Gunnar Hillerström, CUED, div. F

Gunnar Hillerström Ph.D.

Visitor of the Control Group.

Engineering Department
Cambridge University
Trumpington St.
Cambridge CB2 1PZ, United Kingdom

From the autumn 1997 I started to work at FOA, our national Defense Research Establishment, in Linköping, Sweden.
The easiest way to reach me, is by email at ghm@lin.foa.se; or by snailmail at
FOA 75
Box 1165
S-581 11 Linköping, Sweden.

I was earlier with the Control Engineering Group at Luleå University,
in the city of Luleå situated in Norrbotten, which is the northernmost
part of Sweden.
The picture to the right is from my former office.
If you want, you may also take a look into the Control Group's
Virtual Corridor.

Research in short

Control theory, especially Iterative Control Techniques (Repetitive and Learning Control) and Artificial Neural Networks. Computer aided design with focus on applications. Active suppression of vibrations. A reference list may be found here , and also my biased view on repetitive control.

Projects

(In inverse chronological order)

Active Supression of Vibrations
References
G. Hillerström, "Adaptive Suppression of Vibrations -- A Repetitive Control Approach," In IEEE Transactions on Control Systems Technology , 3(1), pp. 72-78, Jan. 1996.
G. Hillerström, "Vibration Suppression with Frequency Adaptation," In Proceedings of the 4th IEEE Conference on Control Applications, pp. 890-895, Albany, New York, Sept. 1995.
G. Hillerström, "Adaptive Suppression of Vibrations -- A Repetitive Control Approach," In Proceedings of the American Control Conference , pp. 3820--3824, Seattle, June 1995.
Angular Velocity Control of a Blood Pump used in Dialysis Treatments
The aim of this project is to study angular velocity control of a rotating axis, a peristaltic pump where the disturbance is associated with certain angular positions. The use of a constant sampling rate then implies varying disturbance period. A discrete repetitive control scheme based on a reduced order disturbance model tuned to the setpoint of the angular velocity is shown to reject the modeled disturbance with asymptotically zero error. With axis angle synchronization of sampling, the plant model is time-varying but it gives a static discrete disturbance model independent of the angular velocity. If the deviation from the nominal working point is not too large this is to prefer while it gives faster convergence.
Navigation in a Corridor System Using Angle Measurements to Identical Beacons
This was a Masters Thesis project performed by myself and Håkan Jonsson. The developed algorithms were evaluated on an autonomous guided vehicle, the Luleå Turbo Turtle (LTT), still being used in research projects by Robotics & Automation. A recent picture of the LTT is included to the right.
References
G. Hillerström & H. Jonsson, "Navigation in Corridors by Angle Measurements," Masters Thesis 1990:113E, Luleå University of Technology (In Swedish)
K. Hyyppä, U. Wiklund, U. Andersson, Å. Wernersson, T. Gustafsson, G. Hillerström and C. Zell, "Navigational Experiments with the Autonomous Mobile Robot LTT Using Angle Measurements to Identical Beacons," Int. Conf. on Machine Automation , pp. 99-109, Tampere, Finland, Febr. 15-18, 1994.
Last edited 1997-10-17 by myself.