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arXiv 2408.01604cs.ROcs.SYeess.SY
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绳驱动手术机器人的高效数据驱动关节级标定

Efficient Data-driven Joint-level Calibration of Cable-driven Surgical Robots

University of Washington(华盛顿大学);Mount Holyoke College(曼荷莲学院);University of California San Diego(加州大学圣迭戈分校);University of Michigan(密歇根大学)

Haonan Peng, Andrew Lewis, Yun-Hsuan Su, Shan Lin, Dun-Tin Chiang, Wenfan Jiang, Helen Lai, Blake Hannaford

AI总结:

本文针对绳驱动手术机器人因绳索拉伸导致的关节定位误差,提出基于原始状态和之字形轨迹的数据驱动关节级标定方法,并在 RAVEN-II 上验证其精度、持久性与实时性。

摘要:

获知准确的关节位置对于腹腔镜手术机器人的安全、精确控制至关重要,尤其是在手术子任务自动化方面。这类机器人通常采用绳驱动机械臂和工具,因为绳索允许将较大的电机布置在机器人基座处,远离空间极其宝贵的手术区域。然而,通过绳索将关节与其电机相连时,绳索的任何拉伸都会导致由电机端编码器进行运动学估计时出现误差,从而给手术工具的精确控制带来困难。在本研究中,我们提出了一种高效的数据驱动方法,用于标定此类机器人的定位关节,本研究以 RAVEN-II 手术机器人研究平台为对象。标定仅需 8–21 分钟,而经过标定的关节在长达 6 小时的高负载运行中仍保持较高精度,表明其在实际应用中具有良好可行性。标定模型以原始机器人状态为输入,并使用具有所需稀疏度的之字形轨迹进行训练,训练后无需额外传感器。与固定偏移补偿相比,Deep Neural Network(深度神经网络)标定模型可进一步降低 76% 的误差,并在关节 1、关节 2 和关节 3 上分别达到 0.104 度、0.120 度和 0.118 毫米的精度。与端到端模型相比,实验表明,DNN 模型在输出误差以校正原始不准确关节位置时,可获得更好的精度和更快的收敛速度。此外,结果显示,线性回归模型的推理速度比 DNN 模型快 160 倍,适用于 1000 Hz 伺服控制回路,但精度会略有下降。

英文摘要:

Knowing accurate joint positions is crucial for safe and precise control of laparoscopic surgical robots, especially for the automation of surgical sub-tasks. These robots have often been designed with cable-driven arms and tools because cables allow for larger motors to be placed at the base of the robot, further from the operating area where space is at a premium. However, by connecting the joint to its motor with a cable, any stretch in the cable can lead to errors in kinematic estimation from encoders at the motor, which can result in difficulties for accurate control of the surgical tool. In this work, we propose an efficient data-driven calibration of positioning joints of such robots, in this case the RAVEN-II surgical robotics research platform. While the calibration takes only 8-21 minutes, the accuracy of the calibrated joints remains high during a 6-hour heavily loaded operation, suggesting desirable feasibility in real practice. The calibration models take original robot states as input and are trained using zig-zag trajectories within a desired sparsity, requiring no additional sensors after training. Compared to fixed offset compensation, the Deep Neural Network calibration model can further reduce 76 percent of error and achieve accuracy of 0.104 deg, 0.120 deg, and 0.118 mm in joints 1, 2, and 3, respectively. In contrast to end-to-end models, experiments suggest that the DNN model achieves better accuracy and faster convergence when outputting the error to correct original inaccurate joint positions. Furthermore, a linear regression model is shown to have 160 times faster inference speed than DNN models for application within the 1000 Hz servo control loop, with slightly compromised accuracy.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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