| 1. |
- Asl, Reza Mohammadi, et al.
(författare)
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Fuzzy-Based Parameter Optimization of Adaptive Unscented Kalman Filter : Methodology and Experimental Validation
- 2020
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Ingår i: IEEE Access. - : IEEE. - 2169-3536. ; 8, s. 54887-54904
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Tidskriftsartikel (refereegranskat)abstract
- This study introduces a fuzzy based optimal state estimation approach. The new method is based on two principles: Adaptive Unscented Kalman filter, and Fuzzy Adaptive Grasshopper Optimization Algorithm. The approach is designed for the optimization of an adaptive Unscented Kalman Filter. To find the optimal parameters for the filter, a fuzzy based evolutionary algorithm, named Fuzzy Adaptive Grasshopper Optimization Algorithm, is developed where its efficiency is verified by application to different benchmark functions. The proposed optimal adaptive unscented Kalman filter is applied to two nonlinear systems: a robotic manipulator, and a servo-hydraulic system. Different simulation tests are conducted to verify the performance of the filter. The results of simulations are presented and compared with a previous version of the unscented Kalman filter. For a realistic test, the proposed filter is applied on the practical servo-hydraulic system. Practical results are discussed, and presented results approve the capability of the presented method for practical applications.
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| 2. |
- Asl, Reza Mohammadi, et al.
(författare)
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Integral Non-Singular Terminal Sliding Mode Controller for nth-Order Nonlinear Systems
- 2019
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Ingår i: IEEE Access. - : Institute of Electrical and Electronics Engineers (IEEE). - 2169-3536. ; 7, s. 102792-102802
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Tidskriftsartikel (refereegranskat)abstract
- In this study, a new integral non-singular terminal sliding mode control method for nonlinear systems is introduced. The proposed controller is designed by defining a new sliding surface with an additional integral part. This new manifold is first introduced into the second-order system and then expanded to nth-order systems. The stability of the control system is demonstrated for both second-order and nth-order systems by using the Lyapunov stability theory. The proposed controller is applied to a robotic manipulator as a case study for second-order systems, and a servo-hydraulic system as a case study for third-order systems. The results are presented and discussed.
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| 3. |
- Bergsten, Pontus, 1971-, et al.
(författare)
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Fuzzy Observers
- 2001
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Ingår i: The 10th IEEE International Conference on Fuzzy Systems (Volym:3). - New York, USA : IEEE conference proceedings. - 078037293X ; , s. 700-703
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Konferensbidrag (refereegranskat)abstract
- We consider the analysis and design of three different types of nonlinear observers for dynamic Takagi-Sugeno fuzzy systems. Our approach is based on extending existing nonlinear observer schemes, namely Thau-Luenberger and sliding mode observers, to the case of interpolated multiple local affine linear models. Then linear matrix inequality based techniques are used for observer analysis and design.
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| 4. |
- Bergsten, Pontus, 1971-, et al.
(författare)
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Observers for Takagi-Sugeno fuzzy systems
- 2002
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Ingår i: IEEE transactions on systems, man and cybernetics. Part B. Cybernetics. - : IEEE Journals & Magazines. - 1083-4419 .- 1941-0492. ; 32:1, s. 114-121
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Tidskriftsartikel (refereegranskat)abstract
- We focus on the analysis and design of two different sliding mode observers for dynamic Takagi-Sugeno (TS) fuzzy systems. A nonlinear system of this class is composed of multiple affine local linear models that are smoothly interpolated by weighting functions resulting from a fuzzy partitioning of the state space of a given nonlinear system subject to observation. The Takagi-Sugeno fuzzy system is then an accurate approximation of the original nonlinear system. Our approach to the analysis and design of observers for Takagi-Sugeno fuzzy systems is based on extending sliding mode observer schemes to the case of interpolated multiple local affine linear models. Thus, our main contribution is nonlinear observer analysis and design methods that can effectively deal with model/plant mismatches. Furthermore, we consider the difficult case when the weighting functions in the Takagi-Sugeno fuzzy system depend on the estimated state
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| 5. |
- Chadalavada, Ravi Teja, 1989-, et al.
(författare)
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Accessing your navigation plans! Human-Robot Intention Transfer using Eye-Tracking Glasses
- 2018
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Ingår i: Advances in Manufacturing Technology XXXII. - Amsterdam, Netherlands : IOS Press. - 9781614999010 - 9781614999027 ; , s. 253-258
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Konferensbidrag (refereegranskat)abstract
- Robots in human co-habited environments need human-aware task and motion planning, ideally responding to people’s motion intentions as soon as they can be inferred from human cues. Eye gaze can convey information about intentions beyond trajectory and head pose of a person. Hence, we propose eye-tracking glasses as safety equipment in industrial environments shared by humans and robots. This paper investigates the possibility of human-to-robot implicit intention transference solely from eye gaze data. We present experiments in which humans wearing eye-tracking glasses encountered a small forklift truck under various conditions. We evaluate how the observed eye gaze patterns of the participants related to their navigation decisions. Our analysis shows that people primarily gazed on that side of the robot they ultimately decided to pass by. We discuss implications of these results and relate to a control approach that uses human eye gaze for early obstacle avoidance.
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| 6. |
- Chadalavada, Ravi Teja, 1989-, et al.
(författare)
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Bi-directional navigation intent communication using spatial augmented reality and eye-tracking glasses for improved safety in human-robot interaction
- 2020
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Ingår i: Robotics and Computer-Integrated Manufacturing. - : Elsevier. - 0736-5845 .- 1879-2537. ; 61
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Tidskriftsartikel (refereegranskat)abstract
- Safety, legibility and efficiency are essential for autonomous mobile robots that interact with humans. A key factor in this respect is bi-directional communication of navigation intent, which we focus on in this article with a particular view on industrial logistic applications. In the direction robot-to-human, we study how a robot can communicate its navigation intent using Spatial Augmented Reality (SAR) such that humans can intuitively understand the robot's intention and feel safe in the vicinity of robots. We conducted experiments with an autonomous forklift that projects various patterns on the shared floor space to convey its navigation intentions. We analyzed trajectories and eye gaze patterns of humans while interacting with an autonomous forklift and carried out stimulated recall interviews (SRI) in order to identify desirable features for projection of robot intentions. In the direction human-to-robot, we argue that robots in human co-habited environments need human-aware task and motion planning to support safety and efficiency, ideally responding to people's motion intentions as soon as they can be inferred from human cues. Eye gaze can convey information about intentions beyond what can be inferred from the trajectory and head pose of a person. Hence, we propose eye-tracking glasses as safety equipment in industrial environments shared by humans and robots. In this work, we investigate the possibility of human-to-robot implicit intention transference solely from eye gaze data and evaluate how the observed eye gaze patterns of the participants relate to their navigation decisions. We again analyzed trajectories and eye gaze patterns of humans while interacting with an autonomous forklift for clues that could reveal direction intent. Our analysis shows that people primarily gazed on that side of the robot they ultimately decided to pass by. We discuss implications of these results and relate to a control approach that uses human gaze for early obstacle avoidance.
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| 7. |
- Driankov, Dimiter, 1952-, et al.
(författare)
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A Takagi-Sugeno fuzzy gain-scheduler
- 1996
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Ingår i: Proceedings of the Fifth IEEE International Conference on Fuzzy Systems. - New York, USA : IEEE conference proceedings. - 0780336453 ; , s. 1053-1059
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Konferensbidrag (refereegranskat)abstract
- In the present paper we describe the design of a fuzzy gain scheduler for tracking a reference trajectory of a nonlinear autonomous system. The proposed fuzzy gain scheduling method has two major advantages over the existing crisp gain scheduling methods. First, it provides a general and formally motivated method for the interpolation of available local control laws into a global gain scheduling control law. Second, the method for determining the weights of the local control laws in the global gain scheduling control law is general and computationally efficient. It is shown that a fuzzy gain scheduler can be designed such that robust asymptotic stability is met. Finally, an LQR control design based method is presented
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| 8. |
- Driankov, Dimiter, 1952-, et al.
(författare)
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Fuzzy control with fuzzy inputs: the need for new rule semantics
- 1994
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Ingår i: Proceedings of the Third IEEE Conference on Fuzzy Systems, 1994. IEEE World Congress on Computational Intelligence, VOLS I-III. - : IEEE conference proceedings. - 078031896X ; , s. 111-114
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Konferensbidrag (refereegranskat)abstract
- The standard computation taking place in a fuzzy logic controller proceeds from crisp inputs and via the consecutive steps of fuzzification, inference, and defuzzification computes a crisp control output. However, this computational practice simplifies to an extent the actual developments taking place in the closed loop. In reality, the knowledge about the current values of the controller input is very often available via sensory measurements. In this case, one has to take into account the negative side effects that come up with the use of sensors, in particular the presence of noisy measurements. In the paper the authors consider one particular way of dealing with noisy controller inputs, namely transforming the noise-distribution into a fuzzy set and then feeding back the so obtained fuzzy signal to the controller input. Adopting this approach requires that the shape of the input fuzzy signal should be reflected as much as possible in the output fuzzy signal so that important noise characteristics are preserved. In the paper the authors describe the requirements on the shape of the fuzzy output signal given a certain fuzzy input signal and show that the existing semantics for fuzzy IF-THEN rules do not satisfy these requirements. The authors propose new semantics for such rules which together with max-min composition produces the desired results.
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| 9. |
- Palm, Rainer, 1942-, et al.
(författare)
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Fluid mechanics for path planning and obstacle avoidance of mobile robots
- 2014
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Ingår i: ICINCO 2014 proceedings of the 11th International Conference on Informatics in Control Automation and Robotics. - : SciTePress. - 9789897580406 ; , s. 231-238
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Konferensbidrag (refereegranskat)abstract
- Obstacle avoidance is an important issue for off-line path planning and on-line reaction to unforeseen appearance of obstacles during motion of a non-holonomic mobile robot along apredefined trajectory. Possible trajectories for obstacle avoidance are modeled by the velocity potential using a uniform flow plus a doublet representing a cylindrical obstacle. In the case of an appearance of an obstacle in the sensor cone of the robot a set of streamlines is computed from which a streamline is selected that guarantees a smooth transition from/to the planned trajectory. To avoid collisions with other robots a combination of velocity potential and force potential and/or the change of streamlines during operation (lane hopping) are discussed.
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| 10. |
- Palm, Rainer, 1942-, et al.
(författare)
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Fuzzy Geometric Approach to Collision Estimation Under Gaussian Noise in Human-Robot Interaction
- 2021
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Ingår i: Computational Intelligence. - Cham : Springer. - 9783030705930 - 9783030705947 - 9783030705961 ; , s. 191-221
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Bokkapitel (refereegranskat)abstract
- Humans and mobile robots while sharing the same work areas require a high level of safety especially at possible intersections of trajectories. An issue of the human-robot navigation is the computation of the intersection point in the presence of noisy measurements or fuzzy information. For Gaussian distributions of positions/orientations (inputs) of robot and human agent and their parameters the corresponding parameters at the intersections (outputs) are computed by analytical and fuzzy methods.This is done both for the static and the dynamic case using Kalman filters for robot/human positions and orientations and thus for the estimation of the intersection positions. For the overdetermined case (6 inputs, 2 outputs) a so-called ’energetic’ approach is used for the estimation of the point of intersection. The inverse task is discussed, specifying the parameters of the output distributions and looking for the parameters of the input distributions. For larger standard deviations (stds) mixed Gaussian models are suggested as approximation of non-Gaussian distributions.
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