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Wernersson, Åke
Alternative names
Publications (10 of 41) Show all publications
Rönnbäck, S. & Wernersson, Å. (2010). Range statistics and suppressing snowflakes: detects for laser range finders in snowfall. In: Vassil Sgurev; Mincho Hadjiski; Janusz Kacprzyk (Ed.), Intelligent Systems: From Theory to Practice (pp. 261-277). Paper presented at . Berlin: Springer Science+Business Media B.V.
Open this publication in new window or tab >>Range statistics and suppressing snowflakes: detects for laser range finders in snowfall
2010 (English)In: Intelligent Systems: From Theory to Practice, Berlin: Springer Science+Business Media B.V., 2010, p. 261-277Chapter in book (Refereed)
Abstract [en]

This paper presents statistics on registrations from laser range finders in snowfall. The sensors are standard laser range finders in robotics, the LMS200 and the URG-04LX. Three different working cases were identified for the pulsed laser range finder. 1) Normal operation with background objects present within the range of the sensor. 2) Close range objects where ranges to objects are shorter than the pulse length. 3) Free-space in the background. The findings are summarized as: Two laser range finders have been used, one that sends out a pulsed wide beam and one with a modulated narrow laser beam. The narrow beam laser has better penetration between the snowflakes. Median filtering shows a substantial reduction in snowflake detects. The gamma distribution describes fairly well the range distribution of detected snowflakes. In an intense snowfall where about 24% of the ranges detected snowflakes. A time-polar median filter showed good results in suppressing snowflakes in range data

Place, publisher, year, edition, pages
Berlin: Springer Science+Business Media B.V., 2010
Series
Studies in Computational Intelligence, ISSN 1860-949X ; 299
National Category
Other Electrical Engineering, Electronic Engineering, Information Engineering
Research subject
Industrial Electronics
Identifiers
urn:nbn:se:ltu:diva-20179 (URN)10.1007/978-3-642-13428-9_12 (DOI)2-s2.0-77957730561 (Scopus ID)29626050-d85f-11df-8b36-000ea68e967b (Local ID)978-3-642-13427-2 (ISBN)29626050-d85f-11df-8b36-000ea68e967b (Archive number)29626050-d85f-11df-8b36-000ea68e967b (OAI)
Note

Validerad; 2011; 20101015 (ysko)

Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2018-07-10Bibliographically approved
Rönnbäck, S. & Wernersson, Å. (2008). On filtering of laser range data in snowfall (ed.). In: (Ed.), (Ed.), 2008 4th International IEEE Conference Intelligent Systems: Varna, Bulgaria, 6 - 8 September 2008. Paper presented at International IEEE Conference Intelligent Systems : 06/09/2008 - 08/09/2008 (pp. 33-39). Piscataway, NJ: IEEE Communications Society, 2
Open this publication in new window or tab >>On filtering of laser range data in snowfall
2008 (English)In: 2008 4th International IEEE Conference Intelligent Systems: Varna, Bulgaria, 6 - 8 September 2008, Piscataway, NJ: IEEE Communications Society, 2008, Vol. 2, p. 33-39Conference paper, Published paper (Refereed)
Abstract [en]

This paper is towards reducing the clutter from snowflakes for outdoor robots. There are three basic cases: 1. Normal operation of the laser with objects within range for detection. 2. Close range with objects close to the laser i.e. shorter than the pulse length. 3. Free space as background i.e. all detects are false. The findings are summarized as: The two lasers used were a pulsed wide beam laser and a modulated narrow beam laser. The narrow beam laser has much better penetration between the snowflakes. We did not use snow and rain threshold setting for the wide beam laser. Median filtering shows a substantial reduction in snowflake detects. The gamma distribution describes fairly well the distribution of detected snowflakes.

Place, publisher, year, edition, pages
Piscataway, NJ: IEEE Communications Society, 2008
National Category
Other Electrical Engineering, Electronic Engineering, Information Engineering
Research subject
Industrial Electronics
Identifiers
urn:nbn:se:ltu:diva-39696 (URN)10.1109/IS.2008.4670551 (DOI)2-s2.0-78650448859 (Scopus ID)e8b4cfb0-5fc6-11dd-82d9-000ea68e967b (Local ID)978-1-4244-1739-1 (ISBN)e8b4cfb0-5fc6-11dd-82d9-000ea68e967b (Archive number)e8b4cfb0-5fc6-11dd-82d9-000ea68e967b (OAI)
Conference
International IEEE Conference Intelligent Systems : 06/09/2008 - 08/09/2008
Note
Godkänd; 2008; 20080801 (sr)Available from: 2016-10-03 Created: 2016-10-03 Last updated: 2018-07-10Bibliographically approved
Rönnbäck, S., Fredriksson, H., Rosendahl, D., Hyyppä, K. & Wernersson, Å. (2007). An autonomous vehicle for a RobotDay (ed.). Paper presented at Mekatronikmöte 2007 : 10/10/2007 - 11/10/2007. Paper presented at Mekatronikmöte 2007 : 10/10/2007 - 11/10/2007.
Open this publication in new window or tab >>An autonomous vehicle for a RobotDay
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2007 (English)Conference paper, Oral presentation only (Other academic)
Abstract [en]

This paper describes the autonomous car that is being built for the RobotDay competition, arranged by SICK GmbH. The basic rule is to let an autonomous vehicle drive a track as fast as possible, based on any sensor technology. For this race SICK donated one S300 professional proximity sensor to each team. Our vehicle will use the circle sector expansion (CSE) method to avoid obstacles and to find its way along the track. We show initial results where the CSE method was used to guide the vehicle through a test track defined by cones and other objects.

National Category
Other Electrical Engineering, Electronic Engineering, Information Engineering
Research subject
Industrial Electronics
Identifiers
urn:nbn:se:ltu:diva-35561 (URN)a2261a20-7356-11dc-86ab-000ea68e967b (Local ID)a2261a20-7356-11dc-86ab-000ea68e967b (Archive number)a2261a20-7356-11dc-86ab-000ea68e967b (OAI)
Conference
Mekatronikmöte 2007 : 10/10/2007 - 11/10/2007
Projects
CASTT - Centre for Automotive Systems Technologies and Testing
Note
Godkänd; 2007; 20071005 (kalevi)Available from: 2016-09-30 Created: 2016-09-30 Last updated: 2017-11-25Bibliographically approved
Fredriksson, H., Rönnbäck, S., Berglund, T., Wernersson, Å. & Hyyppä, K. (2007). snowBOTS: a mobile robot on snow covered ice (ed.). In: (Ed.), K. Schilling (Ed.), Proceedings of the 13th IASTED International Conference on Robotics and Applications: August 29 - 31, 2007, Würzburg, Germany. Paper presented at IASTED International Conference on Robotics and Applications : 29/08/2007 - 31/08/2007 (pp. 222-228). Anaheim, Calif.: ACTA Press
Open this publication in new window or tab >>snowBOTS: a mobile robot on snow covered ice
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2007 (English)In: Proceedings of the 13th IASTED International Conference on Robotics and Applications: August 29 - 31, 2007, Würzburg, Germany / [ed] K. Schilling, Anaheim, Calif.: ACTA Press, 2007, p. 222-228Conference paper, Published paper (Refereed)
Abstract [en]

We introduce snowBOTs as a generic name for robots working in snow. This paper is a study on using scan ning range measuring lasers towards an autonomous snow cleaning robot, working in an environment consisting al most entirely of snow and ice. The problem addressed here is using lasers for detecting the edges generated by "the snow meeting the road". First the laser data were filtered using his togram/median to discriminate against falling snowflakes and small objects. Then the road surface was extracted us ing the range weighted Hough/Radon transform. Finally the left and right edges of the road was detected by thresh olding. Tests have been made with a laser on top of a car driven in an automobile test range just south of the Arctic Circle. Moreover, in the campus area, the algorithms were tested in closed loop with the laser on board a robotized wheelchair.

Place, publisher, year, edition, pages
Anaheim, Calif.: ACTA Press, 2007
National Category
Other Electrical Engineering, Electronic Engineering, Information Engineering
Research subject
Industrial Electronics
Identifiers
urn:nbn:se:ltu:diva-31828 (URN)61ef13e0-5f9b-11dc-807a-000ea68e967b (Local ID)9780889866850 (ISBN)61ef13e0-5f9b-11dc-807a-000ea68e967b (Archive number)61ef13e0-5f9b-11dc-807a-000ea68e967b (OAI)
Conference
IASTED International Conference on Robotics and Applications : 29/08/2007 - 31/08/2007
Projects
CASTT - Centre for Automotive Systems Technologies and Testing
Note
Validerad; 2007; 20070910 (hf)Available from: 2016-09-30 Created: 2016-09-30 Last updated: 2017-11-25Bibliographically approved
Wernersson, Å., Hyyppä, K., Åström, K., Hedström, A. & Rahm, J. (2005). Laser guided vehicles, LGV's: industrial experiences and needs for the future (ed.). In: (Ed.), (Ed.), Proceedings of the Third Swedish Workshop on Autonomous Robotics, Stockholm: . Paper presented at Workshop on Autonomous Robotics : 01/09/2005 - 02/09/2005.
Open this publication in new window or tab >>Laser guided vehicles, LGV's: industrial experiences and needs for the future
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2005 (English)In: Proceedings of the Third Swedish Workshop on Autonomous Robotics, Stockholm, 2005Conference paper, Published paper (Other academic)
National Category
Other Electrical Engineering, Electronic Engineering, Information Engineering
Research subject
Industrial Electronics
Identifiers
urn:nbn:se:ltu:diva-29912 (URN)388ab7e0-1b7d-11dd-8c59-000ea68e967b (Local ID)388ab7e0-1b7d-11dd-8c59-000ea68e967b (Archive number)388ab7e0-1b7d-11dd-8c59-000ea68e967b (OAI)
Conference
Workshop on Autonomous Robotics : 01/09/2005 - 02/09/2005
Note
Godkänd; 2005; 20080506 (ysko)Available from: 2016-09-30 Created: 2016-09-30 Last updated: 2017-11-25Bibliographically approved
Rönnbäck, S., Hyyppä, K. & Wernersson, Å. (2005). On coordinating autonomous vehicles by tracking features using MATLAB (ed.). Paper presented at International Conference on Computing, Communications and Control Technologies : 24/07/2005 - 27/07/2005. Paper presented at International Conference on Computing, Communications and Control Technologies : 24/07/2005 - 27/07/2005.
Open this publication in new window or tab >>On coordinating autonomous vehicles by tracking features using MATLAB
2005 (English)Conference paper, Oral presentation only (Refereed)
National Category
Other Electrical Engineering, Electronic Engineering, Information Engineering
Research subject
Industrial Electronics
Identifiers
urn:nbn:se:ltu:diva-32301 (URN)6c330e70-6cd9-11db-83c6-000ea68e967b (Local ID)6c330e70-6cd9-11db-83c6-000ea68e967b (Archive number)6c330e70-6cd9-11db-83c6-000ea68e967b (OAI)
Conference
International Conference on Computing, Communications and Control Technologies : 24/07/2005 - 27/07/2005
Note
Godkänd; 2005; 20060913 (ysko)Available from: 2016-09-30 Created: 2016-09-30 Last updated: 2017-11-25Bibliographically approved
Rönnbäck, S., Hyyppä, K. & Wernersson, Å. (2005). On passing a doorway with an autonomous Internet connected wheelchair using MATLAB (ed.). In: (Ed.), 2005 IEEE/RSJ International Conference on Intelligent Robots and Systems: Edmonton, AB, Canada, 2 - 6 August 2005. Paper presented at IEEE/RSJ International Conference on Intelligent Robots and Systems : 02/08/2005 - 06/08/2005 (pp. 1532-1537). Piscataway, NJ: IEEE Communications Society
Open this publication in new window or tab >>On passing a doorway with an autonomous Internet connected wheelchair using MATLAB
2005 (English)In: 2005 IEEE/RSJ International Conference on Intelligent Robots and Systems: Edmonton, AB, Canada, 2 - 6 August 2005, Piscataway, NJ: IEEE Communications Society, 2005, p. 1532-1537Conference paper, Published paper (Refereed)
Abstract [en]

If a wheelchair for disabled is used for semi-autonomous navigation indoors it must be able to navigate through doors. A door and doorway can be parameterized with five parameters. A divide and conquer implementation of the Hough transform is used to segment outlines from range scans. The client software remote controls the wheelchair from the MATLAB environment. The software consists of several Java threads that run concurrently. Sensor data are polled by threads and put into databases to reduce the network lag. The databases are used by a controller and a Kalman filter. Since most of the implementation is coded in Java it is possible to run it as a stand alone program on a computer that has Java installed. From 10 runs the trajectory offset was calculated to 0.9 cm with a standard deviation of 1.4 cm. The standard deviation of the heading was 2.2 degrees. This performance is essentially independent of the initial starting pose

Place, publisher, year, edition, pages
Piscataway, NJ: IEEE Communications Society, 2005
National Category
Other Electrical Engineering, Electronic Engineering, Information Engineering
Research subject
Industrial Electronics
Identifiers
urn:nbn:se:ltu:diva-27614 (URN)10.1109/IROS.2005.1545567 (DOI)000235632103123 ()79958002059 (Scopus ID)11af3aa0-4fab-11db-9592-000ea68e967b (Local ID)0-7803-8912-3 (ISBN)11af3aa0-4fab-11db-9592-000ea68e967b (Archive number)11af3aa0-4fab-11db-9592-000ea68e967b (OAI)
Conference
IEEE/RSJ International Conference on Intelligent Robots and Systems : 02/08/2005 - 06/08/2005
Note

Godkänd; 2005; 20060913 (ysko)

Available from: 2016-09-30 Created: 2016-09-30 Last updated: 2018-07-10Bibliographically approved
Rönnbäck, S., Hyyppä, K. & Wernersson, Å. (2004). Remote CAN operations in Matlab over the Internet (ed.). In: (Ed.), (Ed.), Proceedings: 2004 Second International IEEE Conference "Intelligent Systems" : June 22 - 24, 2004, St. Constantine and Helena resort, Varna, Bulgaria. Paper presented at International IEEE Conference on Intelligent Systems : 22/06/2004 - 24/06/2004 (pp. 123-128). Piscataway, NJ: IEEE Communications Society
Open this publication in new window or tab >>Remote CAN operations in Matlab over the Internet
2004 (English)In: Proceedings: 2004 Second International IEEE Conference "Intelligent Systems" : June 22 - 24, 2004, St. Constantine and Helena resort, Varna, Bulgaria, Piscataway, NJ: IEEE Communications Society, 2004, p. 123-128Conference paper, Published paper (Refereed)
Abstract [en]

This paper describes the implementation of a CAN server that acts as a CAN tool to a client. It can be used to monitor, observe and send messages to a distant CAN network over IEEE802.11b (Wave-LAN). The CAN server is controlled by one or several clients that can connect to it by TCP/IP. It is possible to send and receive CAN messages over Internet from a MATLAB environment since the client software is written in Java. The CAN server collects CAN messages and stores them into a ring buffer. The messages in the ring buffer are classified by their identifier and stored into a database. The CAN tool has been used in a demonstrative application example that consist of a remotely controlled wheelchair. In the example the wheelchair was programmed to run in a square. The positions obtained by odometric CAN messages are compared with the position from the navigation system onboard the wheelchair.

Place, publisher, year, edition, pages
Piscataway, NJ: IEEE Communications Society, 2004
National Category
Other Electrical Engineering, Electronic Engineering, Information Engineering
Research subject
Industrial Electronics
Identifiers
urn:nbn:se:ltu:diva-30378 (URN)10.1109/IS.2004.1344865 (DOI)000223848300028 ()42903440-5f54-11db-8cbe-000ea68e967b (Local ID)0-7803-8278-1 (ISBN)42903440-5f54-11db-8cbe-000ea68e967b (Archive number)42903440-5f54-11db-8cbe-000ea68e967b (OAI)
Conference
International IEEE Conference on Intelligent Systems : 22/06/2004 - 24/06/2004
Note
Godkänd; 2004; 20060929 (ysko)Available from: 2016-09-30 Created: 2016-09-30 Last updated: 2018-07-10Bibliographically approved
Wernersson, Å. (2004). Telerobotics: Towards Extending Your Sensing and Hands into a Remote Reality. Paper presented at 1st IFAC Symposium on Telematics Applications in Automation and Robotics (TA 2004), Espoo, Finland, 21-23 June 2004. Elsevier IFAC Publications / IFAC Proceedings series, 37(7), 1-4
Open this publication in new window or tab >>Telerobotics: Towards Extending Your Sensing and Hands into a Remote Reality
2004 (English)In: Elsevier IFAC Publications / IFAC Proceedings series, ISSN 1474-6670, Vol. 37, no 7, p. 1-4Article in journal (Refereed) Published
Abstract [en]

Abstract:

The problem addressed is control of robots and/or sensing, in workspaces at remote locations. Topics taken up in this plenary talk includes laser sensing, scene interpretation, telecommands for local autonomy, research issues especially for multirobot systems. Applications includes aerospace testing in north Sweden.

Telecommands are studied for high level control of robots over a communication channel with a non-neglectable time delay, time jitters and variable bandwidth. The sensors onboard the robot are a time-of-flight range measuring laser and a video camera. A few images are used by the operator for interpreting the scene. From the interpretations of the workspace around the robot, the operator specifies interactively the sequence of individual operations during a composite task. Each telecommand is then executed autonomously by closing the feedback loop between the robot and the objects in the surrounding workspace.

National Category
Other Electrical Engineering, Electronic Engineering, Information Engineering
Research subject
Industrial Electronics
Identifiers
urn:nbn:se:ltu:diva-63368 (URN)10.1016/S1474-6670(17)32114-6 (DOI)
Conference
1st IFAC Symposium on Telematics Applications in Automation and Robotics (TA 2004), Espoo, Finland, 21-23 June 2004
Available from: 2017-05-16 Created: 2017-05-16 Last updated: 2017-11-29Bibliographically approved
Wernersson, Å., Taylor, G. R. & Kleeman, L. (2002). Robust colour range sensing for robotic applications using a stereoscopic light stripe scanner (ed.). In: (Ed.), (Ed.), Proceedings IEEE/RSJ International Conference on Intelligent Robots and Systems: . Paper presented at IEEE/RSJ international conference on intelligent robots and systems : 30/09/2002 - 05/10/2002 (pp. 86-91). : IEEE Communications Society
Open this publication in new window or tab >>Robust colour range sensing for robotic applications using a stereoscopic light stripe scanner
2002 (English)In: Proceedings IEEE/RSJ International Conference on Intelligent Robots and Systems, IEEE Communications Society, 2002, p. 86-91Conference paper, Published paper (Refereed)
Abstract [en]

This paper presents an integrated, low-level approach to removing sensor noise, cross talk, spurious specular reflections, and solving the association problem in a light stripe scanner. Most single-camera scanners rely on the laser brightness exceeding that of the entire image. Our system uses two cameras to measure the stripe and combines knowledge of the light plane orientation to produce useful validation properties. The key result is the development of a condition relating image plane measurements and camera intrinsic parameters, which allows validationlassociation to be performed independently of 3D reconstruction. The same equations are used to improve ranging accuracy compared to single-camera systems. We also show how the system may be self-calibrated using measurements of an arbitrary nonplanar target. As validation allows operation in ambient light, registered colour and range are captured in the same sensor. An experimental scanner demonstrates the effectiveness of the proposed techniques.

Place, publisher, year, edition, pages
IEEE Communications Society, 2002
National Category
Other Electrical Engineering, Electronic Engineering, Information Engineering
Research subject
Industrial Electronics
Identifiers
urn:nbn:se:ltu:diva-29960 (URN)10.1109/IRDS.2002.1041367 (DOI)3998e500-7c9e-11db-8824-000ea68e967b (Local ID)0-7803-7398-7 (ISBN)3998e500-7c9e-11db-8824-000ea68e967b (Archive number)3998e500-7c9e-11db-8824-000ea68e967b (OAI)
Conference
IEEE/RSJ international conference on intelligent robots and systems : 30/09/2002 - 05/10/2002
Note
Godkänd; 2002; 20061031 (ysko)Available from: 2016-09-30 Created: 2016-09-30 Last updated: 2017-11-25Bibliographically approved
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