Convex Optimization of Mutual Inductance between Multi-Antiparallel Coils for Distance-Insensitive Wireless Charging of Air-ground Robots



Zhao, Huapeng, Zhang, Yuxin, Hu, Jun, Chen, Zhizhang, Zhou, Jiafeng ORCID: 0000-0002-3940-3320, Sun, Menghan and Yang, Danyu
(2021) Convex Optimization of Mutual Inductance between Multi-Antiparallel Coils for Distance-Insensitive Wireless Charging of Air-ground Robots. IEEE Internet of Things Journal, 9 (13). p. 1.

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Abstract

This article proposes convex optimization of mutual inductance between multiantiparallel coils (MACs) for distance-insensitive wireless charging of air-ground robots. In order to reduce optimization costs, the proposed optimization method is developed by hybridizing analytical and numerical models. First, it is shown that the commonly used analytical model for MAC design becomes inaccurate as frequency increases. Second, a trial mutual inductance is introduced as an optimization variable. From the trial mutual inductance, an MAC is designed using the analytical model. Third, the realized mutual inductance of the analytically designed MAC is computed by a numerical model to correct the error of the analytical model. The difference vector ρ between the realized and optimal mutual inductances is written as a function of the trial mutual inductance, and the l_2 -norm of ρ is minimized by changing the trial mutual inductance. The resultant optimization problem is shown to be convex, and it is conveniently solved by using a local searching method. Simulation results show that the proposed design method satisfies design specification much better than the conventional analytical-model-based design method. Using the proposed method, an MAC prototype is designed and fabricated, and a wireless charging system for air-ground robots is constructed and tested. Measurement results show that the efficiency of the designed MAC is maintained at around 80% in the transfer distance range of 15-55 mm, and stable efficiency is obtained when charging real air-ground robots of different heights.

Item Type: Article
Divisions: Faculty of Science and Engineering > School of Electrical Engineering, Electronics and Computer Science
Depositing User: Symplectic Admin
Date Deposited: 08 Nov 2021 08:08
Last Modified: 18 Jan 2023 21:25
DOI: 10.1109/jiot.2021.3125566
Related URLs:
URI: https://livrepository.liverpool.ac.uk/id/eprint/3142920