Aiming at the problem of insufficient rigidity of the tool system and unbalanced radial force during deep hole machining, this paper designs a deep hole connector using the fluid dynamic pressure lubrication principle. The deep hole connector includes double-bridge strain gauges and tiltable tiles, which can increase the rigidity of the tool system by using the oil film support stiffness and offset the unbalanced radial force of synchronous detection by adjusting the oil film pressure in real time. First, the mathematical model of tiltable tile is established, the oil film thickness formula is derived, and the formula of oil film pressure is derived. Then, based on Fluent software, the fluid simulation of the deep hole connector is carried out. The simulation adopts a single-factor experiment method, and the change law of oil film pressure on tiltable tile is analyzed under different conditions, respectively. The results show that during deep hole machining, the oil film pressure can be adjusted by adjusting the parameters of workpiece speed, cutting fluid viscosity, tile tilt angle, and tile wrap angle, and then achieve the purpose of increasing the rigidity of the tool system and offsetting the unbalanced radial force.

Transfer learning has been extensively used to build bearings remaining useful life prediction models under multi-operating conditions. However, most models only consider single-target domain, the generalization of the model under across equipment-operating conditions cannot reach the development of modern industry. Therefore, this study proposes a multisource-multitarget domain adaption transfer learning network (MSMTDATLN) hoping to solve across equipment-operating conditions prediction. Constructing a one-total and multi-branch network in MSMTDATLN to extract domain-invariant and domain-specific features from multisource-multitarget domains, adaptively eliminating the differences between domain-specific features, enhancing adaptive regression capabilities by aligning output decision boundaries. Improving model generalization in multitarget domains by the above methods, while enabling end-to-end training and inference. Experimental results on across equipment-operating conditions datasets validate the proposed method reduces RMSE index by 7% compared with other advanced algorithms while providing better model generalization, which can provide theoretical foundation and technical support for the bearing prediction tasks across equipment-operating conditions.

Objective The circular structured light based measurement system can generate circular structured light by reflecting a laser beam through a conical reflector,and utilizing laser triangulation and close-view photogrammetry algorithms to calculate three-dimensional coordinates.This kind of measurement system has been widely studied by researchers due to its advantages such as high flexibility,high accuracy and simple structure.The current circular structured light system has certain problems in measuring roundness.It is difficult for the laser,the camera and the deep hole to be measured to be parallel or coaxial,which leads to the inability to measure the accurate circular cross-section.A measurement system based on circular structured light is constructed,the mechanism of systematic error is analyzed and a method based on the circular structured light system to measure circularity is proposed,which provides some compensation for systematic errors. Methods The mechanism that generates systematic errors in the measurement of roundness by the circular structured light system is analyzed(Fig.3).A high-precision electric linear slide is used to move the deep hole parts to be measured to complete the full-field measurement,and a high-resolution point cloud is obtained and fit the axis.Through the Rodrigues formula,the inner surface point cloud rigid body will be transformed to the point cloud axis and z-axis parallel to the location of the point cloud axis,searching for the z coordinate near the point as a cross-section of the roundness of the assessment point(Fig.4).The roundness evaluation is completed by the grid search algorithm(Fig.5). Results and Discussions The compensation by the proposed method works well in roundness measurement experiments,in which the measurement uncertainty is 4.78 μm(Tab.3).For the circular structured light measurement system,a long rod can be assembled after the laser to increase the axial measurement range of the system.For the proposed circular structured light roundness measurement method,the resolution of the 3D point cloud can be improved by reducing the step length of the motorized linear slide to further improve the measurement accuracy. Conclusions A three-dimensional measurement system of circular structured light is built,the error generated when the circular structured light system measures roundness is analyzed,and a method based on the circular structured light system to accurately measure roundness is proposed.It is verified that the use of the method to measure roundness has a good compensating effect through the measurement experiments.

针对传统机械臂视觉系统标定方法存在标定误差大、精度低以及标定过程复杂的问题,提出一种面向数字孪生的手眼标定方法,通过分析标定原理给出标定方法以及搭建机械臂孪生虚拟平台,实现虚实空间的数据交互.结果表明:提出的手眼标定方法具有抓取精度高、抓取性能良好的优势.

针对六自由度机械臂时间最优轨迹规划问题,提出一种基于改进粒子群算法的4-3-4混合多项式插值轨迹规划算法.算法采用自适应惯性权重,它能根据搜索过程的各个阶段采用相应大小的权重,有利于跳出局部最优陷阱,保持粒子群多样性;以非线性学习因子代替传统粒子群算法中固定的学习因子,有效提高算法的收敛速度和求解精度.通过MATLAB进行仿真验证,结果表明改进粒子群算法收敛速度提高46％,寻优精度提高38％,同时机械臂轨迹规划时间缩短了大约36％,充分地证明了该轨迹规划算法的可靠性和优越性.

针对表面贴装生产线上,机器人在抓取工件的过程之中能够实时地更新调整工件的位置信息,达到准确抓取工件的目的,该文提出了一种基于机器视觉的工件识别与定位算法.通过对工件图像进行预处理并提取出图像的边缘特征,结合图像的Hu矩特征对工件进行识别判断,然后对工件图像外轮廓进行分割,结合图像最小外接矩形的中心点与分割点对工件图像进行定位计算.实验结果为工件的识别匹配度在0～0.02之间,位置定位误差在0.5像素以内,角度定位误差小于0.3°,满足工件的识别定位精度要求.

针对工业中存在的散乱堆叠零件抓取回收困难的问题,提出了一种基于MaskR-CNN的改进目标检测算法.首先通过在特征提取网络中融入平衡特征金字塔思想,改进了损失函数并在网络模型的输出层增加抓取角度预测分支,结合深度相机参数化表示零件抓取问题,最后通过该方法建立数据集进行了网络训练实现了对机器人目标检测方法的优化,验证了该算法的可行性.

In this study, various austenitizing temperatures were selected to explore their influence on the microstructure and mechanical properties of Cr–Mo–Ni–V steels. The dissolution of primary carbides during the quenching process and the precipitation behavior of carbides during the tempering process for the steels were investigated using SEM and EDS analyses. As the austenitizing temperature increases from [Formula: see text]C to [Formula: see text]C, VC can be dissolved into the matrix, and the pinning effect of VC on prior austenite grains is weakened. The dissolved V in the quenched condition has a retarding effect on the carbide precipitation upon tempering. With the austenitizing temperature increasing, both tensile strength and elongation of tempered steels are increased, as well as the impact toughness.

The application of robots in the grinding industry can solve the problems in traditional artificial grinding, such as high labor intensity, low work efficiency, unguaranteed processing quality and serious physical injury to workers. In order to ensure the grinding quality, it is necessary to control the grinding force. The aims of this study is use PID-IMC controller to control the grinding force. Carry on the robot dynamics analysis to establish the dynamics model. Based on the principle of internal model control (IMC), PID controller is optimized and PID-IMC controller is obtained, which is used to realize the constant force control of robot grinding. Simulation and experiments results show that, the dynamics model and control method proposed in this paper have a better effect in the control of robot grinding force.

针对双机器人基坐标系标定过程复杂、定位精度不高,提出一种基于"三点定圆"的改进双机器人基坐标系标定方法.通过分析误差原理以及引入高斯白噪声误差,结合理论分析和软件仿真设计实验.结果表明改进后的双机器人基坐标系标定方法具有准确性和稳定性,保持了良好的定位精度.

为满足多元化需求的用户对数控深孔加工机床的个性化要求,提出了一种基于知识重用的数控深孔加工机的快速设计方法.选用规则推理(RBR)与实例推理(CBR)两种方式相结合的混合推理技术进行数控深孔加工机床知识重用的研究.基于知识重用理论,根据数控深孔加工机床结构和功能的设计要求对其进行模块划分,建立数控深孔加工机床模型库.使用Visual Basic 6.0(VB)对SolidWorks 2010进行二次开发,选择Access为数据库,研究快速设计系统,实现数控深孔加工机床快速化设计.

Robot will be used in the grinding industry widely to liberate human beings from harsh environments. In the grinding process, optimal trajectory planning will not only improve the processing quality but also improve the machining efficiency. The aims of this study are to propose a new algorithm and verify its efficiency in achieving the optimal trajectory planning of the grinding robot. An objective function has been defined terms of both time and jerk. Improved whale optimization algorithm (IWOA) is proposed based on whale optimization algorithm (WOA) and differential evolution algorithm (DE). Mutation operation and selection operation of DE are imitated in the part of initialization to process the population initialized by WOA, and then, the search tasks of WOA are performed. Motion with a constant velocity of the end-effector is considered during fine grinding. The continuity of acceleration and velocity will be achieved by minimizing jerk, and at the same time, smooth robot movement can be obtained. Cubic spline interpolation is implemented. A six-axis industrial robot is used for this research. Results show that optimal trajectory planning based on IWOA is more efficient than others. This method presented in this paper may have some indirect significance in robot business.

刀具的过快磨损不仅增大加工成本,也影响工件的最终加工质量,因此预测和减少刀具磨损率具有重要意义.由于BP神经网络本身容易陷入局部极小值、收敛速度慢等缺陷,且深孔加工过程及其复杂,无法建立加工中刀具磨损率与加工参数之间的准确数学模型,故采用模糊神经网络建立BTA刀具磨损率在线钻削模型.仿真和实验结果表明,该模型能有效预测BTA刀具磨损率,对提高刀具寿命和加工深孔的质量具有一定的意义.

针对传统预测深孔加工中钻削力精度不高的问题以及BP神经网络本身存在的缺陷,提出了BAS-BP神经网络预测模型.文章基于天牛须算法与BP神经网络相互结合,利用天牛须算法计算优化BP神经网络中的初始权值与阀值,从而建立BAS-BP神经网络的预测模型.并与传统BP神经网络预测模型进行对比.结果表明BAS-BP神经网络克服了训练时间长、收敛速度慢的缺点,预测精度明显提高.

基于深孔加工中的BTA钻削方式,通过实验获取了不同转速、进给速度、切削深度下的钻孔粗糙度数据真实值.应用天牛须算法与BP神经网络相互结合,以转速、进给速度、切削深度为输入数据,以孔的表面粗糙度为输出建立了3-6-1的BAS-BP神经网络模型,并绘制折线图将优化前后的预测值进行对比,结果表明BAS-BP神经网络克服了训练时间长、收敛速度慢的缺点,预测精度明显提高.达到了较为理想的效果.也为深孔加工粗糙度研究提供了较好的思路.

The Stewart-Gough platform is optimized by using the differential evolution algorithm.Firstly,the symmetric structure and unsymmetric structure of Stewart-Gough platform are introduced.Secondly,the objective function is defined by considering the effects of the limited of workspace,the singularity con? gura tions existing inside the workspace and the high cost.Finally,the tool selected for optimization is the differential evolution algorithm,and it is used to optimize the structure of Stewart-Gough platform.The results of optimization suggests that the aim of maximize the payload and minimize the forces at each leg needed to counteract external forces applied to the mobile platform can achieved by appropriate select the Stewart-Gough platform structure and parameters.Compared with other algorithms,the differential evolution algorithm has better global search ability,thus select the differential evolution algorithm as optimization tools.The optimization and simulation process are achieved by using MATLAB.

介绍了爪型干式真空泵工作原理与结构特点,利用空间力系相关理论对爪型转子在高速旋转过程中动平衡状态进行了分析与试验研究,利用在不同侧面打减重盲孔的方式来调节转子的动平衡状态.针对真空泵的泄漏问题,提出了利用磁流体密封技术提高泵的真空度,并对流体磁场的强度进行了模拟分析.设计了真空泵检测系统,并利用此装置对磁流体密封和机械密封的方式进行了真空度检测,发现磁流体密封的真空度明显优于机械密封的真空度.

A 3-SPS/S parallel rehabilitation mechanism is proposed for the present situation of ankle rehabilitation institutions and the constitution of mechanism is introduced.The degree of freedom is calculated and the position inverse solution equation is established.Combined with numerical examples,the solution of the inverse equation is solved by MATLAB and the simulation results are verified by ADAMS.The simulation results show that the robot can meet the needs of ankle joint rehabilitation by changing the branching movement input.

以一种新型2T2R大摆角(3-RPR+R)&UPS混联机构构型为基础进行研究,介绍机构组成.通过螺旋理论推导了机构的自由度,且通过G-K公式验证了所得自由度.利用空间坐标变换法建立位置逆解方程,用MATLAB求解方程,计算出并联机构的位置逆解.将建好的三维模型导入ADAMS中添加运动副、 添加点运动激励使其实现假定的运动形式,并进行运动仿真.结果表明可实现给定运动,验证了该混联机构的合理性.