Mechanical design and analysis of a novel variable stiffness actuator with symmetrical pivot adjustment

Abstract The safety of human-robot interaction is an essential requirement for designing collaborative robotics. Thus, this paper aims to design a novel variable stiffness actuator (VSA) that can provide safer physical VSA follows the idea modular design, mainly including module and drive module. transmits motion from in roundabout manner, making modularization possible. As key component module, adjustment mechanism with symmetrical structure applied change positions pair pivots two levers linearly simultaneously, which eliminate additional bending moment caused by asymmetric structure. double-deck grooves lever allows pivot move freely groove, avoiding geometric constraint between parts. Consequently, zero infinity as moves one end groove other. To facilitate building manipulator future, expandable electrical system distributed also proposed. Stiffness calibration control experiments are performed evaluate performance designed VSA. Experiment results show close theoretical stiffness. Furthermore, proportional-derivative feedback plus feedforward controller exhibits fast response regulation good position tracking.