Human-robot cooperation for robust surface treatment using non-conventional sliding mode control

Haptic and Visual Feedback Assistance for Dual-Arm Robot Teleoperation in Surface Conditioning Tasks

Contact driven tasks, such as surface conditioning operations (wiping, polishing, sanding, etc.), are difficult to program in advance to be performed autonomously by a robotic system, specially when the objects involved are moving. In many applications, human-robot physical interaction can be used for the teaching, specially in learning from demonstrations frameworks, but this solution is not always available. Robot teleoperation is very useful when user and robot cannot share the same workspace due to hazardous environments, inaccessible locations, or because of ergonomic issues. In this sense, this article introduces a novel dual-arm teleoperation architecture with haptic and visual feedback to enhance the operator immersion in surface treatment tasks. Two task-based assistance systems are also proposed to control each robotic manipulator individually. To validate the remote assisted control, some usability tests have been carried out using Baxter, a dual-arm collaborative robot. After analysing several benchmark metrics, the results show that the proposed assistance method helps to reduce the task duration and improves the overall performance of the teleoperation.

Adaptive trajectory tracking of wheeled mobile robot based on fixed-time convergence with uncalibrated camera parameters

The problem of fixed-time trajectory tracking control for a wheeled mobile robot with uncalibrated camera parameters is considered. The fixed-time adaptive trajectory tracking control laws are developed. Firstly, the dynamics mode of robot system with unknown parameters is introduced and the tracking error system is given. Secondly, the problem of trajectory tracking is transformed into the problem of fixed-time stabilization for the error system by using the state and input transformations. Then, the fixed-time controller is designed based on nonsingular recursive terminal sliding mode control method, which enables the actual system to track the reference trajectory in fixed time. Finally, the simulation examples verify the validity of the conclusions.