{"title":"Balance control strategy for legged robots with compliant contacts","authors":"M. Azad, M. Mistry","doi":"10.1109/ICRA.2015.7139806","DOIUrl":"https://doi.org/10.1109/ICRA.2015.7139806","url":null,"abstract":"This paper proposes a momentum-based balancing controller for robots which have non-rigid contacts with their environments. This controller regulates both linear momentum and angular momentum about the center of mass of the robot by controlling the contact forces. Compliant contact models are used to determine the contact forces at the contact points. Simulation results show the performance of the controller on a four-link planar robot standing on various compliant surfaces while unknown external forces in different directions are acting on the center of mass of the robot.","PeriodicalId":399819,"journal":{"name":"2015 IEEE International Conference on Robotics and Automation (ICRA)","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131728644","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Traversability analysis for mobile robots in outdoor environments: A semi-supervised learning approach based on 3D-lidar data","authors":"Benjamin Suger, B. Steder, Wolfram Burgard","doi":"10.1109/ICRA.2015.7139749","DOIUrl":"https://doi.org/10.1109/ICRA.2015.7139749","url":null,"abstract":"The ability to safely navigate is a crucial prerequisite for truly autonomous systems. A robot has to distinguish obstacles from traversable ground. Failing on this task can cause great damage or restrict the robots movement unnecessarily. Due to the security relevance of this problem, great effort is typically spent to design models for individual robots and sensors, and the complexity of such models is correlated to the complexity of the environment and the capabilities of the robot. We present a semi supervised learning approach, where the robot learns its traversability capabilities from a human operating it. From this partially and only positive labeled training data, our approach infers a model for the traversability analysis, thereby requiring very little manual effort for the human. In practical experiments we show that our method can be used for robots that need to reliably navigate on dirt roads as well as for robots that have very restricted traversability capabilities.","PeriodicalId":399819,"journal":{"name":"2015 IEEE International Conference on Robotics and Automation (ICRA)","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117096049","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Bayesian fusion using conditionally independent submaps for high resolution 2.5D mapping","authors":"Liye Sun, Teresa Vidal-Calleja, J. V. Miró","doi":"10.1109/ICRA.2015.7139668","DOIUrl":"https://doi.org/10.1109/ICRA.2015.7139668","url":null,"abstract":"Typically 2.5D maps provide a compact and efficient representation of the environment. When sensor data is obtained from multiple sets of noisy measurements at differing resolutions, the problem of compounding this information together to provide an effective and efficient means of mapping is not trivial, particularly as the size of the environment increases. In this paper, we propose a general framework for integrating heterogeneous sensor data to obtain large-scale 2.5D probabilistic maps. Gaussian Processes are used to generate a prior map that learns the spatial correlation between nearby points. Bayesian data fusion is then employed to update these prior maps with new measurements from distinct sensor modalities. In order to deal with large scale data, a novel submapping strategy is introduced to perform the fusion step efficiently in dealing with large covariance matrices. Submaps are first marginalised from the learned correlated prior and then updated based on the property of conditional independence. Most notably, the technique lends itself to generate accurate estimates at arbitrary resolutions and is able to handle varying noise from disparate sensor sources. The framework is applied to pipeline thickness mapping, with experimental results in fusing a high-resolution sensor and a low-resolution sensor showing the ability of the proposed technique to capture spatial correlations to come up with more accurate results when compared with a naïve fusion approach.","PeriodicalId":399819,"journal":{"name":"2015 IEEE International Conference on Robotics and Automation (ICRA)","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115866696","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"An online method for tight-tolerance insertion tasks for string and rope","authors":"Weifu Wang, D. Berenson, Devin J. Balkcom","doi":"10.1109/ICRA.2015.7139532","DOIUrl":"https://doi.org/10.1109/ICRA.2015.7139532","url":null,"abstract":"This paper presents a fast tight-tolerance threading technique for string and rope. Instead of relying on simulations of these deformable objects to plan a path or compute control actions, we control the movement of the string with a virtual magnetic vector field emanating from the narrow openings we wish to thread through. We compute an approximate Jacobian to move the tip of the string through the vector field and propose a method to promote alignment of the head of the string to the opening. We also propose a method for re-grasping the string based on the relationship between the string's configuration, the orientation of the opening, and direction of gravity. This re-grasping method in conjunction with our controller can be used to thread the string through a sequence of openings. We evaluated our method in simulation (with simulated sensor noise) and on the Da Vinci surgical robot. Our results suggest that our method is quite robust to errors in sensing, and is capable of real-world threading tasks with the da Vinci robot, where the diameter of the string (3.5mm) and opening (4.9mm) differ by only 1.4 mm.","PeriodicalId":399819,"journal":{"name":"2015 IEEE International Conference on Robotics and Automation (ICRA)","volume":"171 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115238745","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Masatoshi Ando, Yuuto Chokushi, Kanji Tanaka, Kentaro Yanagihara
{"title":"Leveraging image-based prior in cross-season place recognition","authors":"Masatoshi Ando, Yuuto Chokushi, Kanji Tanaka, Kentaro Yanagihara","doi":"10.1109/ICRA.2015.7139961","DOIUrl":"https://doi.org/10.1109/ICRA.2015.7139961","url":null,"abstract":"In this paper, we address the challenging problem of single-view cross-season place recognition. A new approach is proposed for compact discriminative scene descriptor that helps in coping with changes in appearance in the environment. We focus on a simple effective strategy that uses objects whose appearance remain the same across seasons as valid landmarks. Unlike popular bag-of-words (BoW) scene descriptors that rely on a library of vector quantized visual features, our descriptor is based on a library of raw image data (e.g., visual experience shared by colleague robots, publicly available photo collections from Google StreetView), and directly mines it to identify landmarks (i.e., image patches) that effectively explain an input query/database image. The discovered landmarks are then compactly described by their pose and shape (i.e., library image ID, and bounding boxes) and used as a compact discriminative scene descriptor for the input image. We collected a dataset of single-view images across seasons with annotated ground truth, and evaluated the effectiveness of our scene description framework by comparing its performance to that of previous BoW approaches, and by applying an advanced Naive Bayes Nearest neighbor (NBNN) image-to-class distance measure.","PeriodicalId":399819,"journal":{"name":"2015 IEEE International Conference on Robotics and Automation (ICRA)","volume":"80 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115377179","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Augmenting physical state prediction through structured activity inference","authors":"Nam N. Vo, A. Bobick","doi":"10.1109/ICRA.2015.7139262","DOIUrl":"https://doi.org/10.1109/ICRA.2015.7139262","url":null,"abstract":"We address the problem of predicting the physical state of a an agent performing a known activity. In particular we are interested in predicting human movement during complex composite activities. Our proposed framework combines a graphical model that extends the Sequential Interval Network (SIN) [1] for modeling global temporal structure of activities with a low level dynamic system for modeling the dynamics of the physical state. Specifically, two sets of new hidden state variables are added: one with respect to the temporal structure and one with respect to time. A mapping factor is defined to ensure these variables values remain consistent and hence allows fusing the two sources of information. We then derive an inference algorithm for computing the posterior densities of the hidden variables. The system can run in an on-line predictive mode to recognize on-going activity and make predictions arbitrarily far in the future during execution of the activity. Experiments illustrate that the long term prediction performance benefits from the knowledge about the temporal structure of the activity while short term prediction performance is improved by incorporating the dynamics of physical state.","PeriodicalId":399819,"journal":{"name":"2015 IEEE International Conference on Robotics and Automation (ICRA)","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117342007","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Image based optimisation without global consistency for constant time monocular visual SLAM","authors":"Vincent Lui, T. Drummond","doi":"10.1109/ICRA.2015.7140011","DOIUrl":"https://doi.org/10.1109/ICRA.2015.7140011","url":null,"abstract":"This paper presents a monocular visual SLAM system that does not require a globally consistent 3D model. Instead of generating a globally consistent 3D model and localising the camera from the 3D model, the system merely optimises relative pose parameters for pairs of keyframes that overlap on the scene, providing accurate local information at the expense of global consistency. During run-time, the camera is localised using only 2D measurements from nearby keyframes instead of using correspondences between 2D measurements and 3D features of a 3D model. Extensive experiments using both synthetic and real data sets were performed to evaluate the system's performance. Results show that our system is accurate and runs in real time at an average of 25 frames per second on a standard computer. Finally, we also show how useful applications can be easily developed on top of a framework without global consistency.","PeriodicalId":399819,"journal":{"name":"2015 IEEE International Conference on Robotics and Automation (ICRA)","volume":"7 9","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120840830","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
C. McFarland, M. Jakuba, S. Suman, J. Kinsey, L. Whitcomb
{"title":"Toward ice-relative navigation of underwater robotic vehicles under moving sea ice: Experimental evaluation in the Arctic sea","authors":"C. McFarland, M. Jakuba, S. Suman, J. Kinsey, L. Whitcomb","doi":"10.1109/ICRA.2015.7139392","DOIUrl":"https://doi.org/10.1109/ICRA.2015.7139392","url":null,"abstract":"This paper addresses the problem of ice-relative navigation of underwater robotic vehicles for oceanographic missions under moving sea ice. We define the ice-relative navigation problem and report a novel underwater robot vehicle, Nereid-UI, and its navigation system designed for under-ice oceanographic operations in ice-covered seas. The goal of Nereid-UI is to enable deployments in polar ocean regions traditionally considered difficult or impossible to access such as the ice-ocean interface in marginal ice zones, the water column of ice-covered seas, and the water column underlying ice shelves. This paper also reports the navigation results of Nereid-UI's first under-ice sea trials and science operations conducted under moving multi-year sea ice off the ice breaker Polarstern in the Arctic Ocean at 83° N 6° W - about 200 km NE of Greenland.","PeriodicalId":399819,"journal":{"name":"2015 IEEE International Conference on Robotics and Automation (ICRA)","volume":"4 4","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120897617","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Running beyond the bio-inspired regime","authors":"D. Haldane, R. Fearing","doi":"10.1109/ICRA.2015.7139828","DOIUrl":"https://doi.org/10.1109/ICRA.2015.7139828","url":null,"abstract":"The X2-VelociRoACH is a 54 gram experimental legged robot which was developed to test hypotheses about running with unnaturally high stride frequencies. It is capable of running at stride frequencies up to 45 Hz, and velocities up to 4.9 m/s, making it the fastest legged robot relative to size. The top speed of the robot was limited by structural failure. We present new methods and materials to make more robust folded robotic structures. High-frequency running experiments with the robot shows that the power required to cycle its running appendages increase cubically with the stride rate. Our findings show that although it is possible to further increase the maximum velocity of a legged robot with the simple strategy of increasing stride frequency, considerations must be made for the energetic demands of high stride rates.","PeriodicalId":399819,"journal":{"name":"2015 IEEE International Conference on Robotics and Automation (ICRA)","volume":"609 ","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120939865","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Symmetries and reduction for multi-agent control","authors":"Ashley Nettleman, B. Goodwine","doi":"10.1109/ICRA.2015.7139952","DOIUrl":"https://doi.org/10.1109/ICRA.2015.7139952","url":null,"abstract":"This paper computes all the continuous point-transformation symmetries for a planar multi-agent dynamical control system. The relative configuration among the agents is often the most important aspect of this problem, and this paper presents a method to “factor out” the location and orientation on the plane of a multi-agent formation problem. This is useful in the case where only the relative positioning of the agents is of concern. The method to compute the symmetries and determine the reduced coordinates is well-established. The contributions of this paper are (1) computing the symmetries for a multi-agent system, (2) highlighting the utility of the reduction for the formation control application such as formation stability and (3) analyzing the symmetries to determine a relatively broad class of systems which have the same symmetries and hence identical coordinates for reduction. Although it has been addressed in various ways, essentially all methods to determine the stability properties of the formation control problem need the dynamics to be formulated on a reduced, relative space. Hence, stability (and stability-like notions such as that which follow from LaSalle's Principle) analyses will be the main beneficiary of this work.","PeriodicalId":399819,"journal":{"name":"2015 IEEE International Conference on Robotics and Automation (ICRA)","volume":"97 4","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120940930","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}