Teleoperating a mobile manipulator and a free-flying camera from a single haptic device

© 2016 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other worksThe paper presents a novel teleoperation system that allows the simultaneous and continuous command of a ground mobile manipulator and a free flying camera, implemented using an UAV, from which the operator can monitor the task execution in real-time. The proposed decoupled position and orientation workspace mapping allows the teleoperation from a single haptic device with bounded workspace of a complex robot with unbounded workspace. When the operator is reaching the position and orientation boundaries of the haptic workspace, linear and angular velocity components are respectively added to the inputs of the mobile manipulator and the flying camera. A user study on a virtual environment has been conducted to evaluate the performance and the workload on the user before and after proper training. Analysis on the data shows that the system complexity is not an obstacle for an efficient performance. This is a first step towards the implementation of a teleoperation system with a real mobile manipulator and a low-cost quadrotor as the free-flying camera.Accepted versio

Passivity-Based Tracking Control of a Mobile Manipulator Robot

This work presents a control approach based on the passivity principle, developed to guarantee performance of the application used to track the trajectory of mobile manipulator when disturbed. By exploiting the particularity of the mobile manipulator robots modelling equipped with a nonholonomic mobile base, we present a global control law for the mobile manipulator as a single system. This control allows taking into account the whole system and modifying its dynamics by introducing a highly non-linear regressor matrix to consider uncertainties and modeling constraints. The presented controller is applied to the mobile manipulator robot composed of a manipulator's arm with 2 DDL mounted on a mobile unicycle platform. Simulation tests validate the performance of the proposed approach when external disturbances occur; showing an acceptable performance of the system's stability and validated by exploiting the Lyapunov theory. &nbsp

Passivity-Based Tracking Control of a Mobile Manipulator Robot

This work presents a control approach based on the passivity principle, developed to guarantee performance of the application used to track the trajectory of mobile manipulator when disturbed. By exploiting the particularity of the mobile manipulator robots modelling equipped with a nonholonomic mobile base, we present a global control law for the mobile manipulator as a single system. This control allows taking into account the whole system and modifying its dynamics by introducing a highly non-linear regressor matrix to consider uncertainties and modeling constraints. The presented controller is applied to the mobile manipulator robot composed of a manipulator's arm with 2 DDL mounted on a mobile unicycle platform. Simulation tests validate the performance of the proposed approach when external disturbances occur; showing an acceptable performance of the system's stability and validated by exploiting the Lyapunov theory. &nbsp

Using an UAV to guide the teleoperation of a mobile manipulator

[Abstract] In this paper, a new teleoperation system consisting on the integration of a mobile manipulator, an UAV, and a haptic is presented. The camera of the UAV is used to give visual feedback to the operator. An algorithm is presented to allow the operator to command both the UAV and the mobile manipulator while keeping the point of view pointing towards the robot by only using a single haptic device. The presented algorithm combines a position-position and a position-velocity workspace mapping from the haptic to the mobile manipulator and the UAV, both in position and orientation. Further, a solution is presented that takes advantage of the null space of the mobile manipulator to keep the body and the arm of the mobile manipulator from occluding its own TCP and the object it is carrying, thus easing the teleoperation task. Experimentation has been carried on the system, both in a virtual and a real scenario, showing its potential in teleoperation scenarios. Overall, a novel teleoperation system and the ongoing progress towards its implementation in real situations is presented in this work.Gobierno de España; DPI2013-40882-PGobierno de España; DPI2014-57757-RGobierno de España; DPI2016-80077-RGobierno de España; BES-2012-05489

Performance Investigations of an Improved Backstepping Operational space Position Tracking Control of a Mobile Manipulator

This article implies an improved backstepping control technique for the operational-space position tracking of a kinematically redundant mobile manipulator. The mobile manipulator thought-out for the analysis has a vehicle base with four mecanum wheels and a serial manipulator arm with three rotary actuated joints. The recommended motion controller provides a safeguard against the system dynamic variations owing to the parameter uncertainties, unmodelled system dynamics and unknown exterior disturbances. The Lyapunov’s direct method assists in designing and authenticating the system’s closed-loop stability and tracking ability of the suggested control strategy. The feasibility, effectiveness and robustness of the recommended controller are demonstrated and investigated numerically with the help of computer based simulations. The mathematical model used for the computer-based simulations is derived based on a real-time mobile manipulator and the derived model is further verified with an inbuilt gazebo model in a robot operating system (ROS) environment. In addition, the proposed scheme is verified on an in-house fabricated mobile manipulator system. Further, the recommended controller performance is correlated with the conventional backstepping control design in both computer-based simulations and in real-time experiments

Neuro Adaptive Control of Mobile Manipulators

This research is concemed with an adaptive controller that compensates friction and gravity， for moving operation trave1ing on irregular terrain. Modeling of the friction force is essentially difficult，since the parameters of friction force are depending on the temperature，condition of f1oor and wheel，and reaction force from the f1oor that is depending on the motion of mobile manipulator. Moreover，conventional researches concerning mobile manipulators have assumed that the traveling terrain is f1at. However， irregularities exist even on an artificial floor in factories and buildings，and it is difficult to measure exactly the shape of the terrain. When the end-effecter of the mobile manipulator tracks desired trajectory during the mobile manipulator travels on an unknown irregular terrain with unknown friction， two kinds of compensation must be considered for mobile manipulator to achieve accurate trajectory tracking control performance.We propose an adaptive controller including a neural network that can compensate the unknown friction and unknown irregular terrain. The va1idity of the neuro-adaptive controller is clarified by real experiments

Towards Assistive Feeding with a General-Purpose Mobile Manipulator

General-purpose mobile manipulators have the potential to serve as a versatile form of assistive technology. However, their complexity creates challenges, including the risk of being too difficult to use. We present a proof-of-concept robotic system for assistive feeding that consists of a Willow Garage PR2, a high-level web-based interface, and specialized autonomous behaviors for scooping and feeding yogurt. As a step towards use by people with disabilities, we evaluated our system with 5 able-bodied participants. All 5 successfully ate yogurt using the system and reported high rates of success for the system's autonomous behaviors. Also, Henry Evans, a person with severe quadriplegia, operated the system remotely to feed an able-bodied person. In general, people who operated the system reported that it was easy to use, including Henry. The feeding system also incorporates corrective actions designed to be triggered either autonomously or by the user. In an offline evaluation using data collected with the feeding system, a new version of our multimodal anomaly detection system outperformed prior versions.Comment: This short 4-page paper was accepted and presented as a poster on May. 16, 2016 in ICRA 2016 workshop on 'Human-Robot Interfaces for Enhanced Physical Interactions' organized by Arash Ajoudani, Barkan Ugurlu, Panagiotis Artemiadis, Jun Morimoto. It was peer reviewed by one reviewe