Figure 3
From: Design of a series visco-elastic actuator for multi-purpose rehabilitation haptic device
Series visco-elastic actuator and parallel mechanism. (A) Actuation of the VSP consists of: 1-two sets of DC motors with gears and encoders, 2-elastic springs, 3- mechanical dampers, 4-pulleys and 5-an actuated bar. Schematic presentation of the series visco-elastic actuator and parallel mechanism (only 1 DOF is shown for clarity), with characteristic values of mechanical component parameters used in the VSP. Impedance felt at the arm is 16 times smaller than at the bottom of the actuated bar, because the actuated bar is divided by a spherical joint in ratio 4:1.