新型串联弹性驱动器设计与速度控制

Novel series elastic actuator design and velocity control

针对机械臂与环境间的交互性和安全性问题,设计一种新型串联弹性驱动器(series elastic actuator,SEA)。通过设计平面型扭转弹性元件替代传统弹簧,使得驱动器具有较高的集成度。弹性元件的引入降低了传动机构阻抗上限,增强了对外界环境的顺应能力。为了提高SEA速度控制精确度,提出采用BP神经网络控制的方法,通过补偿负载的重力等非线性特性,以实现基于SEA力矩控制模式下的稳定速度控制。实验结果验证了驱动器良好的速度跟随性和顺应性,实现了与环境之间的安全交互。这类驱动器在腿式机器人、外骨骼机器人和工业机械臂中有着良好的应用前景。

A novel series elastic actuator （SEA） was designed to implement physical human - robot inter- action by embedding a new torsional elasticity between the gear train and driven load which made the ac- tuator more integrated. The elasticity reduced the upper bound of impedance and enhanced the capacity while operating in constructed environment. In order to realize the stable velocity control of SEA, a BP neural network controller which can compensate nonlinear characteristics of the load gravity was pro- posed. Experiment results show that this actuator has great velocity control performance and its low im- pedance makes it possible to adapt to variable environments. This kind of actuator is desirable in many applications including legged robots, exoskeletons and industrial manipulators.