Research on Kinematics and Trajectory Planning for 6-DOF Industrial Robot

2013 ◽  
Vol 823 ◽  
pp. 345-348
Author(s):  
Qi Ping Zhao ◽  
Li Sun ◽  
Zi Gang Zhu ◽  
Guang Chen Chen
Keyword(s):  
Trajectory Planning ◽  
Industrial Robot ◽  
Linear Interpolation ◽  
Industrial Robots ◽  
Robot Motion ◽  
Servo Drive ◽  
Advantages And Disadvantages ◽  
Cartesian Space ◽  
Quadratic Interpolation ◽  
Servo Drive System

The industrial robot is a typical electromechanical integration equipment constituted by operating machine, controller, servo drive system and the detection of sensing device. It is one of the most common industrial robots in the industrial field, which makes it work in almost any track or angle. This paper mainly presents the research on kinematics and trajectory planning for 6-DOF industrial robot. This study has finished the linear interpolation and arc interpolation in the Cartesian space. According to the advantages and disadvantages, this paper proposes the method of quadratic interpolation that meets the demands of 6-DOF industrial robot motion in the joints space and Cartesian space which ensures that the motion of 6-DOF industrial robot is smooth and stable.

Finding Features of Positioning Error for Large Industrial Robots Based on Convolutional Neural Network

2021 ◽  
Author(s):  
Daiki Kato ◽  
Kenya Yoshitugu ◽  
Naoki Maeda ◽  
Toshiki Hirogaki ◽  
Eiichi Aoyama ◽  
...  
Keyword(s):  
Neural Network ◽  
Convolutional Neural Network ◽  
Production Systems ◽  
Industrial Robot ◽  
Three Dimensional ◽  
Industrial Robots ◽  
Numerical Control ◽  
Robot Motion ◽  
Positioning Error ◽  
End Effector

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.

Digital Twin: Concept of Hybrid Programming for Industrial Robots — Use Case

2019 ◽  
Author(s):  
Vladimir Kuts ◽  
Martinš Sarkans ◽  
Tauno Otto ◽  
Toivo Tähemaa ◽  
Yevhen Bondarenko
Keyword(s):  
Industrial Robot ◽  
Industrial Robots ◽  
Programming Method ◽  
Shop Floor ◽  
Cell Design ◽  
Robotic Cell ◽  
Digital Twin ◽  
Advantages And Disadvantages ◽  
University Of Technology ◽  
Programming Process

Abstract Modern Industrial Robot (IR) programming process is mainly performed by using three different methods — manual, offline, and online programming. Each of these methods has various advantages and disadvantages. Prominent automotive industries often use a combination of them, as there is no way to avoid one or another form of programming on one factory. However, the use of a combination of different programming methods is time-consuming and demands the operator’s presence on site for reconfiguration of the IR. The primary goal of this study is to introduce and test the concept of a hybrid IR programming method, which combines both: offline and online robotic cell design, programming, and re-configuration methods. Testing of this method is based on fully synchronized robotic cell’s Digital Twin (DT), developed in Industrial Virtual and Augmented Laboratory of Tallinn University of Technology. Usage of the virtual replica allows to plan and program robotic cell on the means of telepresence and interfere with the predefined path of the robot by online programming method. Moreover, this approach reduces the time for robotic cell design and re-programming, enables to minimize downtime of the robotic cell on the factory shop floor. Included Virtual Reality (VR) environment allows simulating a full-scale operator presence on site. Thus, the proposed approach supports an immersive and safe environment for the IR and similar equipment programming purposes.

A direct approach to solving trajectory planning problems using genetic algorithms with dynamics considerations in complex environments

Robotica ◽  
2014 ◽  
Vol 33 (3) ◽  
pp. 669-683 ◽  
Author(s):  
Fares J. Abu-Dakka ◽  
Francisco J. Valero ◽  
Jose Luis Suñer ◽  
Vicente Mata
Keyword(s):  
Trajectory Planning ◽  
Direct Method ◽  
Industrial Robot ◽  
Industrial Robots ◽  
Computational Time ◽  
Planning Problem ◽  
Complex Environments ◽  
Operational Parameters ◽  
Algorithm Efficiency ◽  
Planning Problems

SUMMARYThis paper presents a new genetic algorithm methodology to solve the trajectory planning problem. This methodology can obtain smooth trajectories for industrial robots in complex environments using a direct method. The algorithm simultaneously creates a collision-free trajectory between initial and final configurations as the robot moves. The presented method deals with the uncertainties associated with the unknown kinematic properties of intermediate via points since they are generated as the algorithm evolves looking for the solution. Additionally, the objective of this algorithm is to minimize the trajectory time, which guides the robot motion. The method has been applied successfully to the PUMA 560 robotic system. Four operational parameters (execution time, computational time, end-effector distance traveled, and significant points distance traveled) have been computed to study and analyze the algorithm efficiency. The experimental results show that the proposed optimization algorithm for the trajectory planning problem of an industrial robot is feasible.

scholarly journals Optimal Robot Motion for Accelerated Life Testing of a 6-DoF Industrial Robot

2020 ◽  
Vol 10 (21) ◽  
pp. 7459
Author(s):  
Seungjin Yoo ◽  
Jin Jang ◽  
Jai-Kyung Lee ◽  
Jong-Won Park
Keyword(s):  
Industrial Robot ◽  
Geometric Mean ◽  
Industrial Robots ◽  
Acceleration Factor ◽  
Accelerated Life Test ◽  
System Level ◽  
Test Time ◽  
Robot Motion ◽  
Life Test ◽  
Accelerated Life

In order to verify the reliability of drive components for industrial robots, component-level life tests must be accompanied by a system-level life test using actual robots in which predefined robot motions are repeated throughout the test. To properly verify the durability of drive components through a system-level life test, it is important to design test modes so that the required test time is the same for all joint drive components of the robot, and it is necessary to design test modes with a high acceleration factor so as to shorten the required test time as much as possible. To solve this problem, the present research proposes a method for designing robot motions that makes the accelerated life test time for all the drive components of the robot equal. In particular, we solve a dynamic based motion optimization problem for an industrial 6-DoF (degrees-of-freedom) robot that minimizes the AM-GM (arithmetic mean to geometric mean) ratio of the acceleration factors of each joint. The results show that C2-continuous test modes with the same acceleration factor, which is inversely proportional to the cycle time of the robot motion, can be derived.

Deburring of Cross Holes in Titanium Using Industrial Robots

2013 ◽  
Vol 769 ◽  
pp. 147-154 ◽  
Author(s):  
Matthias Pischan
Keyword(s):  
Machine Tools ◽  
Industrial Robot ◽  
Industrial Robots ◽  
Movement Speed ◽  
Hydraulic Systems ◽  
Advantages And Disadvantages ◽  
Wear Analysis ◽  
Tool Axis ◽  
Specialized Equipment ◽  
Huge Variety

In aircrafts, hydraulic systems control moveable parts. For example parts like the front strut or the landing flaps. These parts are usually made from aluminium or titanium. Due to an increasing number of functions these valves show an increasing number of cross holes. The production process causes burrs at the intersection of the holes. Until now these burrs cant be removed reliably by an automated process. Remaining burrs can influence dimensional tolerances and reduce the efficiency and technical lifetime of the component. In some applications cross holes are used for the lubricant and coolant supply. In this case burrs can lead to blockades of critical passages or cause turbulences in the fluid. This can lead to leakage or bursting of the valve. Hence an uncontrolled removal of the burr during operation must be avoided. The consequence of these basic conditions is a time consuming manual deburring process. An automated deburring process of cross holes with industrial robots is usually performed with flexible abrasive brushes. Alternatively processes like AFM (Abrasive Flow Machining), ECM (Electro Chemical Machining) or TEM (Thermal Energy Machining) are used. Those processes are very efficient but require specialized equipment and cleaning processes for the used chemicals and the remaining abrasive paste. So they are not suitable for the deburring of safety related parts. This paper presents an experimental based approach for the robot based deburring of cross holes using industrial robots. For the deburring of cross holes several special tools are available. This article gives a short overview over the specific advantages and disadvantages of these tools. As the investigations revealed the best results can be achieved using the so called Orbitool developed by JWDone. The Orbitool is a tungsten carbide cutter developed for the deburring of cross holes. A better control of the required dimension at the intersection compared to brushes and other deburring methods is possible. Furthermore the tool can be used on machine tools and industrial robots and is flexible to a huge variety of bore diameters. The tool mainly consists of a ball shaped carbide milling cutter with a protective disk which is made of polished steel and a shaft of tool steel. To remove the burr the tool is moved along the bore axis into the smallest of the intersecting holes until the tip of the tool is close to the intersection. Then the tool is moved in radial direction to the bore surface until the tool axis corresponds to the interpolation diameter. This causes a deflection of the tool. In this situation only the protective disk is in contact with the bore surface. While the tool rotates it is moved towards the intersection in a helical motion. When the tool tip has reached the intersection the cutting edges get in contact with intersection and the deburring process begins. After the tool has passed the whole intersection it stops its rotation and is moved to the bore hole centre and then moved out of the workpiece. This paper deals with the optimization of the deburring process. The result mainly depends on the parameters movement speed of the robot, slope of the helical movement and rotational speed of the tool. The experiments are planned using DOE (Design Of Experiment) methods. Initial values for the optimization of the movement speed were determined by grid encoder measurements. Robotic specific parameters like the number of interpolating points and the influence of the path smoothing caused by the controller were also investigated. For the analysis of the burr and the secondary burr an optical 3-D measurement system is used. The results show that with the presented approach the burrs can be reliably removed. Before the deburring process the average burr height is about 60 μm and can be reduced so that there is no secondary burr visible. The result is a chamfer between 150 μm and 85 μm that depends on the process parameters. It can be demonstrated that a chamfer that is smaller than 100 μm leads to a secondary burr. Anyway the cycle time can be reduced from about 3 minutes for manual deburring to 30 seconds using an industrial robot. Additional wear analysis show that about 200 bore holes can safely be deburred.

scholarly journals Dynamic Simulation Modeling of Industrial Robot Kinematics in Industry 4.0

2022 ◽  
Vol 2022 ◽  
pp. 1-11
Author(s):  
Guang Jin ◽  
Shuai Ma ◽  
Zhenghui Li
Keyword(s):  
Dynamic Simulation ◽  
Trajectory Planning ◽  
Simulation Modeling ◽  
Industry 4.0 ◽  
Industrial Robot ◽  
Error Model ◽  
Position Error ◽  
Industrial Robots ◽  
Robot Kinematics ◽  
Kinetic Characteristics

This paper studies the kinematic dynamic simulation modeling of industrial robots in the Industry 4.0 environment and guides the kinematic dynamic simulation modeling of industrial robots in the Industry 4.0 environment in the context of the research. To address the problem that each parameter error has different degrees of influence on the end position error, a method is proposed to calculate the influence weight of each parameter error on the end position error based on the MD-H error model. The error model is established based on the MD-H method and the principle of differential transformation, and then the function of uniform variation of six joint angles with time t is constructed to ensure that each linkage geometric parameter is involved in the motion causing error accumulation. Through the analysis of the robot marking process, the inverse solution is optimized for multiple solutions, and a unique engineering solution is obtained. Linear interpolation, parabolic interpolation, polynomial interpolation, and spline curve interpolation are performed on the results after multisolution optimization in the joint angle, and the pros and cons of various interpolation results are analyzed. The trajectory planning and simulation of industrial robots in the Industry 4.0 environment are carried out by using a special toolbox. The advantages and disadvantages of the two planning methods are compared, and the joint space trajectory planning method is selected to study the planning of its third and fifth polynomials. The kinetic characteristics of the robot were simulated and tested by experimental methods, and the reliability of the simulation results of the kinetic characteristics was verified. The kinematic solutions of industrial robots and the results of multisolution optimization are simulated. The methods, theories, and strategies studied in this paper are slightly modified to provide theoretical and practical support for another dynamic simulation modeling of industrial robot kinematics with various geometries.

Industrial Robot

2018 ◽  
pp. 77-110
Keyword(s):  
Industrial Robot ◽  
Industrial Robots ◽  
Robot Motion ◽  
Uncertain Environments ◽  
Power Sources ◽  
Motion Type ◽  
Essential Components ◽  
History Of ◽  
Research Studies

This chapter provides various aspects of industrial robots. The various aspects which have been discussed are history of industrial robots, various application areas of industrial robots, general characteristics, and essential components of industrial robots. After this, concepts of robot motion, type of joints of industrial robots, various power sources for the robots are discussed. Next, the characteristics of various types of industrial robots are presented, followed by a list of leading manufacturers and research studies on industrial robots, along with the research studies on the performance of robots in various uncertain environments.

A fixed-distance planning algorithm for 6-DOF manipulators

2015 ◽  
Vol 42 (6) ◽  
pp. 586-599 ◽  
Author(s):  
Mingyu Gao ◽  
Da Chen ◽  
Yuxiang Yang ◽  
Zhiwei He
Keyword(s):  
Trajectory Planning ◽  
Degrees Of Freedom ◽  
Position Control ◽  
Control Strategies ◽  
Industrial Robot ◽  
Industrial Robots ◽  
Cartesian Coordinates ◽  
Content Type ◽  
Fixed Distance ◽  
Planning Algorithm

Purpose – The purpose of this paper is to propose a new trajectory planning algorithm for industrial robots, which can let the robots move through a desired spatial trajectory, avoid colliding with other objects and achieve accurate movements. Trajectory planning algorithms are the soul of motion control of industrial robots. A predefined space trajectory can let the robot move through the desired spatial coordinates, avoid colliding with other objects and achieve accurate movements. Design/methodology/approach – The mathematical expressions of the proposed algorithm are deduced. The speed control, position control and orientation control strategies are realized and verified with simulations, and then implemented on a six degrees of freedom (6-DOF) industrial robot platform. Findings – A fixed-distance trajectory planning algorithm based on Cartesian coordinates was presented. The linear trajectory, circular trajectory, helical trajectory and parabolic trajectory in Cartesian coordinates were implemented on the 6-DOF industrial robot. Originality/value – A simple and efficient algorithm is proposed. Enrich the kind of trajectory which the industrial robot can realize. In addition, the industrial robot can move more concisely, smoothly and precisely.

scholarly journals SIMULATORS FOR CALIBRATION OF TOOL CENTER OF INDUSTRIAL ROBOTS

2017 ◽  
Vol 2017 (1) ◽  
pp. 44-49 ◽  
Author(s):  
Геннадий Крахмалев ◽  
Gennadiy Krakhmalev ◽  
Дмитрий Петрешин ◽  
Dmitriy Petreshin ◽  
Олег Крахмалев ◽  
...  
Keyword(s):  
Control System ◽  
Robot Control ◽  
Industrial Robot ◽  
Calibration Procedure ◽  
Industrial Robots ◽  
Robot Motion ◽  
Coordinate Transformations ◽  
Permanent Memory

A complex of measures on a new robot tooling envisages a fulfillment of the calibration procedure of the tool before its use in an operation. It is necessary for that the system of industrial robot control could carry out a tool travel in a robot operation space in the correct way. For that purpose the simulators describing coordinate transformations in this robot model must be supplemented by a simulator developed for the tool determined. Simulators describing coordinate trans-formations for a tool are created by a system of control automatically at the fulfillment of a tool calibration before the introduction of a new tool in operation. The simulators created are saved in permanent memory (ROM) of a controller of the control system in a tool library with the indication of logical naming for this tool. In the following at the pro-gramming of industrial robot motion a tool installed on a robot is pointed out to the system of control by means of logical naming a tool chosen. This paper reports the simulators for the tool center calibration of industrial robots corresponding to the methods used most commonly in practice of industrial robot operation. The simulators obtained can be used in systems for industrial robot control.

scholarly journals Numerical evaluation of the interpolation accuracy of simple elementary functions

2018 ◽  
Vol 9 (4) ◽  
pp. 93-116
Author(s):  
Sergej Vital'evich Znamenskij
Keyword(s):  
Polynomial Interpolation ◽  
Piecewise Linear ◽  
Rational Functions ◽  
Linear Interpolation ◽  
Graphical Form ◽  
Elementary Functions ◽  
Advantages And Disadvantages ◽  
Piecewise Linear Interpolation ◽  
Interpolation Accuracy ◽  
Quadratic Interpolation

The paper contains a comparison of the accuracy of the restoration of elementary functions by the values in the nodes for algorithms of low-degree piecewise-polynomial interpolation. The test results demonstrate in graphical form the advantages and disadvantages of the widely used cubic interpolation splines. The comparison revealed that, contrary to popular belief, the smoothness of the interpolant is not directly related to the accuracy of the approximation. In the 20 different examples considered, the piecewise quadratic interpolation is rarely and only slightly inferior in the form of the used classical cubic splines, often by orders of magnitude better than many of them. In several examples, the high interpolation error of simple functions on a fixed grid appears to be almost independent of the degree of the algorithm and the smoothness of the interpolant. The piecewise-linear interpolation unexpectedly appeared the most accurate in one of the examples. A new problem arises: to find a local interpolation algorithm, accurately restoring any rational functions of the second order.

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