Papers by Keyword: Magnetometer

Abstract: The paper deals with the fluxgate transducer intended for navigation and attitude control systems for moving vehicles. The finite element modeling of the half-sine and sawtooth pulse loads of various durations is performed for the proposed fluxgate configuration with regard to the properties of materials used.

Abstract: We explore the magnetic sensing capabilities of two 4H-SiC n⁺p diodes fabricated by NASA Glenn which only differ in the implanted ion species, nitrogen and phosphorus, and the implant activation annealing time. We use low-and high-field electrically detected magnetic resonance (EDMR) to investigate the defect structure used to sense magnetic fields as well as to evaluate the sensitivity. In addition, we expose these devices to high energy electron radiation to evaluate the defect sensing capability in a harsh radiation environment. The results from this work will allow us to tailor our processing methods to design a more optimal 4H-SiC pn diode for magnetic field sensing in harsh environments.

Abstract: Silicon carbide (SiC) is well known by the semiconductor industry to have significant potential for electronics used in high temperature environments due to its wide bandgap. It is not so well-known, however, that SiC also has great potential in the area of magnetic field sensing. Using the recently demonstrated zero-field spin dependent recombination (SDR) phenomenon that naturally arises in SiC based devices, near-zero magnetic field measurements can be made with moderately high sensitivity.

Abstract: Attitude determination system (ADS) is a process to control the orientation of the satellite to make sure that the orientation is relative to inertial references frame such as Earth. ADS is consists of mathematical algorithm and sensor as a references measurement to determine attitude of satellite. Since RazakSAT in the orbit, the sensor such as sun sensor, magnetometer and gyroscopes are used to control angular rotation and prevent high spin rates that can damage the satellite. This paper presents the analysis on sensor of attitude determination system based on RazakSAT data. Matlab was used to analyze the X,Y and Z axis of the sensor to determine the condition of the satellite.

Abstract: Magnetometer is an instrument to measure Earth’s magnetic field magnitude. Microelectromechanical system (MEMS) magnetic sensor is implemented in the device system since it consists of multi-axis magnetic field sensing driven in a single microchip physical scale at low power consumption. The magnetometer is equipped with built-in data logger system as an automatic data storage system to overcome data loss. The Anisotropic Magnetoresistive (AMR) sensor is the best MEMS magnetometer sensors, since it consumes low power (3.3Vdc), small physical size (less than 8.1mm³) and considerable 200nT resolution for Earth’s magnetic field sensing. The magnetometer consumes 5.0Vdc for complete system operation. The instrument device is useful for scientific and geophysical field to observe and measure geomagnetic field magnitude, where the measurement could be taken anywhere around the globe. The mobile wireless magnetometer was tested and experimental measurement was performed at Faculty of Electrical Engineering, Universiti Teknologi MARA, Selangor, Malaysia (coordinate: 3.07°N, 101.50°E).

Abstract: Magnetometers-aided MINS could solve roll angle measurement of air vehicle at fast spinning rate, but magnetometers were easily disturbed and had measuring error, so it was necessary to establish tri-axial magnetometer correction system for magnetometers-aided MINS navigation system. Based on LabWindows/CVI and MATLAB fuzzy programming, earth magnetic field and ellipsoid fitting model were built to complete magnetometers correction system and its virtual instrument. On that basic, magnetometers-aided MINS navigation system and its virtual instrument were established. Results of correction and non-correction magnetometers-aided MINS navigation test showed that the magnetometers correction system can compensate the error of interference, measuring and so on, furthermore geomagnetic attitude computing become more accurate and the higher precision of position and velocity for magnetometers-aided MINS system. All of them are significant for engineering and products.

Abstract: In a measurement of magnetic flux density with high accuracy by using Hall effect sensor must be considered position of Hall sensor, that perfect perpendicular with magnetic flux line for measurement. Only one Hall element can cause measuring error. Therefore, this paper presents an application of independent directional magnetic field measurement technique on two dimensions for high accuracy magnetometer. It is presented by using two Hall sensors locate perpendicular to each other and use the relation of the two voltage output signal from both Hall sensors to calculate constant Hall voltage and Magnetic flux density with high accuracy by using trigonometric function with Lab-View programming. And as the result of experiment, this technique can reduce the limitation in term of this angle in the range magnetic flux density can be measured 0-1800 gauss. A calibration curve of this system compare with standard Gauss meter shows the coefficient of determination (R²) equal to 1 and has the accuracy percentage as less than 0.5%.

Abstract: This paper deals with usability of MEMS sensors for diagnostics of mechatronics system state wirelessly. We can acquire basic kinematics and dynamics mechanism parameters (spatial position, speed, acceleration, vibration, angular rate, orientation, etc.) and some environment condition (local/remote temperature, humidity, pressure, electromagnetic noise) by MEMS sensors. Acquired data are sent to remote application in desktop computer. This system can replace expensive and separate diagnostic tools by small integrated solution with one wireless communication interface (with limitation of MEMS sensors precision). This solution can be battery powered with long operation time, because there is used new wireless technology based on Bluetooth 4 protocol (Low Energy/Smart Bluetooth). Some of integrated MEMS sensors measures same variable on different measuring principle. For example angle can be acquired from three different sensors: magnetometer, accelerometer or gyroscope. Combination of these sensor data can significantly improve value accuracy. The designed diagnostic tool can serve as an inertia measuring unit IMU or Wireless IMU (WIMU).

Abstract: In robotic systems navigation, it is necessary to determine the direction, in which the local coordinate system of a robot is to be turned in regards to the reference, global system. That direction from mathematical point of view is the rotation along one axis of the reference system, such that the reference system coincides with the local system associated with the body, which direction is defined. There is an assumption that the rotations along two other axes do not exist or they were taken into account in the calculations. A question appears: what is the measurement of the direction based on The answer to that question is provided by nature [1, , because it has already solved this problem long ago. In migratory species such as birds, bees and fish, evolved magnetoreception abilities which allow an animal to detect the magnetic field of Earth. These abilities enable such organisms to navigate in space. In many devices magnetic field sensors called magnetometers are already used. However, magnetic measurements are subject to many kinds of distortions and errors. This paper shows a practical approach to a robot navigation problem.

Abstract: Magnetic sensors based on GMI devices are the subject of intensive research, as they appear promising for magnetometry applications. Performances of GMI magnetometers are often limited by the noise of the electronic setup. Thus, the present challenge is to increase the GMI device sensitivity (expressed in V/T) in order to decrease the equivalent magnetic noise of the system. In our previous work, we showed that the use of a pick-up coil in an off-diagonal configuration improves the magnetic sensor sensitivity and offers a promising approach for developing an inexpensive magnetometer with sub-pT/Hz equivalent magnetic noise levels. Ideally, the use of a coil increases the sensitivity linearly as a function of the number of turns. However, this effect is reduced by the parasitic capacitance of the coil. This affects the device sensitivity, noise level and system performance. The parasitic capacitance can degrade all of these, but also induces a resonance effect, which can help to optimize magnetometer sensitivity, and thus, its noise level. We analyze the effects of the parasitic capacitance on the system (sensitivity and noise) and propose optimization routes. We have obtained sensor sensitivity as high as 700 fT/Hz.