Shape Optimization of Cam Profiles Using a B-Spline Representation

Abstract

An arbitrary acceleration profile for the cam follower acceleration is generated using a B-spline representation. The control point locations for the B-spline become the design variables in the nonlinear programming problem. The B-spline representation provides for local control of the acceleration profile which is required in order to generate reliable optimization results. Constraints are imposed in order to place appropriate limits on the contact stress, lift, duration, acceleration, jerk, radius of curvature, manufacturing requirements, and to avoid cam-follower separation. The objective function may take on a number of forms depending upon the design requirements. The optimization is carried out with a gradient based penalty function algorithm. A specific example is presented in which the flow area is maximized for an internal combustion engine.