Identification of friction in joints for multibody dynamics: a Neural-DAE based approach
摘要
Accurate prediction of multibody system dynamics hinges on precise modeling of joint friction moments. Conventional approaches rely on predefined analytical friction models with calibrated parameters, limiting flexibility and introducing selection bias. This work proposes a Neural Differential-Algebraic Equation (Neural-DAE) framework to directly identify friction moments in revolute joints from experimental data. By embedding physics-informed artificial neural networks (ANNs) within the multibody dynamics equations, the method eliminates reliance on ad hoc friction models. The ANN architecture incorporates three key innovations: input transformations using Lagrange multipliers and relative joint velocities, a decoupled structure separating normal forces and friction coefficients, and odd symmetry constraints to enforce antisymmetric friction-velocity relationships. A discrete adjoint method compatible with the generalized-