Behavior-predefined adaptive control for heterogeneous continuum robots

Abstract

Continuum robots have great application value and broad prospects in various fields due to their dexterity and compliance. To fully exploit their advantages, it is crucial to develop an effective, accurate and robust control system for them. However, research on continuum robot control is still in its infancy and there are many problems remaining unsolved in this field. In particular, this paper focuses on the task-space behavior and the generic control of heterogeneous continuum robots. First, a controller is proposed to achieve the kinematic motion control and visual servoing of continuum robots with predefined task-space behavior. The predefined behavior is twofold: prescribed task-space error and predefined convergence time. Then, the proposed controller is integrated with a velocity-level kinematic mapping estimator to obtain a model-free control system, which is applicable to heterogeneous continuum robots. Furthermore, a re-adjustable performance function is proposed to ensure the effectiveness and robustness of the proposed control system in the presence of external disturbance. Finally, extensive simulations and experiments are performed based on heterogeneous continuum robots, including the cable-driven continuum robot, the parallel continuum robot, the concentric-tube robot, the flexible endoscope, and the pneumatic continuum robot. Our results demonstrate that the task-space error of heterogeneous continuum robots complies with the prescribed boundaries and converges to steady state in predefined time, which reveals the efficacy of the proposed control method.

连续体机器人凭借其灵活性和柔顺性，在各个领域都展现出巨大的应用价值和广阔的发展前景。为了充分发挥其优势，开发一套高效、精确且鲁棒的控制系统至关重要。然而，目前关于连续体机器人控制的研究仍处于起步阶段，该领域尚有许多问题亟待解决。具体而言，本文重点关注异构连续体机器人的任务空间行为及其通用控制问题。首先，本文提出了一种控制器，旨在实现具有预定义任务空间行为的连续体机器人的运动学控制与视觉伺服控制。这种预定义的行为包含两个层面：预设的任务空间误差界限以及预设的收敛时间。随后，本文将所提出的控制器与一种速度级运动学映射估计器相结合，构建了一套适用于异构连续体机器人的无模型控制系统。此外，本文还提出了一种可调节的性能函数，以确保该控制系统在面临外部扰动时仍能保持其有效性和鲁棒性。最后，本文基于多种异构连续体机器人（包括索驱动连续体机器人、并联连续体机器人、同心管机器人、柔性内窥镜以及气动连续体机器人）进行了大量的仿真与实验验证。实验结果表明，各类异构连续体机器人的任务空间误差均能严格遵循预设的边界约束，并在预定的时间内收敛至稳态，充分验证了本文所提出的控制方法的有效性