  Motion control of mobile manipulators (a robotic arm mounted on a mobile
base) can be challenging for complex tasks such as material and package
handling. In this paper, a task-space stabilization controller based on
Nonlinear Model Predictive Control (NMPC) is designed and implemented to a 10
Degrees of Freedom (DOF) mobile manipulator which consists of a 7-DOF robotic
arm and a 3-DOF mobile base. The system model is based on kinematic models
where the end-effector orientation is parameterized directly by a rotation
matrix. The state and control constraints as well as singularity constraints
are explicitly included in the NMPC formulation. The controller is tested using
real-time simulations, which demonstrate high positioning accuracy with
tractable computational cost.
