Noether symmetry and form invariance of the Chaplygin system
Chaplygin系统的Noether对称性与形式不变性

Using an invariance of the Chaplygin form for the d'Alembert-Lagrange principle under infinitesimal transformations, we obtain the generalized Noether identity and the form of the conserved quantity of the Chaplygin system. We study also the form invariance of the system and the relation between the invariance and the Noether symmetry.