作者: Yu Bao Fan, Jie Li, Bo Wang, Xiao Chun Tian, Jun Liu

摘要: When the Micro Inertial Measurement Unit is been placed randomly in the case of stationary, the sum vectors that measured by the inertial devices configured orthogonally along three axis, are constant vectors. In view of the above objective facts, a field calibration method of micro inertial measurement unit was proposed. On the base of the establishment and optimization of calibration model, all parameters to be calibrated can be obtained through the least square by the ellipsoid fitting, with the result of high-precision field calibration for micro inertial measurement unit. Finally, a filed calibration program for micro inertial measurement unit is scheduled reasonably. The experiment results show that the method has such characteristics such as easily-operation, time-saving, higher calibration accuracy, and not depending on the baseline direction and datum offered by precision instruments. Especially, it fits for inertial measurement systems which work short time and ask for high accuracy. In addition, it can also significantly increase the measurement accuracy of micro inertial measurement system in practical application.

1140

作者: Ren Hao Liu, Hua Wang

摘要: This paper presents a novel procedure to calibrate the strap-down 3-axis MEMS accelerometers for UAV navigat-ion. Firstly, we establish an explicit calibration model with the measurement values of accelerometers, where the calibration is realized via geometric transformations. Secondly, the transfor-mation parameters are calculated through particle swarm optimization (PSO). For the problem of slower convergence rates near the global optimum, the classical PSO algorithm is improved. Based on the numerical optimization idea, the steepest descent method is introduced to PSO. The parameters are searched in the rough by adopting PSO and the precision ones are found by using steepest descent method. Then, the optimal transformation is achieved by the minimum distance function based on this improved PSO(IPSO) algorithm. Finally, the calibration procedure is tested by comparing the attitude produced by the 3-axis accelerometers with that measured by a turntable. The results show that the IPSO algorithm can significantly improve the performance of the classical PSO algorithm, and the maximum attitude error is reduced to 6% of that before calibration. In addition, the proposed procedure does not rely on prior knowledge of the accelerometers and any equipment. So, it is suitable for calibration in field. Such a method is especially useful in UAV applications.

4572

作者: Xiao Juan Zhang, Xi Sheng Li, Yi Bo Feng

摘要: In this paper, a kind of pedestrian navigation system (PNS) that based on Earth’s magnetic field is introduced, and the error of the build-in electronic compass is analyzed, and an efficient calibration algorithm is presented. The PNS is determined pedestrian’s movement locus by calculating the heading angle and analyzing the movement characteristic, and then using the dead reckoning algorithm to combine the information together. The precision of PNS is affected by the error of the electric compass, because the heading angle is calculated from the magnetic field data measured by the compass. In order to reduce the measure error, a direct method which is used to calibrate the compass, based on ellipsoid fitting, is developed.

1246

作者: Ji Wei Zhang, Xiao Dong Xu, Bo Wang

摘要: In order to solve the problem that in the dual axle rotating modulation inertial navigation system the angle between the horizon roller of the system and horizontal plane can't be removed, this paper provides an on-line self calibration method based on inertial navigation system, and this method realized the on-line self calibration of the inertial navigation system by calculating bias and scale factor both of the gyroscope and accelerometer, solving the problem that in the dual axle rotating modulation inertial navigation system the angle between the horizon roller of the system and horizontal plane can't be removed, providing an calculable basis for the prediction of attitude angle and realizing on-line autonomous self-calibration.

146

作者: Ahmad Faizal Zainal Abidin, Mohamad Huzaimy Jusoh, Syed Abdul Mutalib Al Junid

摘要: 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 8.1mm^{3}) 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).

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