Probabilistic Self-Localization and Mapping: An Asynchronous Multirate Approach

"© 2008 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works."[EN] In this paper, we present a set of robust and efficient algorithms with O(N) cost for the solution of the Simultaneous Localization And Mapping (SLAM) problem of a mobile robot. First, we introduce a novel object detection method, which is mainly based on multiple line fitting method for landmark detection with regular constrained angles. Second, a line-based pose estimation method is proposed, based on LeastSquares (LS). This method performs the matching of lines, providing the global pose estimation under assumption of known Data-Association. Finally, we extend the FastSLAM (FActored Solution To SLAM) algorithm for mobile robot self-localisation and mapping by considering the asynchronous sampling of sensors and actuators. In this sense, multi-rate asynchronous holds are used to interface signals with different sampling rates. Moreover, an asynchronous fusion method to predict and update mobile robot pose and map is also presented. In addition to this, FastSLAM 1.0 has been also improved by considering the estimated pose with the LS-approach to re-allocate each particle of the posterior distribution of the robot pose. This approach has a lower computational cost than the original Extended Kalman Filtering (EKF) approach in FastSLAM 2.0. All these methods have been combined in order to perform an efficient and robust self-localization and map building process. Additionally, these methods have been validated with experimental real data, in mobile robot moving on an unknown environment for solving the SLAM problem.This work has been supported by the Spanish Government (MCyT) research project BIA2005-09377-C03-02 and by the Italian Government (MIUR) research project PRIN2005097207.Armesto, L.; Ippoliti, G.; Longhi, S.; Tornero Montserrat, J. (2008). Probabilistic Self-Localization and Mapping: An Asynchronous Multirate Approach. IEEE Robotics & Automation Magazine. 15(2):77-88. https://doi.org/10.1109/M-RA.2007.907355S778815

Haptic Feedback to Assist Bus Drivers for Pedestrian Safety at Low Speed

Buses and coaches are massive Passenger Transportation Systems (PTS), because they represent more than half of land PTS in the European Union. Despite of that, bus accident figures are lower than other means of transport, but its size and weight increase the severity of accidents in which buses are involved, even at low speed. In urban scenarios, turnings and manoeuvres around bus stops are the main causes of accidents, mostly due to low visibility, blind spots or driver s distractions. Therefore, there is an increasing interest in developing driving assistance systems to avoid these situations, among others. However, even though there are some solutions on the market, they are not meant to work in urban areas at low speed and with the sole purpose of preventing collisions with pedestrians. In this sense, the paper proposes an active safety system for buses in manoeuvres at low speed. The safety system consists of haptic feedback devices together with collision avoidance and risk evaluation systems based on detected people nearby the bus. The performance of the active safety system has been validated in a simulated urban scenario. Our results show that driver s reaction time is reduced and time to collision increased due to the proposed low-speed active safety system. In particular, it is shown that there is a reduction in the number of high risk cases and collisions, which implies a considerable improvement in safety terms. In addition to this, a brief discussion about current regulations for innovative safety systems on a real vehicles is carried out.This paper has been funded by Ministerio de Ciencia e Innovacion (Spain) through the projects "Sistemas Avanzados de Seguridad Integral en Autobuses (SAFEBUS)" (IPT-2011-1165-370000) and "Sistemas de Conduccion Segura de Vehiculos de Transporte de Pasajeros y Materiales con Asistencia Haptica/Audiovisual e Interfaces Biomedicas (SAFETRANS)" (DPI2013-42302-R). This work was also supported by Programa VALi+d (Generalitat Valenciana). The authors wish to thank Jose Luis Sanchez Carrascosa for his dedication and commitment to the project and thank to Ana Isabel Sanchez Galdon for her valuable help regarding ANOVA analysis.Girbés, V.; Armesto Ángel, L.; Dols Ruiz, JF.; Tornero Montserrat, J. (2016). Haptic Feedback to Assist Bus Drivers for Pedestrian Safety at Low Speed. IEEE Transactions on Haptics. 9(3):345-357. https://doi.org/10.1109/TOH.2016.2531686S3453579

On the detection of defects on specular car body surfaces

[EN] The automatic detection of small defects (of up to 0.2 mm in diameter) on car body surfaces following the painting process is currently one of the greatest issues facing quality control in the automotive industry. Although several systems have been developed during the last decade to provide a solution to this problem, these, to the best of our knowledge, have been focused solely on flat surfaces and have been unable to inspect other parts of the surfaces, namely style lines, edges and corners as well as deep concavities. This paper introduces a novel approach using deflectometry- and vision-based technologies in order to overcome this problem and ensure that the whole area is inspected. Moreover, since our approach, together with the system used, computes defects in less than 15 s, it satisfies cycle time production requirements (usually of around 30 s per car). Hence, a two-step algorithm is presented here: in the first step, a new pre-processing step (image fusion algorithm) is introduced to enhance the contrast between pixels with a low level of intensity (indicating the presence of defects) and those with a high level of intensity (indicating the absence of defects); for the second step, we present a novel post-processing step with an image background extraction approach based on a local directional blurring method and a modified image contrast enhancement, which enables detection of defects in the entire illuminated area. In addition, the post-processing step is processed several times using a multi-level structure, with computed image backgrounds of different resolution. In doing so, it is possible to detect larger defects, given that each level identifies defects of different sizes. Experimental results presented in this paper are obtained from the industrial automatic quality control system QEyeTunnel employed in the production line at the Mercedes-Benz factory in Vitoria, Spain. A complete analysis of the algorithm performance will be shown here, together with several tests proving the robustness and reliability of our proposal.This work is supported by VALi+d (APOSTD/2016/044) and PROMETEO (PROMETEOII/2014/044) Programs, both from Conselleria d'Educacio, Generalitat Valenciana.Molina, J.; Solanes Galbis, JE.; Arnal-Benedicto, L.; Tornero Montserrat, J. (2017). On the detection of defects on specular car body surfaces. Robotics and Computer-Integrated Manufacturing. 48:263-278. https://doi.org/10.1016/j.rcim.2017.04.009S2632784

Detecting dings and dents on specular car body surfaces based on optical flow

[EN] This paper introduces a new approach to detect defects cataloged as dings and dents on car body surfaces, which is currently one of the most important issues facing quality control in the automotive industry. Using well-known optical flow algorithms and the deflectometry principle, the method proposed in this work is able to detect all kind of anomalies on specular surfaces. Hence, our method consists of two main steps: first, in the pre-processing step, light patterns projected on the body surface sweep uniformly the area of inspection, whilst a new image fusion law, based on optical flow, is used to obtain a resulting fused image holding the information of all variations suffered by the projected patterns during the sweeping process, indicating the presence of anomalies; second, a new post-processing step is proposed that avoids the need of using pre-computed reference backgrounds in order to differentiate defects from other body features such as style-lines. To that end, the image background of the resulting fused image is estimated in the first place through a method based on blurring the image according to the direction of each pixel. Afterwards, the estimated image background is used in a new subtraction law through which defects are well differentiated from other surface deformations, allowing the detection of defects in the entire illuminated area. In addition, since our approach, together with the system used, computes defects in less than 15 s, it satisfies the assembly plants time requirements. Experimental results presented in this paper are obtained from the industrial automatic quality control system QEyeTunnel employed in the production line at the Mercedes-Benz factory in Vitoria, Spain. A complete analysis of the algorithm performance will be shown here, together with several tests proving the robustness and reliability of our proposal.This work is supported by VALi+d (APOSTD/2016/044) and PROMETEO (PROMETEOII/2014/044) Programs, both from Conselleria d'Educacio, Generalitat Valenciana.Arnal-Benedicto, L.; Solanes Galbis, JE.; Molina, J.; Tornero Montserrat, J. (2017). Detecting dings and dents on specular car body surfaces based on optical flow. Journal of Manufacturing Systems. 45:306-321. https://doi.org/10.1016/j.jmsy.2017.07.006S3063214

An Active Safety System for Low-Speed Bus Braking Assistance

Accidents in which buses or coaches are involved cause thousands of injuries and fatalities every year. To reduce their number and severity, the paper describes an Advanced Driver Assistance Systems (ADAS) based on a haptic throttle pedal and emergency braking. It also proposes a computationally efficient algorithm with a methodology based on three main concepts: a simplified but accurate vehicle model; an efficient collision detection system considering driver's intention and pedestrians wandering around the vehicle; and a risk evaluation system to generate warnings and emergency braking signals. Finally, the performance of the proposed ADAS is validated using a driving simulation cabin with a very realistic urban scenario and original elements from real buses. The results show a statistically significant improvement in safety, as the number of collisions and high risk situations are clearly minimized, reaction time to press the brake pedal is improved and time to collision increased in emergency situations. Implementation of the proposed ADAS into city buses would potentially improve safety, reducing the frequency and severity of accidents with pedestrians.This work was supported in part by Ministry of Science and Innovation of Spain through the SAFEBUS Project "Sistemas Avanzados de Seguridad Integral en Autobuses" under Grant IPT-2011-1165-370000 and the SAFETRANS Project "Sistemas de Conduccion Segura de Vehiculos de Transporte de Pasajeros y Materiales con Asistencia Haptica/Audiovisual e Interfaces Biomedicas" under Grant DPI2013-42302-R and in part by the Generalitat Valenciana, Programa VALi+d (ACIF/2010/206). The Associate Editor for this paper was E. Kosmatopoulos.Girbés, V.; Armesto Ángel, L.; Dols Ruiz, JF.; Tornero Montserrat, J. (2017). An Active Safety System for Low-Speed Bus Braking Assistance. IEEE Transactions on Intelligent Transportation Systems. 18(2):377-387. https://doi.org/10.1109/TITS.2016.2573921S37738718

Virtual Reality-Based Interface for Advanced Assisted Mobile Robot Teleoperation

[EN] This work proposes a new interface for the teleoperation of mobile robots based on virtual reality that allows a natural and intuitive interaction and cooperation between the human and the robot, which is useful for many situations, such as inspection tasks, the mapping of complex environments, etc. Contrary to previous works, the proposed interface does not seek the realism of the virtual environment but provides all the minimum necessary elements that allow the user to carry out the teleoperation task in a more natural and intuitive way. The teleoperation is carried out in such a way that the human user and the mobile robot cooperate in a synergistic way to properly accomplish the task: the user guides the robot through the environment in order to benefit from the intelligence and adaptability of the human, whereas the robot is able to automatically avoid collisions with the objects in the environment in order to benefit from its fast response. The latter is carried out using the well-known potential field-based navigation method. The efficacy of the proposed method is demonstrated through experimentation with the Turtlebot3 Burger mobile robot in both simulation and real-world scenarios. In addition, usability and presence questionnaires were also conducted with users of different ages and backgrounds to demonstrate the benefits of the proposed approach. In particular, the results of these questionnaires show that the proposed virtual reality based interface is intuitive, ergonomic and easy to use.This research was funded by the Spanish Government (Grant PID2020-117421RB-C21 funded byMCIN/AEI/10.13039/501100011033) and by the Generalitat Valenciana (Grant GV/2021/181).Solanes, JE.; Muñoz García, A.; Gracia Calandin, LI.; Tornero Montserrat, J. (2022). Virtual Reality-Based Interface for Advanced Assisted Mobile Robot Teleoperation. Applied Sciences. 12(12):1-22. https://doi.org/10.3390/app12126071122121

CAM-Rob postprocessor based on a fuzzified redundancy resolution scheme

This work highlights the applicability of different redundancy resolution schemes to the postprocessing stage from a computer-aided manufacturing (CAM) system to an industrial redundant workcell. The inverse kinematic problem for redundant manipulators is not straightforward and, therefore, it is commonly solved using an iteratively approach based on redundant resolution schemes at the velocity level. In this work, two conceptions of redundancy resolution schemes are evaluated and a novel fuzzy inference system is developed to improve the performance during the toolpath tracking in order to avoid singularities and to maintain a preferred reference posture. For this purpose, the fuzzy inference engine properly adjusts the weight of each joint in the calculation of the performance criterion vectors. The proposed approach is validated in the real prototyping of a windmill blademold using a KUKA KR15/2manipulator mounted on a linear track and synchronized with a rotary table. To the authors knowledge, the proposed method and the results shown are novel in the context of postprocessing techniques from CAM systems to industrial robots devoted to milling works. With the same guidelines, the postprocessor programmed inside the CAM system is expected to be easily applicable not only to other industrial robots, but also for different applications such as welding or painting labors.This research is partially supported by the Technical University of Valencia (PAID-00-09-3092, PAID-05-11-2640), project PROMETEO 2009/063 of Generalitat Valenciana and research project DPI2009-14744-C03-01 of the Spanish Government.Andrés De La Esperanza, FJ.; Gracia Calandin, LI.; Tornero Montserrat, J. (2012). CAM-Rob postprocessor based on a fuzzified redundancy resolution scheme. International Journal of Advanced Manufacturing Technology. 62(5):705-718. https://doi.org/10.1007/s00170-011-3836-yS705718625Andres J, Gracia L, Tornero J (2011) Calibration and control of a redundant robotic workcell for milling tasks. Int J Comp Int Manuf 24(6):561–573Patel RV, Shadpey F (2005) Control of redundant robot manipulators: theory and experiments. Springer, New YorkHartenberg RS, Denavit J (1955) A kinematic notation for lower pair mechanisms based on matrices. Trans ASME J App Mech 77:215–221Andres J, Gracia L, Tornero J (2009) Inverse kinematics of a redundant manipulator for CAM integration. An industrial perspective of implementation, Proceedings of the 2009 IEEE International Conference on Mechatronics, MalagaWhitney DE (1969) Resolved motion rate control of manipulators and human prostheses. IEEE Trans Man-Machine Syst 10(2):47–53Whitney DE (1972) The mathematics of coordinated control of prosthetic arms and manipulator, ASME J. Dyn Sys Meas Cont 94(4):303–309Angeles J (2003) Fundamentals of robotic mechanical systems: theory, methods and algorithms. Springer, New YorkHuo L, Baron L (2008) The joint-limits and singularity avoidance in robotic welding. Industrial Robot 35(5):456–464Liégeois A (1977) Automatic supervisory control of the configuration and behavior of multibody mechanisms. IEEE Trans Syst Man Cybern SMC-7:245–250Gracia L, Andres J, Tornero J (2009) Trajectory tracking with a 6R serial industrial robot with ordinary and non-ordinary singularities. Int J Cont Auto Syst 7(1):85–96Angeles J, López-Cajún CS (1992) Kinematic isotropy and the conditioning index of serial robotic manipulators. Int J Robot Res 11(6):560–570Khan WA, Angeles J (2006) The kinetostatic optimization of robotic manipulators: the inverse and the direct problems. J Mech Des 128(1):168–178Siemens Corp (2009) NX Documentation. In: {$UGII_base_dir}\UGDOCMaza JI, Ollero A (2000) Herramienta MATLAB-Simulink para la simulación y el control de robots manipuladores y móviles, Actas de las XXI Jornadas de Automática, Sevilla, SpainRoger Jang JS, Gulley N (2008) Fuzzy logic toolbox: user’s guide; revised for version 2.2.7. The Math Works, Inc.Qdesign SRL (2007) CAD-CAM off line programming for industrial robots. ROBOmove on line help v. 2.0 [online]. Available from: http://www.qdrobotics.com/eng/robomove.php . Accessed 28 Nov 2011Andrés J, Gracia L, Marti H, Tornero J (2009) Toolpath postprocessing for three axes milling in redudant robotic workcells by means of fuzzy integration in a CAM platform, Proceedings of the IEEE International Conference on Mechatronics, Malaga, Spai

Hydrodynamic Force calculation over an axisymmetric auv with constant ocean currents at large range of angles of attack

[EN] Mobile robotics has allowed remote exploration of terrestrial, aerial and aquatic environments; environments that present conditions where human could not bear; e.g., extreme temperatures, extremely low or high-pressure and perform surveillance without being detected among others. The incorporation of robots in these activities reduces the risk to which a human would be exposed in these environments. In aquatic environments, specifically in ocean, there are currents that interfere in the development of missions such as data acquisition and structures overhaul, these streams affect robot activities making difficult to maintain a specific position to develop the mission accurately. The application of a control strategy that allows keeping the robot in a specific position requires of the Hydrodynamic Force generated by the marine currents. On the other hand, as the robot moves it is necessary to know the magnitude of the Hydrodynamic Force changes in the new positions. This work was performed on a symmetric Autonomous Underwater Vehicle (AUV) Hull in the X-Y and X-Z planes in a range of attack angles from 0o to 180º. In this article, a series of simulations was developed through Computer Fluid Dynamics (CFD). This method allowed to observe three zones in the graph of the hydrodynamic coefficient (CH) according to the angle of attack (0o ¿ ¿ ¿ 25º, 20o < ¿ ¿ 90º y 90o < ¿ ¿ 180º), for each of these zones a correlation was proposed empirical polynomial of third order to obtain the magnitude of the Hydrodynamic Force (fH). The simulations were performed for a Reynolds number of 1.8 x 106 , based on the diameter of the Hull. This methodology is proposed as a solution to evaluate in an agile and satisfactory way the Hydrodynamic Force for different orientations between the vehicle studied and the flow.Aguirre Gomez, FA.; Vargas, S.; Tornero Montserrat, J. (2018). Hydrodynamic Force calculation over an axisymmetric auv with constant ocean currents at large range of angles of attack. International Journal of Applied Engineering Research. 13(10):8511-8517. http://hdl.handle.net/10251/123456S85118517131

PWM and PFM for visual servoing in fully decoupled approaches

In this paper, novel visual servoing techniques based on Pulse Width Modulation (PWM) and Pulse Frequency Modulation (PFM) are presented. In order to apply previous pulse modulations, a fully decoupled position based visual servoing approach (i.e. with block-diagonal interaction matrix) is considered, controlling independently translational and rotational camera motions. These techniques, working at high frequency, could be considered to address the sensor latency problem inherent in visual servoing systems. The expected appearance of ripple due to the concentration of the control action in pulses is quantified and analyzed under simulated scenario. This high frequency ripple does not affect the system performance since it is filtered by the manipulator dynamics. On the contrary it can be seen as a dither signal to minimize the impact of friction and overcome back-lashing.This work was supported in part by the Spanish Government under Grant BES-2010-038486 and Project DPI2013-42302-R.Muñoz Benavent, P.; Solanes Galbis, JE.; Gracia Calandin, LI.; Tornero Montserrat, J. (2015). PWM and PFM for visual servoing in fully decoupled approaches. Robotics and Autonomous Systems. 65(1):57-64. doi:10.1016/j.robot.2014.11.011S576465

Robust auto tool change for industrial robots using visual servoing

This is an Author's Accepted Manuscript of an article published in Muñoz-Benavent, Pau, Solanes Galbis, Juan Ernesto, Gracia Calandin, Luis Ignacio, Tornero Montserrat, Josep. (2019). Robust auto tool change for industrial robots using visual servoing.International Journal of Systems Science, 50, 2, 432-449. © Taylor & Francis, available online at: http://doi.org/10.1080/00207721.2018.1562129[EN] This work presents an automated solution for tool changing in industrial robots using visual servoing and sliding mode control. The robustness of the proposed method is due to the control law of the visual servoing, which uses the information acquired by a vision system to close a feedback control loop. Furthermore, sliding mode control is simultaneously used in a prioritised level to satisfy the constraints typically present in a robot system: joint range limits, maximum joint speeds and allowed workspace. Thus, the global control accurately places the tool in the warehouse, but satisfying the robot constraints. The feasibility and effectiveness of the proposed approach is substantiated by simulation results for a complex 3D case study. Moreover, real experimentation with a 6R industrial manipulator is also presented to demonstrate the applicability of the method for tool changing.This work was supported in part by the Ministerio de Economia, Industria y Competitividad, Gobierno de Espana under Grant BES-2010-038486 and Project DPI2017-87656-C2-1-R.Muñoz-Benavent, P.; Solanes Galbis, JE.; Gracia Calandin, LI.; Tornero Montserrat, J. (2019). Robust auto tool change for industrial robots using visual servoing. International Journal of Systems Science. 50(2):432-449. https://doi.org/10.1080/00207721.2018.1562129S43244950