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

Abstract

The continuous change of normal vectors and local curvature mutations of complex curved-surface parts cause instantaneous overdetermination or underdetermination of fixture degree-of-freedom constraints, and the force-deformation coupling combined with load time-varying further exacerbates the difficulty of clamping stability control. An adaptive mechanical fixture design and a clamping force optimization strategy are proposed: it establishes a method for characterizing degree-of-freedom fluctuations based on second-order differential geometric parameters and achieves dynamic matching of the configuration to the part morphology through adaptive contact element layout and topology-scale co-design; it constructs a nonlinear force-deformation mapping, solves the minimum norm solution of clamping force via convex quadratic programming, and introduces rolling horizon dynamic programming to adapt to load time-varying; and it designs a parametric scheme for variable stiffness flexible units, establishes a force-position stability criterion under excitation disturbances, and forms an adaptive closed-loop regulation mechanism for the coordination of stiffness and clamping force. This method treats stiffness as a control degree of freedom equal to clamping force, thus providing theoretical support for high-precision machining of complex parts.