In this paper, we present a controller that combines motion generation and control in one loop, to endow robots with reactivity and safety. In particular, we propose a control approach that enables to follow the motion plan of a first order Dynamical System (DS) with a variable stiffness profile, in a closed loop configuration where the controller is always aware of the current robot state. This allows the robot to follow a desired path with an interactive behavior dictated by the desired stiffness. We also present two solutions to enable a robot to follow the desired velocity profile, in a manner similar to trajectory tracking controllers, while maintaining the closed-loop configuration. Additionally, we exploit the concept of energy tanks in order to guarantee the passivity during interactions with the environment, as well as the asymptotic stability in free motion, of our closed-loop system. The developed approach is evaluated extensively in simulation, as well as in real robot experiments, in terms of performance and safety both in free motion and during the execution of physical interaction tasks.

翻译：本文提出了一种将运动生成与控制集成于同一循环中的控制器，以赋予机器人反应性与安全性。具体而言，我们提出了一种控制方法，能够在闭环配置下使机器人遵循一阶动力系统（DS）的运动规划，并具备可变刚度特性，其中控制器始终感知当前机器人状态。这使得机器人能够按照期望路径运动，同时其交互行为由期望刚度决定。我们还提出了两种解决方案，使机器人能够以类似轨迹跟踪控制器的方式遵循期望速度曲线，同时保持闭环配置。此外，我们利用能量储层概念来保证闭环系统在与环境交互过程中的无源性，以及在自由运动中的渐近稳定性。所提出的方法在仿真和真实机器人实验中均得到了广泛评估，重点考察了自由运动和物理交互任务执行过程中的性能与安全性。