Resumen de A new low-energy nonlinear variable stiffness actuator for the knee joint
Zemin Yang, Hexu Yang, Renzhen Chen, Jinchi Xu, Xiaopeng Li
With the increase of safety requirements for human-robot interaction, variable stiffness actuators are increasingly used in joints of medical rehabilitation robots, legged mobile robots and exoskeleton-assisted robots, so the research of the variable stiffness actuator becomes more and more important. In this paper, firstly, according to the human knee joint, a low-energy nonlinear variable stiffness actuator for knee joint is proposed, it conforms to characteristics of biological joints: the actuator can be flexible when it is subjected to the small load, and the actuator can be stabilized when it is subjected to the heavy load. The realization principle of this actuator, which is combining the eccentric cam with the leaf spring, is introduced in detail, and its relatively large range of variable stiffness is accurately deduced and analyzed. Secondly, the energy cost of this actuator is reduced as much as possible by some structural designs. Finally, by experiments, the correctness and accuracy of the resistance moment and expected stiffness of the proposed nonlinear variable stiffness actuator are verified, the high bandwidth and good stability of this actuator are also verified, which meets the design principles and requirements of the actuator, and it is verified that actuator’s low energy cost.
