2017 Volume 30 Issue 3 Pages 87-96
In this paper, we reveal an advantageous dynamic feature of singular conguration in dragging heavy objects with a two-link mobile manipulator. Unlike humans, the mobile manipulator can pull or drag the objects passing through its singular configuration where the manipulator is stretched out. The motion through the singular configuration can generate, by using the kinetic energy that is stored in the manipulator until the object starts to skid, much larger pulling force than the motion that avoids the configuration. Although the large force occurs only for a short period near the singular configuration, it can maximize the distance that the object is moved by the mobile manipulator under the condition that the consumption of joint torques is restricted. This dynamic advantage of singular configuration is verfied by numerical simulations and theoretical analysis.