Monthly Archives: September 2017

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Survey on visual attention in 3D for robotics

September 23, 2017 08:42 ,

Ekaterina Potapova, Michael Zillich, and Markus Vincze, Survey of recent advances in 3D visual attention for robotics, The International Journal of Robotics Research, Vol 36, Issue 11, pp. 1159 – 1176, DOI: 10.1177/0278364917726587.

3D visual attention plays an important role in both human and robotics perception that yet has to be explored in full detail. However, the majority of computer vision and robotics methods are concerned only with 2D visual attention. This survey presents findings and approaches that cover 3D visual attention in both human and robot vision, summarizing the last 30 years of research and also looking beyond computational methods. First, we present work in such fields as biological vision and neurophysiology, studying 3D attention in human observers. This provides a view of the role attention plays at the system level for biological vision. Then, we cover computer and robot vision approaches that take 3D visual attention into account. We compare approaches with respect to different categories, such as feature-based, data-based, or depth-based visual attention, and draw conclusions on what advances will help robotics to cope better with complex real-world settings and tasks.

Posted in: Computer vision, Robot sensors , Tagged:

On how humans run simulations for reasoning about physics

September 20, 2017 08:38 ,

James R. Kubricht, Keith J. Holyoak, Hongjing Lu, Intuitive Physics: Current Research and Controversies, Trends in Cognitive Sciences, Volume 21, Issue 10, 2017, Pages 749-759, DOI: 10.1016/j.tics.2017.06.002.

Early research in the field of intuitive physics provided extensive evidence that humans succumb to common misconceptions and biases when predicting, judging, and explaining activity in the physical world. Recent work has demonstrated that, across a diverse range of situations, some biases can be explained by the application of normative physical principles to noisy perceptual inputs. However, it remains unclear how knowledge of physical principles is learned, represented, and applied to novel situations. In this review we discuss theoretical advances from heuristic models to knowledge-based, probabilistic simulation models, as well as recent deep-learning models. We also consider how recent work may be reconciled with earlier findings that favored heuristic models.

Posted in: Psycho-physiological bases of engineering

On the roots in the ability to control outcomes of human motivation

September 20, 2017 08:35 ,

Justin M. Moscarello, Catherine A. Hartley, Agency and the Calibration of Motivated Behavior, Trends in Cognitive Sciences, Volume 21, Issue 10, 2017, Pages 725-735, DOI: 10.1016/j.tics.2017.06.008.

The controllability of positive or negative environmental events has long been recognized as a critical factor determining their impact on an organism. In studies across species, controllable and uncontrollable reinforcement have been found to yield divergent effects on subsequent behavior. Here we present a model of the organizing influence of control, or a lack thereof, on the behavioral repertoire. We propose that individuals derive a generalizable estimate of agency from controllable and uncontrollable outcomes, which serves to calibrate their behavioral strategies in a manner that is most likely to be adaptive given their prior experience.

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

A novel method for hard real-time communications using the physical layer of Ethernet and a variation of TDMA

September 20, 2017 08:30 ,

Andrzej Przybył, Hard real-time communication solution for mechatronic systems, Robotics and Computer-Integrated Manufacturing, Volume 49, 2018, Pages 309-316, DOI: 10.1016/j.rcim.2017.08.001.

The paper proposes a method to build a highly efficient real-time communication solution for mechatronic systems. The method is based on the Ethernet physical layer (PHY) and on field programmable gate array (FPGA) technology and offers a better performance when compared to commercially available communication solutions. Although it is not directly compatible with the OSI/ISO model of TCP/IP protocol, vertical integration is done with a gateway. This provides simplicity and safety. Moreover, the use of the FPGA allows for integrating the communication solution with the user algorithm of particular distributed device inside a single chip. Therefore, the proposed solution is efficient and highly integrated.

Posted in: Communication networks, Real-Time Systems , Tagged:

Calibrating a robotic manipulator through photogrammetry, and a nice state-of-the-art in the issue of robot calibration

September 20, 2017 08:03 ,

Alexandre Filion, Ahmed Joubair, Antoine S. Tahan, Ilian A. Bonev, Robot calibration using a portable photogrammetry system, Robotics and Computer-Integrated Manufacturing, Volume 49, 2018, Pages 77-87, DOI: 10.1016/j.rcim.2017.05.004.

This work investigates the potential use of a commercially-available portablephotogrammetry system (the MaxSHOT 3D) in industrial robot calibration. To demonstrate the effectiveness of this system, we take the approach of comparing the device with a laser tracker (the FARO laser tracker) by calibrating an industrial robot, with each device in turn, then comparing the obtained robot position accuracy after calibration. As the use of a portablephotogrammetry system in robot calibration is uncommon, this paper presents how to proceed. It will cover the theory of robot calibration: the robot’s forward and inverse kinematics, the elasto-geometrical model of the robot, the generation and ultimate selection of robot configurations to be measured, and the parameter identification. Furthermore, an experimental comparison of the laser tracker and the MaxSHOT3D is described. The obtained results show that the FARO laser trackerION performs slightly better: The absolute positional accuracy obtained with the laser tracker is 0.365mm and 0.147mm for the maximum and the mean position errors, respectively. Nevertheless, the results obtained by using the MaxSHOT3D are almost as good as those obtained by using the laser tracker: 0.469mm and 0.197mm for the maximum and the mean position errors, respectively. Performances in distance accuracy, after calibration (i.e. maximum errors), are respectively 0.329mm and 0.352mm, for the laser tracker and the MaxSHOT 3D. However, as the validation measurements were acquired with the laser tracker, bias favors this device. Thus, we may conclude that the calibration performances of the two measurement devices are very similar.

Posted in: Industrial robots, Robot models , Tagged: ,

Interesting implementation of visual graph SLAM in C++ for educational purposes

September 19, 2017 07:59 ,

Dominik Schlegel, Mirco Colosi, Giorgio Grisetti, ProSLAM: Graph SLAM from a Programmer’s Perspective/strong>, arXiv:1709.04377.

In this paper we present ProSLAM, a lightweight stereo visual SLAM system designed with simplicity in mind. Our work stems from the experience gathered by the authors while teaching SLAM to students and aims at providing a highly modular system that can be easily implemented and understood. Rather than focusing on the well known mathematical aspects of Stereo Visual SLAM, in this work we highlight the data structures and the algorithmic aspects that one needs to tackle during the design of such a system. We implemented ProSLAM using the C++ programming language in combination with a minimal set of well known used external libraries. In addition to an open source implementation, we provide several code snippets that address the core aspects of our approach directly in this paper. The results of a thorough validation performed on standard benchmark datasets show that our approach achieves accuracy comparable to state of the art methods, while requiring substantially less computational resources.

Posted in: Computer vision, Mobile robot SLAM , Tagged: , , ,

Improving efficiency of decision with POMDPs in high-dimension state spaces

September 19, 2017 07:45 ,

Dmitry Kopitkov and Vadim Indelman, No belief propagation required: Belief space planning in high-dimensional state spaces via factor graphs, the matrix determinant lemma, and re-use of calculation, The International Journal of Robotics Research, Vol 36, Issue 10, pp. 1088 – 1130, DOI: 10.1177/0278364917721629.

We develop a computationally efficient approach for evaluating the information-theoretic term within belief space planning (BSP), where during belief propagation the state vector can be constant or augmented. We consider both unfocused and focused problem settings, whereas uncertainty reduction of the entire system or only of chosen variables is of interest, respectively. State-of-the-art approaches typically propagate the belief state, for each candidate action, through calculation of the posterior information (or covariance) matrix and subsequently compute its determinant (required for entropy). In contrast, our approach reduces runtime complexity by avoiding these calculations. We formulate the problem in terms of factor graphs and show that belief propagation is not needed, requiring instead a one-time calculation that depends on (the increasing with time) state dimensionality, and per-candidate calculations that are independent of the latter. To that end, we develop an augmented version of the matrix determinant lemma, and show that computations can be re-used when evaluating impact of different candidate actions. These two key ingredients and the factor graph representation of the problem result in a computationally efficient (augmented) BSP approach that accounts for different sources of uncertainty and can be used with various sensing modalities. We examine the unfocused and focused instances of our approach, and compare it with the state of the art, in simulation and using real-world data, considering problems such as autonomous navigation in unknown environments, measurement selection and sensor deployment. We show that our approach significantly reduces running time without any compromise in performance.

Posted in: Robot task planning , Tagged:

A practical example of mobile robot long term operation

September 14, 2017 08:53 ,

N. Hawes et al., The STRANDS Project: Long-Term Autonomy in Everyday Environments, IEEE Robotics & Automation Magazine, vol. 24, no. 3, pp. 146-156, DOI: 10.1109/MRA.2016.2636359.

Thanks to the efforts of the robotics and autonomous systems community, the myriad applications and capacities of robots are ever increasing. There is increasing demand from end users for autonomous service robots that can operate in real environments for extended periods. In the Spatiotemporal Representations and Activities for Cognitive Control in Long-Term Scenarios (STRANDS) project (http://strandsproject.eu), we are tackling this demand head-on by integrating state-of-the-art artificial intelligence and robotics research into mobile service robots and deploying these systems for long-term installations in security and care environments. Our robots have been operational for a combined duration of 104 days over four deployments, autonomously performing end-user-defined tasks and traversing 116 km in the process. In this article, we describe the approach we used to enable long-term autonomous operation in everyday environments and how our robots are able to use their long run times to improve their own performance.

Posted in: Robot applications , Tagged:

An application of POMDPs to robot surveillance

September 14, 2017 08:47 ,

S. Witwicki et al., Autonomous Surveillance Robots: A Decision-Making Framework for Networked Muiltiagent Systems, IEEE Robotics & Automation Magazine, vol. 24, no. 3, pp. 52-64, DOI: 10.1109/MRA.2017.2662222.

This article proposes an architecture for an intelligent surveillance system, where the aim is to mitigate the burden on humans in conventional surveillance systems by incorporating intelligent interfaces, computer vision, and autonomous mobile robots. Central to the intelligent surveillance system is the application of research into planning and decision making in this novel context. In this article, we describe the robot surveillance decision problem and explain how the integration of components in our system supports fully automated decision making. Several concrete scenarios deployed in real surveillance environments exemplify both the flexibility of our system to experiment with different representations and algorithms and the portability of our system into a variety of problem contexts. Moreover, these scenarios demonstrate how planning enables robots to effectively balance surveillance objectives, autonomously performing the job of human patrols and responders.

Posted in: Robot applications, Robot task planning , Tagged: , ,

Interesting approach to learning the sensorimotor behavior of a robot and of its predictive capabilities through NN

September 14, 2017 08:38 ,

R. Santos, R. Ferreira, Â. Cardoso and A. Bernardino, SNet: Co-Developing Artificial Retinas and Predictive Internal Models for Real Robots, IEEE Transactions on Cognitive and Developmental Systems, vol. 9, no. 3, pp. 213-222, DOI: 10.1109/TCDS.2016.2638885.

This paper focuses on a recently developed biologically inspired architecture, here denoted as sensorimotor network (SNet), able to co-develop sensorimotor structures directly from data acquired by a robot interacting with its environment. Such networks learn efficient internal models of the sensorimotor system, developing simultaneously sensor and motor representations as well as predictive models of the sensorimotor relationships adapted to their operating environment. Here, we describe our recent model of sensorimotor development and compare its performance with neural network models in predicting self-induced stimuli. In addition, we illustrate the influence of available resources and environment characteristics in the development of the SNet structures. Finally, an SNet is trained using real data recorded during a quadricopter drone flight.

Posted in: Developmental robotics , Tagged: ,