Analysis of a hand arm system

• The paper presents an artificial hand-arm system and a study of a human hand.
• The correlation dimension and the Lyapunov exponent are calculated.
• The movement of the wrist joint of the artificial hand is periodic.
• The human hand motion shows the existence of a chaotic system.

For this research a prototype for an anthropomorphic hand arm was developed and manufactured. We analyze the periodic motion of this artificial hand arm system for different angles and velocities. For the time series of the wrist joint of the artificial hand system we can conclude that the movement is periodic. For a better understanding of the robotic system next we study the motion of human hand arm. The kinematic data of the radio-carpal flexion–extension angles were analyzed for different initial conditions. The experimental data were acquired with a complex goniometer system. The human motion was characterized with the correlation dimension and the largest Lyapunov exponent (LLE) as nonlinear measures. The LLE obtained for each test of human hand were positive values and the mean value ranged from 0.020 to 0.032.