Autonomous Person-Specific Following Robot

Following a specific user is a desired or even required capability for service robots in many human-robot collaborative applications. However, most existing person-following robots follow people without knowledge of who it is following. In this paper, we proposed an identity-specific person tracker, capable of tracking and identifying nearby people, to enable person-specific following. Our proposed method uses a Sequential Nearest Neighbour with Thresholding Selection algorithm we devised to fuse together an anonymous person tracker and a face recogniser. Experiment results comparing our proposed method with alternative approaches showed that our method achieves better performance in tracking and identifying people, as well as improved robot performance in following a target individual

Where did it go? : regaining a lost target for robot visual servoing

When a robotic visual servoing/tracking system loses sight of its target, the servo fails due to loss of input. To resolve this problem, a search method is required to generate efficient actions and bring the target back into the camera field of view (FoV) as soon as possible. For high dimensional platforms like a camera-mounted manipulator, an eye-in-hand system, such a search must address the difficult challenge of generating efficient actions in an online manner while avoiding visibility and kinematic constraints. This work considers two common scenarios of visual servoing/tracking failure, when the target leaves the camera FoV and when visual occlusions, occlusions for brevity, disrupt the process. To handle the first scenario, a novel algorithm called lost target search (LTS) is introduced to plan online efficient sensor actions. To handle the second scenario, an improved algorithm called lost target recovery algorithm (LTRA) allows a robot to look behind an occluder during active visual search and re-acquire its target in an online manner. Then the overall algorithm is implemented on a telepresence platform to evaluate the necessity and efficacy of autonomous occlusion handling for remote users. Occlusions can occur when users in remote locations are engaged in physical collaborative tasks. This can yield to frustration and inefficient collaboration between the collaborators. Therefore, two human-subjects experiments are conducted (N=20 and 36 respectively) to investigate the following interlinked research questions: a) what are the impacts of occlusion on telepresence collaborations, and b) can an autonomous handling of occlusions improve telepresence collaboration experience for remote users? Results from the first experiment demonstrate that occlusions introduce a significant social interference that necessitates collaborators to reorient or reposition themselves. Subsequently, results from the second experiment indicate that the use of an autonomous controller yields a remote user experience that is more comparable (in terms of their vocal non-verbal behaviors, task performance and perceived workload) to collaborations performed by two co-located parties. These contributions represent a step forward in making robots more autonomous and user friendly while interacting with human co-workers. This is a necessary next step for successful adoption of robots in human environments.Applied Science, Faculty ofMechanical Engineering, Department ofGraduat

IMECE2008-66355 Position Control of Ionic Polymer-Metal Composites Using Fuzzy Logic

ABSTRACT The Ionic polymer-metal composites (IPMCs) form an important category of electroactive polymers which generate large deformation under a low driving voltage. In this paper an empirical model of IPMC is developed by measuring the step response of a 23 mm×3.6 mm×0.16 mm IPMC strip in a cantilever configuration. Moreover, a model-based precision position control of an IPMC base on the fuzzy logic is presented. Open-loop position responses of an IPMC are not repeatable, and hence closedloop precision control is of critical importance to ensure proper functioning, repeatability and reliability. A CCD camera was used to observe the closed loop response of the IPMC strip in order to control this electro-mechanical actuator experimentally. The IPMC actuator could follow various commanded position trajectories such as sinusoidal and square position profiles. The control architecture presented includes a fuzzy system whose structure and parameters were designed by trail-and-error beside a gain scheduled PID controller using fuzzy system. The performance of the IPMC strip is investigated and compared under these controllers