Journal of Systems Engineering and Electronics ›› 2024, Vol. 35 ›› Issue (3): 769-779.doi: 10.23919/JSEE.2024.000050

• CONTROL THEORY AND APPLICATION • Previous Articles    

Kinematic calibration under the expectation maximization framework for exoskeletal inertial motion capture system

Weiwei QIN(), Wenxin GUO(), Chen HU(), Gang LIU(), Tainian SONG()   

  • Received:2021-12-14 Online:2024-06-18 Published:2024-06-19
  • Contact: Wenxin GUO E-mail:qww_1982@163.com;gwx_97@163.com;chenh628@hotmail.com;1813923249@qq.com;873512274@qq.com
  • About author:
    QIN Weiwei was born in 1982. He received his M.S. degree in guidance, navigation, and control and Ph.D. degree in control science and engineering from the Rocket Force University of Engineering, in 2008 and 2012, respectively, where he is currently an associate professor with the First College. His research interests include model predictive control, robust active control, and human motion capture. E-mail: qww_1982@163.com

    GUO Wenxin was born in 1997. He received his M.S. degree in guidance, navigation, and control in control science and engineering from the Rocket Force University of Engineering in 2021, where he is currently a research assistant with the First College. His research interests include human motion capture, kinematic calibration, model predictive control, and robust active control. E-mail: gwx_97@163.com

    HU Chen was born in 1989. He received his B.S. degree in automation from the Department of Automation, Xiamen University, Xiamen, China, in 2011, and M.S. and Ph.D. degrees in control science and engineering from the Rocket Force University of Engineering, Xi’an, China, in 2014 and 2018, respectively. He is currently a lecturer with the Rocket Force University of Engineering. His research interests include multiagent systems, distributed state estimation, and machine learning. E-mail: chenh628@hotmail.com

    LIU Gang was born in 1964. He received his M.S. degree in guidance, navigation, and control and Ph.D. degree in control science and engineering from Northwestern Polytechnical University, China, in 1995 and 1999, respectively. He is currently a professor with the Rocket Force University of Engineering. His research interests include guidance, navigation and control, and hypersonic flight vehicle. E-mail: 1813923249@qq.com

    SONG Tainian was born in 1997. He received his M.S. degree in guidance, navigation, and control from the Rocket Force University of Engineering in 2021, where he is currently a research assistant with the First College. His research interests include human motion capture and target detection. E-mail: 873512274@qq.com
  • Supported by:
    This work was supported by the National Natural Science Foundation of China (61503392).

Abstract:

This study presents a kinematic calibration method for exoskeletal inertial motion capture (EI-MoCap) system with considering the random colored noise such as gyroscopic drift. In this method, the geometric parameters are calibrated by the traditional calibration method at first. Then, in order to calibrate the parameters affected by the random colored noise, the expectation maximization (EM) algorithm is introduced. Through the use of geometric parameters calibrated by the traditional calibration method, the iterations under the EM framework are decreased and the efficiency of the proposed method on embedded system is improved. The performance of the proposed kinematic calibration method is compared to the traditional calibration method. Furthermore, the feasibility of the proposed method is verified on the EI-MoCap system. The simulation and experiment demonstrate that the motion capture precision is significantly improved by 16.79% and 7.16% respectively in comparison to the traditional calibration method.

Key words: human motion capture, kinematic calibration, exoskeleton, gyroscopic drift, expectation maximization (EM)