| 1. |
- Björkman, Mattias, et al.
(författare)
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A New Concept for Motion Control of Industrial Robots
- 2008
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Ingår i: Proceedings of the 17th IFAC World Congress. - Linköping : Linköping University Electronic Press. - 9783902661005
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Konferensbidrag (refereegranskat)abstract
- This paper gives a short summary of an industrial development work on model-based motion control. This development has resultet in high robot motion performance simultaneously with an efficient use of the installed drive system of the robot.
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| 2. |
- Blomdell, Anders, et al.
(författare)
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Extending an Industrial Robot Controller-Implementation and Applications of a Fast Open Sensor Interface
- 2005
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Ingår i: IEEE Robotics & Automation Magazine. - 1070-9932. ; 12:3, s. 85-94
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Tidskriftsartikel (refereegranskat)abstract
- Many promising robotics research results were obtained during the late 1970s and early 1980s. Some examples include Cartesian force control and advanced motion planning. Now, 20 years and many research projects later, many technologies still have not reached industrial usage. An important question to consider is how this situation can be improved for future deployment of necessary technologies. Today, modern robot control systems used in industry provide highly optimized motion control that works well in a variety of standard applications. To this end, computationally intensive, model-based robot motion control techniques have become standard during the last decade. While the principles employed have been known for many years, deployment in products required affordable computing power, efficientengineering tools, customer needs for productivity/performance, and improved end-user competence in the utilization of performance features. However, applications that are considered nonstandard today motivate a variety of research efforts and system development to package results in a usable form. Actually, robots are not useful for many manufacturing tasks today, in particular those found in small and medium enterprises (SMEs). Reasonsinclude complex configuration, nonintuitive (for the shop floor) programming, and difficulties instructing robots to deal with variations in their environment. The latter challenge includes both task definitions and definition of motion control utilizing external sensors. The key word here is flexibility, and flexible motion control is particularly difficult since the user or system integrator needs to influence the core real-time software functions that are critical for the performance and safe operation of the system. We must find techniques that permit real-time motion controllers to be extended for new, demanding application areas.
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| 3. |
- Carvalho Bittencourt, André, et al.
(författare)
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An Extended Friction Model to capture Load and Temperature effects in Robot Joints
- 2010
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Ingår i: Proceedings of the 2010 IEEE/RSJ International Conference on Intelligent Robots and Systems. - Linköping : Linköping University Electronic Press. - 9781424466740 ; , s. 6161-6167
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Konferensbidrag (refereegranskat)abstract
- Friction is the result of complex interactions between contacting surfaces in a nanoscale perspective. Depending on the application, the different models available are more or less suitable. Available static friction models are typically considered to be dependent only on relative speed of interacting surfaces. However, it is known that friction can be affected by other factors than speed. In this paper, static friction in robot joints is studied with respect to changes in joint angle, load torque and temperature. The effects of these variables are analyzed by means of experiments on a standard industrial robot. Justified by their significance, load torque and temperature are included in an extended static friction model. The proposed model is validated in a wide operating range, reducing the average error a factor of 6 when compared to a standard static friction model.
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| 4. |
- Carvalho Bittencourt, André, et al.
(författare)
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Modeling and Identification of Wear in a Robot Joint under Temperature Uncertainties
- 2010
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- This paper considers the problem of wear estimation in a standard industrial robot joint. The effects of wear to the static friction of a robot joint are analyzed from experiments. An extended static friction model is proposed that explains changes related to joint speed, load, temperature and wear. Based on this model and static friction observations, a model-based wear estimator is proposed. The performance of the estimator under temperature uncertainties is found both by means of simulations and experiments in an industrial robot. Special attention is given to the analyses of the best speed region for wear estimation. As it is shown, the method can distinguish the effects of wear even under large temperature variations, opening up for the use of robust joint diagnosis for industrial robots.
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| 5. |
- Carvalho Bittencourt, André, et al.
(författare)
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Modeling and Identification of Wear in a Robot Joint under Temperature Uncertainties
- 2011
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- This paper considers the problem of wear estimation in a standard industrial robot joint. The effects of wear to the static friction of a robot joint are analyzed from experiments. An extended static friction model is proposed that explains changes related to joint speed, load, temperature and wear. Based on this model and static friction observations, a model-based wear estimator is proposed. The performance of the estimator under temperature uncertainties is found both by means of simulations and experiments in an industrial robot. Special attention is given to the analyses of the best speed region for wear estimation. As it is shown, the method can distinguish the effects of wear even under large temperature variations, opening up for the use of robust joint diagnosis for industrial robots.
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| 6. |
- Crothers, Phil, et al.
(författare)
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Characterization of the Tau parallel kinematic machine for aerospace application
- 2009
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Ingår i: SAE 2009 AeroTech Congress & Exhibition Technical Papers.
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Konferensbidrag (refereegranskat)abstract
- A consortium of interested parties has conducted an experimental characterization of two Tau parallel kinematic machines which were built as a part of the EU-funded project, SMErobot1. Characteristics such as machine stiffness, work envelope, repeatability and accuracy were considered. This paper will present a brief history of the Tau parallel machine, the results of this testing and some comment on prospective application to the aerospace industry.
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| 7. |
- Dressler, Isolde, et al.
(författare)
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A Kinematic Error Model for a Parallel Gantry-Tau Manipulator
- 2010
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Ingår i: ; , s. 3709-3714
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Konferensbidrag (refereegranskat)abstract
- Parallel robots are generally said to be more accurate but to have a smaller workspace compared to serial robots. With the Gantry-Tau robot, a parallel robot with a large, reconfigurable workspace was presented. This article tries to identify the maximum achievable end-effector positioning accuracy of the Gantry-Tau robot. To this end, a couple of new kinematic error models are presented and evaluated. The sources of the remaining positioning errors (0.09 mm) are discussed.
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| 8. |
- Gunnar, Johan, et al.
(författare)
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Nonlinear Grey-box Identification of Linear Actuators Containing Hysteresis
- 2006
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Ingår i: Proceedings of the 2006 IEEE International Conference on Robotics and Automation. - Linköping : Linköping University Electronic Press. - 0780395050 ; , s. 1818-1823
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Konferensbidrag (refereegranskat)abstract
- A new identification procedure for a linear actuator used in parallel kinematic manipulators has been developed. The actuator dynamics contain both hysteresis and backlash resulting in a highly nonlinear system. The results in this paper show that not only can a nonlinear model of the system be successfully identified from measurement data, but the model is also compact enough to be an ideal candidate for inclusion in a high-performance robot control system.
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| 9. |
- Haage, Mathias, et al.
(författare)
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Reconfigurable Parallel Kinematic Manipulator for Flexible Manufacturing
- 2009
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Ingår i: 13th IFAC Symposium on Information Control Problems in Manufacturing. - 9783902661432 ; 42:4, s. 145-150
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Konferensbidrag (refereegranskat)abstract
- Flexible manufacturing puts high demands on industrial automation in terms of affordable and competitive solutions and is of key importance for short-lot production typically found in small and medium sized enterprises, situations where today manual labour is extensively used despite environmental issues and harsh working conditions. Key factors in the successful introduction of new robot automation concepts are that they provide both the desired performance and quality (technical capability), but also that they enable fast deployment and extend available task repertoire. The Gantry-Tau manipulator is a new robot concept which in contrast to other high-performance parallel kinematic manipulators (PKM), has a large, open working range. Its high stiffness makes it ideal for a wide range of tasks such as grinding, deburring, and cutting. An additional aspect of such a PKM is the modularity, which in this work has been studied in terms of possibilities for assembly and mechanical reconfiguration at the end-user site, integration of such a kinematically different robot with a standard industrial controller, and new needs for methods/tools to support simple (re)configuration. A range of software tools and methods were found to be useful and necessary for efficient engineering and integration of the concept in typical SME manufacturing scenarios. For experimental evaluation, two full-scale prototype robots were designed and built, the kinematic software was developed and integrated into a couple of different robot control systems, robot CAD software was adapted to the configuration needs, and both simulations and physical experiments were carried out. Our findings make us believe that enhanced software tools should be integrated on a higher symbolic (or meta-) level to better support transformation of data and code generation, but also that the Gantry-Tau type of robot (with adequate software support) will bring a new dimension of flexibility into SME manufacturing.
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| 10. |
- Holm, Ulf, et al.
(författare)
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Measurement system for magneto-optic sensor materials
- 1984
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Ingår i: Journal of Physics E: Scientific Instruments. - : The Institute of Physics. - 0022-3735. ; 17:10, s. 885-889
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Tidskriftsartikel (refereegranskat)abstract
- A system for the measurements of magneto-optic properties of IR-transparent materials is described. The system is designed for the characterisation of fibre optic magnetic field sensor materials. Measurement results on YIG-crystals are prresented. The accuracy of Faraday rotation and light transmission measurements are ±2 mrad and ±2% respectively. Important features for the sensor characterisation are light beam scanning, temperature control and flexible magnetic field generation. A desktop computer is used for system control and data acquisition. The system is expected to be of great importance for future sensor developments.
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