Visible to the public Biblio

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2020-11-30
Beran, P., Klöhn, M., Hohe, H..  2019.  Measurement Characteristics of Different Integrated Three-Dimensional Magnetic Field Sensors. IEEE Magnetics Letters. 10:1–5.
Datasheets of different commercially available integrated sensors for vector measurements of magnetic fields provide typical specifications, such as measurement range, sampling rate, resolution, and noise. Other characteristics of interest, such as linearity, cross-sensitivity, remanent magnetization, and drifts over temperature, are mostly missing. This letter presents testing results of those characteristics of integrated three-dimensional (3-D) sensors working with different sensor principles and technologies in a reproducible measuring process. The sensors are exposed to temperatures from -20 °C to 80 °C and are cycled in hysteresis loops in fields up to 2.5 mT. For applying high-accuracy magnetic fields, a calibrated 3-D Helmholtz coil setup is used. Commercially available integrated 3-D magnetic field sensors are put in operation on a printed circuit board using nonmagnetic passive components. All sensors are configured for best measurement accuracy according to their data-sheets. The results show that sensors based on anisotropic magnetoresistance have high accuracy and low offsets yet also a high degree of nonlinearity. Hall-based sensors show good linearity but also high cross-sensitivity. A magnetic remanence appears for Hall-based sensors with integrated magnetic concentrators as well as for sensors using anisotropic magnetoresistance. Nearly all sensors show remaining drifts over temperature regarding offset and sensitivity up to several percentages.
2020-04-24
Luo, Xuesong, Wang, Shaoping.  2018.  Multi-work Condition Modeling and Performance Analysis of Linear Oscillating Actuators. 2018 IEEE International Conference on Prognostics and Health Management (ICPHM). :1—7.

Linear oscillating actuators are emerging electrical motors applied to direct-drive electromechanical systems. They merit high efficiency and quick dynamical property due to the unique structure of spring oscillator. Resonant principle is the base of their high performance, which however, is easily influenced by various load, complex environment and mechanical failure. This paper studies the modeling of linear oscillating actuators in multi-work condition. Three kinds of load are considered in performance evaluation model. Simulations are conducted at different frequencies to obtain the actuator behavior, especially at non-resonance frequencies. A method of constant impedance angle is proposed to search the best working points in sorts of conditions. Eventually, analytical results reflect that the resonant parameter would drift with load, while linear oscillating actuators exhibits robustness in efficiency performance. Several evaluating parameters are concluded to assess the actuator health status.

Yu, Jiangfan, Zhang, Li.  2019.  Reconfigurable Colloidal Microrobotic Swarm for Targeted Delivery. 2019 16th International Conference on Ubiquitous Robots (UR). :615—616.

Untethered microrobots actuated by external magnetic fields have drawn extensive attention recently, due to their potential advantages in real-time tracking and targeted delivery in vivo. To control a swarm of microrobots with external fields, however, is still one of the major challenges in this field. In this work, we present new methods to generate ribbon-like and vortex-like microrobotic swarms using oscillating and rotating magnetic fields, respectively. Paramagnetic nanoparticles with a diameter of 400 nm serve as the agents. These two types of swarms exhibits out-of-equilibrium structure, in which the nanoparticles perform synchronised motions. By tuning the magnetic fields, the swarming patterns can be reversibly transformed. Moreover, by increasing the pitch angle of the applied fields, the swarms are capable of performing navigated locomotion with a controlled velocity. This work sheds light on a better understanding for microrobotic swarm behaviours and paves the way for potential biomedical applications.

2019-09-30
Xu, F., Peng, R., Zheng, T., Xu, X..  2019.  Development and Validation of Numerical Magnetic Force and Torque Model for Magnetically Levitated Actuator. IEEE Transactions on Magnetics. 55:1–9.

To decouple the multi-axis motion in the 6 degrees of freedom magnetically levitated actuators (MLAs), this paper introduces a numerical method to model the force and torque distribution. Taking advantage of the Gaussian quadrature, the concept of coil node is developed to simplify the Lorentz integral into the summation of the interaction between each magnetic node in the remanence region and each coil node in the coil region. Utilizing the coordinate transformation in the numerical method, the computation burden is independent of the position and the rotation angle of the moving part. Finally, the experimental results prove that the force and torque predicted by the numerical model are rigidly consistent with the measurement, and the force and torque in all directions are decoupled properly based on the numerical solution. Compared with the harmonic model, the numerical wrench model is more suitable for the MLAs undertaking both the translational and rotational displacements.

2018-12-03
Schlüter, F., Hetterscheid, E..  2017.  A Simulation Based Evaluation Approach for Supply Chain Risk Management Digitalization Scenarios. 2017 International Conference on Industrial Engineering, Management Science and Application (ICIMSA). :1–5.

Supply Chain wide proactive risk management based on real-time risk related information transparency is required to increase the security of modern, volatile supply chains. At this time, none or only limited empirical/objective information about digitalization benefits for supply chain risk management is available. A method is needed, which draws conclusion on the estimation of costs and benefits of digitalization initiatives. The paper presents a flexible simulation based approach for assessing digitalization scenarios prior to realization. The assessment approach is integrated into a framework and its applicability will be shown in a case study of a German steel producer, evaluating digitalization effects on the Mean Lead time-at-risk.

2017-12-04
Kolzer, J. F., Bazzo, T., Carlson, R..  2016.  Optimal design and performance analysis of a ferrite permanent magnet synchronous generator. 2016 12th IEEE International Conference on Industry Applications (INDUSCON). :1–7.

This paper presents the analysis and the design of a ferrite permanent magnet synchronous generator (FePMSG) with flux concentration. Despite the well-known advantages of rare earth permanent magnet synchronous generators (REPMSG), the high cost of the rare earth permanent magnets represents an important drawback, particularly in competitive markets like the wind power. To reduce the cost of permanent magnet machines it is possible to replace the expensive rare earth materials by ferrite. Once ferrite has low remanent magnetization, flux concentration techniques are used to design a cheaper generator. The designed FePMSG is compared with a reference rare earth (NdFeB) permanent magnet synchronous generator (REPMSG), both with 3 kW, 220 V and 350 rpm. The results, validated with finite element analysis, show that the FePMSG can replace the REPMSG reducing significantly the active material cost.