scholarly journals Optimizing Industrial Robots for Accurate High-Speed Applications

2013 ◽  
Vol 2013 ◽  
pp. 1-12 ◽  
Author(s):  
Hubert Gattringer ◽  
Roland Riepl ◽  
Matthias Neubauer
Keyword(s):  
High Speed ◽  
Industrial Robot ◽  
Optimization Techniques ◽  
Industrial Robots ◽  
Industrial Control ◽  
Geometric Calibration ◽  
One Step ◽  
Point Trajectories ◽  
Optimal Efficiency ◽  
Point To Point

Today’s standard robotic systems often do not meet the industry’s demands for accurate high-speed robotic applications. Any machine, be it an existing or a new one, should be pushed to its limits to provide “optimal” efficiency. However, due to the high complexity of modern applications, a one-step overall optimization is not possible. Therefore, this contribution introduces a step-by-step sequence of multiple nonlinear optimizations. Included are optimal configurations for geometric calibration, best-exciting trajectories for parameter identification, model-based control, and time/energy optimal trajectory planning for continuous path and point-to-point trajectories. Each of these optimizations contributes to the improvement of the overall system. Existing optimization techniques are adapted and extended for use with a standard industrial robot scenario and combined with a comprehensive toolkit with discussions on the interplay between the separate components. Most importantly, all procedures are evaluated in practical experiments on a standard robot with industrial control hardware and the recorded measurements are presented, a step often missing in publications in this area.

EFFECT OF SERVO SYSTEMS ON THE CONTOURING ERRORS IN INDUSTRIAL ROBOTS

2012 ◽  
Vol 36 (1) ◽  
pp. 83-96 ◽  
Author(s):  
Mohamed Slamani ◽  
Albert Nubiola ◽  
Ilian A. Bonev
Keyword(s):  
High Speed ◽  
Industrial Robot ◽  
Statistical Tests ◽  
Measurement Instrument ◽  
Servo System ◽  
Industrial Robots ◽  
Structural Vibration ◽  
Tool Centre Point ◽  
Prediction Capability ◽  
Radius Size

Two important aspects of the performance of a servo system, tracking errors and contour errors, significantly affect the accuracy of industrial robots under high-speed motion. Careful tuning of the control parameters in a servo system is essential, if the risk of severe structural vibration and a large contouring error is to be avoided. In this paper, we present an overview of a method to diagnose contouring errors caused by the servo control system of an ABB IRB 1600 industrial robot by measuring the robot’s motion accuracy in a Cartesian circular shape using a double ballbar (DBB) measurement instrument. Tests were carried out at different TCP (tool centre-point) speed and trajectory radii to investigate the main sources of errors that affect circular contouring accuracy. Results show that radius size errors and out-of-roundness are significant. A simple experimental model based on statistical tests was also developed to represent and predict the radius size error. The model was evaluated by comparing its prediction capability in several experiments. An excellent error prediction capability was observed.

HIGH-SPEED INDUSTRIAL REAL-TIME NETWORK OF CYBERPHYSICAL SYSTEMS

2019 ◽  
pp. 46-52
Author(s):  
A. A. Zelensky
Keyword(s):  
Real Time ◽  
Cycle Time ◽  
High Speed ◽  
High Efficiency ◽  
Industrial Robot ◽  
Field Tests ◽  
Industrial Robots ◽  
Third Party ◽  
Industrial Equipment ◽  
Industrial Automation

The construction of a high-speed industrial real-time network based on FPGA (Field-Programmable Gate Array) for the control of machines and industrial robots is considered. A brief comparative analysis of the performance of the implemented Ethernet-based Protocol with industrial protocols of other leading manufacturers is made. The aim of the research and development of its own industrial automation Protocol was to reduce the dependence on third-party real-time protocols based on Ethernet for controlling robots, machines and technological equipment. In the course of the study, the requirements for the network of the motion control system of industrial equipment were analyzed. In order to synchronize different network nodes and provide short exchange cycle time, an industrial managed switch was developed, as well as a specialized hardware controller for processing Ethernet packets for end devices, presented as a IP-core. A key feature of the developed industrial network is that the data transmission in it is completely determined, and the exchange cycle time for each of the network devices can be configured individually. High efficiency and performance of implemented network devices became possible due to the use of hardware solutions based on FPGAs. All solutions described in the article as part of a modular digital system have been successfully tested in the control of machines and industrial robot. The results of field tests show that the use of FPGAs and soft processors with specialized peripheral IP-blocks can significantly reduce the tact of managing industrial equipment through the use of hardware computing structures, which indicates the promise of the proposed approach for solving industrial automation tasks.

Control System Design for High Payload Industrial Robot via High Speed Communication Bus and Real-Time System

2011 ◽  
Vol 464 ◽  
pp. 272-278 ◽  
Author(s):  
Wei You ◽  
Min Xiu Kong ◽  
Li Ning Sun ◽  
Chan Chan Guo
Keyword(s):  
Control System ◽  
Real Time ◽  
High Speed ◽  
Industrial Robot ◽  
Engineering Application ◽  
Industrial Robots ◽  
Centralized Control ◽  
Time System ◽  
Real Time System ◽  
High Payload

In this paper, aiming at solving the problems of dynamic coupling effects and flexibility of joints and links, a kind of control system specialized for high payload industrial robots is proposed . After the comparisons between the control systems in all kinds of robots and numerical machines, industrial PC with TwinCAT real-time system is chosen as the motion control unit, EtherCAT is used for command transmitting. The whole control system has a decoupled and centralized control structure. The proposed control system is applied in control of a kind of high payload material handling robots with complex compound control algorithms. The final results shows that the control commands can be easily calculated and transmitted in one sample unit. The proposed control scheme is meaningful to real engineering application.

scholarly journals Industrial robot-based system design of thickness scanning measurement using ultrasonic

2021 ◽  
Vol 12 (1) ◽  
pp. 479-486
Author(s):  
Haibo Liu ◽  
Baoliang Liu ◽  
Meng Lian ◽  
Pingping Li ◽  
Tianran Liu ◽  
...  
Keyword(s):  
High Speed ◽  
Measurement Method ◽  
Industrial Robot ◽  
Thickness Measurement ◽  
Industrial Robots ◽  
Measurement Unit ◽  
Ultrasonic Probe ◽  
State Discrimination ◽  
Thin Walled ◽  
Ultrasonic Thickness

Abstract. Wall thickness is one of the core indicators for measuring the quality of large thin-walled parts such as rocket siding and aircraft skin. However, the traditional handheld thickness measurement method has high labor intensity, low efficiency and poor accuracy consistency. Therefore, an in situ ultrasonic automatic scanning thickness measurement method for large thin-walled parts based on industrial robots is proposed. This “industrial robot + ultrasound” integrated function is a compact system, and a set of innovative methodological or technical solutions is presented, such as (i) TCP and UDP communication protocols being constructed to realize a high-speed and stable communication relationship between the upper computer, robot motion controller and ultrasonic thickness measurement unit; (ii) a coupling gap adjustment method based on eddy-current sensors being adopted to ensure the adaptability of the ultrasonic probe to surface topography of the measured part during scanning measurement; and (iii) a multi-sensor coordinate unified model and coupling gap state discrimination model being established for robot-aided thickness measurement. To verify the feasibility of the proposed method, a series of calibrations and experiments were designed based on the KUKA robot platform and the developed ultrasonic pulse measurement system. Finally, the industrial robot-based ultrasonic thickness scanning measurement has been built and tested for performing the measurement of a rocket tank wall.

Design of Under-Actuated Open-Chain Planar Robots for Repetitive Cyclic Motions

2006 ◽  
Author(s):  
Sunil K. Agrawal ◽  
Vivek Sangwan
Keyword(s):  
Numerical Methods ◽  
Industrial Robots ◽  
Differential Flatness ◽  
Open Chain ◽  
Revolute Joints ◽  
Planar Robot ◽  
Point Trajectories ◽  
Point To Point ◽  
Three Degree Of Freedom ◽  
Output Space

Under-actuated systems are unavoidable in certain applications. For example, a biped can not have an actuator between the foot and the ground. For industrial robots, underactuation is preferable due to cost considerations. A fully actuated system can execute any joint trajectory. However, if the system is under-actuated, not all joint trajectories are attainable. For such systems, it is difficult to characterize attainable joint trajectories analytically and numerical methods are generally used to characterize them. This paper investigates the property of differential flatness for under-actuated planar open chain robots and study its dependence on inertia distribution within the system. Once this property is established, trajectory between any two points in its differentially flat output space is feasible and can be shown to be consistent with the dynamics of the under-actuated system. It is shown that certain choices of inertia distributions make an under-actuated open-chain planar robot with revolute joints feedback linearizable, i.e., also differentially flat. Hence, both cyclic and point to point trajectories can be guaranteed with these under-actuated systems. The methodology proposed is demonstrated with an under-actuated three degree-of-freedom planar robot.

Industrial robot path planning in a constraint-based computer-aided design and kinematic analysis environment

2009 ◽  
Vol 223 (5) ◽  
pp. 523-533 ◽  
Author(s):  
G-C Vosniakos ◽  
A Chronopoulos
Keyword(s):  
Computer Aided Design ◽  
Industrial Robot ◽  
Industrial Robots ◽  
Constrained Motion ◽  
Virtual Objects ◽  
Computer Aided ◽  
Point Motion ◽  
Point To Point ◽  
Aided Design ◽  
Active Joints

Paths of industrial robots are easier to plan by using constraints on accurate computer-aided design (CAD) models of both objects representing the real industrial robotic cell and virtual objects representing the auxiliary geometry that is necessary to define path points. The motion path normally needs to be split into segments possessing uniform characteristics, e.g. common active joints, at points usually corresponding to position or velocity extremes. Each segment corresponds either to point-to-point motion or to constrained motion. Point-to-point motion is implemented by interpolating between original and final position of each joint separately, positions being determined through inverse kinematics in the CAD environment and motion being imparted to each joint directly. Constrained motion may be defined using several alternatives materialized with stationary and moving virtual objects, real robot joints, virtual joints, contact constraints, and motion constraints. Motion duration is specified after the corresponding path geometry has been specified, by exploiting maximum active joints velocity as well as end-tool velocity as dictated by the process. Collisions are detected using available functionality and are alleviated interactively. A user-defined number of interpolated robot poses are generated per segment. These are all ‘sewn’ together at the motion synthesis stage and frame-based simulation is generated. A realistic robotic lathe loading/unloading example is used to verify the use of the above notions and tools.

Performance Criteria to Evaluate a Kinematically Redundant Robotic Cell for Machining Tasks

2012 ◽  
Vol 162 ◽  
pp. 413-422 ◽  
Author(s):  
Kévin Subrin ◽  
Laurent Sabourin ◽  
Grigore Gogu ◽  
Youcef Mezouar
Keyword(s):  
High Speed ◽  
Dynamic Capabilities ◽  
Industrial Robot ◽  
Kinematic Model ◽  
Geometrical Model ◽  
Industrial Robots ◽  
Machining Process ◽  
Performance Criteria ◽  
Robotic Cell ◽  
Speed Accuracy

Machine tools and robots have both evolved fundamentally and we can now question the abilities of new industrial robots concerning accurate task realization under high constraints. Requirements in terms of kinematic and dynamic capabilities in High Speed Machining (HSM) are increasingly demanding. To face the challenge of performance improvement, parallel and hybrid robotic architectures have emerged and a new generation of industrial serial robots with the ability to perform machining tasks has been designed. In this paper, we propose to evaluate the performance criteria of an industrial robot included in a kinematically redundant robotic cell dedicated to a machining task. Firstly, we present the constraints of the machining process (speed, accuracy etc.). We then detail the direct geometrical model and the kinematic model of a robot with closed chain in the arm and we propose a procedure for managing kinematic redundancy whilst integrating various criteria. Finally, we present the evolution of the criteria for a given trajectory in order to define the best location for a rotary table and to analyze the manipulators stiffness.

scholarly journals Design and Implementation of Admittance Control for a Dual-Arm Robot under Space Limitation

2019 ◽  
Vol 256 ◽  
pp. 02010
Author(s):  
Jinxing Yang ◽  
Yinhui Xie ◽  
Mingqi Feng ◽  
Jun Li
Keyword(s):  
High Speed ◽  
Control Algorithm ◽  
Control Method ◽  
Industrial Robots ◽  
Admittance Control ◽  
Human Machine Interaction ◽  
Space Limitation ◽  
Dual Arm Robot ◽  
Point To Point ◽  
Dual Arm

Aimed at the situation lack of suitable industrial robots with speed requirement and space limitation, a novel simple structured and high speed dual-arm robot is designed. The robot control system has been achieved by using high speed controller, real-time bus EtherCAT and integrating the sensor system via Ethernet interface. Kinematic and dynamic analysis are the basis of its kinematic control and trajectory planning. This paper presents a force-free control method for direct teaching of the robot and adopts a Cartesian admittance control algorithm to realize human-machine interaction. The admittance control is conducted by utilizing six-dimensional force/torque sensor fixed to the end-effector of manipulator. To evaluate the performance of the proposed controller and control algorithm, a point-to-point teaching task is conducted.

Optimization Trajectory in Handling with the Same Object

2014 ◽  
Vol 613 ◽  
pp. 230-235
Author(s):  
Marek Vagaš
Keyword(s):  
Trajectory Optimization ◽  
Industrial Robot ◽  
Optimization Method ◽  
Industrial Robots ◽  
Optimization Strategy ◽  
Mechanical Resonance ◽  
Resonance Modes ◽  
Robot Trajectory ◽  
Point To Point ◽  
Point Type

In this paper, there is presented an industrial robot trajectory optimization method for series of point-to-point type movements. Also contain an optimization strategy that has been built using through proposed automated optimizing system for handling. The optimized trajectories must lead to avoid exciting mechanical resonance modes of the industrial robot structure. This can be achieved by applying of robot interpolation. The testing results show that the trajectory optimization through this method is feasible for industrial robots.

scholarly journals Joint Motion Planning of Industrial Robot Based on Modified Cubic Hermite Interpolation with Velocity Constraint

2021 ◽  
Vol 11 (19) ◽  
pp. 8879
Author(s):  
Yasong Pu ◽  
Yaoyao Shi ◽  
Xiaojun Lin ◽  
Wenbin Zhang ◽  
Pan Zhao
Keyword(s):  
Motion Planning ◽  
Hermite Interpolation ◽  
Industrial Robot ◽  
Industrial Robots ◽  
Joint Motion ◽  
Quintic Polynomial ◽  
C2 Continuity ◽  
Planning Methods ◽  
Velocity Constraints ◽  
Point To Point

As for industrial robots’ point-to-point joint motion planning with constrained velocity, cubic polynomial planning has the problem of discontinuous acceleration; quintic polynomial planning requires acceleration to be specified in advance, which will likely cause velocity to fluctuate largely because appropriate acceleration assigned in advance is hardly acquired. Aiming at these problems, a modified cubic Hermite interpolation for joint motion planning was proposed. In the proposed methodology, knots of cubic Hermite interpolation need to be reconfigured according to the initial knots. The formulas for how to build new knots were put forward after derivation. Using the newly-built knots instead of initial knots for cubic Hermite interpolation, joint motion planning was carried out. The purpose was that the joint planning not only satisfied the displacement and velocity constraints at the initial knots but also guaranteed C2 continuity and less velocity fluctuation. A study case was given to verify the rationality and effectiveness of the methodology. Compared with the other two planning methods, it proved that the raised problems can be solved effectively via the proposed methodology, which is beneficial to the working performance and service life of industrial robots.

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