Map Building Algorithm Research Articles

Localización de robots basada en red neural utilizando características visuales

This paper outlines the development of a module capable of constructing a map-building algorithm using inertial odometry and visual features. It incorporates an object recognition module that leverages local features and unsupervised artificial neural networks to identify non-dynamic elements in a room and assign them positions. The map is modeled using a neural network, where each neuron corresponds to an absolute position in the room. Once the map is constructed, capturing just a couple of images of the environment is sufficient to estimate the robot's location. The experiments were conducted using both simulation and a real robot. The Webots environment with the virtual humanoid robot NAO was used for the simulations. Concurrently, results were obtained using a real NAO robot in a setting with various objects. The results demonstrate notable precision in localization within the two-dimensional maps, achieving an accuracy of ± (0.06, 0.1) m in simulations contrasted with the natural environment, where the best value achieved was ± (0.25, 0.16) m.

Optimal Trajectory Planning Method for the Navigation of WIP Vehicles in Unknown Environments: Theory and Experiment.

Navigation of underactuated wheeled inverted pendulum (WIP) vehicles in unknown environments is still facing great difficulties, especially when the optimal motion is required. This article proposes an optimal trajectory planning method for the navigation of WIP vehicles in unknown environments, where various performance demands, such as security, smoothness, efficiency, etc., are all considered. First, a map-building algorithm based on the improved Rao-Blackwellized particle filter is applied for the WIP vehicle to construct the environmental map. Then, a multiobjective optimization using the genetic algorithm is performed to find an optimized path between the given start and target point with path length, path curvature, and safe distance being taken into consideration simultaneously. Moreover, on the basis of kinematical and dynamical analysis, velocity, and acceleration constraints are parameterized with a path parameter, and the minimum-time trajectory along the optimized path is further planned with a sequence of maximum acceleration and deceleration trajectories. Finally, a WIP vehicle platform based on the robot operating system is designed, and related experiments in a real obstacle environment are conducted to validate the feasibility of the proposed method.

Research on the Mobile Robot Map-Building Algorithm Based on Multi-Source Fusion

In this paper, the mobile robot position fusion algorithm is inaccurate. There is a delay, and the map-construction accuracy is not high; an improvement method is proposed. First, the Cartographer algorithm is optimized. Radius filtering is used for data processing after voxel filtering. In contrast, the idea of multi-sensor fusion is used to fuse the processed IMU data information. This improved method improves the efficiency of the algorithm and the accuracy of the positional pose fusion. We verify the effect of the algorithm applied to the environment map, respectively, in the experimental building promenade environment and the teaching building hall environment, and analyze and compare the effect of map construction before and after the improvement; the experiment proves that in the experimental building promenade environment, the absolute error of measuring and analyzing the obstacles reduces by 0.06 m, and the relative error decreases by 1.63%; in the teaching building hall environment, the absolute error of measuring and analyzing the longest side of the map decreases by 1.121 m and the relative error decreased by 5.52%. In addition, during the experimental operation, the CPU occupancy of the optimized algorithm is around 59.5%. In contrast, the CPU occupancy of the original algorithm is 67% on average, and sometimes it will soar to 75%. The experimental results prove that the algorithm in this paper significantly improves performance in all aspects when constructing real-time environment maps.

Visual SLAM Mapping Based on YOLOv5 in Dynamic Scenes

When building a map of a dynamic environment, simultaneous localization and mapping systems have problems such as poor robustness and inaccurate pose estimation. This paper proposes a new mapping method based on the ORB-SLAM2 algorithm combined with the YOLOv5 network. First, the YOLOv5 network of the tracing thread is used to detect dynamic objects of each frame, and to get keyframes with detection of dynamic information. Second, the dynamic objects of each image frame are detected using the YOLOv5 network, and the detected dynamic points are rejected. Finally, the global map is constructed using the keyframes after eliminating the highly dynamic objects. The test results using the TUM dataset show that when the map is constructed in a dynamic environment, compared with the ORB-SLAM2 algorithm, the absolute trajectory error of our algorithm is reduced by 97.8%, and the relative positional error is reduced by 59.7%. The average time consumed to track each image frame is improved by 94.7% compared to DynaSLAM. In terms of algorithmic real-time performance, this paper’s algorithm is significantly better than the comparable dynamic SLAM map-building algorithm DynaSLAM.

복합재난현장 대응로봇의 한정된 통신 환경에 기반한 전역지도 생성 알고리즘

Complex disaster has disabled the ordinary communication system. For example, fire on LTE routers and their power supply interrupted communication. In our disaster react robot system, we suggested a portable and battery-powered Wi-Fi module dropped by reconnaissance robots. As a result, the communication speed was extremely limited. In this paper, we proposed a global map generation strategy to overcome this communication limit. Our key approach involved the conversion of heterogeneous local maps to 2D occupancy grid maps. The 2D map was treated as an image and image stitching algorithm was applied to build the global map. We made various local map scenarios and applied our global map building algorithms. In conclusion, our proposed strategy was verified with the real robot test.

Camera-LIDAR Integration: Probabilistic Sensor Fusion for Semantic Mapping

An automated vehicle operating in an urban environment must be able to perceive and recognise objects and obstacles in a three-dimensional world for navigation and path planning. In order to plan and execute accurate and sophisticated driving maneuvers, a high-level contextual understanding of the surroundings is essential. Due to the recent progress in image processing, it is now possible to obtain high definition semantic information in 2D from monocular cameras, though cameras cannot reliably provide the high accuracy 3D information provided by lasers. The fusion of these two sensor modalities can overcome the shortcomings of each individual sensor, though there are a number of important challenges that need to be addressed in a probabilistic manner. In this paper we address the common, yet challenging, LIDAR/camera/semantic fusion problems which are seldom approached in a wholly probabilistic manner. Our approach is capable of using a multi-sensor platform to build a three-dimensional semantic voxelized map that considers the uncertainty of all of the processes involved. We present a probabilistic pipeline that incorporates uncertainty from the sensor readings (cameras, LIDAR, IMU and wheel encoders), compensation for the motion of the vehicle, and heuristic label probabilities for the semantic images depicted in <xref ref-type="fig" rid="fig1" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Fig. 1</xref> . We also present a novel and efficient viewpoint validation algorithm to check for occlusions within the camera frame. A probabilistic projection is performed from the camera images to the LIDAR point cloud. Each labelled LIDAR scan then feeds into an octree map-building algorithm that updates the class probabilities of the map voxels every time a new observation is available. We validate our approach using a set of qualitative and quantitative experiments using the USyd Campus Dataset. <xref ref-type="fn" rid="fn1" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">¹</xref> These tests demonstrate the usefulness of a probabilistic sensor fusion approach by evaluating the performance of the perception system in a typical autonomous vehicle application.

Simulation and Implementation of SLAM Drawing Based on ROS Wheeled Mobile Robot

In order to realize the establishment of the unknown terrain map in the indoor environment of the ROS wheeled mobile robot, this article uses Lidar, Raspberry Pi and other hardware to build the wheeled mobile robot, in the ROS environment, the robot is built by the URDF model, and the robot model is configured. Differential controller, keyboard control node, etc. Establish the simulation environment, use different simulation environments to visually simulate the robot, and simulate the two optimization algorithms in the SLAM algorithm to simulate the construction of the map. In order to explore the effect of SLAM’s different optimization algorithms on the construction of graphics, the SLAM algorithm based on filter and the SLAM algorithm based on graph optimization are introduced respectively. The robot is selected. After the robot is built, three different experimental environments are selected. A variety of map-building algorithms are used to experiment, comparing the effects of G-mapping algorithm and Cartographer algorithm to build maps in a small-scale, large-scale and multi-obstacle environment. Use the image processing software under the Linux system to analyse the map created by the robot in the experimental environment, measure the coordinates of the robot feature points in the created map by the number of pixels, and compare the actual coordinates of the location of the special point in the actual environment to evaluate Construction effect. By comparing the effects of the two algorithms on the contours of various obstacles when building a map, the effect of mapping in a multi-obstacle environment is evaluated. The results show that the SLAM graph-building algorithm based on graph optimization has a more stable graph-building effect.

A stigmergetic method based on vector pheromone for target search with swarm robots

ABSTRACTStigmergy is a common social network mechanism in nature, which allows individuals to achieve effective coordination through the environment, and has shown some successful applications on robotic systems. This paper proposes a stigmergetic target search method based on vector pheromone for swarm robots. Robots generate vector pheromones according to the target signal and release them to the environment for other robots to read, so as to achieve the indirect transfer of information. The method is extended from our previous work which has some shortcoming especially in the updating process of pheromones. This paper improves the previous search method by designing a hybrid pheromone updating rule to achieve more efficient and accurate information exchange. Moreover, the improved search method contains a robot navigation algorithm and a pheromone map building algorithm for guiding robots’ motion and building the pheromone map. Numerical experiments are performed to compare the performance of the improved method with the previous one. Results show that the improved method can enhance the robot’s efficiency and success rate in finding the static and dynamic targets. Meanwhile, it can also improve the speed of map building and the accuracy of the pheromone map.

Adaptive GridMap Building Algorithm for Mobile Robot Based on Multiway Tree

In order to solve the problem that uniform grid map occupies large storage space in the process of large-scale map creation, a new adaptive grid map building algorithm based on multiway tree is proposed. The environment map is divided into nine grids. The algorithm determines whether the grid is completely occupied, partially occupied or vacant. Then the part occupied gridsare further subdivided into smaller grids. The algorithm continues to determine whether the smaller grid is completely occupied, partially occupied or vacant.Repeat the above segmentation process until the entire map search is completed and the accuracy requirements are met. Finally, the scale of grid map does not depend on human experience but presenting adaptive characteristics. The algorithm is compared with the uniform grid method.The simulation results show that the algorithm has convergence.Andcompared with the uniform scale raster map, itgreatly saves the storage space.

A safe area search and map building algorithm for a wheeled mobile robot in complex unknown cluttered environments

SUMMARYIn this paper, a safe map building and area search algorithm for a mobile robot in a closed unknown environment with obstacles is presented. A range finder sensor is used to detect the environment. The objective is to perform a complete search of the environment and build a complete map of it while avoiding collision with the obstacles. The developed robot navigation algorithm is randomized. It is proved that with probability 1 the robot completes its task in a finite time. Computer simulations and experiments with a real Pioneer-3DX robot confirm the performance of the proposed method.

Keyframes Global Map Establishing Method for Robot Localization through Content-Based Image Matching

Self-localization and mapping are important for indoor mobile robot. We report a robust algorithm for map building and subsequent localization especially suited for indoor floor-cleaning robots. Common methods, for example, SLAM, can easily be kidnapped by colliding or disturbed by similar objects. Therefore, keyframes global map establishing method for robot localization in multiple rooms and corridors is needed. Content-based image matching is the core of this method. It is designed for the situation, by establishing keyframes containing both floor and distorted wall images. Image distortion, caused by robot view angle and movement, is analyzed and deduced. And an image matching solution is presented, consisting of extraction of overlap regions of keyframes extraction and overlap region rebuild through subblocks matching. For improving accuracy, ceiling points detecting and mismatching subblocks checking methods are incorporated. This matching method can process environment video effectively. In experiments, less than 5% frames are extracted as keyframes to build global map, which have large space distance and overlap each other. Through this method, robot can localize itself by matching its real-time vision frames with our keyframes map. Even with many similar objects/background in the environment or kidnapping robot, robot localization is achieved with position RMSE &lt;0.5 m.

An Odometry-Free Approach for Simultaneous Localization and Online Hybrid Map Building

In this paper, a new approach is proposed for mobile robot localization and hybrid map building simultaneously without using any odometry hardware system. The proposed method termed as Genetic Bayesian ARAM which comprises two main components: 1) Steady state genetic algorithm (SSGA) for self-localization and occupancy grid map building; 2) Bayesian Adaptive Resonance Associative Memory (ARAM) for online topological map building. The model of the explored environment is formed as a hybrid representation, both topological and grid-based, and it is incrementally constructed during the exploration process. During occupancy map building, robot estimated self-position is updated by SSGA. At the same time, robot estimated self position is transmit to Bayesian ARAM for topological map building and localization. The effectiveness of our proposed approach is validated by a number of standardized benchmark datasets and real experimental results carried on mobile robot. Benchmark datasets are used to verify the proposed method capable of generating topological map in different environment conditions. Real robot experiment is to verify the proposed method can be implemented in real world.

Corrigendum to “A Novel Improved Probability-Guided RANSAC Algorithm for Robot 3D Map Building”

Corrigendum to “A Novel Improved Probability-Guided RANSAC Algorithm for Robot 3D Map Building”

A Novel Improved Probability-Guided RANSAC Algorithm for Robot 3D Map Building

This paper presents a novel improved RANSAC algorithm based on probability and DS evidence theory to deal with the robust pose estimation in robot 3D map building. In this proposed RANSAC algorithm, a parameter model is estimated by using a random sampling test set. Based on this estimated model, all points are tested to evaluate the fitness of current parameter model and their probabilities are updated by using a total probability formula during the iterations. The maximum size of inlier set containing the test point is taken into account to get a more reliable evaluation for test points by using DS evidence theory. Furthermore, the theories of forgetting are utilized to filter out the unstable inliers and improve the stability of the proposed algorithm. In order to boost a high performance, an inverse mapping sampling strategy is adopted based on the updated probabilities of points. Both the simulations and real experimental results demonstrate the feasibility and effectiveness of the proposed algorithm.

Global Appearance Applied to Visual Map Building and Path Estimation Using Multiscale Analysis

In this work we present a topological map building and localization system for mobile robots based on global appearance of visual information. We include a comparison and analysis of global-appearance techniques applied to wide-angle scenes in retrieval tasks. Next, we define multiscale analysis, which permits improving the association between images and extracting topological distances. Then, a topological map-building algorithm is proposed. At first, the algorithm has information only of some isolated positions of the navigation area in the form of nodes. Each node is composed of a collection of images that covers the complete field of view from a certain position. The algorithm solves the node retrieval and estimates their spatial arrangement. With these aims, it uses the visual information captured along some routes that cover the navigation area. As a result, the algorithm builds a graph that reflects the distribution and adjacency relations between nodes (map). After the map building, we also propose a route path estimation system. This algorithm takes advantage of the multiscale analysis. The accuracy in the pose estimation is not reduced to the nodes locations but also to intermediate positions between them. The algorithms have been tested using two different databases captured in real indoor environments under dynamic conditions.

Recognition of Indoor Environment by Robot Partner Using Conversation

To support daily life before performing an action, a robot partner must perceive an unknown environment. Much research has been done from various viewpoints on self-localization estimation and environment perception. In our research, the robot partner performs self-localization and environment recognition using Simultaneous Localization and Mapping for self-localization estimation and map building. In this paper, we propose a method for recognizing indoor environments by robot partners based on conversations with human beings. Information acquired from maps is identified in order to share the meaning with human beings after the required interpretation. In this paper, we therefore propose a method for recognizing environmental maps by labeling these maps based on symbolic information developed through conversation with human beings. The proposed method is composed of four parts. First, the robot partner applies a steady-state genetic algorithm for self-localization estimation. Second, we use a map building algorithm for expressing the topological map. Third, conversation with human beings is performed for acquiring symbolic information in order to recognize object and position locations through the map. Fourth, we perform experiments and discuss the effectiveness of the proposed technique.

A Gaussian process-based RRT planner for the exploration of an unknown and cluttered environment with a UAV

A new framework which adopts a rapidly-exploring random tree (RRT) path planner with a Gaussian process (GP) occupancy map is developed for the navigation and exploration of an unknown but cluttered environment. The GP map outputs the probability of occupancy given any selected query point in the continuous space and thus makes it possible to explore the full space when used in conjunction with a continuous path planner. Furthermore, the GP map-generated path is embedded with the probability of collision along the path which lends itself to obstacle avoidance. Finally, the GP map-building algorithm is extended to include an exploration mission considering the differential constraints of a rotary unmanned aerial vehicle and the limitation arising from the environment. Using mutual information as an information-theoretic measure, an informative path which reduces the uncertainty of the environment is generated. Simulation results show that GP map combined with RRT planner can achieve the 3D navigation and exploration task successfully in unknown and complex environments.

Memory-efficient real-time map building using octree of planes and points

This paper presents an octree-based map building algorithm for mobile home-service robots. The robot is equipped with a time-of-flight camera, which produces point clouds of the environment surfaces. Given the successive input of point clouds, a 3D map is incrementally computed in real time. The map is accurate and memory-efficient because the octree nodes containing points on a plane are merged and represented simply by an index to the plane. The real-time performance is achieved largely due to the parallel processing capability of the many-core Graphics Processing Unit used for plane extraction.

Map Building of Unknown Environment Using L1-norm, Point-to-Point Metric and Evolutionary Computation

In the present paper, a method for building a map of an unknown environment (SLAM) derived from the ICP algorithm using point-to-point metric is proposed. The polar- scan matching technology is used for estimation of the robot location change between two scans in sequence estimate the correct position of the robot. Since map building i s fairly time- consuming, the algorithm of differential evolution (DE) is used in the calculation. This efficient optimizer provides very good results in different types of small office environm ent (unstructured and structured). The new type of an algorithm for map building is based purely on simple geometric primitives— vectors and integrates the modern evolutionary algorithm—DE. The presented algorithm falls into the wider group of geometric map builders and is able to build a map of indoor, mostly office, environment without moving objects.

가정환경에서의 분류된 지역정보를 통한 계층적 시맨틱 지도 작성

This paper describes hierarchical semantic map building using the classified area information in home environments. The hierarchical semantic map consists of a grid, CAIG (Classified Area Information in Grid), and topological map. The grid and CAIG maps are used for navigation and motion selection, respectively. The topological map provides the intuitive information on the environment, which can be used for the communication between robots and users. The proposed semantic map building algorithm can greatly improve the capabilities of a mobile robot in various domains, including localization, path-planning and HRI (Human-Robot Interaction). In the home environment, a door can be used to divide an area into various sections, such as a room, a kitchen, and so on. Therefore, we used not only the grid map of the home environment, but also the door information as a main clue to classify the area and to build the hierarchical semantic map. The proposed method was verified through various experiments and it was found that the algorithm guarantees autonomous map building in the home environment.