Design of Adaptive Mechanical Fixture and Optimization of Clamping Force for Complex Parts

Abstract

A change in the normal vector and mutations of the local curvature for complex curved-surface parts will result in immediate overdetermination or underdetermination of the constraints on the degree of freedom of the fixture, and the force-deformation coupling with load variation over time will further worsen the problem of clamping stability control. Design of an Adaptive Mechanical Fixture and Optimization Strategy for Clamping Force: A Method for Characterizing the Degree of Freedom Fluctuation Based on Second-Order Differential Geometry Parameters is Proposed; Dynamic Matching of the Configuration to Part Morphology is Achieved by Adaptive Contact Element Layout and Topology-Scale Co-design; A Nonlinear Force-Deformation Mapping is Constructed; The Minimum-Norm Solution of Clamping Force is Obtained through Convex Quadratic Programming; Rolling Horizon Dynamic Programming is Used to Handle Time-Varying Loads; A Parametric Scheme for Variable-Stiffness Flexible Units is Designed; A Force-Position Stability Criterion Under Excitation Disturbance is Established; And an Adaptive Closed-Loop Regulation Mechanism for Stiffness and Clamping Force Coordination is Built. Stiffness is taken as the control degree of freedom equal to the clamping force in this way, and it can be used to accurately machine complex parts.