Auto-Calibration for Vision-Based 6-D Sensing System to Support Monitoring and Health Management for Industrial Robots

2021 ◽  
Author(s):  
Guixiu Qiao ◽  
Guangkun Li
Keyword(s):  
High Precision ◽  
Health Management ◽  
Calibration Method ◽  
Industrial Robots ◽  
Smart Manufacturing ◽  
Robot Arm ◽  
Sensing System ◽  
Robot Accuracy ◽  
Robot Machining ◽  
Machining Robot

Abstract Industrial robots play important roles in manufacturing automation for smart manufacturing. Some high-precision applications, for example, robot drilling, robot machining, robot high-precision assembly, and robot inspection, require higher robot accuracy compared with traditional part handling operations. The monitoring and assessment of robot accuracy degradation become critical for these applications. A novel vision-based sensing system for 6-D measurement (six-dimensional x, y, z, yaw, pitch, and roll) is developed at the National Institute of Standards and Technology (NIST) to measure the dynamic high accuracy movement of a robot arm. The measured 6-D information is used for robot accuracy degradation assessment and improvement. This paper presents an automatic calibration method for a vision-based 6-D sensing system. The stereo calibration is separated from the distortion calibration to speed up the on-site adjustment. Optimization algorithms are developed to achieve high calibration accuracy. The vision-based 6-D sensing system is used on a Universal Robots (UR5) to demonstrate the feasibility of using the system to assess the robot’s accuracy degradation.

Industrial part localization and grasping using a robotic arm guided by 2D monocular vision

2018 ◽  
Vol 45 (6) ◽  
pp. 794-804 ◽  
Author(s):  
Zhaohui Zheng ◽  
Yong Ma ◽  
Hong Zheng ◽  
Yu Gu ◽  
Mingyu Lin
Keyword(s):  
Camera Calibration ◽  
High Precision ◽  
Calibration Method ◽  
Monocular Vision ◽  
Robotic Arm ◽  
Robot Arm ◽  
Content Type ◽  
Calibration Algorithm ◽  
Target Locating ◽  
Practical Implications

Purpose The welding areas of the workpiece must be consistent with high precision to ensure the welding success during the welding of automobile parts. The purpose of this paper is to design an automatic high-precision locating and grasping system for robotic arm guided by 2D monocular vision to meet the requirements of automatic operation and high-precision welding. Design/methodology/approach A nonlinear multi-parallel surface calibration method based on adaptive k-segment master curve algorithm is proposed, which improves the efficiency of the traditional single camera calibration algorithm and accuracy of calibration. At the same time, the multi-dimension feature of target based on k-mean clustering constraint is proposed to improve the robustness and precision of registration. Findings A method of automatic locating and grasping based on 2D monocular vision is provided for robot arm, which includes camera calibration method and target locating method. Practical implications The system has been integrated into the welding robot of an automobile company in China. Originality/value A method of automatic locating and grasping based on 2D monocular vision is proposed, which makes the robot arm have automatic grasping function, and improves the efficiency and precision of automatic grasp of robot arm.

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.

Modelling of Cutting Force and Robot Load during Machining

2014 ◽  
Vol 1036 ◽  
pp. 715-720 ◽  
Author(s):  
Grzegorz Gołda ◽  
Adrian Kampa
Keyword(s):  
Cutting Force ◽  
Dimensional Space ◽  
Mechanistic Model ◽  
Soft Materials ◽  
Industrial Robots ◽  
Robot Arm ◽  
Skilled Workers ◽  
Robot Machining ◽  
Sharp Edges ◽  
Robot Selection

Industrial robots are used for many tasks, mainly for material handling, welding and cutting. Robots can be also equipped with other tools for example drill or mill cutter and used for machining. Compared to conventional machines, robots have some advantages, which are: large range, flexibility and speed. On the other hand the greater disadvantage is small stiffness of robotic arms. Also the precision of robot positioning is smaller than modern CNC machines. Nowadays small number of robots are used mainly for machining of soft materials, such as plastic, wood, foam and aluminium. We have also executed some experiments with robot machining including styrodur milling. This technique is similar to rapid prototyping technics. Obtained parts can be used as prototypes. Robots can be used also for machining of hard materials and steel, but that is related with greater cutting force. Thanks they flexibility robots can be used for tasks that are performed by hand by locksmiths. An example of deburring and chamfering of sharp edges were analysed. The burrs and sharp edges that remains after some machining operations must be removed. In most cases that is done by chamfering the edges with hand tools. That tasks requires skilled workers and is physically exhausting and therefore industrial robots can be used to perform that work. But the first problem is prediction of cutting force and selection of proper robot with adequate payload. A mechanistic model of cutting force during milling a chamfer on the edge is presented in the article. Obtained results are similar with other experimental results that are described in the analysed bibliography. Afterwards a methodology for robot selection is explained. Because robot manufacturers give only data for static payload of robot arm, there must be a way to take into account the dynamic cutting force. Some problems that are possible during robot machining are discussed, and some solution are proposed. Because milling force is not constant and still subsequently changes value and direction, it can be the source of vibration. Small stiffness of robot arm combined with vibrations can caused losing of robot position and improper surface after machining. Other problem can be robot programming for machining of curved surfaces in 3 dimensional space. There are same CAM system that can be used for that purpose. Results obtained with developed model can be used for design of robotic cell for chamfering and milling.   Normal 0 21 false false false PL X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:Standardowy; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Times New Roman","serif";}

INTRODUCTION TO THE SPECIAL MILLENNIUM ISSUE ON GRASPING AND MANIPULATING

Robotica ◽  
2000 ◽  
Vol 18 (1) ◽  
pp. 1-2 ◽  
Author(s):  
Sugaru Arimoto
Keyword(s):  
20Th Century ◽  
High Precision ◽  
Industrial Robots ◽  
Degree Of Freedom ◽  
The Other ◽  
Robot Hand ◽  
Robot Arm ◽  
Industrial Automation ◽  
Robot Technology ◽  
Very High

At the end of the 20th century robot technology became well established as a reliable and economic source in industrial automation. On the other hand, it is claimed that even a general six or seven degree of freedom robot arm or a multifingered robot hand designed carefully and manufactured with very high precision lacks versatility in its use in a variety of tasks that must be done instead of a human. The lack of versatility or the clumsiness of present industrial robots is not due to the fine mechanism of such robots. Rather, the clumsiness shows a lack of our knowledge of everyday physics, in particular, a lack of knowledge of physics involving grasping and handling of various kinds of things and manipulating them with certain dexterity, in which tactile and vision sensings must be well coordinated.

Dynamic Simulation of the Six Axis Machining Robot for Trajectory Planning in CATIA-LMS

2012 ◽  
Vol 163 ◽  
pp. 74-78
Author(s):  
Yi Luo ◽  
Olivier Gibaru ◽  
Adel Olabi
Keyword(s):  
Dynamic Simulation ◽  
Trajectory Planning ◽  
Machine Tools ◽  
Industrial Robots ◽  
Machining Accuracy ◽  
Aluminum Castings ◽  
Robot Machining ◽  
Machining Robot ◽  
Low Stiffness ◽  
Stiff Joint

Nowadays six axis machining robots are widely used in many fields of industry. Compared to machine tools, industrial robots offer a cheaper yet more flexible alternative to the machine-tools in the cleaning and pre-machining applications of aluminum castings. But the low stiffness has limited the application of industrial robots to the machining tasks with very low precision requirement. This paper presents a practical approach to improve the robot-machining accuracy by developing an off line simulation tool. Firstly we will complete the dynamic simulation of the 6-axis stiff model in CATIA-LMS for trajectory planning. Secondly we will set flexible joints and balancing system for the industry machining robot in LMS. Finally we will make some compare with the position trajectories generated by flexible joint and stiff joint, and then adjust the parameters under the references of the simulation result before the industry machining.

scholarly journals Analysis of the Compliance Properties of an Industrial Robot with the Mozzi Axis Approach

Robotics ◽  
2019 ◽  
Vol 8 (3) ◽  
pp. 80 ◽  
Author(s):  
Doria ◽  
Cocuzza ◽  
Comand ◽  
Bottin ◽  
Rossi
Keyword(s):  
Industrial Robot ◽  
Industrial Robots ◽  
Robotic Assembly ◽  
Robot Arm ◽  
Machined Surface ◽  
End Effector ◽  
Chatter Vibrations ◽  
Modes Of Vibration ◽  
Machining Robot ◽  
Robot Performance

In robotic processes, the compliance of the robot arm plays a very important role. In some conditions, for example, in robotic assembly, robot arm compliance can compensate for small position and orientation errors of the end-effector. In other processes, like machining, robot compliance may generate chatter vibrations with an impairment in the quality of the machined surface. In industrial robots, the compliance of the end-effector is chiefly due to joint compliances. In this paper, joint compliances of a serial six-joint industrial robot are identified with a novel modal method making use of specific modes of vibration dominated by the compliance of only one joint. Then, in order to represent the effect of the identified compliances on robot performance in an intuitive and geometric way, a novel kinematic method based on the concept of “Mozzi axis” of the end-effector is presented and discussed.

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

Robotics ◽  
2013 ◽  
pp. 1482-1499
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.

On-line self-calibration method for unattended manipulators based on Gaussian motion model and visual system

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Ruolong Qi ◽  
Yuangui Tang ◽  
Ke Zhang
Keyword(s):  
Visual System ◽  
High Precision ◽  
Measurement Errors ◽  
Structural Parameters ◽  
Space Station ◽  
Calibration Method ◽  
Nuclear Industry ◽  
Industrial Robots ◽  
Content Type ◽  
On Line

Purpose For some special manipulators such as the ones work at the space station, nuclear or some other unmanned environments, the overload, collision, vibration, temperature change or release of the internal stress would affect the structural parameters. And thus the operation precision might constantly decrease in long-term use. In these unmanned environments, the unattended manipulators should calibrate itself when they execute high precision operations or proceed self-maintenances. The purpose of this paper is to propose an automatic visual assistant on-line calibration (AVOC) method based on multi-markers. Design/methodology/approach A camera fixed on the end of the manipulator is used to measure one to three identification points, which forms an unstable multi-sensor eye-in-hand system. A Gaussian motion method which combines the linear quadratic regulator control and extended Kalman filter together is proposed to make the manipulator track the planned trajectories when its inaccurate structural parameters form uncertain motion errors. And a Monte-Carlo method is proposed to form a high precision and stable signal acquisition when the visual system has measurement errors and intermittent signal feedback. An automatic sampling process is adopted to select the optimal measurement points basing on their variances. Findings Data analysis and experiment results prove the efficiency and feasibility of the method proposed in this paper. With this method, the positioning accuracy is largely promoted from about 2 mm to 0.04–0.05 mm. Originality/value Experiments were carried out successfully on a manipulator in a life sciences glove box that will work at the Chinese space station. It is a low cost and efficient manipulator calibration method. The whole autonomic calibration process takes less than 10 min and requires no human intervention. In addition, this method not only can be used in the calibration of other unmanned articulated manipulator that works in deep ocean, nuclear industry or space but also be useful for the maintenance work in modern factories owing a lot of industrial robots.

Integration of Cutting Robot with CAD/CAM System Based on STEP-NC

2017 ◽  
Vol 868 ◽  
pp. 93-98 ◽  
Author(s):  
Li Jin Fang ◽  
Li Li ◽  
Guo Xun Wang
Keyword(s):  
Processing System ◽  
Industrial Robots ◽  
Machining Process ◽  
Prototype System ◽  
Post Processing ◽  
Cad Cam ◽  
Robot Machining ◽  
Machining Robot ◽  
Key Issues ◽  
Nc Data

In order to solve the problem of openness, intelligence and low integration in the current machining robot control system, STEP-NC standard is introduced into the field of robot machining, and defines the STEP-NC data model of industrial robots. The 6R industrial robots are used to build the machining platform and the connection between the machining robot and the CAD / CAM system and the integrated data stream structure are discussed. The key issues involved in the post processing of the machining robot are studied. Taking the 6R robot as an example, the robot prototype system is established, and the kinematics solution in the post-processing process is studied and deduced. The cutting and post-processing system platform of cutting robot was established and the sample art machining was completed. The experimental and simulation results show that the system can complete the machining process of the cutting robot and generate executable robot machining instructions.

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.

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