| 1. |
- Båberg, Fredrik, et al.
(författare)
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Adaptive object centered teleoperation control of a mobile manipulator
- 2016
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Ingår i: 2016 IEEE International Conference on Robotics and Automation (ICRA). - : Institute of Electrical and Electronics Engineers (IEEE). - 9781467380263 ; , s. 455-461
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Konferensbidrag (refereegranskat)abstract
- Teleoperation of a mobile robot manipulating and exploring an object shares many similarities with the manipulation of virtual objects in a 3D design software such as AutoCAD. The user interfaces are however quite different, mainly for historical reasons. In this paper we aim to change that, and draw inspiration from the 3D design community to propose a teleoperation interface control mode that is identical to the ones being used to locally navigate the virtual viewpoint of most Computer Aided Design (CAD) softwares.The proposed mobile manipulator control framework thus allows the user to focus on the 3D objects being manipulated, using control modes such as orbit object and pan object, supported by data from the wrist mounted RGB-D sensor. The gripper of the robot performs the desired motions relative to the object, while the manipulator arm and base moves in a way that realizes the desired gripper motions. The system redundancies are exploited in order to take additional constraints, such as obstacle avoidance, into account, using a constraint based programming framework.
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| 2. |
- Båberg, Fredrik, et al.
(författare)
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Extended version of Adaptive Object Centered Teleoperation Control of a Mobile Manipulator
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Teleoperation of a mobile robot manipulating and exploring an object shares many similarities with the manipulation of virtual objects in a 3D design software such as AutoCAD. The user interfaces are however quite different, mainly for historical reasons. In this paper we aim to change that, and draw inspiration from the 3D design community to propose a teleoperation interface control mode that is identical to the ones being used to locally navigate the virtual viewpoint of most Computer Aided Design (CAD)softwares.The proposed mobile manipulator control framework thus allows the user to focus on the 3D objects being manipulated, using control modes such as orbit object and pan object. The gripper of the robot performs the desired motions relative to the object, while the manipulator arm and base moves in a way that realizes the desired gripper motions. The system redundancies are exploited in order to take additional constraints, such as obstacle avoidance, into account, using a constraint based programming framework.
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| 3. |
- Båberg, Fredrik, et al.
(författare)
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Formation Obstacle Avoidance using RRT and Constraint Based Programming
- 2017
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Ingår i: 2017 IEEE International Symposium on Safety, Security and Rescue Robotics (SSRR). - : IEEE conference proceedings. - 9781538639221
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Konferensbidrag (refereegranskat)abstract
- In this paper, we propose a new way of doing formation obstacle avoidance using a combination of Constraint Based Programming (CBP) and Rapidly Exploring Random Trees (RRTs). RRT is used to select waypoint nodes, and CBP is used to move the formation between those nodes, reactively rotating and translating the formation to pass the obstacles on the way. Thus, the CBP includes constraints for both formation keeping and obstacle avoidance, while striving to move the formation towards the next waypoint. The proposed approach is compared to a pure RRT approach where the motion between the RRT waypoints is done following linear interpolation trajectories, which are less computationally expensive than the CBP ones. The results of a number of challenging simulations show that the proposed approach is more efficient for scenarios with high obstacle densities.
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| 4. |
- Båberg, Fredrik, et al.
(författare)
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Free Look UGV Teleoperation Control Tested in Game Environment : Enhanced Performance and Reduced Workload
- 2016
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Ingår i: International Symposium on Safety,Security and Rescue Robotics.
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Konferensbidrag (refereegranskat)abstract
- Concurrent telecontrol of the chassis and camera ofan Unmanned Ground Vehicle (UGV) is a demanding task forUrban Search and Rescue (USAR) teams. The standard way ofcontrolling UGVs is called Tank Control (TC), but there is reasonto believe that Free Look Control (FLC), a control mode used ingames, could reduce this load substantially by decoupling, andproviding separate controls for, camera translation and rotation.The general hypothesis is that FLC (1) reduces robot operators’workload and (2) enhances their performance for dynamic andtime-critical USAR scenarios. A game-based environment wasset-up to systematically compare FLC with TC in two typicalsearch and rescue tasks: navigation and exploration. The resultsshow that FLC improves mission performance in both exploration(search) and path following (navigation) scenarios. In the former,more objects were found, and in the latter shorter navigationtimes were achieved. FLC also caused lower workload and stresslevels in both scenarios, without inducing a significant differencein the number of collisions. Finally, FLC was preferred by 75% of the subjects for exploration, and 56% for path following.
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| 5. |
- Båberg, Fredrik
(författare)
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Improving Manipulation and Control of Search and Rescue UGVs Operating Across Autonomy Levels
- 2022
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Robots are often used for “dirty, dull and dangerous” jobs, where time, money or lives can be saved. A field with dangerous situations is search and rescue, with structural collapses and toxic environment. In those situations, robots have the potential to save lives.In this thesis we discuss improvements to unmanned ground vehicles (UGVs) for search and rescue in terms of manipulation and control. From the use of developments in video games for teleoperation, presentation of signal strength prediction, to ideas from 3D CAD for inspection tasks, and finally formation keeping for mobile manipulators. The problems will be addressed at different autonomy levels, regarding the robot operator interaction.We first consider teleoperation of an unmanned ground vehicle. Through a user study we compare two control modes, the traditional Tank Control and the video game inspired Free Look Control. Then, knowing how important connectivity is for teleoperation, where low connectivity can lead to the robot being abandoned, we propose a user interface which combines predicted radio signal strength with Free Look Control.Next we consider teleoperation of a mobile manipulator, which allows for inspection tasks. This adds complexity to the operator in terms of control, where not only the platform itself, but also the manipulator, has to be controlled. Inspired by 3D CAD software, where a core functionality is inspection of an object, we propose the control method Orbit Control. The system can assist with controlling some degrees of freedom of the robot, while the operator focuses on the final inspection and interaction.Finally, we consider a group of mobile manipulators transporting a larger object in a high obstacle density environment. A partially collapsed structure can contain areas which are not suitable to move in. To find a path for navigation, moving information while avoiding obstacles, can be challenging. We propose a combination of rapidly-exploring random tree (RRT) and constraint based programming, leading to a more efficient approach at high obstacle densities.
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| 6. |
- Caccamo, Sergio, et al.
(författare)
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Extending a UGV Teleoperation FLC Interface with Wireless Network Connectivity Information
- 2015
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Ingår i: 2015 IEEE/RSJ INTERNATIONAL CONFERENCE ON INTELLIGENT ROBOTS AND SYSTEMS (IROS). - : IEEE. - 9781479999941 ; , s. 4305-4312
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Konferensbidrag (refereegranskat)abstract
- Teleoperated Unmanned Ground Vehicles (UGVs) are expected to play an important role in future search and rescue operations. In such tasks, two factors are crucial for a successful mission completion: operator situational awareness and robust network connectivity between operator and UGV. In this paper, we address both these factors by extending a new Free Look Control (FLC) operator interface with a graphical representation of the Radio Signal Strength (RSS) gradient at the UGV location. We also provide a new way of estimating this gradient using multiple receivers with directional antennas. The proposed approach allows the operator to stay focused on the video stream providing the crucial situational awareness, while controlling the UGV to complete the mission without moving into areas with dangerously low wireless connectivity. The approach is implemented on a KUKA youBot using commercial-off-the-shelf components. We provide experimental results showing how the proposed RSS gradient estimation method performs better than a difference approximation using omnidirectional antennas and verify that it is indeed useful for predicting the RSS development along a UGV trajectory. We also evaluate the proposed combined approach in terms of accuracy, precision, sensitivity and specificity.
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| 7. |
- Parasuraman, Ramviyas, et al.
(författare)
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A New UGV Teleoperation Interface for Improved Awareness of Network Connectivity and Physical Surroundings
- 2017
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Ingår i: Journal of Human-Robot Interaction. - : Journal of Human-Robot Interaction. - 2163-0364. ; 6:3, s. 48-70
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Tidskriftsartikel (refereegranskat)abstract
- A reliable wireless connection between the operator and the teleoperated unmanned ground vehicle (UGV) is critical in many urban search and rescue (USAR) missions. Unfortunately, as was seen in, for example, the Fukushima nuclear disaster, the networks available in areas where USAR missions take place are often severely limited in range and coverage. Therefore, during mission execution, the operator needs to keep track of not only the physical parts of the mission, such as navigating through an area or searching for victims, but also the variations in network connectivity across the environment. In this paper, we propose and evaluate a new teleoperation user interface (UI) that includes a way of estimating the direction of arrival (DoA) of the radio signal strength (RSS) and integrating the DoA information in the interface. The evaluation shows that using the interface results in more objects found, and less aborted missions due to connectivity problems, as compared to a standard interface. The proposed interface is an extension to an existing interface centered on the video stream captured by the UGV. But instead of just showing the network signal strength in terms of percent and a set of bars, the additional information of DoA is added in terms of a color bar surrounding the video feed. With this information, the operator knows what movement directions are safe, even when moving in regions close to the connectivity threshold.
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| 8. |
- Smets, N. J. J. M., et al.
(författare)
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Ontology-based situation awareness support for shared control : Extended abstract
- 2017
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Ingår i: ACM/IEEE International Conference on Human-Robot Interaction. - New York, NY, USA : IEEE Computer Society. - 9781450348850 ; , s. 289-290
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Konferensbidrag (refereegranskat)abstract
- Situation Awareness (SA) during tele-operation in robot-assisted disaster management has a major impact on the effectiveness and efficiency. Data perceived by the human and robot agents should be processed and shared in such a way that these agents can understand and direct the other agent's behaviors. E.g., for safe and effective tele-operation, the human (team leader and/or operator) and robot need to be aware of (1) the state, location, position and movement of the robot platform and its arms, and (2) the state of robot's environment (such as obstacles, ...). This paper presents an SA-ontology that formalizes the effects of SA-components on the shared control performance. It is based on literature research, interviews with subject matter experts and a field test during a disaster management exercise. The SA-ontology captured all information needs for the teleoperation, and provided further requirements for SA-support functions.
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