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  • 1.
    Bergblomma, Marcus
    et al.
    Mälardalen University, School of Innovation, Design and Engineering.
    Ekström, Martin
    Mälardalen University, School of Innovation, Design and Engineering.
    Björkman, Mats
    Mälardalen University, School of Innovation, Design and Engineering.
    Ekström, Mikael
    Mälardalen University, School of Innovation, Design and Engineering.
    Gerdtman, Christer
    Motion Control AB, Västerås, Sweden .
    Lindén, Maria
    Mälardalen University, School of Innovation, Design and Engineering.
    A wireless low latency control system for harsh environments2012In: IFAC Proceedings Volumes (IFAC-PapersOnline): Vol. 11, PART 1, 2012, p. 17-22Conference paper (Refereed)
    Abstract [en]

    The use of wireless communication technologies in the industry offer severaladvantages. One advantage is the ability to deploy sensors where they previously could noteasily be deployed, for instance on parts that rotate. To use wireless communication in industrialcontrol loops, demands on reliability and latency requirements has to be met. This in anenvironment that may be harsh for radio communication. This work presents a reliable, lowlatency wireless communication system. The system is used in a wireless thyristor control loopin a hydro power plant generator. The wireless communication is based on Bluetooth radiomodules. The work shows a latency analysis together with empirical hardware based latencyand packet error rate measurements. The background noise of a hydro power plant station isalso investigated. The average latency between the Bluetooth modules for the proposed systemis 5.09 ms. The packet error rate is 0.00288 for the wireless low latency control system deployedin a hydro power plant.

  • 2.
    Folke, Mia
    et al.
    Mälardalen University, School of Innovation, Design and Engineering.
    Bexander, Catharina
    Mälardalen University, School of Innovation, Design and Engineering.
    Gerdtman, Christer
    Mälardalen University, School of Innovation, Design and Engineering.
    Brodd, Anita
    Mälardalen University, School of Innovation, Design and Engineering.
    Lindén, Maria
    Mälardalen University, School of Innovation, Design and Engineering.
    Sensor system for rehabilitation of patients suffering from WAD 2009In: Medicinteknikdagarna, Vasteras, 2009Conference paper (Refereed)
  • 3.
    Gerdtman, Christer
    Mälardalen University, School of Innovation, Design and Engineering.
    Avancerade alternativa inmatningsenheter till datorer för funktionshindrade2011Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    Computers are important tools. People with motion disabilities sometimes are dependent on a computer and used as a technical aid the computer has improved the possibilities to perform meaningfull tasks, as writing, reading and communicating. However, disabled often need an alternative input device to control a computer.

     

    The aim with this licentiate theses has been to develope techniques to support persons with motion limitations. Focus has been to develope alternative techniqes to control a computer. Important aspects have been user-friendlieness, possiblilities to perform individual adaptions and incorporatation of specifications from the intended users. Further, the input device has been evaluated by users and applied as a rehabilitation tool for a smaller patient group of persons with whiplash associated disorders.

     

    Further, production aspects are important. To make the unit into a product, it has to be possible to produce and sell to a reasonable price. This has to be considered during the whole development process.

     

    An alternative computer mouse based on a MEMS gyroscope has been developed. The specifications made by the users has been used as a starting point in the development and the unit has been evaluated and improved in an iterative process, so called user centric development. MEMS-gyros were the type of motion sensors most corresponding to the demands. The users that participated in a longer field test were all satisfied and wanted to keep the mouse.

     

    To improve the process to choose right kind of gyro and to be able to evaluate their stability depending on factors as temperature and vibration, a test-rigg for gyros has been developed. Human motion pattern differs from industrial applications and therefor a special test-rigg was needed. The testrigg rotates the gyros and measures the sensor signal. Several gyros can be tested simultaneously and data can be stored and analysed afterwards.

     

    An interactive computerbased training program has been developed and evaluated in a pilot study together with the altrenative computer mouse. The aim has been to let people with neck injuries perform head motions and get feedback that they perform the right kind of training. The result is promising.

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  • 4.
    Gerdtman, Christer
    et al.
    Mälardalen University, School of Innovation, Design and Engineering.
    Ahlfont, Jesper
    Lindén, Maria
    Mälardalen University, School of Innovation, Design and Engineering.
    Oscillating Test Rig for MEMS gyroscopes2012Conference paper (Refereed)
    Abstract [en]

    Motion sensors like MEMS accelerometers and gyroscopes (gyros) are rather small, cheap and reliable sensors that have found their place in a variety of applications. Some of the applications are in the field of human motion measurements. This is a growing market field and an increasing number of MEMS sensors find their way into products for human measurements, such as fall detection, running sensor, movement capacity analysis and stress measurement. In many of these applications the sensors are supposed to be worn by a human for a longer time to track their movements in one way or another. For MEMS gyros in particular, it is interesting to study the sensors reactions to typical human movements over time. Comparing humans and machines, human movements are often smoother and more oscillating than the more linear movement pattern of a machine. Datasheets for gyros usually only specify hard performance like resistance to impact and shock. It is also quite common that the datasheets are incorrect, especially for brand new sensors being released in new versions.

  • 5.
    Gerdtman, Christer
    et al.
    Mälardalen University, School of Innovation, Design and Engineering.
    Bergblomma, Marcus
    Mälardalen University, School of Innovation, Design and Engineering.
    Tradlost I/O i en tuff industrimiljo2010In: Scandinavian Electronic Event, Stockholm, Sweden, 2010Conference paper (Refereed)
    Abstract [en]

    Seminariet handlade om hur det ar att bedriva ett samverkansprojekt mellan akademi och foretag med ett for bada parter lyckat resultat. Har har ett tradlost I/O tagits fram. I/O-kortet har designats for att kunna verka i en kravande industrimiljo med magnetfalt, extremt hoga g-krafter och krav pa korta svarstider. Bakgrunden ar ett behov fran industrin dar man onskar en tradlos losning som ar robust och tillforlitlig samt gar att producera till en modest kostnad. Darfor onskar man anvanda standardkomponenter samt etablerade industristandarder sa langt som mojligt. I detta fall har en egen hognivastack tagits fram for att anvandas med en Bluetooth-kontrollerkrets.

  • 6.
    Gerdtman, Christer
    et al.
    Mälardalen University, School of Innovation, Design and Engineering.
    Bäcklund, Ylva
    Office for Science and Technology, Uppsala University, Uppsala, Sweden.
    Lindén, Maria
    Mälardalen University, School of Innovation, Design and Engineering.
    A gyro sensor based computer mouse with a USB interface: A technical aid for motor-disabled people2012In: Technology and disability, ISSN 1055-4181, Vol. 24, no 2, p. 117-127Article in journal (Refereed)
    Abstract [en]

    The aim of this study was to develop an alternative computer mouse for disabled persons. The mouse developed is a flexible input device with a multi-click function, which can be attached to a selectable body part (eg head, arm, foot). The mouse has a MEMS-gyroscope as the motion sensor, which is both small and sensitive. A USB-interface with a HID-profile is used to make the installation easy, "plug & play", and to make it compatible for use on any modern computer, independent of the operating system (Windows, Linux, Mac etc.). The structure is modular to achieve a flexible functionality. The mouse has individually adapted click-functions with selectable click devices, in addition to which, it is possible to define individual settings of the mouse parameters. The functionality can be extended by adding further personal settings, thereby programming the mouse for individual optimal performance. The result is a reliable and useful computer mouse for people with disabilities. In the development process, 23 users have been interviewed, three of whom participated in a 6 month long-term test. The study shows that a computer mouse incorporating a MEMS-gyroscope is a good, flexible solution, providing a high performance technical aid with extremely good sensitivity at a modest cost.

  • 7.
    Gerdtman, Christer
    et al.
    Mälardalen University, School of Innovation, Design and Engineering.
    Bäcklund, Ylva
    Uppsala University.
    Lindén, Maria
    Mälardalen University, School of Innovation, Design and Engineering.
    Development of a Test Rig for MEMS-based Gyroscopic Motion Sensors in Human Applications2011In: IFMBE Proceedings,  Volume 34 IFMBE, 2011, 2011, p. 203-206Conference paper (Refereed)
    Abstract [en]

    This paper describes the development of a test rig for MEMS gyroscopes. The purpose of the test rig is testing and verification of various gyroscopes that are intended for human motion analysis. The test rig will be a tool to test functionality and help in the selection process of appropriate MEMS-gyroscopes. Human movement pattern differs from mechanical motion and thus puts specific demands on the test equipment and verification procedures. The main function of the test rig is to rotate the gyroscope and measure the precision in the sensor signal response in different situations. This includes detection of different movement patterns and performances in different environment conditions (e.g. temperature, vibrations, etc). Several components can be tested at the same time in the test rig. Among the things that can be evaluated is the performance of the components, comparisons between different individual components or batches, aging processes of components and verification of the component performance for comparison of the specifications from the manufacturer. There are several different pre-programmed test-programs available but the test rig can also be manually operated. The data from the tests are stored and can be analyzed and processed afterwards.

  • 8.
    Gerdtman, Christer
    et al.
    Mälardalen University, School of Innovation, Design and Engineering.
    Folke, Mia
    Mälardalen University, School of Innovation, Design and Engineering.
    Bexander, Catharina
    Hälsans hus.
    Brodd, Anita
    Mälardoktorerna HB.
    Lindén, Maria
    Mälardalen University, School of Innovation, Design and Engineering.
    Portable sensor system for rehabilitation of WAD patients2009In: Proceedings of the 6th International Workshop on Wearable, Micro, and Nano Technologies for Personalized Health: "Facing Future Healthcare Needs", IEEE , 2009, p. 65-68Conference paper (Refereed)
    Abstract [en]

    Whiplash Associated Disorders (WAD) are several remaining symptoms after an acceleration-/deceleration injury of the neck, often due to a road accident. Common symptoms are neck pain, headache, stiffness, loss of sensation, memory impairment and concentration difficulties. The whiplash-related injuries were estimated to cost Sweden more than SEK 4 billion 2005, the main part of these costs takes the form of compensation for loss of income, as a result of incapacity for work. The aim of this project has been to develop a training and rehabilitation system for patients suffering from WAD. The portable system is based on a 2-axis gyroscopic sensor with a computer interface. The sensor system is placed on the head of the patient and movements of the head are mirrored on the computer screen. The patient is supposed to follow a visible track on the screen. This enables interactive training facilities for patients, who can use the system unsupervised in their home environment.

  • 9.
    Gerdtman, Christer
    et al.
    Motion Control AB, Västerås, Sweden.
    Lindén, Maria
    Mälardalen University, Department of Computer Science and Electronics.
    A MEMS-gyro based computer mouse for disabled2006Conference paper (Refereed)
    Abstract [en]

    Computers are an important part of our daily lifes, and to be able to control them is in many cases necessary to be able to work, communicate or take part in our modern society of today. Therefore are persons that can not use an ordinary computer mouse in need of an alternative mouse. The reason of why an ordinary mouse can not be used is very different from person to person, depending on their abilities and needs. The need can also vary over time, not all persons are permanent handicapped, it can be a disability or bodily injury that can be healed. From these aspects, a computer mouse that can be used by a wide range of people with different types of disabilties and that can be applied on different body parts has been developed and evaulated.

  • 10.
    Gerdtman, Christer
    et al.
    Mälardalen University, Department of Computer Science and Electronics.
    Lindén, Maria
    Mälardalen University, Department of Computer Science and Electronics.
    Development of a gyro sensor based computer mouse with USB interface interface as technical aid for disabled persons2005In: 3rd European Medical & Biological Engineering Conference (EMBEC’05), Vienna (Austria): Society for the Organization of the European Medical and Biological Engineering Conference EMBEC , 2005Conference paper (Refereed)
    Abstract [en]

    This paper describes the development of an alternative computer mouse for disabled persons. The mouse is an advanced technical aid for a large group of disabled (handicapped) persons, and can be placed on variuos suitable body parts. The mouse is module based and have many functions that enable a disabled persons to control a computer. It also allows the person to work efficent on the computer. The functions have been developed togehter with disabled persons and are based on their wishes and needs. Therfor it is not only a «head-mouse», it is an alternative mouse! The device is a gyro sensor based computer mouse and it operates by sensing the rotation of a body part. The disabled users appreciated the high sensitivity of the mouse and that it is easy to install and use, thanks the USB «plug&play» functionality. The mouse is a small and comfortable computer mouse that suits a various groups of disabled persons with different types of movement handicaps.

  • 11.
    Gerdtman, Christer
    et al.
    Mälardalen University, School of Innovation, Design and Engineering.
    Lindén, Maria
    Mälardalen University, School of Innovation, Design and Engineering.
    MultiPos – en gyrobaserad datormus for rörelsehindrade2009Conference paper (Refereed)
  • 12.
    Gerdtman, Christer
    et al.
    Mälardalen University, School of Innovation, Design and Engineering.
    Lindén, Maria
    Mälardalen University, School of Innovation, Design and Engineering.
    Six-button Click Interface for a Disabled User by a adjustable multilevel Sip-and-Puff Switch2010In: Proceedings of SIGRAD 2010, V�ster�s, 2010, p. 59-64Conference paper (Refereed)
  • 13.
    Gerdtman, Christer
    et al.
    Mälardalen University, School of Innovation, Design and Engineering.
    Lindén, Maria
    Mälardalen University, School of Innovation, Design and Engineering.
    Test Rig for MEMS-accelerometers2010In: MSW 2010, Micronano Systems Workshop, Stockholm, Sweden, 2010Conference paper (Refereed)
    Abstract [en]

    MEMS-accelerometers are rather cheap, small and reliable motion sensors that have found new application areas and are available in a variety of performance. They exist in many different performance, such as single, dual or triple axis, for high- or low-g application, with analog or digital output, different packages and size etc. Their performance parameters also exist in a wide spectrum, like high sensitivity, bandwidth, noise density, temperature range, shock tolerance etc. Moreover, there are a variety of manufacturers that you can choose from. So when it is time to choose sensor, there are many aspects and parameters to take in the consideration of choosing the right accelerometer. If it is possible to managed to choose one sensor above all others, a question arises. How can you be sure that the chosen sensor fulfils its requirement specification?

  • 14.
    Gerdtman, Christer
    et al.
    Mälardalen University, School of Innovation, Design and Engineering.
    Lindén, Maria
    Mälardalen University, School of Innovation, Design and Engineering.
    Test Rig for MEMS-gyros2008Conference paper (Refereed)
  • 15.
    Gerdtman, Christer
    et al.
    Mälardalen University, Department of Computer Science and Electronics.
    Lindén, Maria
    Mälardalen University, Department of Computer Science and Electronics.
    Utveckling av en gyrobaserad datormus for funktionshindrade med begränsad rörelseförmåga2006Conference paper (Refereed)
    Abstract [en]

    Att kunna anvanda en dator ar ofta en forutsattning idag for att en person ska kunna utfora sitt arbete, ta del av information, kommunicera med andra och pa andra satt ta del av vart moderna samhalle. Darfor behover personer som inte kan anvanda en vanlig datormus, en alternativ inmatningsenhet for att kunna styra datorn. Personer med begransad rorelseformaga har behov av en mycket kanslig mus, som kan kanna av aven sma rorelser. Syftet med denna studie var att undersoka vilka kriterier som kan stallas pa en alternativ mus jamfort med en vanlig datormus som styrs via ena handen, att utveckla en prototyp samt att lata anvandarna prova och utvardera prototypen.

1 - 15 of 15
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