| 1. |
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| 2. |
- Nilsson, Klas, et al.
(författare)
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Integrated Architecture for Industrial Robot Programming and Control
- 1999
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Ingår i: Robotics and Autonomous Systems. - 0921-8890. ; 29:4, s. 205-226
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Tidskriftsartikel (refereegranskat)abstract
- As robot control systems are traditionally closed, it is difficult to add supplementary intelligence. Accordingly, as based on a new notion of user views, a layered system architecture is proposed. Bearing in mind such industrial demands as computing efficiency and simple factory-floor operation, the control layers are parameterized by means of functional operators consisting of pieces of compiled code that can be passed as parameters between the layers. The required interplay between application-specific programs and built-in motion control is thereby efficiently accomplished. The results from experimental evaluation and several case studies suggest the architecture to be very useful also in an industrial context.
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| 3. |
- Baerveldt, Albert-Jan
(författare)
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A vision system for object verification and localization based on local features
- 2001
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Ingår i: Robotics and Autonomous Systems. - Amsterdam : Elsevier. - 0921-8890 .- 1872-793X. ; 34:2-3, s. 83-92
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Tidskriftsartikel (refereegranskat)abstract
- An object verification and localization system should answer the question whether an expected object is present in an image or not, i.e. verification, and if present where it is located. Such a system would be very useful for mobile robots, e.g. for landmark recognition or for the fulfilment of certain tasks. In this paper, we present an object verification and localization system specially adapted to the needs of mobile robots. The object model is based on a collection of local features derived from a small neighbourhood around automatically detected interest points. The learned representation of the object is then matched with the image under consideration. The tests, based on 81 images, showed a very satisfying tolerance to scale changes of up to 50%, to viewpoint variations of 20, to occlusion of up to 80% and to major background changes as well as to local and global illumination changes. The tests also showed that the verification capabilities are very good and that similar objects did not trigger any false verification.
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| 4. |
- Baerveldt, Albert-Jan, et al.
(författare)
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Editorial
- 2003
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Ingår i: Robotics and Autonomous Systems. - Amsterdam : Elsevier. - 0921-8890 .- 1872-793X. ; 44:1, s. 1-
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Tidskriftsartikel (populärvet., debatt m.m.)
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| 5. |
- Bengtsson, Ola, et al.
(författare)
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Robot localization based on scan-matching - estimating the covariance matrix for the IDC algorithm
- 2003
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Ingår i: Robotics and Autonomous Systems. - Amsterdam : Elsevier. - 0921-8890 .- 1872-793X. ; 44:1, s. 29-40
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Tidskriftsartikel (refereegranskat)abstract
- We have previously presented a new scan-matching algorithm based on the IDC (iterative dual correspondence) algorithm, which showed a good localization performance even in environments with severe changes. The problem of the IDC algorithm is that there is no good way to estimate a covariance matrix of the position estimate, which prohibits an effective fusion with other position estimates of other sensors. This paper presents two new ways to estimate the covariance matrix. The first estimates the covariance matrix from the Hessian matrix of the error function minimized by the scan-matching algorithm. The second one, which is an off-line method, estimates the covariance matrix of a specific scan, from a specific position by simulating and matching scans around the position. Simulation results show that the covariance matrix provided by the off-line method fully corresponds with the real one. Some preliminary tests on real data indicate that the off-line method gives a good quality value of a specific scan position, which is of great value in map building.
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| 6. |
- Coradeschi, Silvia, et al.
(författare)
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An introduction to the anchoring problem
- 2003
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Ingår i: Robotics and Autonomous Systems. - 0921-8890 .- 1872-793X. ; 43:2-3, s. 85-96
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Tidskriftsartikel (refereegranskat)abstract
- Anchoring is the problem of connecting, inside an artificial system, symbols and sensor data that refer to the same physical objects in the external world. This problem needs to be solved in any robotic system that incorporates a symbolic component. However, it is only recently that the anchoring problem has started to be addressed as a problem per se, and a few general solutions have begun to appear in the literature. This paper introduces the special issue on perceptual anchoring of the Robotics and Autonomous Systems journal. Our goal is to provide a general overview of the anchoring problem, and to highlight some of its subtle points
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| 7. |
- Duckett, Tom, et al.
(författare)
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Mobile robot self-localisation using occupancy histograms and a mixture of Gaussian location hypotheses
- 2001
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Ingår i: Robotics and Autonomous Systems. - 0921-8890 .- 1872-793X. ; 34:2-3, s. 117-129
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Tidskriftsartikel (refereegranskat)abstract
- The topic of mobile robot self-localisation is often divided into the sub-problems of global localisation and position tracking. Both are now well understood individually, but few mobile robots can deal simultaneously with the two problems in large, complex environments. In this paper, we present a unified approach to global localisation and position tracking which is based on a topological map augmented with metric information. This method combines a new scan matching technique, using histograms extracted from local occupancy grids, with an efficient algorithm for tracking multiple location hypotheses over time. The method was validated with experiments in a series of real world environments, including its integration into a complete navigating robot. The results show that the robot can localise itself reliably in large, indoor environments using minimal computational resources
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| 8. |
- Emami, Reza, et al.
(författare)
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Systematic design and analysis of fuzzy-logic control and application to robotics : Part II. Control
- 2000
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Ingår i: Robotics and Autonomous Systems. - 0921-8890 .- 1872-793X. ; 33:2-3, s. 89-108
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Tidskriftsartikel (refereegranskat)abstract
- This paper (Part II) follows the task of systematic synthesis and analysis of fuzzy-logic control (FLC) systems introduced in Part I [M.R. Emami, et al., Robotics and Autonomous Systems 33 (2000) 65–88]. First, a generalized formulation of the sliding mode control is obtained for a class of nonlinear multi-input–multi-output systems. This formulation has two distinguishing features that are necessary for the formulation of the proposed approach: (i) it is applicable to “black box” systems with no need to identify the internal parameters or to assume a specific structure; (ii) it is possible to design the robust controller for each system state independently while the stability and robustness of the entire system is guaranteed. The robust fuzzy control rules are designed based on the generalized formulation to guarantee the stability and satisfactory system performance. The proposed FLC has been applied to trajectory control of the four degree-of-freedom IRIS arm (Emami et al., 2000), and was compared with high-gain PID controllers. A superior tracking performance was achieved.
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| 9. |
- Emami, Reza, et al.
(författare)
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Systematic design and analysis of fuzzy-logic control and application to robotics : Part 1. Modeling
- 2000
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Ingår i: Robotics and Autonomous Systems. - 0921-8890 .- 1872-793X. ; 33:2-3, s. 65-88
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Tidskriftsartikel (refereegranskat)abstract
- A systematic methodology for synthesis and analysis of fuzzy-logic controllers is proposed in this paper (Part I) and its follow up (Part II) [M.R. Emami, et al., Robotics and Autonomous Systems 33 (2000) 89–108]. A robust model-based control structure is suggested that includes a fuzzy-logic inverse dynamics model and several robust fuzzy control rules. The model encapsulates the knowledge of the system dynamics in the form of IF–THEN rules. The paper focuses on how to obtain this knowledge systematically from the input–output data of a complex system; one that is ill-defined or contains complicated phenomena that are difficult to interpret analytically. All practical steps, from data acquisition to model validation, are illustrated using a four degree-of-freedom robot manipulator. Comparing the results with those of a complete analytical model and a heuristic fuzzy modeling technique illustrates the strength of the proposed methodology in terms of capturing effects that are difficult to model. In the follow-up paper, this model is used in the proposed control structure.
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| 10. |
- Fabrizi, Elisabetta, et al.
(författare)
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Augmenting topology-based maps with geometric information
- 2002
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Ingår i: Robotics and Autonomous Systems. - 0921-8890 .- 1872-793X. ; 40:2, s. 91-97
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Tidskriftsartikel (refereegranskat)abstract
- Topology-based maps are a new representation of the workspace of a mobile robot, which capture the structure of the free space in the environment in terms of the basic topological notions of connectivity and adjacency. A topology-based map can represent the environment in terms of open spaces (rooms and corridors) connected by narrow passages (doors and junctions). In this paper, we show how to enrich a topology-based map with geometric information useful for the generation and execution of navigation plans. Both the topology-based map and its geometric information are automatically extracted from sensor data. We illustrate the use of topology-based maps for planned behavior-based navigation on a real robot.
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