scholarly journals Self-Calibration of an Industrial Robot Using a Novel Affordable 3D Measuring Device

Sensors ◽  
2018 ◽  
Vol 18 (10) ◽  
pp. 3380 ◽  
Author(s):  
Martin Gaudreault ◽  
Ahmed Joubair ◽  
Ilian Bonev
Keyword(s):  
Industrial Robot ◽  
Low Cost ◽  
Least Square Method ◽  
Calibration Method ◽  
Least Square ◽  
Geometrical Parameters ◽  
Robot Arm ◽  
Measuring Device ◽  
Self Calibration ◽  
Position Errors

This work shows the feasibility of calibrating an industrial robot arm through an automated procedure using a new, low-cost, wireless measuring device mounted on the robot’s flange. The device consists of three digital indicators that are fixed orthogonally to each other on an aluminum support. Each indicator has a measuring accuracy of 3 µm. The measuring instrument uses a kinematic coupling platform which allows for the definition of an accurate and repeatable tool center point (TCP). The idea behind the calibration method is for the robot to bring automatically this TCP to three precisely-known positions (the centers of three precision balls fixed with respect to the robot’s base) and with different orientations of the robot’s end-effector. The self-calibration method was tested on a small six-axis industrial robot, the ABB IRB 120 (Vasteras, Sweden). The robot was modeled by including all its geometrical parameters and the compliance of its joints. The parameters of the model were identified using linear regression with the least-square method. Finally, the performance of the calibration was validated with a laser tracker. This validation showed that the mean and the maximum absolute position errors were reduced from 2.628 mm and 6.282 mm to 0.208 mm and 0.482 mm, respectively.

scholarly journals DOA Estimation and Self-Calibration under Unknown Mutual Coupling

Sensors ◽  
2019 ◽  
Vol 19 (4) ◽  
pp. 978
Author(s):  
Dong Qi ◽  
Min Tang ◽  
Shiwen Chen ◽  
Zhixin Liu ◽  
Yongjun Zhao
Keyword(s):  
Mutual Coupling ◽  
Linear Equations ◽  
Least Square Method ◽  
Calibration Method ◽  
Least Square ◽  
Frequency Distributions ◽  
Steering Vector ◽  
Practical Applications ◽  
Time Frequency ◽  
Self Calibration

In practical applications, the assumption of omnidirectional elements is not effective in general, which leads to the direction-dependent mutual coupling (MC). Under this condition, the performance of traditional calibration algorithms suffers. This paper proposes a new self-calibration method based on the time-frequency distributions (TFDs) in the presence of direction-dependent MC. Firstly, the time-frequency (TF) transformation is used to calculate the space-time-frequency distributions (STFDs) matrix of received signals. After that, the estimated steering vector and corresponding noise subspace are estimated by the steps of noise removing, single-source TF points extracting and clustering. Then according to the transformation relationship between the MC coefficients, steering vector and MC matrix, we deduce a set of linear equations. Finally, with two-step alternating iteration, the equations are solved by least square method in order to estimate DOA and MC coefficients. Simulations results show that the proposed algorithm can achieve direction-dependent MC self-calibration and outperforms the existing algorithms.

scholarly journals New Method and Portable Measurement Device for the Calibration of Industrial Robots

Sensors ◽  
2020 ◽  
Vol 20 (20) ◽  
pp. 5919
Author(s):  
Caglar Icli ◽  
Oleksandr Stepanenko ◽  
Ilian Bonev
Keyword(s):  
Industrial Robot ◽  
Calibration Method ◽  
Industrial Robots ◽  
Laser Tracker ◽  
Calibration Model ◽  
Measuring Device ◽  
End Effector ◽  
New Device ◽  
Position Errors ◽  
Measuring Machine

This paper presents an automated calibration method for industrial robots, based on the use of (1) a novel, low-cost, wireless, 3D measuring device mounted on the robot end-effector and (2) a portable 3D ball artifact fixed with respect to the robot base. The new device, called TriCal, is essentially a fixture holding three digital indicators (plunger style), the axes of which are orthogonal and intersect at one point, considered to be the robot tool center point (TCP). The artifact contains four 1-inch datum balls, each mounted on a stem, with precisely known relative positions measured on a Coordinate Measuring Machine (CMM). The measurement procedure with the TriCal is fully automated and consists of the robot moving its end-effector in such as a way as to perfectly align its TCP with the center of each of the four datum balls, with multiple end-effector orientations. The calibration method and hardware were tested on a six-axis industrial robot (KUKA KR6 R700 sixx). The calibration model included all kinematic and joint stiffness parameters, which were identified using the least-squares method. The efficiency of the new calibration system was validated by measuring the accuracy of the robot after calibration in 500 nearly random end-effector poses using a laser tracker. The same validation was performed after the robot was calibrated using measurements from the laser tracker only. Results show that both measurement methods lead to similar accuracy improvements, with the TriCal yielding maximum position errors of 0.624 mm and mean position errors of 0.326 mm.

Self-Calibration of Eye-to-Hand and Workspace for Mobile Service Robot

2012 ◽  
pp. 229-246
Author(s):  
Jwu-Sheng Hu ◽  
Yung-Jung Chang
Keyword(s):  
Visual Information ◽  
Calibration Method ◽  
Industrial Robots ◽  
Service Robots ◽  
Service Robot ◽  
Mobile Service ◽  
Robot Arm ◽  
Self Calibration ◽  
Laser Distance Sensor ◽  
Distance Sensor

The geometrical relationships among robot arm, camera, and workspace are important to carry out visual servo tasks. For industrial robots, the relationships are usually fixed and well calibrated by experienced operators. However, for service robots, particularly in mobile applications, the relationships might be changed. For example, when a mobile robot attempts to use the visual information from environmental cameras to perform grasping, it is necessary to know the relationships before taking actions. Moreover, the calibration should be done automatically. This chapter proposes a self-calibration method using a laser distance sensor mounted on the robot arm. The advantage of the method, as compared with pattern-based one, is that the workspace coordinate is also obtained at the same time using the projected laser spot. Further, it is not necessary for the robot arm to enter the view scope of the camera for calibration. This increases the safety when the workspace is unknown initially.

scholarly journals Cylindricity Error Measuring and Evaluating for Engine Cylinder Bore in Manufacturing Procedure

2016 ◽  
Vol 2016 ◽  
pp. 1-7
Author(s):  
Qiang Chen ◽  
Xueheng Tao ◽  
Jinshi Lu ◽  
Xuejun Wang
Keyword(s):  
Least Square Method ◽  
Least Square ◽  
Zone Method ◽  
Method Error ◽  
Measuring Device ◽  
Engine Cylinder ◽  
Minimum Zone ◽  
Cylinder Method ◽  
Cylinder Bore ◽  
Cylindricity Error

On-line measuring device of cylindricity error is designed based on two-point method error separation technique (EST), which can separate spindle rotation error from measuring error. According to the principle of measuring device, the mathematical model of the minimum zone method for cylindricity error evaluating is established. Optimized parameters of objective function decrease to four from six by assuming thatcis equal to zero andhis equal to one. Initial values of optimized parameters are obtained from least square method and final values are acquired by the genetic algorithm. The ideal axis of cylinder is fitted in MATLAB. Compared to the error results of the least square method, the minimum circumscribed cylinder method, and the maximum inscribed cylinder method, the error result of the minimum zone method conforms to the theory of error evaluation. The results indicate that the method can meet the requirement of engine cylinder bore cylindricity error measuring and evaluating.

scholarly journals How To Build Customer Loyalty: Through Customer Experience, Perceived Price, And Customer Satisfaction

2021 ◽  
Vol 12 (4) ◽  
pp. 1546-1554
Author(s):  
Edhie Budi Setiawan, Et. al.
Keyword(s):  
Customer Satisfaction ◽  
Customer Loyalty ◽  
Structural Equation ◽  
Low Cost ◽  
Least Square Method ◽  
Customer Experience ◽  
Partial Least Square ◽  
Least Square ◽  
Perceived Price ◽  
The Impact

The competition to get the highest Market Share among Low-Cost Carrier airlines in Indonesia is getting fierce. Airlines are competing to offer prices that are appropriate for passengers to perceive them in this era of tariff wars. The degree of satisfaction that is felt is needed to get loyal customers. The purpose of this research is to analyze the impact of customer experience and perceived price on customer loyalty through customer satisfaction. The method of analysis in this study uses the SEM-PLS (Structural Equation Model - Partial Least Square) method with 250 respondents taken by purposive sampling. The result of this research is there is effect positive and significant between customer experience on customer satisfaction and customer loyalty, also there is effect of perceived price on customer satisfaction and customer loyalty. Airlines must pay attention to the services provided to create a memorable experience for passengers and adjust prices to be accepted by passengers.

scholarly journals The tides in the south-western Kara sea. Tides calibration method effects

2017 ◽  
pp. 98-115
Author(s):  
G. N. Voinov ◽  
A. K. Naumov
Keyword(s):  
Sea Level ◽  
Least Square Method ◽  
Calibration Method ◽  
Kara Sea ◽  
Least Square ◽  
The South ◽  
Quality Estimation ◽  
Annual Series ◽  
Method Effects ◽  
Statistical Estimations

The estimates of the tides harmonic constants are given over the period from 1962 to 1993. They were received using a least square method according to AARI. Quality estimation of the sea level observations was performed. The annual series with bad observations were transformed by means of tides calibration. The Estimation of the tides fi ne structure – harmonics of the second and third degree of the potential according to analysis over the period from 1962–1985 was received. The statistical estimations of the sea level in the separate typical years were calculated using initial and corrected series.

A self-calibration method with high-accuracy and low-cost for large-area motion stage based on digital grating projection mode

2019 ◽  
Vol 12 (12) ◽  
pp. 126503
Author(s):  
Shengzhou Huang ◽  
Mujun Li ◽  
Lei Wang ◽  
Yongsheng Su ◽  
Yi Liang
Keyword(s):  
Low Cost ◽  
Calibration Method ◽  
High Accuracy ◽  
Large Area ◽  
Self Calibration ◽  
Motion Stage

Camera Calibration Based on Snell’s Law

2005 ◽  
Vol 128 (3) ◽  
pp. 548-557 ◽  
Author(s):  
Psang Dain Lin ◽  
Chi-Kuen Sung
Keyword(s):  
Camera Calibration ◽  
Least Square Method ◽  
Calibration Method ◽  
Least Square ◽  
Camera System ◽  
Optical Elements ◽  
Snell’S Law ◽  
Snell's Law ◽  
Geometric Relationship ◽  
Pinhole Model

In this paper we present a camera calibration method using Snell’s Law. Traditional camera calibration is based on the pinhole model, which is an approximation algorithm using untrue geometrical assumptions and giving a single lumped result for the various optical elements in the camera system. Using full modeling of lens geometry, the proposed method establishes the geometric relationship between images and objects via Snell’s Law. A matrix equation that relates the intrinsic/extrinsic parameters of image the plane and six pose parameters of each element is determined from sensitivity analysis. These parameters can be identified using the least square method by observing points with known coordinates. An illustrative example using a two-camera stereo coordinate measurement system demonstrates that system performance via the proposed method is better than the pinhole model.

Study on Two-Step Method for Robot Dynamics Parameters Calibration

2012 ◽  
Vol 605-607 ◽  
pp. 1557-1562 ◽  
Author(s):  
Qing Xuan Jia ◽  
Tong Li ◽  
Gang Chen
Keyword(s):  
Inverse Method ◽  
Least Square Method ◽  
Calibration Method ◽  
Least Square ◽  
Second Step ◽  
Robot Dynamics ◽  
Joint Movement ◽  
Step Method ◽  
Multidimensional Matrix ◽  
Pseudo Inverse

In order to obtain accurate dynamics parameters, a two-step method for robot dynamics parameters calibration is presented. In the first step a multidimensional matrix is constituted through transforming the configurations of robot manipulators and the product of quality and centroid coordinate about links is solved by using the least square method. In the second step decoupling dynamic equation of robot is deduced based on Newton-Euler algorithm, and through planning specific joint movement, the inertia tensor and centroid coordinate of robot links are calibrated making use of the pseudo inverse method. By the above two steps, the entire calibration of robot dynamic parameters is achieved. The correctness and feasibility of the presented calibration method is manifested by simulations and experiments.

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