Contribution of internal forces to the dynamics of closed chain mechanisms

The kinematic structure of closed chain mechanisms is suitable for putting an excess number of inputs in addition to the required number to control their position and orientation. With the addition of these excess inputs, it is possible to generate and control the internal forces within the mechanisms by simultaneously activating joints whose action opposes each other. The internal forces balance inside the structure of mechanisms and do not create any resultant force. However, at the static or quasi-static cases they change the stiffness of the mechanisms. In dynamic cases, in addition to the change in stiffness, they may also generate a damping effect. As a result of these effects, the dynamic behavior of closed chain mechanisms changes. This study analyzes the dynamics of the closed chain mechanisms under the effect of internal forces through the simulation and experimental results using a planar closed chain mechanism.