{"title":"Joint on-manifold self-calibration of odometry model and sensor extrinsics using pre-integration","authors":"Jérémie Deray, J. Solà, J. Andrade-Cetto","doi":"10.1109/ECMR.2019.8870942","DOIUrl":"https://doi.org/10.1109/ECMR.2019.8870942","url":null,"abstract":"This paper describes a self-calibration procedure that jointly estimates the extrinsic parameters of an exteroceptive sensor able to observe ego-motion, and the intrinsic parameters of an odometry motion model, consisting of wheel radii and wheel separation. We use iterative nonlinear on-manifold optimization with a graphical representation of the state, and resort to an adaptation of the pre-integration theory, initially developed for the IMU motion sensor, to be applied to the differential drive motion model. For this, we describe the construction of a pre-integrated factor for the differential drive motion model, which includes the motion increment, its covariance, and a first-order approximation of its dependence with the calibration parameters. As the calibration parameters change at each solver iteration, this allows a posteriori factor correction without the need of re-integrating the motion data. We validate our proposal in simulations and on a real robot and show the convergence of the calibration towards the true values of the parameters. It is then tested online in simulation and is shown to accommodate to variations in the calibration parameters when the vehicle is subject to physical changes such as loading and unloading a freight.","PeriodicalId":435630,"journal":{"name":"2019 European Conference on Mobile Robots (ECMR)","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125546649","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":"Similarity criteria: evaluating perceptual change for visual localization","authors":"Stephanie M. Lowry","doi":"10.1109/ECMR.2019.8870962","DOIUrl":"https://doi.org/10.1109/ECMR.2019.8870962","url":null,"abstract":"Visual localization systems may operate in environments that exhibit considerable perceptual change. This paper proposes a method of evaluating the degree of appearance change using a similarity criteria based on comparing the subspaces spanned by the principal components of the observed image descriptors. We propose two criteria - θmin measures the minimum angle between subspaces and Stotal measures the total similarity between the subspaces. These criteria are introspective - they evaluate the performance of the image descriptor using nothing more than the image descriptor itself. Furthermore, we demonstrate that these similarity criteria reflect the ability of the image descriptor to perform visual localization successfully, thus allowing a measure of quality control on the localization output.","PeriodicalId":435630,"journal":{"name":"2019 European Conference on Mobile Robots (ECMR)","volume":"51 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117129740","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}
Timo Korthals, Daniel Wolf, Daniel Rudolph, Marc Hesse, U. Rückert
{"title":"Fiducial Marker based Extrinsic Camera Calibration for a Robot Benchmarking Platform","authors":"Timo Korthals, Daniel Wolf, Daniel Rudolph, Marc Hesse, U. Rückert","doi":"10.1109/ECMR.2019.8870969","DOIUrl":"https://doi.org/10.1109/ECMR.2019.8870969","url":null,"abstract":"Evaluation of robotic experiments requires physical robots as well as position sensing systems. Accurate systems detecting sufficiently all necessary degrees of freedom, like the famous Vicon system, are commonly too expensive. Therefore, we target an economical multi-camera based solution by following these three requirements: Using multiple cameras to track even large laboratory areas, applying fiducial marker trackers for pose identification, and fuse tracking hypothesis resulting from multiple cameras via extended Kalman filter (i.e. ROS's robot_localization). While the registration of a multi-camera system for collaborative tracking remains a challenging issue, the contribution of this paper is as follows: We introduce the framework of Cognitive Interaction Tracking (CITrack). Then, common fiducial marker tracking systems (ARToolKit, April-Tag, ArUco) are compared with respect to their maintainability. Lastly, a graph-based camera registration approach in SE(3), using the fiducial marker tracking in a multi-camera setup, is presented and evaluated.","PeriodicalId":435630,"journal":{"name":"2019 European Conference on Mobile Robots (ECMR)","volume":"63 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127025844","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}
Filip Majer, Zhi Yan, G. Broughton, Y. Ruichek, T. Krajník
{"title":"Learning to see through haze: Radar-based Human Detection for Adverse Weather Conditions","authors":"Filip Majer, Zhi Yan, G. Broughton, Y. Ruichek, T. Krajník","doi":"10.1109/ECMR.2019.8870954","DOIUrl":"https://doi.org/10.1109/ECMR.2019.8870954","url":null,"abstract":"In this paper, we present a lifelong-learning multisensor system for pedestrian detection in adverse weather conditions. The proposed method combines two people detection pipelines which process data provided by a lidar and an ultrawideband radar. The outputs of these pipelines are combined not only by means of adaptive sensor fusion, but they can also be used to help one another learn. In particular, the lidar-based detector provides labels to the incoming radar data, efficiently training the radar data classifier. In several experiments, we show that the proposed learning-fusion not only results in a gradual improvement of the system performance during routine operation, but also efficiently deals with lidar detection failures caused by thick fog conditions.","PeriodicalId":435630,"journal":{"name":"2019 European Conference on Mobile Robots (ECMR)","volume":"146 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115185858","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":"Drone's Attitude Estimation in Corridor-Like Environments","authors":"D. Jano, S. Arogeti","doi":"10.1109/ECMR.2019.8870961","DOIUrl":"https://doi.org/10.1109/ECMR.2019.8870961","url":null,"abstract":"In this study, we suggest an attitude estimation algorithm for drones flying indoors. In particular, we consider a corridor-like environment and adapt ideas from the aerospace field, where algorithms were developed for satellite's attitude estimation. Many algorithms can be found that estimate satellite's attitude, based on rate gyroscopes and a sensor called, star-tracker. The star-tracker identifies celestial objects, and by that, determines their directions compared to the satellite. Using star maps, the same celestial objects directions, compared to the earth, is known. By comparing the celestial objects directions in the satellite frame and in the earth frame, the attitude of the satellite can be estimated. Complementing the star-tracker with rate gyroscopes provides smooth attitude estimation, while also compensating for the rate gyroscope's drift. The novelty in this paper comes from the implementation of the star-tracker method on a drone in a corridor-like environment, and by finding features, which replace the celestial objects used by a star-tracker.","PeriodicalId":435630,"journal":{"name":"2019 European Conference on Mobile Robots (ECMR)","volume":"107 5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128993839","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":"Prioritized Multi-agent Path Finding for Differential Drive Robots","authors":"K. Yakovlev, A. Andreychuk, Vitaly Vorobyev","doi":"10.1109/ECMR.2019.8870957","DOIUrl":"https://doi.org/10.1109/ECMR.2019.8870957","url":null,"abstract":"Methods for centralized planning of the collision-free trajectories for a fleet of mobile robots typically solve the discretized version of the problem and rely on numerous simplifying assumptions, e.g. moves of uniform duration, cardinal only translations, equal speed and size of the robots etc., thus the resultant plans can not always be directly executed by the real robotic systems. To mitigate this issue we suggest a set of modifications to the prominent prioritized planner - AA-SIPP(m) - aimed at lifting the most restrictive assumptions (syncronized translation only moves, equal size and speed of the robots) and at providing robustness to the solutions. We evaluate the suggested algorithm in simulation and on differential drive robots in typical lab environment (indoor polygon with external video-based navigation system). The results of the evaluation provide a clear evidence that the algorithm scales well to large number of robots (up to hundreds in simulation) and is able to produce solutions that are safely executed by the robots prone to imperfect trajectory following. The video of the experiments can be found at https://youtu.be/Fer_irn4BG0.","PeriodicalId":435630,"journal":{"name":"2019 European Conference on Mobile Robots (ECMR)","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126787496","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}
M. Luperto, Danilo Fusi, N. A. Borghese, F. Amigoni
{"title":"Robot Exploration Using Knowledge of Inaccurate Floor Plans","authors":"M. Luperto, Danilo Fusi, N. A. Borghese, F. Amigoni","doi":"10.1109/ECMR.2019.8870925","DOIUrl":"https://doi.org/10.1109/ECMR.2019.8870925","url":null,"abstract":"Exploration is a task in which autonomous mobile robots incrementally discover features of interest in initially unknown environments. Usually, robots use exploration strategies to select their next best locations in partially explored environments. Most of the current exploration strategies ignore prior knowledge about the environments to explore that, in some practical cases, could be available. In this paper, we present a method that includes a priori knowledge in an exploration strategy for a mobile robot. Our exploration strategy selects the next best locations the robot should reach by exploiting the knowledge of the floor plan of the indoor environment that is being explored. Although the floor plan can be inaccurate (e.g., it typically does not include furniture and could represent a topology that does not fully match with that of the actual environment), we experimentally show, both in simulation and with real robots, that knowing the floor plan improves the exploration performance under a wide range of conditions.","PeriodicalId":435630,"journal":{"name":"2019 European Conference on Mobile Robots (ECMR)","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123650043","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":"Improving Navigation with the Social Force Model by Learning a Neural Network Controller in Pedestrian Crowds","authors":"P. Regier, Ibrahim Shareef, Maren Bennewitz","doi":"10.1109/ECMR.2019.8870923","DOIUrl":"https://doi.org/10.1109/ECMR.2019.8870923","url":null,"abstract":"In this paper, we present a novel, efficient approach to improve the acceleration commands computed by the popular social force model (SFM) [1] for navigation through pedestrian crowds. Our method consists of two stages. In the first phase, we collect training data with a simulated approach. In this step, we modify the steering acceleration commands from the SFM according to a set of discrete alterations and simulate the motion of the robot as well as the pedestrians into the future for each alteration. We rate each resulting trajectory based on a cost function and apply the best steering command to the robot. While controlling the robot in such way, we collect for every time step the input and output training data. In the second stage, we then learn a neural network given the collected training data. We use the best acceleration values experienced in the first phase as target values for the neural network and define simple input features describing the local surrounding of the robot. In extensive simulation experiments using different pedestrian densities, we demonstrate that the controls generated by the learned neural network lead to a significantly reduced number of collisions with pedestrians compared to the results of the basic SFM controller, while achieving similar or even shorter completion times.","PeriodicalId":435630,"journal":{"name":"2019 European Conference on Mobile Robots (ECMR)","volume":"35 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134052851","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}
Cassandra McCord, J. P. Queralta, Tuan Anh Nguyen Gia, Tomi Westerlund
{"title":"Distributed Progressive Formation Control for Multi-Agent Systems: 2D and 3D deployment of UAVs in ROS/Gazebo with RotorS","authors":"Cassandra McCord, J. P. Queralta, Tuan Anh Nguyen Gia, Tomi Westerlund","doi":"10.1109/ECMR.2019.8870934","DOIUrl":"https://doi.org/10.1109/ECMR.2019.8870934","url":null,"abstract":"Coordination of multiple robots in order to cooperatively perform a given task requires a certain distribution of the different units in space. Furthermore, individual robots, or agents, might have different tasks, or positions, assigned. Formation control algorithms might rely on a priori information, a centralized controller, or communication among the agents to assign roles. Distributed approaches that only need local interaction between agents have limited possibilities, such as flocks where agents actively control the distance to neighboring agents. Alternatively, two-way local communication has been applied to progressively assign roles and converge towards a given configuration. We propose a progressive assignment algorithm and formation control scheme that extends leader-follower formations in order to enable cooperation of multiple robots with minimal, one-way, local communication between agents. The proposed algorithm progressively generates a directed, locally convex, path graph to uniquely assign formation positions to all agents. The low computational complexity of our algorithm enables its implementation in resource-limited devices. Agents only require information about neighboring agents and be able to locally broadcast their status. This algorithm enables almost arbitrary two-dimensional configurations, with the only limitation being the sensing range enabling the definition of a series of convex hulls in a certain subset of agents such that agents sharing an edge in the hull are able to sense each other. Moreover, we propose a methodology for deploying agents to an arbitrary three-dimensional configuration after the assignment process is made on the plane.","PeriodicalId":435630,"journal":{"name":"2019 European Conference on Mobile Robots (ECMR)","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115615217","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}
Clara Gómez, A. C. Hernández, Erik Derner, R. Barber
{"title":"Semantic Localization through Propagation of Scene Information in a Hierarchical Model","authors":"Clara Gómez, A. C. Hernández, Erik Derner, R. Barber","doi":"10.1109/ECMR.2019.8870972","DOIUrl":"https://doi.org/10.1109/ECMR.2019.8870972","url":null,"abstract":"The success of mobile robots, and particularly these coexisting with humans, relies on the ability to understand human environments. Representing the world and analysing spaces in a similar way to humans will enhance their comprehension and enable higher abstraction capabilities and interactions. The purpose of this work is to develop a localization framework that takes into account the different scenes common in a human environment and a hierarchical model of the environment. A probabilistic model for recognizing scenes is employed to determine the scene in which the robot is located. To allow that, the information about the objects and the relationships between them are considered. Besides that, a hierarchical model formed by different topological representations according to different levels of abstraction is proposed. Localization is performed at different levels to improve the localization accuracy. In this work, scene information is used to improve the localization of a mobile robot in a hierarchical model using hidden Markov models. The experiments of our framework working in real environments uphold the usefulness of the inclusion of the understanding and abstraction of the environment in localization.","PeriodicalId":435630,"journal":{"name":"2019 European Conference on Mobile Robots (ECMR)","volume":"339 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114728741","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}