Design of Cam Profile for Variable Stiffness Actuator Based on Bezier Spline

This paper focuses on a new method designing cam profile for variable stiffness actuator with Bezier spline. Firstly, a new kind of variable stiffness actuator is proposed and principle for changing stiffness is analyzed. This kind of variable stiffness actuator bears advantage that no empty return journey exists during the reverse rotation. Before introducing Bezier spline, some standard curves for the design of cam profile are investigated and effects on stiffness and torque are analyzed. Then expressions of Bezier spline are given and constraints for constructing cam profile are developed. In order to obtain desired stiffness, several different cost functions are investigated on the range of stiffness with the help of swarm particle algorithm. Comparison is conducted during the process of determining control points of Bezier spline. In the end, prototype of the cam disk is produced with 3D printing method based on Bezier curve.