Darmstadt, Techn. Universiẗat, Diss., 1999. / Dateien im PDF-Format.

Zugl.: Darmstadt, Techn. Univ., Diss., 2005

Zugl.: Bremen, University, Diss., 2006.

Zugl.: Ilmenau, Techn. Univ., Diss., 2009

<p>Tractors of today come equipped with a CAN-system. A CAN-system sends information from sensors to electronic control units who process the signals. The sensors measure several interesting parameters such as force, pressure and speed for various components of the tractor. This thesis discuss a force sensor which is placed in the pivot of the tractors three point linkage, the sensor measure the horizontal reaction force from the load that the tractor is exposed to. Signals from this sensor can be used to measure the force from any implement that the tractor is exposed to during an operation. The results from this thesis can be used for research purposes, for example, to compare implements from different manufacturer or to optimize the implement settings during an operation. However, there is a problem that this thesis aimed to solve by developing a method which can be put into practice. When a constant force from an implement is acting on the three point linkage, the reaction force in the pivot of the three point linkage (where the force sensor is attached) is going to vary depending on the angel of the lower lift arm. It is not uncommon that the angel of the lower lift arm is varying, because different implement and soil require different settings on the linkage. This means that the force which is measured by the sensor may vary in size even though the actual force does not vary. To solve this problem, theoretical calculations have been performed and equations to describe the variation of the reaction force depending on the geometry have been created. The theory has also been verified by a finite element analysis and a practical verification test. The conclusions from these three parts correspond to each other. Theoretically that means by knowing the horizontal reaction force (measured by the force sensor) and the angles of the geometry on the three point linkage (can be measured with a position sensor) you can calculate the force an implement influence the tractor with. However, there is a problem which prevents this method from being completely reliable. It is only working when the impact force is completely parallel to the horizontal plane. Since many implements are being pulled to the soil (plow, cultivator, etc.) in practice there are also vertical forces affecting the tractor. This is no problem to solve in theory, but in practice this method does not compensate for the vertical force. This vertical force should be examined more carefully before the method can be used reliably in full scale.</p>

Tractors of today come equipped with a CAN-system. A CAN-system sends information from sensors to electronic control units who process the signals. The sensors measure several interesting parameters such as force, pressure and speed for various components of the tractor. This thesis discuss a force sensor which is placed in the pivot of the tractors three point linkage, the sensor measure the horizontal reaction force from the load that the tractor is exposed to. Signals from this sensor can be used to measure the force from any implement that the tractor is exposed to during an operation. The results from this thesis can be used for research purposes, for example, to compare implements from different manufacturer or to optimize the implement settings during an operation. However, there is a problem that this thesis aimed to solve by developing a method which can be put into practice. When a constant force from an implement is acting on the three point linkage, the reaction force in the pivot of the three point linkage (where the force sensor is attached) is going to vary depending on the angel of the lower lift arm. It is not uncommon that the angel of the lower lift arm is varying, because different implement and soil require different settings on the linkage. This means that the force which is measured by the sensor may vary in size even though the actual force does not vary. To solve this problem, theoretical calculations have been performed and equations to describe the variation of the reaction force depending on the geometry have been created. The theory has also been verified by a finite element analysis and a practical verification test. The conclusions from these three parts correspond to each other. Theoretically that means by knowing the horizontal reaction force (measured by the force sensor) and the angles of the geometry on the three point linkage (can be measured with a position sensor) you can calculate the force an implement influence the tractor with. However, there is a problem which prevents this method from being completely reliable. It is only working when the impact force is completely parallel to the horizontal plane. Since many implements are being pulled to the soil (plow, cultivator, etc.) in practice there are also vertical forces affecting the tractor. This is no problem to solve in theory, but in practice this method does not compensate for the vertical force. This vertical force should be examined more carefully before the method can be used reliably in full scale.

Zugl.: Bremen, Univ., Diss., 2008

Zugl.: Bayreuth, Universiẗat, Diss., 2008.

Universiẗat, Diss., 1999--Kassel.

Inom kanotsporten är synkronisering av paddeltag i en kanot med fler än en kanotist väldigt viktig för att uppnå en så hög hastighet som möjligt. Hans Rosdahl från Gymnastik- och Idrottshögskolan har därför gett i uppdrag att utveckla en mobilapplikation som ger respons till kanotisten som använder applikationen om dennes paddeltag är synkroniserad med frontkanotisten. En förstudie har därför utförts för att bland annat undersöka de olika sensoralternativen som fanns tillgängliga och en applikation inom operativsystemet Android har utvecklats. Applikationen ansluter sig till IMU-sensorer, Intertial Measurement Unit, som sitter på varje paddel och som mäter tröghetskrafterna för att bestämma orientering av sensorn. Applikationen tar emot IMU-data från sensorerna som sitter på användarkanotistens och frontkanotistens paddlar och varje sensor avgör när ett paddeltag har utförts genom orienteringen på sensorn. Denna sensordata som visar ett utfört paddeltag används för att beräkna tidsskillnaden är på paddeltagen från båda kanotister. När tidsskillnaden har räknats ut får användaren visuell respons på mobilskärmen om denne är synkroniserad med frontkanotisten eller inte och på vilken nivå synkroniseringen ligger. / Synchronisation of paddle stroke is an important aspect within the sports of paddling with multiple paddles in one boat to maximise the velocity. Hans Rosdahl from The Swedish School of Sport and Health Sciences, GIH, therefore provided a task to develop a mobile phone application that offers feedback to the paddlers using the application if their paddle stroke is synchronised with the paddler in front. A pre-study has been carried out to investigate possible sensor alternatives that are available, and an application has been developed for the mobile operative system Android. The application connects to an IMU, Inertial Measurement Unit, sensor that measures inertia to determine the orientation of the sensor node. The application receives sensor data from the IMU from the user paddler’s and the front paddler’s sensor nodes and each sensor determines when a paddle stroke has occurred using its orientation. The data showing a stroke is used to calculate the time difference between these strokes to evaluate if the user is synchronised with the front paddler or not. After this evaluation, the user receives a visual response of their synchronisation level on their screen.