Modelling the Dynamics of an Anthropomorphic Index Digit During Flexion and Extension of PIP and DIP Joints

This model is an attempt to optimize the design and control of anthropomorphic hands, and highlight some aspects that should be considered in that context. Matlab environment was used to model an index digit and move its PIP and DIP joints based on the behavior observed in natural human digits. The static model considered the correlation between PIP and DIP joints, as well as their range of motion, and it included phalanges, joints, and two flexion tendons, each to flex one joint. An animation was introduced to represent that motion using Matlab plots. After that, a third partially-elastic tendon was attached for extension, of which the dynamics were modelled using Simulink, in order to study the time required for the digit to completely extend from its maximum flexion for different elasticity constants. Finally, a search algorithm was used to optimize the elasticity constant required for an extension time of 0.5 second from full flexion.