A novel framework for the analysis of underactuated fingers

S. Liu, C. Chen, J. Angeles

Research output: Contribution to journalArticleResearchpeer-review

1 Citation (Scopus)


Due to their inherent adaptability, underactuated grippers have seen increasing applications in robotic grasping and prostheses. However, the analysis of the underactuated grasping process remains a challenge. This work introduces a novel framework for determining the configuration and the relevant forces of underactuated grippers. Our framework explicitly maps the contact forces into Lagrange multipliers, upon expressing the constraint equations in a suitable format. Lagrange multipliers allow the kinetostatic-constraint equations for the gripper backbone to be derived exclusively from the kinematic-constraint equations. Four selection matrices couple the arrays of unknown variables and the kinetostatic-governing equations for various contact cases to the full array of unknown variables and the full kinetostatic-governing equations, respectively, thereby obviating the re-derivation of the governing equations. A case study is included for the validation of the formulation.

Original languageEnglish
Article number105238
Number of pages13
JournalMechanism and Machine Theory
Publication statusPublished - Apr 2023


  • Constraint analysis
  • Gripper
  • Lagrange multipliers
  • Underactuated system

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