Adaptive autonomous navigation system for coal mine inspection robots: overcoming intersection challenges

An autonomous, adaptive navigation system, tightly coupled with the overall mission management system, can provide unmanned systems with the capability to autonomously change and execute mission plans. Legislative issues, the difficulty to meet the extremely high reliability requirements of an autonomous collision avoidance function and the associated development and certification challenges can all be reasons to limit the authority of such an adaptive system by involving/requiring a human operator at the decision making level. The role of the human operator is to make decisions during situations in which significant changes in the navigation plan are needed to accomplish the mission. Such a concept of operation imposes specific challenges that must be addressed during the design of the systems that support the operator with this supervisory task. The paper starts with addressing the commonality in the associated challenges between nautical and aeronautical platforms and between manned and unmanned systems. It will be illustrated how during the past 60 years, research in both the nautical and the aeronautical domain has addressed aspects of these challenges and how developments in the area of sensors, processors and display capabilities increased the possibilities to both increase system autonomy and keep the human operator involved with the required authority. Following this background, it will be discussed how components of a system designed to support a UAS pilot with the separation assurance task have been re-used in the realization of a prototype operator support system for an unmanned vessel, the CSHIELD platform. Results of an initial simulation-based evaluation are also presented.

Mobile robot, especially wheeled mobile robot, with its simple mechanical structure and inherent agility, has attracted significant attentions for dynamic environment applications in the last two decades (Pin et al. 1994 and Purwin 2006). A general mobile robot Guidance, Navigation and Control (GNC) system is illustrated in the following figure. The main function of guidance system is to generate a feasible trajectory command, usually in multiple dimension of freedom (DOF) to achieve a robot task. The objective of control system is to drive the mobile robot following the commanded trajectory with acceptable tracking errors and stability margin. The function of robot navigation system is to provide accurate position, velocity and/or orientation information for the control system and guidance system. A stable and accurate navigation system is the bridge between the guidance system and control system of mobile robots, which ultimately determines the robot performance.

In recent years, due to the declining birthrate, there are more and more situations where elderly people need to be cared for. As a result, the burden per caregiver has been increasing. As a technology to solve this problem, indoor robot navigation systems that support indoor mobility of those who need care are attracting attention. A navigation system using a mobile robot has components such as position estimation and movement control. As a conventional technique for location estimation, there is a location estimation method using QR codes. In addition, there is a conventional method of mobile control using RSSI. The proposed method presented in this paper is a robot navigation system that replaces QR codes with RFID tags and uses the RSSI-based mobile control method. In addition, we propose a path recovery system when the mobile robot deviates from the path during navigation. In the performance evaluation of navigation between arbitrary points, the maximum error from the ideal trajectory was found to be 13 cm. We also found that the average error between the destination tag and the stop position was 20 cm, while the maximum error was 51 cm. In the performance evaluation of the path recovery system, the maximum error between the ideal path and the stop position was found to be 30 cm.

One of the technologies in the industrial world that utilizes robots is the delivery of goods in warehouses, especially in the goods distribution process. This is very useful, especially in terms of resource efficiency and reducing human error. The existing system in this process usually uses the line follower concept on the robot's path with a camera sensor to determine the destination location. If the line and destination are not detected by the sensor or camera, the robot's navigation system will experience an error. it can happen if the sensor is dirty or the track is faded. The aim of this research is to develop a robot navigation system for efficient goods delivery in warehouses by integrating odometry and Dijkstra's algorithm for path planning. Holonomic robot is a robot that moves freely without changing direction to produce motion with high mobility. Dijkstra's algorithm is added to the holonomic robot to obtain the fastest trajectory. by calculating the distance of the node that has not been passed from the initial position, if in the calculation the algorithm finds a shorter distance it will be stored as a new route replacing the previously recorded route. the distance traversed by the djikstra algorithm is 780 mm while a distance of 1100 mm obtains the other routes. The time for using the Djikstra method is proven to be 5.3 seconds faster than the track without the Djikstra method with the same speed. Uneven track terrain can result in a shift in the robot's position so that it can affect the travel data. The conclusion is that odometry and Dijkstra's algorithm as a planning system and finding the shortest path are very efficient for warehouse robots to deliver goods than ordinary line followers without Dijkstra, both in terms of distance and travel time.

Measurements on ultra-wideband (UWB) pulse propagation over the ground show the presence of three distinct propagation regimes: (1) in the first regime, the signal power decreases as ~ d <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-2</sup> , where d is the separation distance between the transmitter and the receiver; (2) in the second regime, the signal power decreases on the average as ~ d <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-2</sup> with distance, but exhibits interference maxima and minima; (3) in the third regime, the signal power decreases as ~ d <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-4</sup> . Theoretical analysis indicates two characteristic length scales d <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">i</sub> and d <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> , called first and second breakpoint distances, determine the sizes of the three propagation regimes. These characteristic lengths depend both on the geometrical parameters such as the heights of the transmitter (h <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1</sub> ) and the receiver (h <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> ) over the ground as well as on UWB pulse properties such as pulse duration (t <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">p</sub> ) and cycle time (t <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">c</sub> ). Simple expressions for break points exist when h <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">i</sub> , h <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> >> ct <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">p</sub> and d >> h <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1</sub> : d <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1</sub> ≈ 4h <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1</sub> h <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> /cT <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">p</sub> ≈ 4h <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1</sub> h <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> B/c, and d <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> ≈ 4h <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1</sub> h <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> /cT <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">c</sub> ≈ 4h <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1</sub> h <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> f <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">c</sub> /c, where B ~ 1/t <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">p</sub> is the bandwidth and f <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">c</sub> ~ 1/t <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">c</sub> is the center frequency of the UWB pulse. For a given transmitter height h <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">i</sub> , the loci of first and second breakpoints in the (d, h <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> ) plane are hyperbolas with the transmitter and its image as the foci. Based on the propagation results presented here, we suggest that waveform diversity can effectively be used to improve the performance of a UWB based adaptive communication or navigation system.

Purpose – The high-velocity wind caused by a methane-air explosion is one of the important hazardous effects in explosion events of coal mines, and, however, until now it has not been received much attention from scientific works. The paper aims to discuss this issue. Design/methodology/approach – In consideration of the difficulties in observing particle velocities of high-velocity flows, this work presented a study to reveal the regularity during a methane-air explosion happening in the tunnel of coal mine through the numerical analysis approach. Findings – The strong wind caused by a methane-air explosion is a significant hazard and can cause damage in the accidents of methane-air explosion in underground coal mines, especially at structural opening, according to this work. Obtained results show that maximum particle velocity of the high-velocity wind occurs in the outside region of the premixed area, with a peak value of 400∼500 m/s, and the peak velocity of the high-velocity wind decreases exponentially with distance beyond the premixed area. Originality/value – The objective of this work was to examine the effect of wind caused by a methane-air explosion in a tunnel. Other information, such as shock wave and flame and temperature distribution, has been reported in the previous literatures. However, in the accidents of methane-air explosion in underground coal mines, some phenomena (structural opening is destroyed badly) can not be understood by using shock wave and flame and temperature distribution caused by the explosion. The strong wind caused by a methane-air explosion is another significant hazard and can cause damage in the methane-air explosion accidents in underground coal mines, especially at structural opening, according to this work.

Localization of a vehicle is a key component for driving assistance or autonomous navigation. In this work, we propose a visual positioning system (VPS) for vehicle or mobile robot navigation. Different from general landmark-based or model-based approaches, which rely on some predefined known landmarks or a priori information about the environment, no assumptions on the prior knowledge of the scene are made. A stereo-based vision system is built for both extracting feature correspondences and recovering 3-D information of the scene from image sequences. Relative positions of the camera motion are then estimated by registering the 3-D feature points from two consecutive image frames. Localization of the vehicle is finally given by the reference to its initial position. I. INTRODUCTION Localization and tracking of a vehicle are major compo- nents for providing positions, directions and travel informa- tion to the driver. They also serve as key technologies for building autonomous navigation systems. Many approaches have been proposed for locating a mobile robot or a ve- hicle based on various techniques. The most commonly used methods include dead-reckoning techniques, navigation using active beacons, landmark-based navigation, map-based navigation, global positioning system (GPS), and vision- based positioning. Dead-reckoning is a procedure for determining the present location of a vehicle by advancing some previous position through known path and velocity information over a given period of time. Since an odometer and optical sensors for wheel direction detection are easily installed on a vehicle, dead-reckoning is usually a less expensive method for vehicle localization. However, the integration of incremental motion information over time will lead to accumulation of errors. In the case of long distance travel, accumulation of orientation error will make position errors diverge as the increase of driving time. Active beacons such as laser, sonar or radio can be used as media for vehicle or mobile robot navigation. These approaches use triangulation to measure the distance between a number of beacons and the mobile platform and then deter- mine the current location. The problems associated with this technique are the inaccuracy of the distance measurement caused by time-delay of the signals, and the installation and maintenance cost of a large number of beacons required for an area. Satellite based differential global positioning system (DGPS) is probably the most advanced and accurate method for identifying the position and orientation of an object. However, DGPS does not work well if the satellite signals are blocked. This situation commonly happens in the indoor environments, or urban areas with tall buildings, etc. In this work, we propose a visual positioning system (VPS) for vehicle or mobile robot navigation. Different from general landmark-based or model-based approaches which rely on some predefined known landmarks or ap rioriinfor- mation about the environment (e.g., 3-D models of buildings, objects, etc.), no assumptions on the prior knowledge of the scene are made. A stereo-based vision system is built for both extracting feature correspondences and recovering 3- D information of the scene from image sequences. A robust feature tracking method based on simultaneously considering the inter-frame images from the same camera and the stereo image pair from different cameras at a fixed time instant is developed. The relative position of the camera motion is then estimated by registering the 3-D feature points from two consecutive image frames. Our system includes the following basic modules:

The use of robotics in surgery is nothing new. However, there are areas of surgery, such as in fracture fixation, where robots have yet to be implemented. This paper considers the choice of robot, gripper and ancillary equipment together with navigation systems necessary for their application.

Unmanned aerial vehicles are successfully exploited in different spheres of humans' life for the last decades. At tremendous increase of UAV-related market it is very important to develop own reliable and accurate navigation and automatic flight control systems. This paper presents some questions related with navigation system development and practical implementation. Its prototype has been developed in Aerospace Center of National Aviation University. The results approving integrated navigation system efficiency of functioning from one of the experimental validations have been presented.

The transmission mode of wireless waves in coal mine tunnel is different from the mode in free space.The multipath propagation of wireless wave is severe in tunnel.As a result,the characteristics study of multipath propagation is very important to the design of wireless communication system in coal mine tunnel.After analyzing the multipath propagation attenuation in tunnel,the statistics of single frequency signal,narrowband signal and broadband signal are obtained.This is the foundation for the application of resisting multipath decline techniques.

This paper proposes a multi-sensor data-fusion-based method for real-scene 3D reconstruction and digital twin visualization of coal mine tunnels, aiming to address issues such as low accuracy in non-photorealistic modeling and difficulties in feature object recognition during traditional coal mine digitization processes. The research employs cubemap-based mapping technology to project acquired real-time tunnel images onto six faces of a cube, combined with navigation information, pose data, and synchronously acquired point cloud data to achieve spatial alignment and data fusion. On this basis, inner/outer corner detection algorithms are utilized for precise image segmentation, and a point cloud region growing algorithm integrated with information entropy optimization is proposed to realize complete recognition and segmentation of tunnel planes (e.g., roof, floor, left/right sidewalls) and high-curvature feature objects (e.g., ventilation ducts). Furthermore, geometric dimensions extracted from segmentation results are used to construct 3D models, and real-scene images are mapped onto model surfaces via UV (U and V axes of texture coordinate) texture mapping technology, generating digital twin models with authentic texture details. Experimental validation demonstrates that the method performs excellently in both simulated and real coal mine environments, with models capable of faithfully reproducing tunnel spatial layouts and detailed features while supporting multi-view visualization (e.g., bottom view, left/right rotated views, front view). This approach provides efficient and precise technical support for digital twin construction, fine-grained structural modeling, and safety monitoring of coal mine tunnels, significantly enhancing the accuracy and practicality of photorealistic 3D modeling in intelligent mining applications.

Aiming at the indoor location and navigation problem of humanoid biped robot with complex motion structure, a humanoid biped robot localization and navigation system based on ORB-SLAM is designed. Firstly, the working principle of ORB-SLAM is analyzed, and it is improved to realize the function of missing map reading and generating dense point cloud map. Secondly, the dense point cloud map is converted to octomap, and then the conversion of 3D map to 2D map is completed. The SBPL planning library is improved to carry out the path planning of the robot, and the path planning based on the boundary exploration is realized. Finally, the experimental verification is carried out on the biped robot to verify the effectiveness of the location and navigation system design in the indoor environment.

In this paper, we first describe some goal-unreachable problems found in fuzzy logic-based algorithms for mobile robot navigation systems. Then, a new algorithm is developed to solve one of the problems, i.e., a problem with nearby obstacles. The resulting navigation system has been implemented on a real mobile robot, Koala, and tested in various environments. Experimental results are presented which demonstrate the effectiveness and improvement of the resulting fuzzy navigation system over conventional fuzzy-logic navigation algorithms.

Advanced robot's navigation system based on GPS/INS is established in order to meet its working surroundings and taskpsilas demand. Centralized open-loop Kalman filter is applied in the navigation system. GPS/INS devices' output difference is the filter's input. The position-velocity integrated measurement equation is deduced based on the robotpsilas locomotion performance and measurement demand. Simulation experiments are conducted under MATLAB software environment. The experiment results show that the systempsilas noise is retained and the navigation precision is improved effectively.

Abstract. 3D LiDAR sensors play an important part in several autonomous navigation and perception systems with the technology evolving rapidly over time. This work presents the preliminary evaluation results of a 3D solid state LiDAR sensor. Different aspects of this new type of sensor are studied and their data are characterized for their effective utilization for object detection for the application of Autonomous Ground Vehicles (AGV). The paper provides a set of evaluations to analyze the characterizations and performances of such LiDAR sensors. After characterization of the sensor, the performance is also evaluated in real environment with the sensors mounted on top of a vehicle and used to detect and classify different objects using a state-of-the-art Super-Voxel based method. The 3D point cloud obtained from the sensor is classified into three main object classes “Building”, “Ground” and “Obstacles”. The results evaluated on real data, clearly demonstrate the applicability and suitability of the sensor for such type of applications.