- Prof Rolf Johansson
Lund University
Dept. Automatic Control
PO Box 118
SE22100 Lund Sweden - +46462228791
Rolf Johansson
Lund University, Automatic Control, Faculty Member
- Rolf Johansson is with the Dept. Automatic Control, Lund University, where he is Professor of control science and Dir... moreRolf Johansson is with the Dept. Automatic Control, Lund University, where he is Professor of control science and Director of Robotics Laboratory. He was involved in research in adaptive system theory, mathematical modeling, system identification, robotics and signal processing. Since 1987, he also participated in research and as a graduate advisor at the Faculty of Medicine, Lund University Hospital. He had the following visiting appointments: Researcher, 1985, Centre National de la Recherche Scientifique (CNRS), Grenoble, France; Visiting scientist CalTech, CA, June 1997, June 2001; Rice Univ., Houston, TX, May 1998, May 2001; Supélec, France, June 1998; Univ. Illinois at Urbana-Champaign, IL; UC Santa Barbara, CA, Aug. 1999; Univ. Napoli Fed II, Italy, July 2000; Guest Professor, NTNU, Trondheim, NO, Aug. 2001, Aug. 2012; Guest Professor at CIDAC, Univ. Newcastle, Australia, July 2003. Tsinghua Univ., China, Nov. 2003, Aug. 2004, Sep-Dec 2012; Hon.Visiting Professor, North China Univ. Science and Technology (NCUST), China, 2003; Hon. Visiting Professor, Wuhan Univ. Science and Technology (WUST), China, 2004; Russell S. Springer Visiting Professor 2004, UC Berkeley, Berkeley, CA; Univ. Valladolid, Spain, June 2004; Univ. Jaén, Spain, July 2005; SIMTech Fellow, SIMTech, A*STAR, Singapore, Mar 2010; Oct-Nov 2010; Oct-Nov 2011; Tsinghua Univ., China, Sep-Dec 2012.
Rolf Johansson is IEEE Fellow and Fellow of the Royal Physiographic Society, Section of Medicine. He was awarded the 1995 Ebeling Prize of the Swedish Society of Medicine for distinguished contribution to the study of human balance through application and development of system analysis and robotics. He was co-recipient of EURON Technology Transfer Award 2004, 2007, and ICRA2012 Best Automation Paper Award. He is Assoc. Editor of Int. J. Adaptive Control & Signal Processing; Editor, Intelligent Service Robotics; Editorial Board Member, Robotics and Biomimetics; Editor of Mathematical Biosciences.edit
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Two-Degree-of-Freedom Control for Trajectory Tracking and Perturbation Recovery during Execution of Dynamical Movement Primitives * *The authors are members of the LCCC Linnaeus Center and the ELLIIT Excellence Center at Lund University. The research leading to these results has received funding ...more
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Objectives: Atrial fibrillation AF in man has previously been shown to include a wide variety of atrial activity. Assessment of the characteristics of this arrhythmia with a commonly applicable tool may therefore be important in the... more
Objectives: Atrial fibrillation AF in man has previously been shown to include a wide variety of atrial activity. Assessment of the characteristics of this arrhythmia with a commonly applicable tool may therefore be important in the choice and evaluation of different therapeutic strategies. As the AF cycle length has been shown to correlate locally with atrial refractoriness and globally with the degree of atrial organization, with, in general, shorter cycle length during apparently random AF compared to more organized AF, we have . developed a new method for non-invasive assessment of the AF cycle length using the surface and the esophagus ESO ECG. Methods and Results: From the frequency spectrum of the residual ECG, created by suppression of the QRST complexes, the dominant atrial . cycle length DACL was derived. By comparison with multiple intracardiac simultaneously acquired right and left AF cycle lengths in patients with paroxysmal AF, we found that the DACL in lead V1, ranging from 130 to 185 ms, well represented a spatial average of the right AF cycle lengths, whereas the DACL in the ESO ECG, ranging from 140 to 185 ms, reflected both the right and the left AF cycle length, where the influence from each structure depended on the atrial anatomy of the individual, as determined by MRI. In patients with chronic AF, the method was capable of following changes in the AF cycle length due to administration of D,L-sotalol and 5 min of ECG recording was sufficient for the DACL to be reproducible. Conclusions: We conclude that this new non-invasive method, named . 'Frequency Analysis of Fibrillatory ECG' FAF-ECG , is capable of assessing both the magnitude and the dynamics of the atrial fibrillation cycle length in man. q 1998 Elsevier Science B.V.
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M. Holm, P. Blomstrom, J. Brandt, R. Johansson, C. Luhrs, and S. B. Olsson. Determination of preferable wavelet propagation directions in atrial fibrillation. In Erik K. Fernstrom Symp. Atrial Fibrillation, Lund, Sweden, June 1993.
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We consider temperature stabilization of the phase-reference line at the European Spallation Source, a facility for neutron spallation currently under construction. Based on extensive modeling of the heat dynamics, a prototype model-based... more
We consider temperature stabilization of the phase-reference line at the European Spallation Source, a facility for neutron spallation currently under construction. Based on extensive modeling of the heat dynamics, a prototype model-based control system with associated hardware architecture is developed and experimentally evaluated on a small-scale setup. The results indicate that temperature stability within ±0.1°C is possible to achieve, also with significant disturbances in the ambient temperature expected during operation.
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Model Predictive Control (MPC) is an efficient point-to-point trajectory-generation method for robots that can be used in situations that occur under time constraints. The motion plan can be recalculated online to increase the accuracy of... more
Model Predictive Control (MPC) is an efficient point-to-point trajectory-generation method for robots that can be used in situations that occur under time constraints. The motion plan can be recalculated online to increase the accuracy of the trajectory when getting close to the goal position. We have implemented this strategy in a Franka Emika Panda robot, a redundant collaborative robot, by extending previous research that was performed on a 6-DOF robot. We have also used null-space motion to ensure a continuous movement of all joints during the entire trajectory execution as an approach to avoid joint stiction and allow accurate kinesthetic teaching. As is conventional for collaborative and industrial robots, the Panda robot is equipped with an internal controller, which allows to send position and velocity references directly to the robot. Therefore, null-space motion can be added directly to the MPC-generated velocity references. The observed trajectory deviation caused by discretization approximations of the Jacobian matrix when implementing null-space motion has been corrected experimentally using sensor feedback for the real-time velocity-reference recalculation and by performing a fast sampling of the null-space vector. Null-space motion has been experimentally seen to contribute to reducing the friction torque dispersion present in static joints.
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Dataset used for evaluation of a recurrent neural network (RNN) for recognition of transients, in order to detect events during robotic assembly. Inputs are robot joint torque data. Outputs are probabilities that the event is occurring,... more
Dataset used for evaluation of a recurrent neural network (RNN) for recognition of transients, in order to detect events during robotic assembly. Inputs are robot joint torque data. Outputs are probabilities that the event is occurring, as estimated by the RNN. Possible to use for detection models other than RNNs. Used as experimental results in the paper Martin Karlsson, Anders Robertsson, Rolf Johansson, <em>Detection and Control of Contact Force Transientsin Robotic Manipulation without a Force Sensor, </em>by to be presented at ICRA, Brisbane, May 2018.
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We consider the classical 3-state Moore-Greitzer model, which is commonly used for approximating dynamics of deviations of flow and pressure variables in an axial compressor from their nominal steady-state values. The linearization of the... more
We consider the classical 3-state Moore-Greitzer model, which is commonly used for approximating dynamics of deviations of flow and pressure variables in an axial compressor from their nominal steady-state values. The linearization of the nonlinear system is not controllable and, therefore, even local asymptotic stability cannot be achieved using methods of linear control theory. We propose a family of parametrized partial-state feedback control laws and derive sufficient conditions to guarantee global asymptotic stability of the closed-loop system. The stability analysis uses the integral quadratic constraints technique for the case of non-strict frequency condition and novel arguments for characterization of ω-limit sets.