Novelty detection as a way for enhancing learning capabilities of a robot, and a brief but interesting survey of motivational theories and their difference with attention

April 24, 2015 12:46 ,

Y. Gatsoulis, T.M. McGinnity, Intrinsically motivated learning systems based on biologically-inspired novelty detection, Robotics and Autonomous Systems, Volume 68, June 2015, Pages 12-20, ISSN 0921-8890, DOI: 10.1016/j.robot.2015.02.006.

Intrinsic motivations play an important role in human learning, particularly in the early stages of childhood development, and ideas from this research field have influenced robotic learning and adaptability. In this paper we investigate one specific type of intrinsic motivation, that of novelty detection and we discuss the reasons that make it a powerful facility for continuous learning. We formulate and present one original type of biologically inspired novelty detection architecture and implement it on a robotic system engaged in a perceptual classification task. The results of real-world robot experiments we conducted show how this original architecture conforms to behavioural observations and demonstrate its effectiveness in terms of focusing the system’s attention in areas that are potential for effective learning.

Posted in: Psycho-physiological bases of engineering, Robotics , Tagged: , ,

On the history of IEEE Transactions on Robotics and Automation, ICRA, and others

April 24, 2015 12:23 ,

Sabanovic, S.; Milojevic, S.; Asaro, P.; Francisco, M., Robotics Narratives and Networks [History], Robotics & Automation Magazine, IEEE , vol.22, no.1, pp.137,146, March 2015, DOI: 10.1109/MRA.2014.2385564.

Somewhere around 1983, maybe late 1982, there was talk beginning about doing something more formal within IEEE that dealt with robotics and automation. Informally, activity was getting started through the Control Society,…also Systems, Man and Cybernetics, which obviously makes a lot of sense with the telerobotics things and a few others. But we wanted to build a more permanent home for it, so there was one of the first meetings. George Saridis chaired the meeting. I know George Bekey was there, Tony Bejczy, Lou Paul, probably another half dozen people.

Posted in: History of robotics

Abstract data-type for exchanging information in real-time systems, prioritizing the access to newest data rather than to oldest

April 24, 2015 12:19 ,

Dantam, N.T.; Lofaro, D.M.; Hereid, A.; Oh, P.Y.; Ames, A.D.; Stilman, M., The Ach Library: A New Framework for Real-Time Communication, Robotics & Automation Magazine, IEEE , vol.22, no.1, pp.76,85, March 2015, DOI: 10.1109/MRA.2014.2356937.

Correct real-time software is vital for robots in safety-critical roles such as service and disaster response. These systems depend on software for locomotion, navigation, manipulation, and even seemingly innocuous tasks such as safely regulating battery voltage. A multiprocess software design increases robustness by isolating errors to a single process, allowing the rest of the system to continue operation. This approach also assists with modularity and concurrency. For real-time tasks, such as dynamic balance and force control of manipulators, it is critical to communicate the latest data sample with minimum latency. There are many communication approaches intended for both general-purpose and real-time needs [9], [13], [15], [17], [19]. Typical methods focus on reliable communication or network transparency and accept a tradeoff of increased message latency or the potential to discard newer data. By focusing instead on the specific case of real-time communication on a single host, we reduce communication latency and guarantee access to the latest sample. We present a new interprocess communication (IPC) library, Ach which addresses this need, and discuss its application for real-time multiprocess control on three humanoid robots (Figure 1). (Ach is available at http://www.golems.org/projects/ach.html. The name Ach comes from the common abbreviation for the motor neurotransmitter Acetylcholine and the computer networking term ACK.).

Posted in: Real-Time Systems, Robotic software , Tagged: ,

Reinforcement learning used for an adaptive attention mechanism, and integrated in an architecture with both top-down and bottom-up vision processing

April 24, 2015 11:26 ,

Ognibene, D.; Baldassare, G., Ecological Active Vision: Four Bioinspired Principles to Integrate Bottom–Up and Adaptive Top–Down Attention Tested With a Simple Camera-Arm Robot, Autonomous Mental Development, IEEE Transactions on , vol.7, no.1, pp.3,25, March 2015. DOI: 10.1109/TAMD.2014.2341351.

Vision gives primates a wealth of information useful to manipulate the environment, but at the same time it can easily overwhelm their computational resources. Active vision is a key solution found by nature to solve this problem: a limited fovea actively displaced in space to collect only relevant information. Here we highlight that in ecological conditions this solution encounters four problems: 1) the agent needs to learn where to look based on its goals; 2) manipulation causes learning feedback in areas of space possibly outside the attention focus; 3) good visual actions are needed to guide manipulation actions, but only these can generate learning feedback; and 4) a limited fovea causes aliasing problems. We then propose a computational architecture (“BITPIC”) to overcome the four problems, integrating four bioinspired key ingredients: 1) reinforcement-learning fovea-based top-down attention; 2) a strong vision-manipulation coupling; 3) bottom-up periphery-based attention; and 4) a novel action-oriented memory. The system is tested with a simple simulated camera-arm robot solving a class of search-and-reach tasks involving color-blob “objects.” The results show that the architecture solves the problems, and hence the tasks, very efficiently, and highlight how the architecture principles can contribute to a full exploitation of the advantages of active vision in ecological conditions.

Posted in: Applications of reinforcement learning to robots, Computer vision, Psycho-physiological bases of engineering , Tagged: , , , ,

Survey of Hierarchical Task Planning

March 11, 2015 15:28 ,

Ilche Georgievski, Marco Aiello, 2015, HTN planning: Overview, comparison, and beyond, Artificial Intelligence, Volume 222, May 2015, Pages 124-156, ISSN 0004-3702, DOI: 10.1016/j.artint.2015.02.002.

Hierarchies are one of the most common structures used to understand and conceptualise the world. Within the field of Artificial Intelligence (AI) planning, which deals with the automation of world-relevant problems, Hierarchical Task Network (HTN) planning is the branch that represents and handles hierarchies. In particular, the requirement for rich domain knowledge to characterise the world enables HTN planning to be very useful, and also to perform well. However, the history of almost 40 years obfuscates the current understanding of HTN planning in terms of accomplishments, planning models, similarities and differences among hierarchical planners, and its current and objective image. On top of these issues, the ability of hierarchical planning to truly cope with the requirements of real-world applications has been often questioned. As a remedy, we propose a framework-based approach where we first provide a basis for defining different formal models of hierarchical planning, and define two models that comprise a large portion of HTN planners. Second, we provide a set of concepts that helps in interpreting HTN planners from the aspect of their search space. Then, we analyse and compare the planners based on a variety of properties organised in five segments, namely domain authoring, expressiveness, competence, computation and applicability. Furthermore, we select Web service composition as a real-world and current application, and classify and compare the approaches that employ HTN planning to solve the problem of service composition. Finally, we conclude with our findings and present directions for future work. In summary, we provide a novel and comprehensive viewpoint on a core AI planning technique.

Posted in: Artificial Intelligence , Tagged:

On the process of the brain for detecting similarities, with a proposal for its structure and its timing

March 11, 2015 15:20 ,

Qingfei Chen, Xiuling Liang, Peng Li, Chun Ye, Fuhong Li, Yi Lei, Hong Li, 2015, The processing of perceptual similarity with different features or spatial relations as revealed by P2/P300 amplitude, International Journal of Psychophysiology, Volume 95, Issue 3, March 2015, Pages 379-387, ISSN 0167-8760, DOI: 10.1016/j.ijpsycho.2015.01.009.

Visual features such as “color” and spatial relations such as “above” or “beside” have complex effects on similarity and difference judgments. We examined the relative impact of features and spatial relations on similarity and difference judgments via ERPs in an S1–S2 paradigm. Subjects were required to compare a remembered geometric shape (S1) with a second one (S2), and made a “high” or “low” judgment of either similarity or difference in separate blocks of trials. We found three main differences that suggest that the processing of features and spatial relations engages distinct neural processes. The first difference is a P2 effect in fronto-central regions which is sensitive to the presence of a feature difference. The second difference is a P300 in centro-parietal regions that is larger for difference judgments than for similarity judgments. Finally, the P300 effect elicited by feature differences was larger relative to spatial relation differences. These results supported the view that similarity judgments involve structural alignment rather than simple feature and relation matches, and furthermore, indicate the similarity judgment could be divided into three phases: feature or relation comparison (P2), structural alignment (P3 at 300–400 ms), and categorization (P3 at 450–550 ms).

Posted in: Psycho-physiological bases of engineering , Tagged:

On the role of emotions in cognition, in particular in cognitive control

March 11, 2015 15:14 ,

Michael Inzlicht, Bruce D. Bartholow, Jacob B. Hirsh, 2015, Emotional foundations of cognitive control, Trends in Cognitive Sciences, Volume 19, Issue 3, March 2015, Pages 126-132, DOI: 10.1016/j.tics.2015.01.004.

Often seen as the paragon of higher cognition, here we suggest that cognitive control is dependent on emotion. Rather than asking whether control is influenced by emotion, we ask whether control itself can be understood as an emotional process. Reviewing converging evidence from cybernetics, animal research, cognitive neuroscience, and social and personality psychology, we suggest that cognitive control is initiated when goal conflicts evoke phasic changes to emotional primitives that both focus attention on the presence of goal conflicts and energize conflict resolution to support goal-directed behavior. Critically, we propose that emotion is not an inert byproduct of conflict but is instrumental in recruiting control. Appreciating the emotional foundations of control leads to testable predictions that can spur future research.

Posted in: Cognitive sciences , Tagged: ,

On the not-so-domain-generic nature of statistical learning in the human brain

March 11, 2015 15:09 ,

Ram Frost, Blair C. Armstrong, Noam Siegelman, Morten H. Christiansen, 2015, Domain generality versus modality specificity: the paradox of statistical learning, Trends in Cognitive Sciences, Volume 19, Issue 3, March 2015, Pages 117-125, DOI: 10.1016/j.tics.2014.12.010.

Statistical learning (SL) is typically considered to be a domain-general mechanism by which cognitive systems discover the underlying distributional properties of the input. However, recent studies examining whether there are commonalities in the learning of distributional information across different domains or modalities consistently reveal modality and stimulus specificity. Therefore, important questions are how and why a hypothesized domain-general learning mechanism systematically produces such effects. Here, we offer a theoretical framework according to which SL is not a unitary mechanism, but a set of domain-general computational principles that operate in different modalities and, therefore, are subject to the specific constraints characteristic of their respective brain regions. This framework offers testable predictions and we discuss its computational and neurobiological plausibility.

Posted in: Machine learning, Psycho-physiological bases of engineering , Tagged: ,

Automatic synthetis of controllers for robotic tasks from the specification of state-machine-like missions, nonlinear models of the robot and a representation of the robot workspace

March 11, 2015 11:52 ,

Jonathan A. DeCastro and Hadas Kress-Gazit, 2015, Synthesis of nonlinear continuous controllers for verifiably correct high-level, reactive behaviors, The International Journal of Robotics Research, 34: 378-394, DOI: 10.1177/0278364914557736.

Planning robotic missions in environments shared by humans involves designing controllers that are reactive to the environment yet able to fulfill a complex high-level task. This paper introduces a new method for designing low-level controllers for nonlinear robotic platforms based on a discrete-state high-level controller encoding the behaviors of a reactive task specification. We build our method upon a new type of trajectory constraint which we introduce in this paper, reactive composition, to provide the guarantee that any high-level reactive behavior may be fulfilled at any moment during the continuous execution. We generate pre-computed motion controllers in a piecewise manner by adopting a sample-based synthesis method that associates a certificate of invariance with each controller in the sample set. As a demonstration of our approach, we simulate different robotic platforms executing complex tasks in a variety of environments.

Posted in: Robot motion planning

A nice review of the problem of kinematic modeling of wheeled mobile robots and a new approach that delays the use of coordinate frames

March 11, 2015 11:42 ,

Alonzo Kelly and Neal Seegmiller, 2015, Recursive kinematic propagation for wheeled mobile robots, The International Journal of Robotics Research, 34: 288-313, DOI: 10.1177/0278364914551773.

The problem of wheeled mobile robot kinematics is formulated using the transport theorem of vector algebra. Doing so postpones the introduction of coordinates until after the expressions for the relevant Jacobians have been derived. This approach simplifies the derivation while also providing the solution to the general case in 3D, including motion over rolling terrain. Angular velocity remains explicit rather than encoded as the time derivative of a rotation matrix. The equations are derived and can be implemented recursively using a single equation that applies to all cases. Acceleration kinematics are uniquely derivable in reasonable effort. The recursive formulation also leads to efficient computer implementations that reflect the modularity of real mechanisms.

Posted in: Robot models , Tagged: ,