This paper focusses on the energy-efficient control of a cable-driven robot for tasks that only require precise positioning at few points in their motion, and where that accuracy can be obtained through contacts. This includes the majority of pick-and-place operations. Knowledge about the task is directly taken into account when specifying the control execution. The natural dynamics of the system can be exploited when there is a tolerance on the position of the trajectory. Brakes are actively used to replace standstill torques, and as passive actuation. This is executed with a hybrid discrete-continuous controller. A discrete controller is used to specify and coordinate between subtasks, and based on the requirements of these specific subtasks, specific, robust, continuous controllers are constructed. This approach allows for less stiff and thus saver, and cheaper hardware to be used. For a planar pick-and-place operation, it was found that this results in energy savings of more than 30%. However, when the payload moves with the natural dynamics, there is less control of the followed trajectory and its timing compared to a traditional trajectory-based execution. Also, the presented approach implies a fundamentally different way to specify and execute tasks.

翻译：本文聚焦于缆索驱动机器人的能效控制，针对运动过程中仅需在少数点位实现精确定位、且可通过接触达成该精度的任务。这涵盖了大多数拾放操作。在指定控制执行时，任务知识被直接纳入考量。当轨迹位置存在容差时，可充分利用系统的自然动力学特性。制动器被主动用于替代静态扭矩，并作为被动执行机构发挥作用。该系统采用混合离散-连续控制器：离散控制器负责子任务的分配与协调，并基于这些特定子任务的需求构建相应的鲁棒连续控制器。该方法允许使用刚度较低、更安全且成本更低的硬件。针对平面拾放操作的实验表明，该方法可实现超过30%的节能效果。然而，当负载随自然动力学运动时，相比传统基于轨迹的执行方式，对运动轨迹及其时序的控制能力有所下降。此外，该方案本质上改变了任务的指定与执行方式。