Multitasking Capabilities of an Autonomous quad-Arm Mobile Manipulator (qAMM) for Smart City Operations

Additional robotic arms on a mobile manipulator invariably enhance its multi-tasking capabilities and offer greater flexibility in performing multiple complex operations. This paper presents a four-arm or quad-arm car-like mobile manipulator (qAMM) that can address the issue of labor shortage in emerging smart city operations that require multi-tasking such as garbage collection, construction, maintenance, and cleaning. Lyapunov-based acceleration controllers are derived and utilized to solve the proposed mobile manipulator’s motion planning and control problem. First, a dual-step algorithm is used to move the car-like base in an obstacle-ridden environment from an initial position to its pseudo-target and, second, maneuver the four end-effectors to their designated targets and enable qAMM to perform multiple tasks through the synchronous and asynchronous motion of its revolute links. Furthermore, by using the Direct Method of Lyapunov and LaSalle’s invariance principle, stability and convergence analyses of the four-arm car-like system have been proved. Finally, the effectiveness of the proposed approach and qAMM’s acceleration-based motion controllers is verified by computer simulations.