Abstract: Eating is an essential activity for the disabled with upper limb impairments, and therefore numerous feeding robots are born. However, safety and reliability are two basic elements to build trust in assistive robots. Thus, planning and control methods for a safe and reliable robot-assisted feeding system are developed. Firstly, the feeding task is expanded to include both pre-meal preparation and eating. The feeding task is then divided into five subtasks including door opening, bowl grasping and transferring, utensil fetching, food skewering, and food transferring. Meanwhile, the system is built from five levels, i.e., user interface, task planning, motion planning, control, and perception. Secondly, the feeding task is decomposed into a series of motion primitives based on a motion-centric taxonomy. Then a set of states utilizing those primitives is constructed and then a finite state machine is employed as the task manager which can regulate the workflow during the feeding task. Thirdly, a safety-oriented motion planner, a food item selector, an admittance controller, and a collision detector are depicted. Finally, experiments in the laboratory and further in a rehabilitation hospital with stroke patients are conducted. The experimental results indicate that the system is safe and reliable.

Key words: assistive robots, robot-assisted feeding, admittance control, motion planning, task planning

摘要： 对于有上肢障碍的残疾人来说，进食是一项必不可少的活动，因此诞生了许多喂养机器人。然而，安全性和可靠性是建立对辅助机器人信任的两个基本要素。因此，开发了一种安全可靠的机器人辅助喂食系统的规划和控制方法。首先，喂养任务扩展到包括餐前准备和进食。然后将喂食任务分为开门，抓取和转移，取餐具，叉取食物，和转移食物五个子任务。同时，系统从用户界面、任务规划、运动规划、控制和感知五个层面进行构建。其次，基于以运动为中心的分类方法，将馈送任务分解为一系列运动原语；然后利用这些原语构造一组状态集，然后使用有限状态机作为任务管理器，在馈送任务中调节工作流程。第三，描述了面向安全的运动规划器、食品选择器、导纳控制器和碰撞检测器。最后，在实验室进行了实验，并进一步在康复医院进行了脑卒中患者的实验。实验结果表明，该系统安全可靠。

关键词: 辅助机器人，机器人助餐，导纳控制，运动规划，任务规划