A novel magnetoelastic torque sensor with planar spiral coil probes for humanoid robot joints

Abstract

Humanoid robot joints require real-time torque detection to provide accurate force feedback information for the control system. To meet the measurement requirements and realize the miniaturization of the sensor, a torque sensor based on the magnetoelastic effect is developed, utilizing planar spiral coils as detection probes. In this work, a planar spiral coil mutual inductance calculation model is established to solve the mutual inductance coefficient, and the mechanical structure and circuit design of the sensor are completed. Finally, a torque loading platform is built to perform calibration experiments, and the hysteresis model is improved to compensate for the hysteresis phenomenon. The calibration results indicate that the sensor shows excellent loaded nonlinearity of 3.08%F.S., unloaded nonlinearity of 2.71%F.S., loaded repeatability of 2.48%F.S., unloaded repeatability of 1.89%F.S. and hysteresis of 1.9%F.S., at a compact probe size of 13.8×9.9×1.8 mm.

Keywords

Magnetoelastic effect / Torque sensor / Planar spiral coil / Mutual inductance calculation / Hysteresis model

CRediT authorship contribution statement

Zijian Zhang: Writing - review & editing, Supervision, Methodology. Zitao Wang: Writing - original draft. Ming Shao: Formal analysis. Yangyang Dong: Writing - review & editing, Supervision, Project administration. Fenglei Ni: Funding acquisition, Formal analysis.

Declaration of competing interest

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Acknowledgments

This work is supported in part by Guangxi Science and Technology Program, China (2024AB12006), the Open Fund of Innovation Center for Control Actuators, China (ICCA18-202405)and China Huaneng Group.,Ltd. Headquarters Technology Project (HNKJ24-HF15).

Appendix A. Supplementary data

Supplementary material related to this article can be found online at https://doi.org/10.1016/j.birob.2025.100229.

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