3-axis Measurement Research Articles

Derivation of riding risk precursors using 100 delivery motor scooter naturalistic riding study

The rapid growth of the delivery service market in Korea due to the impact of COVID-19 has resulted in an increase in crashes associated with delivery motor scooters. In particular, required minimum delivery time, which is an important factor for food delivery service, can lead to hazardous riding situations leading to traffic crashes. Although the food delivery service industry is continuously increasing, effective measures to improve the traffic safety of delivery motor scooters are insufficient. This study derived precursors in order to detect risky riding events using real-world naturalistic riding study data. It is essential to understand the riding characteristics of food delivery motor scooters to conduct the riding safety monitoring in more scientific and automated manners. Various candidate precursors were derived from riding characteristics data collected from GPS sensors and inertial measurement unit sensors. A decision tree model was then adopted to classify unsafe and normal riding events in order to determine the priority of precursors. A classification accuracy of 95.7% was obtained using three salient riding risk precursors including the norm of the angular velocity, which represents composite vector quantity of 3-axis measurements, acceleration, and X-axis angular velocity. The results of this study are expected to be used as a fundamental data to prepare for riding safety management systems that contribute to enhancing the safety of food delivery motor scooters.

Accurate 3-axis measurement of inhomogeneous magnetic fields

Abstract Hall effect based Teslameters/Gaussmeters measure DC and AC magnetic flux densities in the range from a few µT to about 30 T. For accurate measurement a 3-axis Hall probe is applied with small magnetic field sensitive volume (MFSV) of 100 µm × 10 µm × 100 µm, with vertical and horizontal Hall elements integrated on a single chip. The planar Hall effect, that produces additional measurement errors is suppressed by the spinning current technique. The orthogonality error of the 3-axis Hall probe is reduced to smaller than 0.1° by the described calibration procedure. This paper explains why the above features are crucial for some applications in industry and modern science for accurate measurement of inhomogeneous magnetic fields and how to achieve them. The future technology trends in magnetic metrology are introduced and the newly developed Nanomapper that incorporates a 3-axis Hall probe with a MFSV of smaller than 10×10×10 micrometer is presented.

Методика калибровки тепловой модели блока чувствительных элементов, состоящего из трех датчиков угловой скорости

Методика калибровки тепловой модели блока чувствительных элементов, состоящего из трех датчиков угловой скорости

Design and Characterization of a Three-Axis Hall Effect-Based Soft Skin Sensor.

This paper presents an easy means to produce a 3-axis Hall effect–based skin sensor for robotic applications. It uses an off-the-shelf chip and is physically small and provides digital output. Furthermore, the sensor has a soft exterior for safe interactions with the environment; in particular it uses soft silicone with about an 8 mm thickness. Tests were performed to evaluate the drift due to temperature changes, and a compensation using the integral temperature sensor was implemented. Furthermore, the hysteresis and the crosstalk between the 3-axis measurements were evaluated. The sensor is able to detect minimal forces of about 1 gf. The sensor was calibrated and results with total forces up to 1450 gf in the normal and tangential directions of the sensor are presented. The test revealed that the sensor is able to measure the different components of the force vector.

Quantitative assessment of severity of ventricular septal defect by three-dimensional reconstruction of color Doppler-imaged vena contracta and flow convergence region.

The aim of the present study was to investigate the feasibility and potential value of the computer-controlled, 3D, echocardiographic reconstruction of the color Doppler-imaged vena contracta (CDVC) and the flow convergence (FC) region as a means of accurately and quantitatively estimating the severity of a ventricular septal defect (VSD). We performed a 3D reconstruction of the CDVC and the FC region in 19 patients with an isolated VSD using an ultrasound system interfaced with a Tomtec computer. The variable asymmetric geometry of the CDVC and the FC region could be 3D-visualized in all patients. The 3D-measured areas of CDVC correlated well with volumetric measurements of the severity of VSD (r=0.97, P:<0.001). Regression analysis between the shunt flow rate (calculated from the product of the area of CDVC and the continuous Doppler-derived velocity time integral) and the corresponding reference results (calculated by cardiac catheterization) demonstrated a close correlation (r=0.95, P:<0.001). There was also a good correlation between shunt flow rates calculated using the conventional 2D, 1-axis measurement of the FC isovelocity surface area with the hemispheric assumption (r=0.95, P:<0.001); shunt flow rates calculated using 3D, 3-axis measurements of the FC region (r=0.97, P:<0.01); and reference results by cardiac catheterization. However, the 2D method substantially underestimated the actual shunt flow rate. The 3D reconstruction of the CDVC and the FC region may aid in quantifying the severity of VSD.

Full Satellite State Determination from Vector Observations

An Extended Kalman Filter (EKF) is proposed to extract full attitude, body rate and disturbance torque information for a LEO gravity gradient stabilized micro satellite by using only 3-axis measurement and modelling vector information. In this article a magnetometer and IGRF model are used to obtain the 3-axis geomagnetic vectors to be used as filter innovations The attitude is parameterized using quaternions and therefore avoiding any singularities.