In this paper, we address the development of a robotic rehabilitation system for the upper limbs based on collaborative end-effector solutions. The use of commercial collaborative robots offers significant advantages for this task, as they are optimized from an engineering perspective and ensure safe physical interaction with humans. However, they also come with noticeable drawbacks, such as the limited range of sizes available on the market and the standard control modes, which are primarily oriented towards industrial or service applications. To address these limitations, we propose an optimization-based design method to fully exploit the capability of the cobot in performing rehabilitation tasks. Additionally, we introduce a novel control architecture based on an admittance-type Virtual Fixture method, which constrains the motion of the robot along a prescribed path. This approach allows for an intuitive definition of the task to be performed via Programming by Demonstration and enables the system to operate both passively and actively. In passive mode, the system supports the patient during task execution with additional force, while in active mode, it opposes the motion with a braking force. Experimental results demonstrate the effectiveness of the proposed method.

翻译：本文针对基于协作末端执行器解决方案的上肢康复机器人系统开发进行了研究。商用协作机器人在此任务中展现出显著优势，因其从工程角度进行了优化设计，并确保与人体实现安全的物理交互。然而，这类机器人也存在明显缺陷，例如市场上可选尺寸范围有限，且标准控制模式主要面向工业或服务应用。为克服这些局限，我们提出一种基于优化的设计方法，以充分挖掘协作机器人在执行康复任务中的潜力。此外，我们引入一种基于导纳型虚拟夹具方法的新型控制架构，该架构可将机器人运动约束在预设轨迹上。该方法支持通过示教编程直观定义待执行任务，并使系统能够同时实现被动与主动两种工作模式。在被动模式下，系统通过施加辅助力支持患者执行任务；在主动模式下，系统则通过制动力对抗患者运动。实验结果验证了所提方法的有效性。