This study introduces the development of hands-free control schemes for a riding ballbot, designed to allow riders including manual wheelchair users to control its movement through torso leaning and twisting. The hardware platform, Personal Unique Rolling Experience (PURE), utilizes a ballbot drivetrain, a dynamically stable mobile robot that uses a ball as its wheel to provide omnidirectional maneuverability. To accommodate users with varying torso motion functions, the hanads-free control scheme should be adjustable based on the rider's torso function and personal preferences. Therefore, concepts of (a) impedance control and (b) admittance control were integrated into the control scheme. A duo-agent optimization framework was utilized to assess the efficiency of this rider-ballbot system for a safety-critical task: braking from 1.4 m/s. The candidate control schemes were further implemented in the physical robot hardware and validated with two experienced users, demonstrating the efficiency and robustness of the hands-free admittance control scheme (HACS). This interface, which utilized physical human-robot interaction (pHRI) as the input, resulted in lower braking effort and shorter braking distance and time. Subsequently, 12 novice participants (six able-bodied users and six manual wheelchair users) with different levels of torso motion capability were then recruited to benchmark the braking performance with HACS. The indoor navigation capability of PURE was further demonstrated with these participants in courses simulating narrow hallways, tight turns, and navigation through static and dynamic obstacles. By exploiting pHRI, the proposed admittance-style control scheme provided effective control of the ballbot via torso motions. This interface enables PURE to provide a personal unique rolling experience to manual wheelchair users for safe and agile indoor navigation.

翻译：本研究介绍了骑行球型机器人免手控方案的开发，旨在使包括手动轮椅使用者在内的骑行者能够通过躯干倾斜和扭转来控制其运动。硬件平台"个人独特滚动体验"采用球型机器人驱动系统，这是一种利用球体作为轮子以实现全向机动性的动态稳定移动机器人。为适应具有不同躯干运动功能的用户，免手控方案需根据骑行者的躯干功能和个人偏好进行调整。因此，控制方案整合了(a)阻抗控制与(b)导纳控制的概念。采用双代理优化框架评估该骑行者-球型机器人系统在安全关键任务中的效能：从1.4米/秒速度制动。候选控制方案进一步在实体机器人硬件上实现，并由两名经验丰富的用户验证，证明了免手导纳控制方案的高效性与鲁棒性。该利用物理人机交互作为输入的界面，实现了更低的制动负荷、更短的制动距离和时间。随后招募12名具有不同躯干运动能力的新手参与者，以基准测试免手导纳控制方案的制动性能。通过模拟狭窄走廊、急转弯及静态与动态障碍物导航的路线，进一步向这些参与者展示了该平台的室内导航能力。通过利用物理人机交互，所提出的导纳式控制方案实现了通过躯干运动对球型机器人的有效控制。该界面使手动轮椅使用者能够获得安全灵活的室内导航体验。