Polydyne servo-cam design

The polydyne approach of cam design, successfully used in automobile valve systems, has been developed into an effective method for designing high-speed cam-follower systems. However, the polydyne cam system shows strong sensitivity to parameter variations. This paper adopts the traditional polydyne theory and the recently proposed concept of "integrated design of cam mechanisms and servo control systems" to propose a novel method, named "polydyne servo-cam design", to achieve superior dynamic performance of high-speed cam-follower systems. With this method, a microprocessorcontrolled servomotor is used to actively vary the input speed trajectory of the cam so that the output vibrations can be minimized in spite of parameter variations. The principle and process of this method are presented. A design example is given to verify its feasibility.