Future operating theatres will be equipped with robots to perform various surgical tasks including, for example, endoscope control. Human-in-the-loop supervisory control architectures where the surgeon selects from several autonomous sequences is already being successfully applied in preclinical tests. Inserting an endoscope into a trocar or introducer is a key step for every keyhole surgical procedure -- hereafter we will only refer to this device as a "trocar". Our goal is to develop a controller for autonomous trocar docking. Autonomous trocar docking is a version of the peg-in-hole problem. Extensive work in the robotics literature addresses this problem. The peg-in-hole problem has been widely studied in the context of assembly where, typically, the hole is considered static and rigid to interaction. In our case, however, the trocar is not fixed and responds to interaction. We consider a variety of surgical procedures where surgeons will utilize contact between the endoscope and trocar in order to complete the insertion successfully. To the best of our knowledge, we have not found literature that explores this particular generalization of the problem directly. Our primary contribution in this work is an optimal control formulation for automated trocar docking. We use a nonlinear optimization program to model the task, minimizing a cost function subject to constraints to find optimal joint configurations. The controller incorporates a geometric model for insertion and a force-feedback (FF) term to ensure patient safety by preventing excessive interaction forces with the trocar. Experiments, demonstrated on a real hardware lab setup, validate the approach. Our method successfully achieves trocar insertion on our real robot lab setup, and simulation trials demonstrate its ability to reduce interaction forces.

翻译：未来的手术室将配备机器人执行各种外科任务，例如内窥镜操控。采用外科医生从多个自主序列中选择的人机协同监督控制架构已在临床前测试中成功应用。将内窥镜插入套管或导入器是每个微创外科手术的关键步骤——下文我们将此装置统称为“套管”。本研究旨在开发一种用于自主套管对接的控制器。自主套管对接是“轴孔装配问题”的一种变体。机器人学文献中已有大量研究针对该问题展开探讨。轴孔装配问题在装配领域得到了广泛研究，通常假定孔位静态且对交互作用呈现刚性响应。然而在本研究中，套管并非固定装置且会对交互产生动态响应。我们考察了多种外科手术场景，其中外科医生需利用内窥镜与套管之间的接触力才能成功完成插入操作。据我们所知，尚未发现文献直接探讨该问题的这一特定泛化形式。本研究的主要贡献在于提出了自动化套管对接的最优控制框架。我们采用非线性优化程序对任务进行建模，通过最小化受约束的成本函数来求解最优关节构型。该控制器融合了插入过程的几何模型与力反馈项，通过限制套管交互力来保障患者安全。在真实硬件实验平台上的验证实验证明了该方法的有效性。我们的方法在真实机器人实验平台上成功实现了套管插入，仿真实验进一步表明其能有效降低交互作用力。