Journal articles: 'Moving obstacles'

1

Aivar, M. Pilar, Eli Brenner, and Jeroen B. J. Smeets. "Avoiding moving obstacles." Experimental Brain Research 190, no. 3 (July 16, 2008): 251–64. http://dx.doi.org/10.1007/s00221-008-1475-9.

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Graffstein, Jerzy. "The Avoiding Manoeuvre Against Aggregated Group of Obstacles Moving Around the Airplane." Pomiary Automatyka Robotyka 25, no. 1 (March 31, 2021): 5–12. http://dx.doi.org/10.14313/par_239/5.

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Successful avoidance of a mid air collision with moving obstacles depends on solutions of some most essential problems, e.g.: quick detection of an obstacle, verification whether detected obstacle is a critical one and making right decision on evasive manoeuvre. This decision – making process requires an appropriate identification of a threat’s nature, including whether detected obstacles should be treated as one aggregated group. Aggregation of obstacles moving in short distance one to the other is a typical case. The paper addresses also the case of inclusion the obstacle to the group objects moving in longer distances one to the other. The algorithm used for deciding whether a moving obstacle should be added to (aggregated with) a given group has been presented. A method for computing its characteristic parameters has been presented too. Selected scenarios of avoiding the aggregated group of moving obstacles have been simulated and results obtained illustrates problems considered.

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Burnett, Nicholas P., Marc A. Badger, and Stacey A. Combes. "Wind and obstacle motion affect honeybee flight strategies in cluttered environments." Journal of Experimental Biology 223, no. 14 (June 19, 2020): jeb222471. http://dx.doi.org/10.1242/jeb.222471.

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ABSTRACTBees often forage in habitats with cluttered vegetation and unpredictable winds. Navigating obstacles in wind presents a challenge that may be exacerbated by wind-induced motions of vegetation. Although wind-blown vegetation is common in natural habitats, we know little about how the strategies of bees for flying through clutter are affected by obstacle motion and wind. We filmed honeybees Apis mellifera flying through obstacles in a flight tunnel with still air, headwinds or tailwinds. We tested how their ground speeds and centering behavior (trajectory relative to the midline between obstacles) changed when obstacles were moving versus stationary, and how their approach strategies affected flight outcome (successful transit versus collision). We found that obstacle motion affects ground speed: bees flew slower when approaching moving versus stationary obstacles in still air but tended to fly faster when approaching moving obstacles in headwinds or tailwinds. Bees in still air reduced their chances of colliding with obstacles (whether moving or stationary) by reducing ground speed, whereas flight outcomes in wind were not associated with ground speed, but rather with improvement in centering behavior during the approach. We hypothesize that in challenging flight situations (e.g. navigating moving obstacles in wind), bees may speed up to reduce the number of wing collisions that occur if they pass too close to an obstacle. Our results show that wind and obstacle motion can interact to affect flight strategies in unexpected ways, suggesting that wind-blown vegetation may have important effects on foraging behaviors and flight performance of bees in natural habitats.

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Lakshmi, Dr K. Prasanna. "Motion Planning of Moving Robots Amongst Static Obstacles." International Journal of Scientific Research 2, no. 5 (June 1, 2012): 167–70. http://dx.doi.org/10.15373/22778179/may2013/57.

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Kownacki, Cezary, and Leszek Ambroziak. "A New Multidimensional Repulsive Potential Field to Avoid Obstacles by Nonholonomic UAVs in Dynamic Environments." Sensors 21, no. 22 (November 11, 2021): 7495. http://dx.doi.org/10.3390/s21227495.

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The ability of autonomous flight with obstacle avoidance should be a fundamental feature of all modern unmanned aerial vehicles (UAVs). The complexity and difficulty of such a task, however, significantly increase in cases combining moving obstacles and nonholonomic UAVs. Additionally, since they assume the symmetrical distribution of repulsive forces around obstacles, traditional repulsive potential fields are not well suited for nonholonomic vehicles. The limited maneuverability of these types of UAVs, including fixed-wing aircraft, requires consideration not only of their relative position, but also their speed as well as the direction in which the obstacles are moving. To address this issue, the following work presents a novel multidimensional repulsive potential field dedicated to nonholonomic UAVs. This field generates forces that repulse the UAV not from the obstacle’s geometrical center, but from areas immediately behind and in front of it located along a line defined by the obstacle’s velocity vector. The strength of the repulsive force depends on the UAV’s distance to the line representing the obstacle’s movement direction, distance to the obstacle along that line, and the relative speed between the UAV and the obstacle projected to the line, making the proposed repulsive potential field multidimensional. Numerical simulations presented within the paper prove the effectiveness of the proposed novel repulsive potential field in controlling the flight of nonholonomic UAVs.

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Fujimori, A. "Navigation of mobile robots with collision avoidance for moving obstacles." Proceedings of the Institution of Mechanical Engineers, Part I: Journal of Systems and Control Engineering 219, no. 1 (February 1, 2005): 99–110. http://dx.doi.org/10.1243/095440705x9416.

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This paper presents a collision avoidance technique of mobile robots for moving obstacles in unknown environments. The mobile robot considered in this paper has a sensor measuring the distance between the robot and a moving obstacle, such as an ultrasonic sonar or infrared sensor. Avoidance behaviour for moving obstacles is proposed. The collision avoidance conditions for two typical aspects under which the robot encounters a moving obstacle are derived and are used as guidelines for designing the navigation parameters. The effectiveness of the proposed technique is demonstrated by numerical simulation examples.

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Hoshino, Satoshi, and Tomoki Yoshikawa. "Motion Planning of Mobile Robots for Occluded Obstacles." Journal of Robotics and Mechatronics 30, no. 3 (June 20, 2018): 485–92. http://dx.doi.org/10.20965/jrm.2018.p0485.

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Motion planning of mobile robots for occluded obstacles is a challenge in dynamic environments. The occlusion problem states that if an obstacle suddenly appears from the occluded area, the robot might collide with the obstacle. To overcome this, we propose a novel motion planner, the Velocity Obstacle for occlusion (VOO). The VOO is based on a previous motion planner, the Velocity Obstacle (VO), which is effective for moving obstacles. In the proposed motion planner, information uncertainties about occluded obstacles, such as position, velocity, and moving direction, are quantitatively addressed. Thus, the robot based on the VOO is able to move not only among observed obstacles, but also among the occluded ones. Through simulation experiments, the effectiveness of the VOO for the occlusion problem is demonstrated by comparison with the VO.

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Beghin, Luisa, and Enzo Orsingher. "Moving randomly amid scattered obstacles." Stochastics 82, no. 2 (April 2010): 201–29. http://dx.doi.org/10.1080/17442500903359163.

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Vaĭnberg, B. R. "SCATTERING BY PERIODICALLY MOVING OBSTACLES." Mathematics of the USSR-Sbornik 73, no. 1 (February 28, 1992): 289–304. http://dx.doi.org/10.1070/sm1992v073n01abeh002546.

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10

Williams, Robert L., and Jianhua Wu. "Dynamic Obstacle Avoidance for an Omnidirectional Mobile Robot." Journal of Robotics 2010 (2010): 1–14. http://dx.doi.org/10.1155/2010/901365.

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We have established a novel method of obstacle-avoidance motion planning for mobile robots in dynamic environments, wherein the obstacles are moving with general velocities and accelerations, and their motion profiles are not preknown. A hybrid system is presented in which a global deliberate approach is applied to determine the motion in the desired path line (DPL), and a local reactive approach is used for moving obstacle avoidance. A machine vision system is required to sense obstacle motion. Through theoretical analysis, simulation, and experimental validation applied to the Ohio University RoboCup robot, we show the method is effective to avoid collisions with moving obstacles in a dynamic environment.

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Jin, Ying Lian, and Bin Rui Wang. "Virtual Force Field Integrated with Human Avoiding Obstacles Strategies for Robot." Applied Mechanics and Materials 16-19 (October 2009): 1071–76. http://dx.doi.org/10.4028/www.scientific.net/amm.16-19.1071.

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Humanoid strategies of avoiding obstacles were analyzed and formulated into virtual force field (VFF) algorithm. In view of obstacles moving, smoothing accumulation computing method was designed for updating credibility factors (CF) of grid held by obstacle, and two examples were given. Uncertainty reasoning was adopted for computing complex CF with uncertainty of sensors signal, and synthesize method was designed. The weight of repulsive force was designed to be varying with angle from robot moving direction to obstacles, in order to make robot more sensitivity to obstacles on moving way. Indoor and outdoor virtual environment were established and simulations were carried out. The results demonstrate that the path is better using proposed than common VFF.

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Huai, Chuang Feng, and Xue Yan Jia. "Path Planning for Mobile Robot Based on Autoregressive Model." Applied Mechanics and Materials 431 (October 2013): 269–74. http://dx.doi.org/10.4028/www.scientific.net/amm.431.269.

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Proposed an uncertain environment path planning method for mobile robot in the presence of moving obstacles. Combining the global planning with the local planning, this dissertation presents a new approach to on-line real-time path planning with respect to the dynamic uncertain environment. With current sampling position, the autoregressive model predicts motion trajectories of moving obstacles. And the predicted positions are treated as instantaneously static. So moving obstacles in the predicted positions can be considered as static in the path planning process. Simulation examples demonstrated the effectiveness, feasibility, real-time capability, high stability and perfect performance of obstacle avoidance.

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13

He, Zhenqi, and Lu Yao. "Research on an Obstacle Avoidance Method for UAV." Mathematical Problems in Engineering 2021 (September 10, 2021): 1–9. http://dx.doi.org/10.1155/2021/3798990.

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With the continuous development of UAV technology, UAV has been widely used in various industries. In the flight process of UAV, UAV often changes the given path because of obstacles (including static nonliving body and moving living body). According to the properties of obstacles and the characteristics of UAV, standard Kalman filter is used for nonmaneuvering targets, and sigma point Kalman filter is used for maneuvering targets. In the aspect of obstacle avoidance, the minimum search method is used to get the initial population of local programming. Then, the improved genetic algorithm is run. Combined with the predicted obstacle features, the local planning path can be obtained. Finally, the local planning path and global planning path are combined to generate the planning path with new obstacles. At the end of the paper, the obstacle avoidance strategies of static and moving obstacles are simulated. The simulation results show that this method has fast convergence speed and good feasibility and can flexibly deal with the obstacle avoidance and local path planning of various new obstacles.

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Yin, Zhang-Cai, Hui Liu, Zhi-Jun Zhang, Zhang-Hao-Nan Jin, San-Juan Li, and Jia-Qiang Xiao. "Probabilistic Model of Random Encounter in Obstacle Space." ISPRS International Journal of Geo-Information 8, no. 1 (January 15, 2019): 32. http://dx.doi.org/10.3390/ijgi8010032.

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Based on probabilistic time-geography, the encounter between two moving objects is random. The quantitative analysis of the probability of encounter needs to consider the actual geographical environment. The existing encounter probability algorithm is based on homogeneous space, ignoring the wide range of obstacles and their impact on encounter events. Based on this, this paper introduces obstacle factors, proposes encounter events that are constrained by obstacles, and constructs a model of the probability of encounters of moving objects based on the influence of obstacles on visual perception with the line-of-sight view analysis principle. In realistic obstacle space, this method provides a quantitative basis for predicting the encountering possibility of two mobile objects and the largest possible encounter location. Finally, the validity of the model is verified by experimental results. The model uses part of the Wuhan digital elevation model (DEM) data to calculate the encounter probability of two moving objects on it, and analyzes the temporal and spatial distribution characteristics of these probabilities.

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Lu, Li, and Chenyu Liu. "Research on Trajectory Planning in Thunderstorm Weather Based on Dynamic Window Algorithm during Approach Segment." Scientific Programming 2022 (January 10, 2022): 1–10. http://dx.doi.org/10.1155/2022/7031928.

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Dynamic window algorithm (DWA) is a local path-planning algorithm, which can be used for obstacle avoidance through speed selection and obtain the optimal path, but the algorithm mainly plans the path for fixed obstacles. Based on DWA algorithm, this paper proposes an improved DWA algorithm based on space-time correlation, namely, space-time dynamic window approach. In SDWA algorithm, a DWA associated with obstacle position and time is proposed to achieve the purpose of path planning for moving obstacles. Then, by setting the coordinates of the initial moving obstacle and identifying safety distance, we can define the shape of the obstacle and the path planning of the approach segment in thunderstorm weather based on the SDWA model was realized. Finally, the superior performance of the model was verified by setting moving obstacles for path planning and selecting the aircraft approach segment in actual thunderstorm weather. The results showed that SDWA has good path-planning performance in a dynamic environment. Its path-planning results were very similar to an actual aircraft performing thunderstorm-avoidance maneuvers, but with more smooth and economical trajectory. The proposed SDWA model had great decision-making potential for approach segment planning in thunderstorm weather.

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16

FERRARI, FABRICIO. "A NEW PARAMETERIZED POTENTIAL FAMILY FOR PATH PLANNING ALGORITHMS." International Journal on Artificial Intelligence Tools 18, no. 06 (December 2009): 949–57. http://dx.doi.org/10.1142/s0218213009000470.

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In this work, it is proposed a new family of potentials for path planning algorithms, one kind to the goal and other to the obstacles. With these new potentials it is possible to parameterize the potential scale length and strength easily, providing better control over the moving object path characteristics. In this way, the path problem can be treated analytically. For example, the minimum distance between the moving object and the obstacles can be calculated as a function of the potential parameters. Simulations are made to test its ability to guide a vehicle through an obstacle-free path towards the goal. The success rate of the moving object on reaching the goal is compared with the potential parameters and with obstacle configuration and distribution parameters.

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17

de Lamadrid, J. G., and M. Gini. "Path tracking through uncharted moving obstacles." IEEE Transactions on Systems, Man, and Cybernetics 20, no. 6 (1990): 1408–22. http://dx.doi.org/10.1109/21.61210.

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Chai, Yi, and Vahid Hassani. "Hybrid Collision Avoidance with Moving Obstacles." IFAC-PapersOnLine 52, no. 21 (2019): 302–7. http://dx.doi.org/10.1016/j.ifacol.2019.12.324.

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19

Stefanov, Plamen D. "Inverse scattering problem for moving obstacles." Mathematische Zeitschrift 207, no. 1 (May 1991): 461–80. http://dx.doi.org/10.1007/bf02571402.

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20

Engel, A., and W. Ebeling. "Interaction of moving interfaces with obstacles." Physics Letters A 122, no. 1 (May 1987): 20–24. http://dx.doi.org/10.1016/0375-9601(87)90768-7.

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21

Finaev, V. I., M. Yu Medvedev, V. Kh Pshikhopov, V. A. Pereverzev, and V. V. Soloviev. "Unmanned Powerboat Motion Terminal Control in an Environment with Moving Obstacles." Mekhatronika, Avtomatizatsiya, Upravlenie 22, no. 3 (March 2, 2021): 145–54. http://dx.doi.org/10.17587/mau.22.145-154.

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The major point for consideration throughout this paper is controlling the motion of an unmanned powerboat in an obstructed environment with stationary and moving objects. It offers a procedure for the terminal control law development based on the powerboat programmed motion trajectory in a polynomial form and proposes position-trajectory-based control algorithms. A hybrid method based on virtual fields and unstable driving modes, taking into account powerboat speeds and obstacles, is used to plan motion trajectories for obstacle avoidance. There were experiments carried out to test the developed methods and algorithms meanwhile estimating the energy consumption for control, the length of the trajectory and the safety indicator for obstacle avoidance. The novelty of the proposed approach lies in the method used to develop a local movement trajectory in the field with obstacles and in the hybridization of trajectory scheduling methods. This approach allows us to achieve a given safe distance when avoiding obstacles and virtually eliminate the chances of an emergency collision. The presented results can be used in systems of boats autonomous motion control and allow safe stationary and dynamic obstacles avoidance.

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Haug, E. J., F. A. Adkins, and D. Coroian. "Domains of Mobility for a Planar Body Moving Among Obstacles." Journal of Mechanical Design 120, no. 3 (September 1, 1998): 462–67. http://dx.doi.org/10.1115/1.2829174.

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A formulation is presented for defining domains of mobility for a planar convex body moving with three degrees-of-freedom among convex planar obstacles. Applications included are determination of areas of a factory floor or material storage facility in which objects can he manipulated without impacting fixed obstacles. Mobility of the moving body is defined to encompass (1) dexterous mobility of the body; i.e., points that can be reached by a reference point on the body and at which the body can be rotated through a specified range of admissible orientations without penetrating any stationary obstacle, and (2) limited mobility of the body; i.e., points that can be reached by the reference point and at which the body does not penetrate any stationary obstacle, for some admissible orientation. Analytical criteria for points on boundaries of domains of mobility are derived and numerical methods suitable for mapping these boundaries are summarized. An elementary example involving a moving and a stationary ellipse, with and without orientation restrictions, is solved analytically to illustrate the method. A more general application with one moving body and three stationary obstacles is solved numerically.

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Azizi, Aydin, Farshid Entesari, Kambiz Ghaemi Osgouie, and Mostafa Cheragh. "Intelligent Mobile Robot Navigation in an Uncertain Dynamic Environment." Applied Mechanics and Materials 367 (August 2013): 388–92. http://dx.doi.org/10.4028/www.scientific.net/amm.367.388.

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This paper presents a modified sensor-based online method for mobile robot navigation generating paths in dynamic environments. The core of the navigation algorithm is based on the velocity obstacle avoidance method and the guidance-based tracking algorithm. A fuzzy decision maker is designed to combine the two mentioned algorithms intelligently. Hence the robot will be able to decide intelligently in various situations when facing the moving obstacles and moving target. A noble noise cancellation algorithm using Neural Network is designed to navigate the robot in an uncertain dynamic environment safely. The results show that the robot can track a moving target while maneuvering safely in dynamic environment and avoids stationary and moving obstacles.

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Grimshaw, Roger H. J., and Montri Maleewong. "Transcritical flow over two obstacles: forced Korteweg–de Vries framework." Journal of Fluid Mechanics 809 (November 21, 2016): 918–40. http://dx.doi.org/10.1017/jfm.2016.722.

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We consider free-surface flow over two localised obstacles using the framework of the forced Korteweg–de Vries equation in a suite of numerical simulations. Our main concern is with the transcritical regime when the oncoming flow has a Froude number close to unity. The flow behaviour can be characterised by the Froude number and the maximum heights of the obstacles. In the transcritical regime at early times, undular bores are produced upstream and downstream of each obstacle. Our main aim is to describe the interaction of these undular bores between the obstacles, and to find the outcome at very large times. We find that the flow development can be defined in three stages. The first stage is described by the well-known development of undular bores upstream and downstream of each obstacle. The second stage is the interaction between the undular bore moving downstream from the first obstacle and the undular bore moving upstream from the second obstacle. The third stage is the very large time evolution of this interaction, when one of the obstacles controls criticality. For equal obstacle heights, our analytical and numerical results indicate that either one of the obstacles can control flow criticality, that being the first obstacle when the flow is slightly subcritical and the second obstacle otherwise. For unequal obstacle heights the larger obstacle controls criticality. The results obtained here complement a recent numerical study using the fully nonlinear, but non-dispersive, shallow water equations.

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Wu, Chia-Pin, Tsu-Tian Lee, and Chau-Ren Tsai. "Obstacle avoidance motion planning for mobile robots in a dynamic environment with moving obstacles." Robotica 15, no. 5 (September 1997): 493–510. http://dx.doi.org/10.1017/s0263574797000593.

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A new real-time obstacle avoidance method for mobile robots has been developed. This method, namely the vector-distance function method, permits the detection of obstacles (both moving and stationary) and generates a path that can avoid collisions. The proposed approach expresses the distance information in a vector form. Then the notion of weighting is introduced to describe relationship between sensors of mobile robots and the target to be reached. Furthermore, R-mode, L-mode and T-mode are introduced to generate a safe path for the mobile robot in a dynamic environment filled with both stationary and moving obstacles. The algorithm can deal with a complicated obstacle environment, such as multiple concave and convex obstacles. Simulation results are included to demonstrate the applicability and effectiveness of the developed algorithm.

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Soltan, Reza A., Hashem Ashrafiuon, and Kenneth R. Muske. "ODE-based obstacle avoidance and trajectory planning for unmanned surface vessels." Robotica 29, no. 5 (October 4, 2010): 691–703. http://dx.doi.org/10.1017/s0263574710000585.

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SUMMARYA new method for real-time obstacle avoidance and trajectory planning of underactuated unmanned surface vessels is presented. In this method, ordinary differential equations (ODEs) are used to define transitional trajectories that can avoid obstacles and reach a final desired target trajectory using a robust tracking control law. The obstacles are approximated and enclosed by elliptical shapes. A transitional trajectory is then defined by a set of ordinary differential equations whose solution is a stable elliptical limit cycle defining the nearest obstacle on the vessel's path to the target. When no obstacle blocks the vessel's path to its target, the transitional trajectory is defined by exponentially stable ODE whose solution is the target trajectory. The planned trajectories are tracked by the vessel through a sliding mode control law that is robust to environmental disturbances and modeling uncertainties and can be computed in real time. The method is illustrated using a complex simulation example with a moving target and multiple moving and rotating obstacles and a simpler experimental example with stationary obstacles.

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Zhou, Fei, Jianjun Gao, Xinyue Fan, and Kangning An. "Covering Algorithm for Different Obstacles and Moving Obstacle in Wireless Sensor Networks." IEEE Internet of Things Journal 5, no. 5 (October 2018): 3305–15. http://dx.doi.org/10.1109/jiot.2018.2816596.

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Owens, J., and W. Warren. "Avoiding moving obstacles on foot: Can people learn to anticipate obstacle motion?" Journal of Vision 7, no. 9 (March 23, 2010): 757. http://dx.doi.org/10.1167/7.9.757.

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Maltugueva, Nadezhda, and Nikolay Pogodaev. "Modeling of crowds in regions with moving obstacles." Discrete & Continuous Dynamical Systems 41, no. 11 (2021): 5009. http://dx.doi.org/10.3934/dcds.2021066.

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<p style='text-indent:20px;'>We present a model of crowd motion in regions with moving obstacles, which is based on the notion of measure sweeping process. The obstacle is modeled by a set-valued map, whose values are complements to <inline-formula><tex-math id="M1">\begin{document}$ r $\end{document}</tex-math></inline-formula>-prox-regular sets. The crowd motion obeys a nonlinear transport equation outside the obstacle and a normal cone condition (similar to that of the classical sweeping processes theory) on the boundary. We prove the well-posedness of the model, give an application to environment optimization problems, and provide some results of numerical computations.</p>

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Xin, Zhou, Xu Rongwu, and Cheng guo. "AUV Path Planning in Dynamic Environment Based on Improved Artificial Potential Field Method Based on Visibility Graph." Journal of Physics: Conference Series 2383, no. 1 (December 1, 2022): 012090. http://dx.doi.org/10.1088/1742-6596/2383/1/012090.

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In order to solve the forced shaking problem of the Autonomous Underwater Vehicle (AUV) facing dynamic obstacles in the path planning when the Artificial Potential Field Method is used, a method of removing the shaking state based on a favorable path is proposed, and on this basis, Visibility Graph Method is used to optimize the path of the AUV to avoid dynamic obstacles. By judging the relative motion direction of AUV and dynamic obstacle, the moving direction of AUV is adjusted based on Visibility Graph Method when it is far away from the obstacle. When it is close to the obstacle, the direction conducive to approaching the target point is selected as the favorable forward direction to bypass the obstacle. The simulation results show that the dynamic obstacle avoidance path optimization method based on the Visibility Graph Method reduces the number of moving steps by about 19% compared with the traditional method when dealing with a single dynamic obstacle, and can be applied in complex environments with multiple dynamic obstacles.

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Cohen, J. A., H. Bruggeman, and W. H. Warren. "Combining moving targets and moving obstacles in a locomotion model." Journal of Vision 6, no. 6 (March 18, 2010): 135. http://dx.doi.org/10.1167/6.6.135.

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Qiu, Zhengjun, Nan Zhao, Lei Zhou, Mengcen Wang, Liangliang Yang, Hui Fang, Yong He, and Yufei Liu. "Vision-Based Moving Obstacle Detection and Tracking in Paddy Field Using Improved Yolov3 and Deep SORT." Sensors 20, no. 15 (July 22, 2020): 4082. http://dx.doi.org/10.3390/s20154082.

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Using intelligent agricultural machines in paddy fields has received great attention. An obstacle avoidance system is required with the development of agricultural machines. In order to make the machines more intelligent, detecting and tracking obstacles, especially the moving obstacles in paddy fields, is the basis of obstacle avoidance. To achieve this goal, a red, green and blue (RGB) camera and a computer were used to build a machine vision system, mounted on a transplanter. A method that combined the improved You Only Look Once version 3 (Yolov3) and deep Simple Online and Realtime Tracking (deep SORT) was used to detect and track typical moving obstacles, and figure out the center point positions of the obstacles in paddy fields. The improved Yolov3 has 23 residual blocks and upsamples only once, and has new loss calculation functions. Results showed that the improved Yolov3 obtained mean intersection over union (mIoU) score of 0.779 and was 27.3% faster in processing speed than standard Yolov3 on a self-created test dataset of moving obstacles (human and water buffalo) in paddy fields. An acceptable performance for detecting and tracking could be obtained in a real paddy field test with an average processing speed of 5–7 frames per second (FPS), which satisfies actual work demands. In future research, the proposed system could support the intelligent agriculture machines more flexible in autonomous navigation.

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Vorochaeva (Volkova), L. Y., S. I. Savin, and A. V. Malchikov. "An Approach to Moving over Obstacles for a Wheeled Jumping Robot." Nelineinaya Dinamika 16, no. 1 (2020): 105–14. http://dx.doi.org/10.20537/nd200109.

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Ni, Yong, Li Li, Jiahui Qiu, Yi Sun, Guodong Qin, Qingfei Han, and Aihong Ji. "A Novel Wheel-Legged Hexapod Robot." Biomimetics 7, no. 4 (September 29, 2022): 146. http://dx.doi.org/10.3390/biomimetics7040146.

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Traditional mobile robots are mainly divided into wheeled robots and legged robots. They have good performance at fast-moving speeds and crossing obstacles, and weak terrain adaptability and moving speeds, respectively. Combining the advantages of these two types mentioned, a multi-functional wheel-legged hexapod robot with strong climbing capacity was designed in this paper. Each wheel-leg of the robot is driven directly by a single motor and can move smoothly and quickly in a diagonal tripod gait. Based on the obstacle-crossing way of the wheel-leg and combined with the characteristics of insects moving stably in nature, the middle part of the robot body is wider than head and tail. Tripod gait was selected to control the robot locomotion. A series of simulations and experiments were conducted to validate its excellent adaptability to various environmental conditions. The robot can traverse rugged, broken, and obstacle-ridden ground and cross rugged surfaces full of obstacles without any terrain sensing or actively controlled adaptation. It can negotiate obstacles of approximately its own height, which is much higher than its centre of gravity range.

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Dowlatabadi, Masrour, Ahmad Afshar, and Ali Moarefianpour. "Fusión, clasificación y tracción simultáneas de obstáculos en movimiento mediante LIDAR y cámara usando algoritmo bayesiano." Innovaciencia Facultad de Ciencias Exactas Físicas y Naturales 8, no. 1 (December 1, 2020): 1–10. http://dx.doi.org/10.15649/2346075x.997.

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In the near future, preventing collisions with fixed or moving, alive, and inanimate obstacles will appear to be a severe challenge due to the increased use of Unmanned Ground Vehicles (UGVs). Light Detection and Ranging (LIDAR) sensors and cameras are usually used in UGV to detect obstacles. The definite tracing and classification of moving obstacles is a significant dimension in developed driver assistance systems. It is believed that the perceived model of the situation can be improved by incorporating the obstacle classification. The present study indicated a multi-hypotheses monitoring and classifying approach, which allows solving ambiguities rising with the last methods of associating and classifying targets and tracks in a highly volatile vehicular situation. This method was tested through real data from various driving scenarios and focusing on two obstacles of interest vehicle, pedestrian.

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Choi, Su Il, and Byung Kook Kim. "Obstacle avoidance control for redundant manipulators using collidability measure." Robotica 18, no. 2 (March 2000): 143–51. http://dx.doi.org/10.1017/s0263574799001861.

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We present an efficient obstacle avoidance control algorithm for redundant manipulators using a new measure called collidability measure. Considering moving directions of manipulator links, the collidability measure is defined as the sum of inverse of predicted collision distances between links and obstacles: This measure is suitable for obstacle avoidance since directions of moving links are as important as distances to obstacles. For kinematic or dynamic redundancy resolution, null space control is utilized to avoid obstacles by minimizing the collidability measure: We present a velocity-bounded kinematic control law which allows reasonably large gains to improve the system performance. Also, by clarifying decomposition in the joint acceleration level, we present a simple dynamic control law with bounded joint torques which guarantees tracking of a given end-effector trajectory and improves a kinematic cost function such as collidability measure. Simulation results are presented to illustrate the effectiveness of the proposed algorithm.

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Chen, S. F., J. H. Oliver, and D. Fernandez-Baca. "A Fast Algorithm for Planning Collision-Free Paths With Rotations." Journal of Mechanical Design 120, no. 1 (March 1, 1998): 52–57. http://dx.doi.org/10.1115/1.2826676.

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Motion planning is a major problem in robotics. The objective is to plan a collision-free path for a robot moving through a workspace populated with obstacles. In this paper, we present a fast and practical algorithm for moving a convex polygonal robot among a set of polygonal obstacles with translations and rotations. The running time is O(c((n + k)N + n log n)), where c is a parameter controlling the precision of the results, n is the total number of obstacle vertices, k is the number of intersections of configuration space obstacles, and N is the number of obstacles, decomposed into convex objects. This work builds upon the slabbing method proposed by Ahrikencheikh et al. [2], which finds an optimal motion for a point among a set of nonoverlapping obstacles. Here, we extend the slabbing method to the motion planning of a convex polygonal robot with translations and rotations, which also allows overlapping configuration space obstacles. This algorithm has been fully implemented and the experimental results show that it is more robust and faster than other approaches.

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Bernstein, Adam. "Moving on." Journal of Aesthetic Nursing 11, no. 9 (November 2, 2022): 421–23. http://dx.doi.org/10.12968/joan.2022.11.9.421.

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Moving premises can be expensive and fraught at the best of times. Adam Bernstein, in collaboration with Jessica Booz and Nathan Hinks, explores the options when contractual issues place obstacles in the way of a relocation

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Coolen, Bert, Peter J. Beek, Daphne J. Geerse, and Melvyn Roerdink. "Avoiding 3D Obstacles in Mixed Reality: Does It Differ from Negotiating Real Obstacles?" Sensors 20, no. 4 (February 17, 2020): 1095. http://dx.doi.org/10.3390/s20041095.

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Mixed-reality technologies are evolving rapidly, allowing for gradually more realistic interaction with digital content while moving freely in real-world environments. In this study, we examined the suitability of the Microsoft HoloLens mixed-reality headset for creating locomotor interactions in real-world environments enriched with 3D holographic obstacles. In Experiment 1, we compared the obstacle-avoidance maneuvers of 12 participants stepping over either real or holographic obstacles of different heights and depths. Participants’ avoidance maneuvers were recorded with three spatially and temporally integrated Kinect v2 sensors. Similar to real obstacles, holographic obstacles elicited obstacle-avoidance maneuvers that scaled with obstacle dimensions. However, with holographic obstacles, some participants showed dissimilar trail or lead foot obstacle-avoidance maneuvers compared to real obstacles: they either consistently failed to raise their trail foot or crossed the obstacle with extreme lead-foot margins. In Experiment 2, we examined the efficacy of mixed-reality video feedback in altering such dissimilar avoidance maneuvers. Participants quickly adjusted their trail-foot crossing height and gradually lowered extreme lead-foot crossing heights in the course of mixed-reality video feedback trials, and these improvements were largely retained in subsequent trials without feedback. Participant-specific differences in real and holographic obstacle avoidance notwithstanding, the present results suggest that 3D holographic obstacles supplemented with mixed-reality video feedback may be used for studying and perhaps also training 3D obstacle avoidance.

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Lee, Chao Yang, Fu Tian Lin, and Chu Sing Yang. "Mobile Sensor Navigation in Wireless Hybrid Sensor Networks." Advanced Materials Research 694-697 (May 2013): 1013–16. http://dx.doi.org/10.4028/www.scientific.net/amr.694-697.1013.

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With recent advances in mobile platforms, hybrid sensor networks are becoming very popular technology. Mobile sensors can dynamically move to monitor uncovered areas and thus improve the coverage quality. Due to the obstacles may exist in the monitor fields, mobile sensors need to find an obstacle-free moving path for mobile sensor movement. However, in practical, sensors are difficult to obtain the geographic information of obstacles. Additionally, sensors have resource constraints. Hence, this work proposed an obstacle-free and geographic-free dispatch scheme (OGDS) for mobile sensor navigation with low computational complexity. The moving path for mobile sensor dispatch has obtained by using the Dynamic Source Routing protocol (DSR) protocol. Experimental results reveal that the proposed scheme can be efficiently executed.

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Gonzalez-de-Soto, Mariano, Rocio Mora, José Antonio Martín-Jiménez, and Diego Gonzalez-Aguilera. "A New Roadway Eventual Obstacle Detection System Based on Computer Vision." Sensors 20, no. 18 (September 8, 2020): 5109. http://dx.doi.org/10.3390/s20185109.

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A new roadway eventual obstacle detection system based on computer vision is described and evaluated. This system uses low-cost hardware and open-source software to detect and classify moving elements in roads using infra-red and colour video images as input data. This solution represents an important advancement to prevent road accidents due to eventual obstacles which have considerably increased in the past decades, mainly with wildlife. The experimental evaluation of the system demonstrated that the proposed solution detects and classifies correctly different types of moving obstacles on roads, working robustly under different weather and illumination conditions.

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Tsubouchi, Takashi, Tomohide Naniwa, and Suguru Arimoto. "Planning and Navigation by a Mobile Robot in the Presence of Multiple Moving Obstacles and Their Velocities." Journal of Robotics and Mechatronics 8, no. 1 (February 20, 1996): 58–66. http://dx.doi.org/10.20965/jrm.1996.p0058.

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This paper presents a navigation scheme for a mobile robot which works even in an environment with multiple moving obstacles. An “iterated forecast and planning” approach is proposed by the authors. It is assumed that each obstacle moves at a constant velocity in the approach. The most feasible path for a robot is planned in (x,y,t) space. The planning and motion execution according to the plan are iterated frequently to cope with changes of motion of the moving obstacles. The behavior of the proposed navigation algorithm is also presented by means of computer simulations.

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Shuaib, Mohammed, and Zarita Zainuddin. "Incorporating Intelligence for Overtaking Moving Threatening Obstacles." International Arab Journal of Information Technology 17, no. 4A (July 30, 2020): 598–606. http://dx.doi.org/10.34028/iajit/17/4a/3.

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Crowd management and fire safety studies indicate that the correct prediction of the threat caused by fire is crucial behavior which could lead to survival. Incorporating intelligence into exit choice models for accomplishing evacuation simulations involving such behavior is essential. Escaping from moving source of panic such as fire is of tremendous frightening event while evacuation situation. Predicting the dynamic of fire spreading and the exit clogging are intelligent aspects which help the individuals follow the correct behaviors for their evacuation. This article proposes an intelligent approach to accomplishing typical evacuations. The agents are provided with the ability to find optimal routes that enable them overcome spreading fire. Fire and safe floor fields are proposed to provide the agents with the capability of determining intermediate points to compose optimal routes toward the effective chosen exit. The instinct human behavior of being far from the fire to protect himself from sudden unexpected attack is introduced as essential factor risen in emergency situation. Simulations are conducted in order to examine the simulated evacuees’ behavior regarding overtaking the fire and to test the efficiency of making smart and effective decisions during emergency evacuation scenarios

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HARA, Isao, and Tadashi NAGATA. "Describing Moving Obstacles in a Configuration Space." Journal of the Robotics Society of Japan 11, no. 2 (1993): 255–62. http://dx.doi.org/10.7210/jrsj.11.255.

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Hsu, David, Robert Kindel, Jean-Claude Latombe, and Stephen Rock. "Randomized Kinodynamic Motion Planning with Moving Obstacles." International Journal of Robotics Research 21, no. 3 (March 2002): 233–55. http://dx.doi.org/10.1177/027836402320556421.

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Srikant, R., and Kamala Krithivasan. "Fastest path across constrained moving rectilinear obstacles." Information Processing Letters 37, no. 6 (March 1991): 349–53. http://dx.doi.org/10.1016/0020-0190(91)90153-9.

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Liu, Sheng, Fengji Dai, Shaobo Zhang, Yangqing Wang, and Zhenhua Wang. "Trend-aware motion planning for wheeled mobile robots operating in dynamic environments." International Journal of Advanced Robotic Systems 17, no. 4 (July 1, 2020): 172988142092529. http://dx.doi.org/10.1177/1729881420925292.

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Planning collision-free trajectories is essential for wheeled mobile robots operating in dynamic environments safely and efficiently. Most current trajectory generation methods focus on achieving optimal trajectories in static maps and considering dynamic obstacles as static depending on the precise motion estimation of the obstacles. However, in realistic applications, dealing with dynamic obstacles that have low reliable motion estimation is a common situation. Furthermore, inaccurate motion estimation leads to poor quality of motion prediction. To generate safe and smooth trajectories in such a dynamic environment, we propose a motion planning algorithm called trend-aware motion planning (TAMP) for dynamic obstacle avoidance, which combines with timed-elastic band. Instead of considering dynamic obstacles as static, our planning approach predicts the moving trends of the obstacles based on the given estimation. Subsequently, the approach generates a trajectory away from dynamic obstacles, meanwhile, avoiding the moving trends of the obstacles. To cope with multiple constraints, an optimization approach is adopted to refine the generated trajectory and minimize the cost. A comparison of our approach against other state-of-the-art methods is conducted. Results show that trajectories generated by TAMP are robust to handle the poor quality of obstacles’ motion prediction and have better efficiency and performance.

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Graffstein, Jerzy. "The Influence of Airplane’s Dynamics and Its’ State of Flight on Safety of an Evasive Manoeuvre Performed to Avoid Moving Obstacles." Pomiary Automatyka Robotyka 26, no. 1 (March 21, 2022): 33–39. http://dx.doi.org/10.14313/par_243/33.

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The exact identification of essential factors affecting the course of evasive manoeuvre, that has been computed to avoid a collision with moving obstacles, is necessary to ensure a safe passing by a moving obstacle. At the same time, during the evasive manoeuvre the pre-defined separation between the airplane and obstacles is required. The matter of presented work is defined as the analysis of influence of factors on execution of anti collision manoeuvre taking into account deformation of flight trajectory and changes of time histories of distance from the airplane to detected obstacles. Attention has been focused on internal interactions, resulting from the essential changes of the airplane’s behaviour. Discussion has been illustrated by selected results of computer simulations, executed for typical manoeuvres performed to avoid obstacles, while affected by adverse impacts of selected factors. The appropriate guidelines have been proposed, that should counteract these adverse effects on realisation of computed manoeuvre.

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Gil de Lamadrid, James, and Jill Zimmerman†. "Avoidance of obstacles with unknown trajectories: locally optimal paths and path complexity, Part I." Robotica 11, no. 4 (July 1993): 299–308. http://dx.doi.org/10.1017/s0263574700016556.

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SUMMARYWe consider the problem of moving a point robot through a two dimensional workspace containing polygonal obstacles moving on unknown trajectories. We propose to use sensor information to predict the trajectories of the obstacles, and interleave path planning and execution. In this paper, we present preliminary work in which we propose our basic algorithm and define a locally minimum velocity path as an optimal robot trajectory, given only local information about obstacle trajectories. In the sequel (part II) to this paper we will show that the complexity of a path planning problem can be characterized by how frequently the robot must change directions to approximate the locally minimum velocity path.

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de Lamadrid, James Gil, and Jill Zimmermanf. "Avoidance of obstacles with unknown trajectories: locally optimal paths and path complexity, Part II." Robotica 11, no. 5 (September 1993): 403–12. http://dx.doi.org/10.1017/s0263574700016957.

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SUMMARYContinuing the work presented in part I, ‡ we consider the problem of moving a point robot through a two dimensional workspace containing polygonal obstacles moving on unknown trajectories. We propose to use sensor information to predict the trajectories of the obstacles, and interleave path planning and execution. We define a locally minimum velocity path as an optimal robot trajectory, given only local information about obstacle trajectories. We show that the complexity of a path planning problem can be characterized by how frequently the robot must change directions to approximate the locally minimum velocity path. Our results apply to both robots with and without maximum velocity limits.

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Journal articles on the topic 'Moving obstacles'

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