Journal of South China University of Technology(Natural Science Edition) ›› 2023, Vol. 51 ›› Issue (5): 86-94.doi: 10.12141/j.issn.1000-565X.220374

Special Issue: 2023年电子、通信与自动控制

• Electronics, Communication & Automation Technology • Previous Articles     Next Articles

Research on Dynamic Characteristics of Force Sensor Based on VFF-RLS

YAO Bin ZHANG Zihao DAI Yu ZHANG Jianxun   

  1. College of Artificial Intelligence/ Institute of Robotics and Automatic Information System,Nankai University,Tianjin 300350,China
  • Received:2022-06-15 Online:2023-05-25 Published:2023-01-13
  • Contact: 代煜(1981-),男,教授,博士生导师,主要从事医疗手术机器人研究。 E-mail:daiyu@nankai.edu.cn
  • About author:姚斌(1996-),男,博士生,主要从事手术机器人力感知及力反馈研究。E-mail:yaobin0317@foxmail.com
  • Supported by:
    the National Key R&D Program of China(2017YFC0110402)

Abstract:

In scientific experiments and industrial production, the dynamic characteristics of the force sensor will directly affect the accuracy, so it is of great significance to research the dynamic characteristics of the force sensor. Aiming at the practical problem that the dynamic characteristics of strain gauge force sensor used in surgical robots are difficult to meet the accuracy requirements, this paper studied the application of least square parameter identification method in the vibration structure of force sensor. Because recursive least squares (RLS) is difficult to ensure the rapidity and anti-interference of the second order vibration system model identification, therefore, this paper proposed a recursive least squares parameter identification method based on variable forgetting factor. Firstly, the parameters of the forgetting factor function were determined by establishing the random vibration system model, simulating and analyzing the input/output characteristics of the system. The simulation results show that the proposed method in the paper can significantly reduce the parameter identification error and convergence prediction error compared with RLS while maintaining a faster convergence speed, and has better time variability compared with the least squares. Furthermore, the dynamic parameters of the force sensor used in minimally invasive surgical robot were identified based on the step test calibration method to obtain the structural dynamic characteristics (i.e. natural frequency and damping ratio) of the sensor system. The experimental results show that the proposed method in the paper has good convergence and stability, and can effectively improve the identification accuracy.

Key words: forgetting factor, vibration model, dynamic performance calibration, recursive least squares, parameter identification

CLC Number: