The design of dwell-rise-dwell cams with reduced sensitivity to parameter variation

This paper presents a new approach to designing dwell-rise-dwell profiles for cam follower systems. The cam profiles are designed such that perturbations in the system parameters have a reduced influence on the dynamic response. This is accomplished by minimizing the parameter sensitivity of output mass motion. The system parameters considered are those that appear in the equation of motion, namely, the mass, spring stiffness, damping coefficient, and the speed of cam rotation. The design optimization problem is formulated as a linear quadratic optimal control problem that is easy to solve. Comparisons with a polydyne cam design shows that the approach developed here yields a cam design that has superior performance in terms of residual vibration, peak contact stress, energy loss and the required preload force. The new design also exhibits better attributes despite possible variations in the system parameters.