Hybrid Humanoid Robotic Head Mechanism: Design, Modeling, and Experiments with Object Tracking

The head mechanism is a critical part of a humanoid healthcare robot for potential healthcare or elderly care. The head structure of a humanoid robot should provide both motion and perception capabilities to mimic head function (e.g. object tracking) for Human-robot interaction (HRI) at the head level. In this paper, an innovative hybrid head mechanism consisting of one rotational servo motor and two linear servos has been proposed. Structural design, kinematic analysis, and automation have been studied to advance locomotive capability as well as functionality. Additionally, a visual servoing object tracking system was implemented as a perception unit to achieve real-time object tracking function. For the structural design, a parallel configuration of two linear actuators was selected to simplify the kinematic analysis, which enables precise control of joint angles. For the perception part, a vision-based real-time Aruco maker tracking system with proportional-integral-derivative (PID) control was set as a test scenario to mimic human head function with joint control of 3 DOFs (yaw, pitch, and roll). The functionality of this head mechanism has been validated by tests on potential use case (visual servoing object tracking). This head mechanism can servo as a valuable platform for broader HRI applications with humanoid healthcare robots.

头部机构是用于潜在医疗保健或老年护理的人形医疗机器人的关键部分。人形机器人的头部结构应具备运动和感知能力，以在头部层面模拟头部功能（例如物体跟踪），实现人机交互（HRI）。在本文中，提出了一种由一个旋转伺服电机和两个线性伺服电机组成的创新型混合头部机构。对结构设计、运动学分析和自动化进行了研究，以提高运动能力和功能性。此外，还实施了一个视觉伺服物体跟踪系统作为感知单元，以实现实时物体跟踪功能。在结构设计方面，选择了两个线性执行器的并联配置以简化运动学分析，从而能够精确控制关节角度。在感知部分，设置了一个基于视觉的带有比例 - 积分 - 微分（PID）控制的实时Aruco标记跟踪系统作为测试场景，通过3个自由度（偏航、俯仰和翻滚）的关节控制来模拟人类头部功能。通过对潜在用例（视觉伺服物体跟踪）的测试，验证了这种头部机构的功能性。这种头部机构可作为人形医疗机器人更广泛的人机交互应用的有价值平台。