基于折纸的被动触发双稳态机器人手设计

Design of passively-triggered bistable robotic hand based on origami

传统机器人手通常需要驱动器连续地提供保持抓握状态的扭矩或力。若驱动器失效,则机器人手无法稳定地抓取物体。针对上述问题,提出了一种基于折纸的被动触发双稳态机器人手。该机器人手由具有单自由度的抓握机构和具有双稳态特性的驱动机构组成。基于抓握机构和驱动机构的运动学模型,结合抓握状态的要求对机器人手的结构进行了设计,可通过设置扭转弹簧的刚度参数来实现对能量壁垒的灵活调整。最后,通过开展跌落捕获实验来验证所设计机器人手的抓握性能。结果表明,当跌落高度为400 mm时,机器人手的抓握运动未被触发;当跌落高度为440 mm时,机器人手成功抓握物体;当跌落高度为480 mm时,机器人手虽被触发了抓握运动但未能抓住物体。实验结果不仅验证了机器人手在无驱动条件下稳定抓取特定大小物体的能力,还揭示了不同外部冲击下能量壁垒的存在。基于折纸的被动触发双稳态机器人手在被动式和自适应机器人中具有潜在应用前景。

Conventional robotic hands usually require drives to continuously provide torque or force to maintain grasping state.If the drive fails,the robotic hand cannot grasp the object stably.To solve these problems,a passively-triggered bistable robotic hand based on origami is proposed.The robotic hand was composed of a grasping mechanism with single-degree-of-freedom and a driving mechanism with bistable characteristics.Based on the kinematics models of the grasping mechanism and driving mechanism,the structure of robotic hand was designed according to the requirements of grasping state,and the energy barrier could be adjusted flexibly by setting the stiffness parameters of the torsion spring.Finally,the drop capture experiments were carried out to verify the grasping performance of the designed robotic hand.The results showed that when the drop height was 400 mm,the grasping motion of the robotic hand was not triggered;When the drop height was 440 mm,the robotic hand successfully grasped the object;When the drop height was 480 mm,the robotic hand failed to grasp the object although the grasping motion was triggered.The experimental results not only validate the ability of robotic hand to grasp objects of a certain size stably without driving,but also reveal the existence of energy barriers under different external shocks.The passive-triggered bistable robotic hand based on origami has potential applications in passive and adaptive robots.