Improving the Hybrid A* method for a non-holonomic wheeled robot

Nemec, Dušan; Gregor, Michal; Bubeníková, Emília; Hruboš, Marián; Pirník, Rastislav

doi:10.1177/1729881419826857

Cited by 13 publications

(5 citation statements)

References 15 publications

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“…The high-frequency SLAM localisation output and the corrected LiDAR scans are used on a 3D probabilistic GPU-based occupancy grid map [25] to generate a high-resolution voxelised 3D snapshot of the robot's surroundings. Then, a height map is extracted for 2.5D navigation purposes and turned into a 2D costmap on which an implementation of hybrid A* [26] was used to plan robot trajectories to move towards goals while avoiding obstacles detected by the LiDAR [27]. The generated trajectories are then turned into velocity commands, while taking into account the UGV velocity and acceleration constraints.…”

Section: Local Navigationmentioning

confidence: 99%

Robotic Exploration of an Unknown Nuclear Environment Using Radiation Informed Autonomous Navigation

Groves

Hernández²,

West

et al. 2021

Robotics

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This paper describes a novel autonomous ground vehicle that is designed for exploring unknown environments which contain sources of ionising radiation, such as might be found in a nuclear disaster site or a legacy nuclear facility. While exploring the environment, it is important that the robot avoids radiation hot spots to minimise breakdowns. Broken down robots present a real problem: they not only cause the mission to fail but they can block access routes for future missions. Until now, such robots have had no autonomous gamma radiation avoidance capabilities. New software algorithms are presented that allow radiation measurements to be converted into a format in which they can be integrated into the robot’s navigation system so that it can actively avoid receiving a high radiation dose during a mission. An unmanned ground vehicle was fitted with a gamma radiation detector and an autonomous navigation package that included the new radiation avoidance software. The full system was evaluated experimentally in a complex semi-structured environment that contained two radiation sources. In the experiment, the robot successfully identified both sources and avoided areas that were found to have high levels of radiation while navigating between user defined waypoints. This advancement in the stateoftheart has the potential to deliver real benefit to the nuclear industry, in terms of both increased chance of mission success and reduction of the reliance on human operatives to perform tasks in dangerous radiation environments.

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Section: Local Navigationmentioning

confidence: 99%

Robotic Exploration of an Unknown Nuclear Environment Using Radiation Informed Autonomous Navigation

Groves

Hernández²,

West

et al. 2021

Robotics

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show abstract

“…Based on the concept of a cooperative workplace, the actual proposal will construct. Workplace requirements consider the mechanical, electrical, and software structure and the implementation of the robot's communication interface [Nemec 2019]. In connection with mechanical construction, some necessary mechanical interfaces are designed and manufactured.…”

Section: Figure 3 Cooperation Between Robot and Operator During The Assembly Processmentioning

confidence: 99%

Application of Speed and Separation Monitoring Technique at Automated Assembly Process

Vagaš¹,

Interactions²,

Galajdová³

2021

MM SJ

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The realization and implementation of a collaborative robotic system in the automotive industry has many advantages in productivity, product quality, and worker ergonomics, but worker safety aspects play a crucial role in these activities. This paper presents the results of ongoing research into developing an automated workplace for an assembly of industrial limit switches based on the cooperation between human and robotic systems. Operating speed and worker-robot separation monitoring methodology (SSM) was used as one of the available methods to reduce the risk of injury according to the technical specification ISO 15066 on collaborative method sharing space with humans. The virtual environment simulation aims to determine the SSM algorithm’s parameters to estimate the minimum protective distance between the robot and the operator. The cooperation between the human and the robot and the safety issues specified by the SSM system assumed operational safety and reduced the operator fatigue during the assembly process.

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“…The algorithm adds direction of motion as the fourth dimension for robot's state space: two Cartesian coordinates x, y, orientation q, and forward/reversing direction d 2 fÀ1, 1g, and expands nodes by taking orientation change, direction change, and reversing movement into its cost calculation consideration. Nemec et al proposed an improved hybrid A* method for nonholonomic wheeled robot 28 with parameter greed to change the weight of heuristic cost in total cost to increase search efficiency by changing the strategy of node expansion method.…”

Section: Introductionmentioning

confidence: 99%

Improved hybrid A* path planning method for spherical mobile robot based on pendulum

Zhang

Wan

You

et al. 2021

International Journal of Advanced Robotic Systems

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This article proposes a modification of hybrid A* method used for navigation of spherical mobile robots with the ability of limited partial lateral movement driven by pendulum. For pendulum-driven spherical robots with nonzero minimal turning radius, our modification helps to find a feasible and achievable path, which can be followed in line with the low time cost. Because of spherical shell shape, the robot is point contact with the ground, showing different kinematic model compared with common ground mobile robots such as differential robot and wheeled car-like robot. Therefore, this article analyzes the kinematic model of spherical robot and proposes a novel method to generate feasible and achievable paths conforming to kinematic constraints, which can be the initial value of future trajectory tracking control and further optimization. A concept of optimal robot’s minimum area for rotation is also proposed to improve search efficiency and ensure the ability of turning to any orientation by moving forward and backward in a finite number of times within limited areas.

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Improving the Hybrid A* method for a non-holonomic wheeled robot

Cited by 13 publications

References 15 publications

Robotic Exploration of an Unknown Nuclear Environment Using Radiation Informed Autonomous Navigation

Robotic Exploration of an Unknown Nuclear Environment Using Radiation Informed Autonomous Navigation

Application of Speed and Separation Monitoring Technique at Automated Assembly Process

Improved hybrid A* path planning method for spherical mobile robot based on pendulum

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