Modeling Method for Mechanism Configuration of the Articulated Industrial Robot

2013 ◽  
Vol 694-697 ◽  
pp. 1696-1699 ◽  
Author(s):  
Ping Liu ◽  
Jian Qin Fu
Keyword(s):  
Coordinate System ◽  
Industrial Robot ◽  
Modeling Method ◽  
Terminal Link ◽  
Direction Vector ◽  
Kinematical Parameter

Modeling method for mechanism configuration of the articulated industrial robot is proposed. Each link of mechanism configuration is modeled by a type of variable coordinate system based on UG system. The variable coordinate system is changed with a type of variable kinematical parameter of the links. Thus the position and direction vector of terminal link by reference to frame at any time can be obtained by using inquiry command in UG system. The typical modeling example of the FANUC articulated industrial robot which possesses 6 rotation freedoms in space is as shown in figure. It is appearance that the Modeling method by this way is simple and the modeling result of the articulated industrial robot is visual, believable and reliable.

scholarly journals Research of Calibration Method for Industrial Robot Based on Error Model of Position

2021 ◽  
Vol 11 (3) ◽  
pp. 1287
Author(s):  
Tianyan Chen ◽  
Jinsong Lin ◽  
Deyu Wu ◽  
Haibin Wu
Keyword(s):  
Coordinate System ◽  
Industrial Robot ◽  
Calibration Method ◽  
Error Model ◽  
Position Error ◽  
Industrial Robots ◽  
Positioning Error ◽  
Robot Position ◽  
General Measurement ◽  
Parameter Error

Based on the current situation of high precision and comparatively low APA (absolute positioning accuracy) in industrial robots, a calibration method to enhance the APA of industrial robots is proposed. In view of the "hidden" characteristics of the RBCS (robot base coordinate system) and the FCS (flange coordinate system) in the measurement process, a comparatively general measurement and calibration method of the RBCS and the FCS is proposed, and the source of the robot terminal position error is classified into three aspects: positioning error of industrial RBCS, kinematics parameter error of manipulator, and positioning error of industrial robot end FCS. The robot position error model is established, and the relation equation of the robot end position error and the industrial robot model parameter error is deduced. By solving the equation, the parameter error identification and the supplementary results are obtained, and the method of compensating the error by using the robot joint angle is realized. The Leica laser tracker is used to verify the calibration method on ABB IRB120 industrial robot. The experimental results show that the calibration method can effectively enhance the APA of the robot.

A simple and rapid calibration methodology for industrial robot based on geometric constraint and two-step error

2018 ◽  
Vol 45 (6) ◽  
pp. 715-721 ◽  
Author(s):  
Jiabo Zhang ◽  
Xibin Wang ◽  
Ke Wen ◽  
Yinghao Zhou ◽  
Yi Yue ◽  
...  
Keyword(s):  
Coordinate System ◽  
Large Scale ◽  
Industrial Robot ◽  
Geometric Constraint ◽  
Machining Process ◽  
Kinematic Parameters ◽  
Robot Calibration ◽  
Positioning Accuracy ◽  
Content Type ◽  
Rapid Calibration

Purpose The purpose of this study is the presentation and research of a simple and rapid calibration methodology for industrial robot. Extensive research efforts were devoted to meet the requirements of online compensation, closed-loop feedback control and high-precision machining during the flexible machining process of robot for large-scale cabin. Design/methodology/approach A simple and rapid method to design and construct the transformation relation between the base coordinate system of robot and the measurement coordinate system was proposed based on geometric constraint. By establishing the Denavit–Hartenberg model for robot calibration, a method of two-step error for kinematic parameters calibration was put forward, which aided in achievement of step-by-step calibration of angle and distance errors. Furthermore, KUKA robot was considered as the research object, and related experiments were performed based on laser tracker. Findings The experimental results demonstrated that the accuracy of the coordinate transformation could reach 0.128 mm, which meets the transformation requirements. Compared to other methods used in this study, the calibration method of two-step error could significantly improve the positioning accuracy of robot up to 0.271 mm. Originality/value The methodology based on geometric constraint and two-step error is simple and can rapidly calibrate the kinematic parameters of robot. It also leads to the improvement in the positioning accuracy of robot.

The Drawing Simulation for Configuration of the Articulated Industrial Robot Based on UG

2012 ◽  
Vol 591-593 ◽  
pp. 1633-1637
Author(s):  
Ping Liu ◽  
Wen Xia Wang
Keyword(s):  
Industrial Robot ◽  
Terminal Link ◽  
Relevant Object ◽  
Variable Element ◽  
Kinematical Parameters

This paper proposes a drawing simulating method by means of drawing out coordinated system and relevant object for every link of the articulated industrial robot in UG system. Because the structural and kinematical parameters are defined with variable element in UG system, the conFiguration of terminal link and other link are all simulated. It is appearance that the drawing course by this way is simple and the drawing result of the articulated industrial robot is visual, believable and reliable.

Research on Geometric Error Modeling and Compensation Method of CNC Precision Cylindrical Grinder Based on Differential Motion Matrix and Jacobian Matrix

2021 ◽  
Author(s):  
Jinwei Fan ◽  
Qian Ye
Keyword(s):  
Coordinate System ◽  
Jacobian Matrix ◽  
Geometric Error ◽  
Modeling Method ◽  
Error Modeling ◽  
Compensation Method ◽  
Machining Accuracy ◽  
Differential Motion ◽  
Function Fitting ◽  
Error Terms

Abstract In this paper, the geometric error modeling method of CNC cylindrical grinder based on the differential motion relationship between coordinate systems, the function fitting model method of basic geometric error terms based on cftool toolbox and the error compensation method based on Jacobian matrix are proposed. Firstly, the differential motion theory, which is widely used in the field of robot kinematics error modeling, is used to build the machine tool space machining error model of CNC cylindrical grinder. Different from the multi-body theory, this modeling method can clearly reflect the influence degree of each moving part on the grinding wheel cutter. Secondly, SJ6000 laser interferometer was used to measure and identify the geometric error terms of B2-K3032 CNC precision cylindrical grinder. MATLAB cftool toolbox was used to perform mathematical function fitting on the known error data, and the mathematical relationship between 24 geometric errors and machining instructions was found. Finally, combining with the 24 Sum of Sine function model, the known verticality error and position deviation, the differential motion matrix of each moving part in the tool coordinate system and the corresponding Jacobian matrix, the compensation quantity (dx dz db dc) of the comprehensive geometric error in the tool coordinate system by the CNC precision cylindrical grinder is obtained. In order to verify the feasibility of the above method, RA1000 series roundness meter was used to measure the radial circular runout error before and after the correction. The experimental results show that the precision of each shaft section is increased by 17.54%, 15.22%, 15.71%, 18.4%, 12.87%, respectively, and the average machining accuracy is increased by 15.948%. Therefore, the above methods are effective and reasonable for improving the precision of spindle workpieces, and can also be used for reference in the initial design stage of CNC cylindrical grinder manufacturing enterprises or improving the machining accuracy of existing machine tools.

The Method of the Computer Vision System Coordinate Transformation for an Industrial Robot for a Laser Welding Operation

2020 ◽  
Vol 21 (3) ◽  
pp. 166-173
Author(s):  
A. Y. Polivanov ◽  
Y. V. Ivanov ◽  
D. V. Kholin
Keyword(s):  
Computer Vision ◽  
Laser Welding ◽  
Coordinate System ◽  
Coordinate Transformation ◽  
Industrial Robot ◽  
Three Dimensional ◽  
Industrial Robots ◽  
Main Task ◽  
Welding Joint ◽  
Video Sensor

In this article, the authors consider the problem of coordinate transformation in computer vision systems (CVS) of robotic system (RS) for laser welding. Laser welding is a highly efficient technological operation in many respects superior to common types of welding due to the high concentration of energy at the welding point. However, laser welding has a number of requirements, including a high requirement for the accuracy of positioning the laser head relative to the welding joint. Adaptive control systems based on CVS allow to provide the required accuracy. The main task of CVS is to determine the three-dimensional coordinates of the welding joint using a video sensor, convert the received coordinates into a coordinate system in which the RS is controlled, and the converted coordinates are transferred to the control system. Note, the accuracy and determination of coordinates are important factors. To accomplish this task, it is necessary to consider the coordinate transformation as a set of actions performed taking into account the specifics of using CVS as part of an RS for laser welding. For this purpose, the article analyzes typical schemes for placing CVS on industrial robots and proposes the most suitable configuration for laser welding. A methodology was also developed for measuring the three-dimensional coordinates of the welding joint using the triangulation method. The authors carried out a comparative analysis of the main existing methods for calibrating CVS video sensors and proposed an original method for calibrating videosensors taking into account the specifics of the functioning of the RS for laser welding. As a result, the article presents the rationale for the need to consider coordinate conversion to CVS as part of an RS for laser welding, as well as a set of methods that allows to perform conversions from a virtual coordinate system of a video sensor to a coordinate system of a robot, which allows direct control based on CVS data. In conclusion, the authors give a method for calibrating a video sensor, which allows achieving the requirements specified in the article for the accuracy of determining the coordinates of the welding joint.

Kinematic Performance Evaluation for Heavy Duty Industrial Robot

2014 ◽  
Vol 940 ◽  
pp. 148-152
Author(s):  
S.Q. Li ◽  
Y.Y. Zou ◽  
Y.J. Li ◽  
Yan Jie Li
Keyword(s):  
Performance Evaluation ◽  
Coordinate System ◽  
Traditional Method ◽  
Industrial Robot ◽  
Experimental Results ◽  
Cartesian Coordinate System ◽  
Heavy Duty ◽  
Spherical Coordinate ◽  
Kinematic Performance ◽  
Cartesian Coordinate

Serial industrial robot has been widely used in assembly, welding, painting and other fields in which high kinematic performance is required. In this study, an non-contact approach for accuracy measuring is presented. Comparing with the traditional method based on spherical coordinate system, the approach presented in this study is based on the Cartesian coordinate system which has higher measuring accuracy. Furthermore, kinematic performance evaluation experiments for two types of industrial robot prototypes are proceeded. Experimental results testified that the accuracy of the target robot and proved the efficiency of the approach.

Using 3D Matching for Picking and Placing on UR Robot

2017 ◽  
Vol 870 ◽  
pp. 289-294 ◽  
Author(s):  
Hong Zhen Zhao ◽  
Gui Lin Yang ◽  
Chin Yin Chen
Keyword(s):  
Coordinate System ◽  
Industrial Robot ◽  
Special Method ◽  
Cad Model ◽  
Object Model ◽  
3D Object ◽  
3D Cad ◽  
Novel Method ◽  
Technology Users ◽  
The Given

Due to conventional industrial robot moving has been known that programing is either tedious or simplex and operating platform requires a pure environment without unnecessary distractions from other objects. This paper presents a novel method which using shape based 3Dmatching technology for picking and placing object by UR robot. This method is able to help the robot catch a specified object in any complex environment. To do this, we need only one camera and the targets' 3D CAD model. There are many efforts was indeed carried out in order to improve the control accuracy, first , the 3D coordinates of the interested points should be high-resolution calculated with the images that areprovided by the camera and we use a special method to optimize internal and external camera parameters when calibrating the camera, Then, A 3D-matching-operator is used to search for the specific objects in the real-time images based on the given 3D model, which is realized by projects the edges of the 3D object model that was used to create the 3D shape model into the image coordinate system and return projected edges. Finally, the coordinates of the 3D object model is obtained in the PTU coordinate system through the integration of a PTU and a Laser range finder , and a transformational matrix is obtained for calculate the coordinates of the targets on UR robot’s base coordinate system. Based on this technology, users only simply need to import a 3D CAD model and click on the image of the workplace to define the end point, the robot will exceed the procedure of pick and place automatically.

Digital mapping aerial camera – a measuring instrument

2018 ◽  
Vol 934 (4) ◽  
pp. 40-45 ◽  
Author(s):  
S.A. Kadnichanskiy ◽  
S.S. Nekhin ◽  
A.I. Spiridonov
Keyword(s):  
Coordinate System ◽  
Nodal Point ◽  
Image Sensor ◽  
Measurement Range ◽  
Measuring Instrument ◽  
Direction Vector ◽  
Interest Points ◽  
Frame Size ◽  
The Matrix ◽  
The Difference

The difference between the topographic digital aerial cameras and the analogue ones are analyzed. The first one allows considering a digital aerial camera as a means of measurement. A regular rectangular grid of pixels of digital aerial cameras image sensor is a two-dimensional scale with divisions equal to the physical size of the pixel. It allows determining the position of interest points of the image in the coordinate system of a matrix of pixels, the axis of which is directed along rows and columns of the matrix. Wherein the measured value for aerial cameras, should be considered as the coordinates of the vector pointing from the perspective center to the point of interest in the coordinate system of aerial cameras, the beginning of which is located at the front nodal point of the lens, and the Sz axis is directed along the principal ray. Exactly they are directly used in the solutions of photogrammetric tasks for determination of coordinates of the locality object point. The accuracy of the result of determining the coordinates depends on the accuracy of the coordinates of a direction vector and the accuracy of the exterior orientation parameters of aerial cameras (the image). Metrological characteristics of digital topographic aerial cameras should be considered measurement range (the frame size in pixels and pixel size) and the error of a measuring instrument (the error of the coordinates of a direction vector) as the accuracy characteristics and the parameters of calibration of aerial cameras, allowing to determine the measured values according to indications of measurements with estimates of the errors of the calibration parameters.

Study on Single-Axis Tracking PV System Measurement

2013 ◽  
Vol 724-725 ◽  
pp. 185-189
Author(s):  
Ying Hua Dong ◽  
Jing Sheng Huang ◽  
Mei Yin Liu ◽  
Lei Cao
Keyword(s):  
Coordinate System ◽  
Test Method ◽  
Experimental Results ◽  
Normal Vector ◽  
Direction Vector ◽  
Pv System ◽  
Pv Module ◽  
Precision Test ◽  
Test Uncertainty

In this paper, the precision test method of single-axis PV track device is proposed by analyzing generator mechanism of PV module. In the process of the rotation of single-axis track device, the change of corner in space is considered. Suitable coordinate system is built in order to evaluate track device precision which normal vector of PV module and solar direction vector can be decomposed in this coordinate system. Meanwhile, the comparison on the tracking precision of PV track devices tested by different devices is made and the test uncertainty is researched as well. Experimental results verify the effectiveness of the method which is proposed in this paper.

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