1. |
- Hjalmarsson, Håkan, 1962-, et al.
(författare)
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Iterative feedback tuning : Theory and applications
- 1998
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Ingår i: IEEE Control Systems Magazine. - : Institute of Electrical and Electronics Engineers (IEEE). - 0272-1708 .- 2374-9385 .- 1066-033X .- 1941-000X. ; 18:4, s. 26-41
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Tidskriftsartikel (refereegranskat)
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2. |
- Möllerstedt, Erik, et al.
(författare)
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Out of Control Because of Harmonics - An Analysis of Harmonic Response of an Inverter Train
- 2000
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Ingår i: Control Systems Magazine. - : Institute of Electrical and Electronics Engineers (IEEE). - 0272-1708 .- 1066-033X .- 1941-000X. ; 20:4, s. 70-81
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Tidskriftsartikel (refereegranskat)abstract
- Presents a method to use linear analysis to capture the frequency coupling of nonlinear and time-varying components. System stability is analyzed by connecting the harmonic transfer functions of the different component models. This facilitates an object-oriented approach to modeling, which supports reuse of models. An analysis of the complete railway system is, of course, difficult. Several locomotives can be moving along the power distribution line at the same time, and depending on the distance between them, the interaction changes. The power consumption also changes, depending on operating modes. During normal operation, energy is consumed from the network, but as modern locomotives use electrical braking, the power flow changes direction during deceleration, and energy is delivered back to the grid. The inverter trains are not passive systems. The converters are controlled with only limited system knowledge (local measurements of currents and voltages), making analysis and control design an even bigger challenge
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3. |
- Wittenmark, Björn, et al.
(författare)
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Dynamic pictures and interactive learning
- 1998
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Ingår i: Control Systems Magazine. - : Institute of Electrical and Electronics Engineers (IEEE). - 0272-1708 .- 1066-033X .- 1941-000X. ; 18:3, s. 26-32
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Tidskriftsartikel (refereegranskat)abstract
- The paper presents interactive learning tools used in courses in automatic control at Lund Institute of Technology. The learning tools are aimed at improving the understanding of and intuition for the abstract parts of the control courses. The paper presents dynamic interactive modules for a course in sampled-data systems. The tools are implemented in Matlab and used over the Internet.
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4. |
- Ahlen, Anders, et al.
(författare)
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Toward Wireless Control in Industrial Process Automation : A Case Study at a Paper Mill
- 2019
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Ingår i: IEEE Control Systems. - : Institute of Electrical and Electronics Engineers (IEEE). - 1066-033X .- 1941-000X. ; 39:5, s. 36-57
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Tidskriftsartikel (refereegranskat)abstract
- Wireless sensors and networks are used only occasionally in current control loops in the process industry. With rapid developments in embedded and highperformance computing, wireless communication, and cloud technology, drastic changes in the architecture and operation of industrial automation systems seem more likely than ever. These changes are driven by ever-growing demands on production quality and flexibility. However, as discussed in "Summary," there are several research obstacles to overcome. The radio communication environment in the process industry is often troublesome, as the environment is frequently cluttered with large metal objects, moving machines and vehicles, and processes emitting radio disturbances [1], [2]. The successful deployment of a wireless control system in such an environment requires careful design of communication links and network protocols as well as robust and reconfigurable control algorithms.
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5. |
- Ahlén, Anders, et al.
(författare)
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Towards Wireless Control in Industrial Process Automation : A Case Study at a Paper Mill
- 2019
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Ingår i: IEEE CONTROL SYSTEMS MAGAZINE. - : IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC. - 1066-033X .- 1941-000X. ; 39:5, s. 36-57
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Tidskriftsartikel (refereegranskat)abstract
- Wireless sensors and networks are used only occasionally in current control loops in the process industry. With rapid developments in embedded and highperformance computing, wireless communication, and cloud technology, drastic changes in the architecture and operation of industrial automation systems seem more likely than ever. These changes are driven by ever-growing demands on production quality and flexibility. However, as discussed in "Summary," there are several research obstacles to overcome. The radio communication environment in the process industry is often troublesome, as the environment is frequently cluttered with large metal objects, moving machines and vehicles, and processes emitting radio disturbances [1], [2]. The successful deployment of a wireless control system in such an environment requires careful design of communication links and network protocols as well as robust and reconfigurable control algorithms.
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6. |
- Annaswamy, A. M., et al.
(författare)
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Control for Societal-Scale Challenges: Road Map 2030
- 2024
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Ingår i: IEEE Control Systems. - : Institute of Electrical and Electronics Engineers (IEEE). - 1066-033X .- 1941-000X. ; 44:3, s. 30-32
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Tidskriftsartikel (refereegranskat)abstract
- The world faces some of the greatest challenges of modern times. How we address them will have a dramatic impact on society at large for generations to come. The field of control systems pertains to specific methods and principles to control dynamic systems and produce desired outcomes despite uncertainties in the system and in the environment. The development of these principles and methods has been both broad and deep, from aerospace systems and wireless networks to bioengineering and traffic control. These methods are deeply embedded in many sectors, including energy, transportation, health care, manufacturing, and robotics. With their advanced toolbox for understanding and designing feedback, robustness, dynamics, and decision making in complex systems, control systems have an opportunity to play a central role in the development of technologies and solutions for many of the key challenges that society faces.
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7. |
- Bergman, Niclas, et al.
(författare)
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Terrain Navigation using Bayesian Statistics
- 1999
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Ingår i: IEEE Control Systems. - : Institute of Electrical and Electronics Engineers (IEEE). - 1066-033X .- 1941-000X. ; 19:3, s. 33-40
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Tidskriftsartikel (refereegranskat)abstract
- The performance of terrain-aided navigation of aircraft depends on the size of the terrain gradient in the area. The point-mass filter (PMF) described in this work yields an approximate Bayesian solution that is well suited for the unstructured nonlinear estimation problem in terrain navigation. It recursively propagates a density function of the aircraft position. The shape of the point-mass density reflects the estimate quality; this information is crucial in navigation applications, where estimates from different sources often are fused in a central filter. Monte Carlo simulations show that the approximation can reach the optimal performance, and realistic simulations show that the navigation performance is very high compared with other algorithms and that the point-mass filter solves the recursive estimation problem for all the types of terrain covered in the test. The main advantages of the PMF is that it works for many kinds of nonlinearities and many kinds of noise and prior distributions. The mesh support and resolution are automatically adjusted and controlled using a few intuitive design parameters. The main disadvantage is that it cannot solve estimation problems of very high dimension since the computational complexity of the algorithm increases drastically with the dimension of the state space. The implementation used in this work shows real-time performance for 2D and in some cases 3D models, but higher state dimensions are usually intractable.
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8. |
- Birk, Wolfgang, et al.
(författare)
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Model based control for a fine coal injection plant
- 1999
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Ingår i: I E E E Control Systems Magazine. - : Institute of Electrical and Electronics Engineers (IEEE). - 0888-0611. ; 19:1, s. 33-43
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Tidskriftsartikel (refereegranskat)abstract
- Modeling, control, and gas leakage detection in the coal injection process are discussed. It is shown that by use of model-based methods, the flow and pressure of the coal injection vessel are reliably controlled. With the new control law, the coal mass flow can be used as a control parameter for the blast furnace. High injection rates can be used and more coke substituted, This is expected to yield a cost reduction in the iron production. An experimental comparison of the conventional control unit with the one suggested in this article shows that an improvement of the process efficiency can be reached by other means than increasing the capacity of the plant
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9. |
- Forsling, Robin, et al.
(författare)
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A Quarter Century of Covariance Intersection: Correlations Still Unknown? [Lecture Notes]
- 2024
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Ingår i: IEEE CONTROL SYSTEMS MAGAZINE. - : IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC. - 1066-033X .- 1941-000X. ; 44:2, s. 81-105
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Tidskriftsartikel (refereegranskat)abstract
- Over the past two and a half decades, covariance intersection (CI) has provided a means for robust estimation in scenarios where the uncertainty information is incomplete. Estimation in distributed and decentralized data fusion (DDF) settings is typically characterized by having nonzero cross-correlations between the estimates to be merged. Mean-square-error (MSE) optimal estimators, such as the Kalman filter (KF), are limited to data fusion problems where these cross-correlations are fully known. Keeping track of cross-correlations is unfortunately not always possible. To quantify confidence in the estimate's uncertainty, the concept of conservativeness has been introduced. A conservative estimator guarantees that the computed covariance matrix is not smaller than the actual covariance matrix. It turns out that CI guarantees conservativeness for any degree of unknown cross-correlations as long as the estimates to be fused are conservative. It should be noted that, in the CI literature, the notion of covariance consistency is often used to characterize conservativeness. In this work, we use the latter term.
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10. |
- Gustafsson, Fredrik
(författare)
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Monitoring Tire-Road Friction using the Wheel Slip
- 1998
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Ingår i: IEEE Control System. - : Institute of Electrical and Electronics Engineers (IEEE). - 1066-033X .- 1941-000X. ; 18:4, s. 42-49
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Tidskriftsartikel (refereegranskat)abstract
- Tire-road friction estimation has become an intense research area as the interest of information technology in vehicles increases. In this work, we follow a model-based approach where the difference in wheel velocities of driven and non-driven wheels is used. The perhaps most important feature is that only existing sensors are needed if the car is supplied with ABS brakes. The goal is to compute certain parameters from available standard sensors in the car, which depend directly or indirectly on the friction, and to find rules regarding how to evaluate the maximal friction forces that can be used for braking or cornering.
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