This article presents assistive control sche-mes for rehabilitation robots. The objective was to develop control strategies to follow a predefined path by maximizing the active participation of impaired subjects during training sessions. For this purpose, the path following task was defined in the velocity domain by constructing a desired velocity field around the path, and two different controllers were designed, which adjust the intervention of the robot according to the performance of the users, delivering an assist-as-needed (AAN) feature with adequate timing freedom. First, we developed an impedance controller for velocity tracking, which gains the AAN property by means of modulating the target impedance. Second, we designed a velocity tracking controller, which adjusts its contribution, in an AAN way, by monitoring the tracking error. Utilizing force sensors, the first method does not require a compliant robotic system, while the second approach does not need force sensors but provides its best AAN performance whenever the system is compliant. The controllers were featured by a force field component to avoid large position errors. The performance of the controllers was evaluated through experimental tests performed on a planar upper-limb training robot.

中文翻译：

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康复机器人的基于现场的按需辅助控制方案

本文介绍了康复机器人的辅助控制方案。目的是通过在培训课程中最大程度地使有障碍的受试者积极参与，制定遵循预定路径的控制策略。为此，通过在路径周围构建所需的速度场，在速度域中定义了路径跟随任务，并设计了两个不同的控制器，它们根据用户的性能调整机器人的干预，并提供辅助按需（AAN）功能，具有足够的时序自由度。首先，我们开发了一种用于速度跟踪的阻抗控制器，该控制器通过调制目标阻抗来获得AAN属性。其次，我们设计了速度跟踪控制器，该控制器通过监视跟踪误差以AAN方式调整其贡献。利用力传感器，第一种方法不需要兼容的机器人系统，而第二种方法不需要力传感器，但是只要系统兼容，它就可以提供最佳的AAN性能。控制器具有力场组件，可避免出现较大的位置误差。通过在平面上肢训练机器人上进行的实验测试来评估控制器的性能。