Simultaneous motion and interaction force control of a nonholonomic mobile manipulator

In this thesis we focus on the problem of combined motion and force control of a nonholonomic mobile manipulator system. The mobile manipulator under consideration consists of a differentially-driven mobile base with a planar two-link manipulator mounted on top. Both the mobile base and the two-link manipulator operate in the horizontal plane. Such a combination of a mobile base and manipulator provides for a larger workspace and a broader set of capabilities to manipulate the motions and forces with the environment. However, such systems also feature considerable redundancy which needs to be effectively resolved in order to achieve these goals.; We first develop a kinematic model of the mobile manipulator system and formulate the nonholonomic wheel constraints. Next we develop the dynamic mathematical model of the system using the energy-based constrained Lagrange dynamic modeling technique. This dynamic model serves as the basis for subsequent dynamic control and becomes the virtual prototype for control-law simulation/validation.