is presented. In order to evaluate the algorithms and models presented in this paper, a welding robot systems with single camera fixed on the weld torch end-effector has been established for the robot to identify the dimensional position of typical weld seam by one-item and two-position method. The experiment results on S-shape and saddle-shape weld seams show that the vision computing method developed in this paper can be used for acquiring weld seam dimensional position information in welding robot system. Thus the welding path is mapped before the welding operation is executed.     

Adaptive parameter optimization approach for robotic grinding of weld seam based on laser vision sensor

Automatic robot grinding technology has been widely applied in the modern manufacturing industry. A flexible abrasive belt wheel used to grind the weld can avoid burns on the base material and improve the processing efficiency. However, when the robot grinds a weld seam, the material removal depth does not coincide with the feed depth because of the soft contact and uneven weld height, affecting the weld seam surface uniformity. Given these problems, an adaptive parameter optimization approach for the robotic grinding of a weld seam was proposed based on a laser vision sensor and a material removal model. First, the depth of weld seam removal was obtained by a laser vision sensor based on triangulation in real-time. Then, a macroscopic material removal model considering flexible deformation was established to determine the relationship between the weld height and process parameters, and the model coefficient was experimentally fitted to ensure the accuracy and reliability of the model. In addition, the data of real-time interaction structure between the robot controller and grinding system were obtained and used to unsure that the rotational speed of the belt wheel increased in the convex part and decreased in the concave part, in order to obtain a uniform weld seam surface. Comparative experiments were performed to verify the effectiveness and superiority of the method, and experiments on the surface roughness and weld seam surface height difference were conducted to verify the universality of the method. Experimental results show that the residual height of the weld after grinding can be controlled within 0.2mm, and the maximum removal height difference can be controlled within 0.05mm. The surface roughness Ra of the weld after grinding could reach 0.408 µm.     

Design and analysis of a wall-climbing robot for passive adaptive movement on variable-curvature metal facades

To facilitate the safe adsorption and stable motion of robots on curved metal surfaces, a wall-climbing robot with a wheeled-type mobile mechanism that can passively self-adapt to walls with different curvature is proposed. The robot is composed of two relatively independent passive adaptive mobile mechanisms and overrunning permanent magnetic adsorption devices to achieve effective fitting of the driving wheels to the wall surface and adaptive surface motion. The overall design is based on a double-hinged connection scheme and gap-type permanent magnetic adsorption. The minimum adsorption force required for the robot to achieve stable climbing motion with no risk of slipping or capsizing is determined by developing a static analysis model. The effects of air-gap size and wall thickness on the adsorption force are analyzed by means of magnetic circuit design studies and parametric simulations on the permanent magnet adsorption device, as well as design optimization of the permanent magnet device. The motion performance test of the fabricated prototype shows that the robot can achieve adaptive curvature motion with self-attitude adjustment, and has a certain load capacity, obstacle crossing capability, and good surface adaptivity.     

基于B样条曲线的电力巡检机器人越障控制

为了提高电力巡检机器人越障控制能力,该文提出基于B样条曲线的电力巡检机器人越障控制技术,首先构建电力巡检机器人的被控对象模型,结合电力巡检机器人驱动动力学分布,进行电力巡检机器人的定位控制,同时采用避障算法进行电力巡检机器人巡检过程中的越障控制,结合位姿参数的自适应调节方法进行电力巡检机器人越障运动学模型构造。在此基础上,建立电力巡检机器人越障控制目标函数,采用B样条曲线跟踪寻优方法进行机器人的越障路径规划,采用自适应的模糊信息加权方法,进行电力巡检机器人越障控制优化。仿真结果表明,采用该方法进行电力巡检机器人运动轨迹测定分布结果稳定,接近运动轨迹的标准值。其越障控制的灵敏度较高,自适应控制能力较强,电力巡检机器人运动轨迹测定分布结果稳定,提高了电力巡检机器人越障性能。     

计算机视觉在焊缝跟踪控制中的应用

研究一种基于计算机视觉的焊缝跟踪控制系统,重点论述焊缝图象分割和边缘提取的理论方法,通过对视觉传感器CCD检测到的弧焊区图象进行处理来准确地识别焊缝位置,从而有效地提高焊缝跟踪精度。     

Seam tracking and visual control for robotic arc welding based on structured light stereovision

A real-time arc welding robot visual control system based on a local network with a multi-level hierarchy is developed in this paper. It consists of an intelligence and human-machine interface level, a motion planning level, a motion control level and a servo control level. The last three levels form a local real-time open robot controller, which realizes motion planning and motion control of a robot. A camera calibration method based on the relative movement of the end-effector connected to a robot is proposed and a method for tracking weld seam based on the structured light stereovision is provided. Combining the parameters of the cameras and laser plane, three groups of position values in Cartesian space are obtained for each feature point in a stripe projected on the weld seam. The accurate three-dimensional position of the edge points in the weld seam can be calculated from the obtained parameters with an information fusion algorithm. By calculating the weld seam parameter from position and image data, the movement parameters of the robot used for tracking can be determined. A swing welding experiment of type Ⅴgroove weld is successfully conducted, the results of which show that the system has high resolution seam tracking in real-time, and works stably and efficiently.     

A tactual weld seam tracking method in super narrow gap of thick plates

The contact-type displacement and angular sensors were improved and utilized in weld seam trajectory detection. A detection–compensation–tracking system was developed. The mechanical part of this system was installed and independent of the robot, which can realize the detection of right-left deviation and up–down offset of the weld path. In the experiment, the position coordinates of the detection point in weld groove were calculated and weld seam tracking was carried out simultaneously owing to its single control system. When the absolute interpolation algorithm was adopted, the average error of width deviation and depth deviation were 0.1817 mm and 0.1449 mm, respectively.