A Kinematic Model for Parallel-Joint Coordinate Measuring Machine

2013 ◽  
Vol 5 (4) ◽  
Author(s):  
Jie Li ◽  
Lian-Dong Yu ◽  
Jing-Qi Sun ◽  
Hao-Jie Xia
Keyword(s):  
Mathematical Modeling ◽  
Data Processing ◽  
Newton Method ◽  
Measurement Accuracy ◽  
Kinematic Model ◽  
Coordinate Measuring Machine ◽  
Experimental Results ◽  
Kinematic Modeling ◽  
Kinematic Parameters ◽  
Measuring Machine

The typical nonorthogonal coordinate measuring machine is the portable coordinate measuring machine (PCMM), which is widely applied in manufacturing. In order to improve the measurement accuracy of PCMM, structural designing, data processing, mathematical modeling, and identification of parameters of PCMM, which are essential for the measurement accuracy, should be taken into account during the machine development. In this paper, a kind of PCMM used for detecting the crucial dimension of automobile chassis has been studied and calibrated. The Denavit–Hartenberg (D–H) kinematic modeling method has often been used for modeling traditional robot, but the D–H error representation is ill-conditioned when it is applied to represent parallel joints. A modified four-parameter model combined with D–H model is put forward for this PCMM. Based on the kinematic model, Gauss–Newton method is applied for calibrating the kinematic parameters. The experimental results indicate the improvement of measuring accuracy and the effectiveness of the PCMM based on the proposed method.

Kinematic Modeling and Error Analysis for a 3DOF Parallel-Link Coordinate Measuring Machine

2006 ◽  
Vol 532-533 ◽  
pp. 313-316 ◽  
Author(s):  
De Jun Liu ◽  
Hua Qing Liang ◽  
Hong Dong Yin ◽  
Bu Ren Qian
Keyword(s):  
Kinematic Model ◽  
Coordinate Measuring Machine ◽  
Inverse Kinematic ◽  
Differential Method ◽  
Error Model ◽  
Structural Parameter ◽  
Kinematic Modeling ◽  
Position Errors ◽  
Measuring Machine ◽  
Parallel Link

First, the forward kinematic model, the inverse kinematic model and the error model of a kind of coordinate measuring machine (CMM) using 3-DOF parallel-link mechanism are established based on the spatial mechanics theory and the total differential method, and the error model is verified by computer simulation. Then, the influence of structural parameter errors on probe position errors is systematically considered. This research provides an essential theoretical basis for increasing the measuring accuracy of the parallel-link coordinate measuring machine. It is of particular importance to develop the prototype of the new measuring equipment.

Kinematic Modeling and Analysis of Articulated Arm Coordinate Measuring Machines

2012 ◽  
Vol 241-244 ◽  
pp. 494-497
Author(s):  
Guan Bin Gao ◽  
Wen Wang ◽  
Hong Qiang Li ◽  
Jian Jun Zhou
Keyword(s):  
Structural Characteristics ◽  
Structural Parameters ◽  
Kinematic Model ◽  
Coordinate Measuring Machine ◽  
Measurement Range ◽  
Kinematic Modeling ◽  
Modeling And Analysis ◽  
Graphical Simulation ◽  
Measuring Machine ◽  
Numerical Computing

The articulated arm coordinate measuring machine (AACMM) is a new type coordinate measuring machine (CMM) base on the linkage structure with the characteristics of small size, light weight, large measurement range and flexible movement. The kinematic modeling methods of six degree of freedom (6-DOF) AACMMs are studied in this paper. By analyzing the structural characteristics of AACMMs the kinematic model of a 6-DOF AACMM with DH method was established. From the kinematic model the coordinate systems and structural parameters of the AACMM are obtained. Then the homogeneous transformation matrixes from the probe to the base of the AACMM are derived. Finally, methods of numerical computing and graphical simulation are used in verifying the kinematic model. The kinematic model provides a basis for measurement, calibration and error compensation of the AACMM.

A new approach of kinematic geometry for error identification and compensation of industrial robots

2018 ◽  
Vol 233 (5) ◽  
pp. 1783-1794
Author(s):  
Zhi Wang ◽  
Huimin Dong ◽  
Shaoping Bai ◽  
Delun Wang
Keyword(s):  
Curve Fitting ◽  
Kinematic Model ◽  
Coordinate Measuring Machine ◽  
Reference Points ◽  
Industrial Robots ◽  
Kinematic Calibration ◽  
Kinematic Pair ◽  
Good Efficiency ◽  
New Approach ◽  
Measuring Machine

A new approach for kinematic calibration of industrial robots, including the kinematic pair errors and the link errors, is developed in this paper based on the kinematic invariants. In most methods of kinematic calibration, the geometric errors of the robots are considered in forms of variations of the link parameters, while the kinematic pairs are assumed ideal. Due to the errors of mating surfaces in kinematic pairs, the fixed and moving axes of revolute pairs, or the fixed and moving guidelines of prismatic pairs, are separated, which can be concisely identified as the kinematic pair errors and the link errors by means of the kinematic pair errors model, including the self-adaption fitting of a ruled surface, or the spherical image curve fitting and the striction curve fitting. The approach is applied to the kinematic calibration of a SCARA robot. The discrete motion of each kinematic pair in the robot is completely measured by a coordinate measuring machine. Based on the global kinematic properties of the measured motion, the fixed and moving axes, or guidelines, of the kinematic pairs are identified, which are invariants unrelated to the positions of the measured reference points. The kinematic model of the robot is set up using the identified axes and guidelines. The results validate the approach developed has good efficiency and accuracy.

scholarly journals Influence of measuring force on CMM accuracy

2018 ◽  
Vol 208 ◽  
pp. 03004
Author(s):  
Bin Wang
Keyword(s):  
Cross Sections ◽  
Measurement Accuracy ◽  
Coordinate Measuring Machine ◽  
Point Of View ◽  
Signal Acquisition ◽  
Force Model ◽  
Thin Part ◽  
Measuring Machine ◽  
The Relationship ◽  
Measuring Force

The measuring accuracy of CMM (Coordinate Measuring Machine) is influenced by many factors, such as temperature, humidity, measuring force and method of signal acquisition. For thin parts, the influence of measuring force is especially obvious. In this paper, the relationship between measuring force and measurement accuracy is studied for a thin part with a U-shaped cross-section. By analyzing the structure of the probe and establishing the force model, the influencing factors of the accuracy of CMM are obtained, and the influence of the contact deformation and the bending deformation on the measurement accuracy is analyzed from the point of view of material mechanics. At the same time, the measurement accuracy of different measuring cross-sections is analyzed. Through the research of this paper, the relationship between measuring force and CMM is established, and an effective method to improve the accuracy of CMM is also found.

Error Modeling and Analysis of Articulated Arm Coordinate Measuring Machines

2013 ◽  
Vol 798-799 ◽  
pp. 464-467
Author(s):  
Jian Lu ◽  
Guan Bin Gao ◽  
Hui Ping Yang
Keyword(s):  
Kinematic Model ◽  
Coordinate Measuring Machine ◽  
Calibration Method ◽  
Error Model ◽  
Error Modeling ◽  
Modeling And Analysis ◽  
Low Weight ◽  
New Type ◽  
Measuring Machine ◽  
Value Decomposition

The Articulated Arm Coordinate Measuring Machine (AACMM) is a new type of non-orthogonal system precision instrument with the advantages of large measuring range, small volume, low weight and portability. To improve the measurement accuracy of AACMMs, an error analysis and calibration method for AACMMs is proposed. The kinematic model of the AACMM was established with D-H model, and then the error model of the AACMM was established on the basis of kinematic model with total differential transforming method and the singular value decomposition of Jacobian matrix and the decomposition of orthogonal matrix elementary row transform. Finally, the error model was validated by position error residual calculation. The error model provides a theoretical foundation for calibration and compensation of the AACMM.

Modeling and Calibration of the Orthogonality Deviation between the "X" and "Y" Axes of Coordinate Measuring Machines

2018 ◽  
Vol 875 ◽  
pp. 84-88
Author(s):  
César Augusto Galvão de Morais ◽  
Marilia da Silva Bertolini ◽  
Benedito di Giacomo
Keyword(s):  
Mathematical Modeling ◽  
Coordinate Measuring Machine ◽  
Displacement Transducer ◽  
Linear Displacement ◽  
Calibration Data ◽  
Correct Operation ◽  
Compensation Plans ◽  
Main Plane ◽  
Productive Process ◽  
Measuring Machine

The increase of the quality in a productive process allows reduction of costs besides adding value to the product. When manufacturing a product within the tolerances specified in the design it is possible to obtain a correct operation of this product, ensuring the minimum time of use and with a lower risk of early failure. In this sense, machines and equipments involved in the manufacturing and inspection processes must also maintain an acceptable quality of operation by knowing the errors present in the machine structure through the calibration, such as errors due to lack of orthogonality between the axes, caused by inaccurate assemblies. The calibration errors in these machines allow elaborate error compensation plans and thus improve the rate of flawless products in production. The objective of this paper was to identify the influence of errors due to a lack of orthogonality in a bridge type coordinate measuring machine (CMM) through calibration and mathematical modeling of errors. Error calibration is performed with a linear displacement transducer, a granite square and a set support brackets for the granite square. By means of the calibration data and the mathematical modeling of the orthogonality deviation an influence of the measured deviation on the "X" and "Y" directions of the CMM is obtained. The error due to the lack of orthogonality between the "X" and "Y" axes of the CMM was approximately 8.9558 negative arcoseg; in this way, it is evidenced that the angle formed between these axes is 89.9975°. Through this study it can be concluded that orthogonality deviation in the main plane of the machine produces negative components for the axes "X" and "Y", with higher influence on the points collected as it away from machine scales, making greater the error intensity on the results of measurements made at positions farthest from the "X" and "Y" scales.

scholarly journals A New Kinematic Model of Portable Articulated Coordinate Measuring Machine

2016 ◽  
Vol 6 (7) ◽  
pp. 181 ◽  
Author(s):  
Hui-Ning Zhao ◽  
Lian-Dong Yu ◽  
Hua-Kun Jia ◽  
Wei-Shi Li ◽  
Jing-Qi Sun
Keyword(s):  
Kinematic Model ◽  
Coordinate Measuring Machine ◽  
Measuring Machine

Hardware Design of a Planar Platform for Naro-CMM

2013 ◽  
Vol 706-708 ◽  
pp. 1146-1149
Author(s):  
Hui Zhi Sun
Keyword(s):  
Hardware Design ◽  
Coordinate Measuring Machine ◽  
Modern Technology ◽  
Experimental Results ◽  
Power Module ◽  
Positioning Accuracy ◽  
Technology Platform ◽  
Fast Development ◽  
Measuring Machine ◽  
Planar Mode

Nanometer three Coordinate Measuring Machine (Naro-CMM) has got fast development especially in the advancement of modern technology. Platform is an important part of the Naro-CMM, paper puts forward a new way to drive platform. “Planar” mode is adopted, and the power module is designed based on L6234PD, the experimental results express that the positioning accuracy of the platform reaches nanometer accuracy. So the drive method satisfied the demand of this platform’s movement.

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