基于Preisach模型的微创手术器械钢丝绳驱动滞回特性分析与建模

Analysis and Modeling of Hysteretic Characteristics of Wire Rope Drive for Minimally Invasive Surgical Instruments Based on Preisach Model

  • 摘要: 微创手术中,在手术器械末端不安装传感器的条件下,系统仍需要得到末端准确的位置信息,以保证控制精度和医生手眼协调控制的一致性。为解决这一问题,本文基于改进Preisach模型的原理建立钢丝绳驱动手术器械传动模型,并采用多目标遗传算法NSGA-Ⅱ(nondominated sorting genetic algorithm Ⅱ)对模型的参数进行辨识,基于该模型对手术器械进行运动补偿。首先搭建微创手术器械钢丝绳驱动实验平台,其次采集电机传动信息与末端执行器运动信息,最后开展模型辨识和验证,得到模型的最大误差小于1°。为检验该算法的有效性,将该算法与线性回归、随机森林和神经网络方法进行对比,得出该算法综合指标最优,具有精度高、结果稳定、过拟合程度小等特点。

     

    Abstract: In minimally invasive surgery, accurate position information of the instrument end is indispensable to provide a high control accuracy, and a satisfactory consistency of hand-eye coordination control for surgeons, even if sensors are not installed at the end of surgical instrument. To address this issue, a transmission model of wire rope driven surgical instrument is established based on the principle of the improved Preisach model. The model parameters are fitted using NSGA-Ⅱ (nondominated sorting genetic algorithm Ⅱ), a multi-objective genetic algorithm. Thus, motion compensation for surgical instruments based on the proposed model is achieved. Firstly, an experiment platform of the wire rope drive for minimally invasive surgical instrument is built. Subsequently, motor drive information and end-effector movement information are collected. Finally, model identification and verification are carried out, and the resulting maximum error of the model is less than 1°. To evaluate the algorithm effectiveness, it is compared with the methods of linear regression, random forest, and neural networks. The proposed algorithm demonstrates the best comprehensive index, exhibiting high precision, stable results, and low overfitting.

     

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