基于光纤光栅的软体机器人末端力测量方法研究

手术机器人的末端操作力测量是实现机器人精准控制的关键，对保证手术操作的安全性至关重要。文中针对微创手术软体机器人末端三维力测量的实际需求，提出一种基于光纤光栅的微创软体机器人末端三维力的测量方法。基于光纤光栅传感原理，分析光纤传感器植入在软体机器人中的传感特性，建立基于最小二乘法线性标定和基于伯恩斯坦多项式非线性补偿的软体机器人末端力解耦模型，研究光纤光栅中心波长漂移量和软体机器人末端三维力之间的关系。并通过实验测试和对比分析验证了基于线性标定和非线性解耦算法的光纤传感软体机器人末端力测量性能研究结果表明:光纤光栅传感的可重复性平均为1.5 pm，末端力在XYZ三个方向上的测量精度误差均低于满量程的5%，且残差分布大部分集中在可靠区间，具有良好的重复性。所提出的基于光纤光栅的软体机器人末端力解耦算法为微创手术软体机器人的末端力精确测量提供了有效的方法，在生物医学等软体机器人的末端力测量中具有应用前景。

Research on end force measurement method of soft robot based on fiber Bragg grating

The measurement of the terminal operating force of the surgical robot is the key to achieve the precise control of the robot, which is crucial to ensure the safety of the surgical operation. In this paper, a method of measuring the three-dimensional force of soft robot terminal end based on fiber Bragg grating was proposed to meet the requirement of minimally invasive surgery. Based on the principle of fiber grating sensing, the sensing characteristics of fiber sensor embedded in soft robot were analyzed and a soft robot terminal force decoupling model based on linear calibration with least square method and nonlinear compensation with Bernstein polynomial was established. Then the relationship between the central wavelength shift of the fiber Bragg grating and the three-dimensional force at the end of the soft robot was studied. The results show that the average repeatability of FBG sensor is 1.5 pm. The measurement accuracy error of the end force in the three directions of XYZ is lower than 5% of the full range, and the residual distribution is mostly concentrated in the reliable range, with good repeatability. The proposed FBG decoupling algorithm provides an effective method for the precise measurement of the terminal force of soft robot in minimally invasive surgery, and has a promising application prospect in the measurement of the terminal force of soft robot in biomedicine.