外骨骼足端人机接触力测量装置研究

Research on Human-machine Foot Contact Force Measuring Device for Exoskeleton Robot

下肢外骨骼机器人系统中,足端接触力的测量是人机交互运动控制的基础,针对设计上面临的足地接触状态复杂、趾关节挠曲运动、重量及尺寸空间限制等问题,提出基于分布式传感器布局,以及刚柔结合的足端人机接触力测量装置结构方案。采用6自由度全约束的人机连接方案实现与人足的可靠连接,通过多传感器布置方式来应对复杂的足端受力状况,采用刚柔结合的双层结构,结合多个运动副,解决传感器之间内应力问题,并实现顺应趾关节弯曲的需求,设计了高精度的供电及信号放大电路,并建立力平衡方程实现力信号的合成,最后开展了与三维力台的对比实验,验证了功能指标和测量精度符合设计需求。

In the lower limb exoskeleton robot system,the measurement of foot contact force is the basis of human-computer interactive motion control.Aiming at the design challenges,such as complex foot ground contact state,flexure movement of toe joint,weight and space constraints,the structure of the rigid-flexible foot human-machine contact force measurement device based on distributed sensors is proposed.The 6-DOF fully constrained man-machine connection is adopted to realize a reliable connection with the human foot.The multi-sensor layout is used to deal with the complex stress condition at the foot end.The rigid-flexible double-layer structure and multiple motion pairs are adapted to release the internal stress between the sensors and to meet the needs of toe joints bending.A high-precision power supply and signal amplification circuit are designed,and the force balance equation is established to realize the synthesis of the force signal.Finally,the comparative experiment with a three-dimensional force platform is carried out to verify that the functional index and measurement accuracy meet the design requirements.