PMC650坐标测量机自动校准方法研究

三坐标测量机机械测头的校准过程数据繁多冗长,费时费力且容易出错,针对德国马尔公司生产的PMC650坐标测量机,研究了其机械测头及同轴光学测头的自动校准方法、不确定度分析及其自动校准软件,自动实现坐标测量机的校准功能.数据分析表明,该软件操作简单,测量精度高,同时对机械光学测头同轴校准方法做了研究探索.     

三坐标测量机非接触式测量在丝杆测量中的应用

提出了一种基于三坐标测量机视觉测量技术应用在丝杆测量中的新方法。本方法的特点是不需要将丝杆抬起升角角度就可实现测量,给出了在螺纹轴截面和正交投影间基准转换的关系式,并以此讨论分析了补偿量。本方法在测量时丝杆无需旋转升角角度,减少了对夹具的要求,使测量简单易行,大大提高了工作效率。     

三坐标测量机直线度误差的测量

误差补偿是提高三坐标测量机整体精度的经济而有效的手段,本文利用精度等级更高的激光干涉仪对三坐标测量机的X轴直线度误差进行了测量,并得出了初步结论,为以后进行误差补偿提供了依据。     

假肢接受腔阳模数控加工刀具的运动轨迹规划

应用表面建模方法，建立了假肢接受腔的三维数学模型。针对假肢接受腔的独特外形特征，研制了加工假肢接受腔阳模的三轴联动数控机床，该机床控制系统采用开环系统，可以运行CAD／CAM软件。对加工假肢接受腔阳模的刀具进行了运动轨迹规划，推导出了切削点的计算公式。根据三维刀具半径补偿原理，确定了刀具的刀位点运动轨迹。经过临床实例加工表明：该数控机床和刀具运动轨迹规划算法完全满足实际应用要求。     

Haptic modeling for a virtual coordinate measuring machine

Introducing a haptic device into coordinate measuring machine (CMM) inspection path planning leads to the proposal of a novel CMM off-line inspection path planning environment, a haptic virtual coordinate measuring machine (HVCMM), which makes use of the haptic modeling technique for CMM off-line programming. The HVCMM is an accurate model of a real CMM, which simulates a CMM's operation and its measurement process in a virtual environment with haptic perception. In this paper, a simple and effective mechanics model is implemented for the proposed HVCMM. The HVCMM enables CMM off-line programming to take place exactly as if an operator were in front of a real CMM and moving a real CMM probe. Even more, operators can feel the collision between the CMM and a part. Since there is a force feedback when the probe reaches the surface of the part, besides showing the contact in the HVCMM environment, it is much easier to generate a collision-free probe path than using other off-line inspection planning methods. The HVCMM not only facilitates inspection path planning, but also speeds it up because the operator does not need to slow the probe down when it is approaching an object. Combined visual and force feedback is the best indicator for selecting measurement points.     

用于移动机器人路径规划的曲线轨迹算法

针对移动机器人路径规划方法--人工势场法在相近障碍物之间不能发现路径的局限性,经改进,提出了一种圆弧路径算法.该改进算法从轨迹方程的角度出发,将移动机器人的路径以规则曲线的形式进行规划,确定路径方程,并以圆的曲线方程来表示,以求便于计算,同时综合考虑了路径规划的实时性和最短路径,从而可得出最优路径.构建了三维激光扫描系...     

基于半闭环控制的三坐标测量机的平面测量研究

介绍了一种基于半闭环控制的三坐标测量机的测量原理。主要研究了测量运动控制系统和数据处理系统在平面测量时的相关问题。     

Noncontact interferometric optical probe for calibration of coordinate measuring machines

Our work deals with point length standards, which can be practically realized by two precise spheres or parts of spheres connected by a bar or array of spherical surfaces. The distance between the centers of spheres precisely determines the length. Two methods (mechanical and optical) are shown for determination of the centers of spheres of the length standard. The proposed optical method is based on the interference of light. General formulas are derived that make it possible to calculate accurately the center position of the spherical surface, which is used for the length standards. An analysis of the proposed method is described based on the third-order aberration theory. The proposed technique can be used for calibration and checking of computer numerical controlled machines.     

利用iGPS进行大尺寸空间坐标测量的不确定度评估

iGPS是一种基于激光旋转扫描定位的网络式大尺寸空间坐标测量系统。为分析系统的空间坐标测量不确定度,建立空间坐标测量模型,分析影响系统测量精度的误差源,利用蒙特卡罗法进行了仿真。针对其典型的四站网络测量系统,对系统的测量不确定度进行评估,获得系统的误差分布规律,为iGPS现场大尺寸精密测量系统的具体应用提供有利的支撑。     

The optimal feedrate planning on five-axis parametric tool path with geometric and kinematic constraints for CNC machine tools

The optimal feedrate planning on five-axis parametric tool path with multi-constraints remains challenging due to the variable curvature of tool path curves and the nonlinear relationships between the Cartesian space and joint space. The methods for solving this problem are very limited at present. The optimal feedrate associated with a programmed tool path is crucial for high speed and high accuracy machining. This paper presents a novel feedrate optimisation method for feedrate planning on five-axis parametric tool paths with preset multi-constraints including chord error constraint, tangential kinematic constraints and axis kinematic constraints. The proposed method first derives a linear objective function for feedrate optimisation by using a discrete format of primitive continuous objective function. Then, the preset multi-constraints are converted to nonlinear constraint conditions on the decision variables in the linear objective function and are then linearised with an approximation strategy. A linear model for feedrate optimisation with preset multiple constraints is then constructed, which can be solved by well-developed linear programming algorithms. Finally, the optimal feedrate can be obtained from the optimal solution and fitted to the smooth spline curve as the ultimate feedrate profile. Experiments are conducted on two parametric tool paths to verify the feasibility and applicability of the proposed method that show both the planning results and computing efficiency are satisfactory when the number of sampling positions is appropriately determined.     

关节式坐标测量机激光测量头参数标定

在三维视觉测量中,标定方法对测量结果的影响是决定性的.本文通过分析、比较各种视觉模型及标定方法,采用考虑镜头畸变因素的三维视觉模型以满足高精度测量系统的需求.由于关节式坐标测量机的激光测量头,使用单摄像机和线结构光来匹配被测物体表面的三维数据,本文设计了一种新型的阶梯形标定块,通过标定块图像和激光条纹图像完成了摄像机的内外参数标定和激光平面参数标定.实验证明,该标定操作过程简单,易于实现自动化,且具有较高的标定精度.     

CNC tool path planning for multi-patch sculptured surfaces

A new CNC tool path generation method for a multi-patch sculptured surface in the parametric plane is developed to obtain a minimum number of cutter location points while maintaining the required machining accuracy. In this study, a method to obtain intersecting points is suggested to generate the continuous tool path among different patches. In addition, a method of selecting a reference plane and a simple error analysis method are proposed to determine the step and side-step sizes. The effectiveness of the proposed method is demonstrated through simulation and experimental study.     

室内地面清洁机器人路径规划

采用栅格法建立环境地图模型,利用沿边走的路径规划算法进行室内地面清洁机器人无障碍与避障路径规划与仿真试验.结果表明,在静态结构化环境中,清洁机器人能够沿内螺旋式“回”字型路径完成清扫任务,并成功避开障碍物和边界,自动定位和转向,清洁完毕机器人能够自动返回到初始位置.这说明沿边走的内螺旋式“回”字型路径规划方式是可行的.     

Decentralized path planning for cooperating autonomous mobile units

Forschung im Ingenieurwesen - In various domains, e.g. robotics or autonomous driving, automated path planning for conflict-free movements of the participating vehicles,...     

Minimum time collision-free path planning for robotic assembly

Optimum path planning of manipulator arms in assembly applications involves the selection of the optimum combination of the robot control variables under the constraints imposed by the robot's physical capabilities and the condition of the working area. The present paper describes an approach based on numerical optimization techniques to plan collision-free paths, and on Taguchi parameter design methodology to optimize the control parameters of the pick-and-place operation that would yield minimum cycle time     

Automated feature accessibility algorithm for inspection on a coordinate measuring machine

In this paper, the issue of inspection planning for a coordinate measuring machine (CMM) is addressed. A method is presented for the automation of the probe selection decision, with the ultimate goal of determining the set of workpiece orientations recommended for use on a CMM equipped with an indexable probe. The methodology uses a computer-aided design (CAD) model of the workpiece and a list of tolerance information as input to a feature accessibility algorithm. For each inspection feature, the algorithm generates a feasible set of probe orientations using information about potential probe/workpiece collisions, and computes an estimate of its percentage accessibility.     

Measurement of the coordinate dimensions of machine parts

Definitions are formulated for the real values of linear and angular coordinate dimensions of machine parts in accordance with the theory of basing, taking into account their purpose and informativeness of their geometric elements. The informativeness of the coordinate planes and axes of generalized and auxiliary coordinate systems of machine parts with normalization of the coordinate dimensions are demonstrated. A methodology of true measurements of coordinate dimensions is proposed. Translated from Izmeritel'naya Tekhnika, No. 7, pp. 18–22, July, 1998.