Advantage of singular configuration in pulling heavy object with a two-link mobile manipulator

In this paper, we reveal the advantage of singular configuration in pulling 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 singular configuration can generate, from the same amount of joint torques, 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 advantage of singular configuration is verified by numerical simulations and theoretical analysis.