Kinematic Identification of Industrial Robot using End-effector Mounted Monocular Camera bypassing Measurement of 3D Pose

Author(s):  
Riby Abraham Boby
2021 ◽  
Author(s):  
Daiki Kato ◽  
Kenya Yoshitugu ◽  
Naoki Maeda ◽  
Toshiki Hirogaki ◽  
Eiichi Aoyama ◽  
...  

Abstract Most industrial robots are taught using the teaching playback method; therefore, they are unsuitable for use in variable production systems. Although offline teaching methods have been developed, they have not been practiced because of the low accuracy of the position and posture of the end-effector. Therefore, many studies have attempted to calibrate the position and posture but have not reached a practical level, as such methods consider the joint angle when the robot is stationary rather than the features during robot motion. Currently, it is easy to obtain servo information under numerical control operations owing to the Internet of Things technologies. In this study, we propose a method for obtaining servo information during robot motion and converting it into images to find features using a convolutional neural network (CNN). Herein, a large industrial robot was used. The three-dimensional coordinates of the end-effector were obtained using a laser tracker. The positioning error of the robot was accurately learned by the CNN. We extracted the features of the points where the positioning error was extremely large. By extracting the features of the X-axis positioning error using the CNN, the joint 1 current is a feature. This indicates that the vibration current in joint 1 is a factor in the X-axis positioning error.


2019 ◽  
Vol 299 ◽  
pp. 05005
Author(s):  
Melania Tera ◽  
Claudia–Emilia Gîrjob ◽  
Cristina–Maria Biriș ◽  
Mihai Crenganiș

Incremental forming can be usually unfolded either on CNC milling machine–tools or serial industrial robots. The approach proposed in this paper tackles the problem of designing a modular fastening system, which can be adapted for both above mentioned technological equipment. The fastening system of the sheet–metal workpiece is composed of a fixing plate and a retaining plate. The fixing and retaining plates will be made up of different individual elements, which can be easily repositioned to obtain different sizes of the part. Moreover, the fastening system has to be able to be positioned either horizontally (to be fitted on CNC milling machines) or vertically (to be fitted on industrial robots. The paper also presents the design of a tool–holder working unit which will be fitted on KUKA KR 210 industrial robot. The working unit will be mounted as end–effector of the robot and will bear the punch, driving it on the processing toolpaths.


2018 ◽  
Vol 15 (4) ◽  
pp. 172988141878791 ◽  
Author(s):  
Sepehr Gharaaty ◽  
Tingting Shu ◽  
Ahmed Joubair ◽  
Wen Fang Xie ◽  
Ilian A Bonev

In this article, a dynamic pose correction scheme is proposed to enhance the pose accuracy of industrial robots. The dynamic pose correction scheme uses the dynamic pose measurements as feedback to accurately guide the robot end-effector to the desired pose. The pose is measured online with an optical coordinate measure machine, that is, C-Track 780 from Creaform. A root mean square method is proposed to filter the noise from the pose measurements. The dynamic pose correction scheme adopts proportional-integral-derivaitve controller and generates commands to the FANUC robot controller. The developed dynamic pose correction scheme has been tested on two industrial robots, FANUC LR Mate 200iC and FANUC M20iA. The experimental results on both robots demonstrate that the robots can reach the desired pose with an accuracy of ±0.050 mm for position and ±0.050° for orientation. As a result, the developed pose correction can make the industrial robots meet higher accuracy requirement in the applications such as riveting, drilling, and spot welding.


2014 ◽  
Vol 592-594 ◽  
pp. 2134-2138
Author(s):  
S.K. Naveen ◽  
Kumaar Devaraj Rajesh ◽  
P. Pal Pandian

Flexibility plays a key role in robot based applications, where the ability to perform complex tasks in semi structured or even unstructured environments is strategic.Most industrial robot operates inside a security fence which separates them from human workers, but not all. Flexibility, lightness in relation to the mass to be displaced and energy efficiency are acquiring increasing significance in automation. We can achieve higher performance in robots by optimizing the parameters like high-speed operation, lower energy consumption, lighter weight and safer operation. In this paper a pick and place robot is designed and developed to achieve effective automation with higher safety and with greater ease. The main objectives of designing this flexible manipulator are to reduce its mass and to minimize its vibrations in the end-effector, which enhances good accuracy in positioning.This can be achieved by bringing down the number of working components and jointswhich reduce various losses. The greater mass can be transferred from one place to another place with relatively lesser mass of flexible three link manipulator. The various problems were encountered and rectified during the design and fabrication of flexible three link manipulator for pick and place application.


1984 ◽  
Vol 106 (3) ◽  
pp. 371-375 ◽  
Author(s):  
F. Freudenstein ◽  
R. W. Longman ◽  
C.-K. Chen

A general procedure has been developed for the kinematic analysis of complex bevel-gear trains in which the motion of the arm can be of mobility two or greater (i.e. the arm can rotate about two or more nonparallel, intersecting axes). The analysis of a three-degree-of-freedom gear train used in guiding the motion of the end effector of a recently developed industrial robot is described in detail.


2010 ◽  
Vol 22 (1) ◽  
pp. 100-111 ◽  
Author(s):  
Yukiyasu Domae ◽  
◽  
Haruhisa Okuda ◽  
Yasuo Kitaaki ◽  
Yuta Kimura ◽  
...  

We have constructed 3-D sensing system for alignment of connector-fitted cables as flexible linear objects which used to be difficult to be automated at the production sites. In the system an industrial robot has a 3-D sensor and a monocular camera mounted at the hand. 3-D sensor, using space encoding method, allows the robot to make high-precision measurements of the order of sub-millimeters, but emphasis is placed on precision at the expense of fields of view. In addition, active sensing methods such as the space encoding method is hard to take measurements for black cables, as well as it has some difficulties with measurements of semitransparent plastic connectors depending on view-points. To cope with those problems, our system is such that the monocular camera on the robot is moved for motion stereo to take measurements on cable shapes; connector’s poses are coarsely estimated from the measurement results; and such view-points as will ensure stable measurements are computed by space encoding method to take precision measurements of connectors. Technical features of the system could be summarized as follows: 1) Determination of view-points to measure connectors, based on measurements of cable shapes, requires no more than two measurements, without repeated searches, to grab semitransparent plastic connectors. 2) Performance of stereo correspondence for plain or black cables, which tends to result in a failure with the aids of no more than irradiated slit patterns and epipolar constraints, has been improved through sequential correspondence inmotion image sequence and its stability evaluations. At the operation tests in the validation system, the robot is assigned a task to assemble the cables into industrial servo amplifiers available on the market, in which automatic alignment of 200 connector-fitted cables has successfully been accomplished in succession to confirm constant performance of the system.


Robotica ◽  
2015 ◽  
Vol 34 (12) ◽  
pp. 2689-2728 ◽  
Author(s):  
Feng Han ◽  
Kui Sun ◽  
Yu Liu ◽  
Hong Liu

SUMMARYTwo identical end-effectors are indispensable for self-relocation of a space manipulator, which is an effective way of extending its servicing capability. The prototype design is intimately linked to the requirements. The significant features and functionality of the end-effector and its grapple fixture are described, including the key analysis efforts. The characteristics of the end-effector and their suitability for self-relocation and payload handling were confirmed by testing, which used two prototype end-effectors, a semi-physical simulation testbed system with two, six degrees of freedom (DOF) industrial robot arms, and an air-bearing testbed system with a seven DOF manipulator. The results demonstrate that the end-effector satisfies the requirements and it can work well in a simulated space environment. With the compliance motion of the manipulator, the end-effector can perform soft capture and the manipulator can securely self-relocate and handle the payload.


Robotica ◽  
2013 ◽  
Vol 32 (3) ◽  
pp. 447-466 ◽  
Author(s):  
Albert Nubiola ◽  
Mohamed Slamani ◽  
Ahmed Joubair ◽  
Ilian A. Bonev

SUMMARYThe absolute accuracy of a small industrial robot is improved using a 30-parameter calibration model. The error model takes into account a full kinematic calibration and five compliance parameters related to the stiffness in joints 2, 3, 4, 5, and 6. The linearization of the Jacobian is performed to iteratively find the modeled error parameters. Two coordinate measurement systems are used independently: a laser tracker and an optical CMM. An optimized end-effector is developed specifically for each measurement system. The robot is calibrated using fewer than 50 configurations and the calibration efficiency validated in 1000 configurations using either the laser tracker or the optical CMM. A telescopic ballbar is also used for validation. The results show that the optical CMM yields slightly better results, even when used with the simple triangular plate end-effector that was developed mainly for the laser tracker.


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