Aerial manipulators have the potential to perform various tasks with high agility and mobility, but the requirement of system parameters and the complicated dynamic model impede the implementation in practice. To deal with uncertain parameters and complexity of the coupled dynamic model, a decoupling approach is presented in this article by utilizing the adaptive/robust techniques and reinforcement learning approach for the tracking control of quadrotors with position control on the robotic arm. A reinforcement learning approach is proposed to control the robotic arm ensuring minimal effect on the quadrotor dynamics while following the desired trajectory. With the design of nominal inputs, the dynamic uncertainties from the quadrotor, robotic arm, and payload are coped with by utilizing the proposed adaptive algorithms. In addition, the residue of interactive force/torque after the use of DDPG is compensated by robust controllers so that the stability and tracking performance are guaranteed. Numerical examples and experiments are illustrated to demonstrate the efficacy of the presented aerial manipulator control structure and algorithms.

This paper addresses distributed coordination and cooperation control for networked mobile manipulators over a jointly connected topology with time delays. First, tracking control is proposed to guarantee the position and velocity synchronization of the networked mobile manipulators, while keeping a formation. For cooperation control, the decoupled dynamics is considered so that the task and null space of the mobile manipulators can be designed to achieve different missions. For end-effector motion, synchronization control works in combination with force controls to ensure that the network of mobile manipulators achieves cooperative manipulation and transportation. The motion of the mobile bases is controlled in the null space, which can be designed to track a trajectory, avoid colliding with obstacles, and achieve velocity consensus without influencing the main task. Numerical examples are addressed to demonstrate the performance of the proposed networked robotic system.

This article presents an effective design of omnidirectional four-mecanum-wheeled vehicles to transport an object and track a predefined trajectory cooperatively. Furthermore, a novel design of the rotary platform is presented for multiple unmanned ground vehicles (m-UGVs) to load objects and provide better maneuverability in confined spaces during cooperative transportation. The number of unmanned ground vehicles (UGVs) is adjustable according to the object’s weight and size in the proposed framework because transportation is accomplished without physical grippers. Moreover, to minimize the complexity in dealing with the interactive force between the object and UGVs, no force/torque sensor is used in the design of the control algorithm. Instead, an adaptive sliding-mode controller is formulated to cope with the dynamic uncertainties and smoothly transport an object along a desired trajectory. Thus, three external force analyses—gradient projection method, adaptive force estimation, and radial basis function neural network force estimation—are proposed for m-UGVs. In addition, the stability and the performance tracking of the m-UGV system in the presence of dynamic uncertainties using the proposed force estimation are investigated by employing the Lyapunov theory. Finally, experiments on cooperative transportation are presented to demonstrate the efficiency and efficacy of the m-UGV system.