The development of mobile robots has led to their wide application in a variety of fields. This study focuses on the intelligent application of mobile robots in laboratory management, especially the ...environmental awareness and self-positioning of a robot in the laboratory. In this study, a wheeled mobile robot is selected and equipped with a 2D laser scanner. Based on this, a Robot Operating System (ROS) environment is built. The nearest neighbor iterative closest point (ICP) matching algorithm is utilized to perceive the laboratory service environment, construct the indoor map in real time, and locate the robot precisely. Subsequently, data collected in the corridors and indoor environment of the experimental building are used to test the accuracy of the ICP matching algorithm. The results showed that the minimum translation error is as low as 0.0003 m and that the minimum rotation angle error is less than 0.5°. In addition, the positioning and mapping of the robot were analyzed. The experimental results show that the ICP matching algorithm is well suited to map construction and positioning of the laboratory service robot. This is of great significance for further research on laboratory service robots.
Complex terrains in coastal zones and shallow water areas around islands and reefs can be quickly detected via airborne LiDAR bathymetry (ALB) technology. Due to equipment placement deviations and ...measurement uncertainty, measurement deviations can occur in the overlapping areas of adjacent strips, so it is particularly necessary to register point clouds. To address areas with few seafloor structures and to overcome the challenges of extracting features in water areas with small terrain changes, a registration method for airborne LiDAR bathymetry seafloor point clouds based on the adaptive matching of corresponding points is proposed. First, the normal vector zenith angle, curvature change and omnidirectional variance in the seafloor points are calculated. Then, the corresponding points are adaptively matched according to the terrain feature similarity and distance constraints. Finally, the RANSAC algorithm and ICP algorithm are used for coarse registration and fine registration, respectively. The experimental results show that the method provides high accuracy and a uniform distribution of corresponding points. The root mean square error (RMSE) values when the registration method is applied to a flat area and coral reef area are 0.102 m and 0.041 m, respectively. Compared with that of the ICP alignment algorithm, the accuracy of the proposed method is improved by 0.114 m and 0.227 m, respectively, and compared with that of the NDT algorithm, the accuracy is improved by 0.316 m and 0.452 m, respectively; hence, the proposed method provides an effective solution for the registration of ALB data.
With the continuous improvement of various radio system performance indicators, the research work on antenna has become particularly important. According to different scenarios and requirements, ...practical projects also need the corresponding antennas to produce different radiation patterns. By reasonably setting the parameters of the array antenna, the target radiation pattern can be obtained to meet real life applications. When the array antenna has a large number of basic units and the expected far-field pattern is complicated, the design of the array antenna becomes a complicated optimization problem. To solve this problem, Whale Optimization Algorithm (WOA) is proposed. WOA is not only simple and fast, but can also get the global optimal solution. Therefore, WOA has developed rapidly in recent years. However, the application of this algorithm in the field of antenna design is still relatively rare, thus using WOA to solve the optimization problem of array antenna design is very valuable.
•A modified ICP for registration of point cloud and CAD model is proposed.•We propose a method to compute corresponding point based on STL triangular mesh.•The method can improve the efficiency and ...accuracy of registration.•A dynamic adjustment factor proposed can speed up the registration further.
Display omitted
This paper presents a modified ICP algorithm based on dynamic adjustment factor to speed up registration of point cloud and CAD model with high accuracy. The algorithm comes from a two-step optimization on the basic of original ICP. First, aiming at original ICP algorithm’s time consuming in searching for corresponding point, we present a novel solution to search for the corresponding point based on STL (STereo Lithography) triangular mesh in CAD model. The solution makes full use of the advantages of STL file which consists of lists of facet data and vector information of triangular mesh to search for point cloud’s corresponding points. Second, aiming at the algorithm’s very slow iterative process, we put forward a kind of dynamic adjustment factor—the factor of dynamically adjusting the rigid transformation parameters which can make point cloud over-travel by rigid transformation along original trend in each iteration. When adding dynamic adjustment factor, the algorithm could search more effective corresponding points in next iteration, thus reducing the number of iterations and speeding up the registration. Experiments show that the modified ICP can effectively reduce time consuming in registration of point cloud and CAD model, meanwhile improving the registration accuracy.
This paper first discusses the use of traditional elements in animation creation and analyzes the linear narrative and artistic expression involved in its creation. Secondly, in order to carry out ...the image design of animation creation, the color adaptive mathematical morphology is used to carry out the image edge calculation, and the ICP algorithm in the visual reconstruction theory is introduced to carry out the point cloud alignment and fusion. Finally, the effectiveness of this paper’s method is evaluated by comparing algorithms and examples. According to the findings, the loss rate of expansion and corrosion details using the color adaptive mathematical morphology operator is 0.05% and 5.69%, respectively. The overall evaluation of the visual reconstruction presentation is 94.93% at grade C or above. This shows that using the method of this paper can accurately realize the image design of animation creation, enhance the audience’s perception of animation with a clearer view, and then promote the prosperity of the animation industry.
In order to solve the problem of correct monitoring of underground roadway shape variables, a monitoring algorithm of underground roadway shape variables based on laser radar is designed based on the ...installation of high-precision laser radar and vehicle aided positioning system in underground intelligent vehicle; the overall framework of the monitoring algorithm is established, and the key technologies in laser radar data acquisition and preprocessing are described in detail; based on the existing knowledge accumulation of underground roadway scene monitoring and around the feature extraction of discrete points, an improved special point registration algorithm is constructed, which solves the problem that the feature points of roadway scene are sparse and can not be registered effectively; the distance from point to surface is used to pick out outliers, quickly calculate the offset of points, quickly extract high-density outliers through the density clustering algorithm of DBSCAN, quickly screen the deformat
This paper presents a robust six-degree-of-freedom relative navigation by combining the iterative closet point (ICP) registration algorithm and a noise-adaptive Kalman filter in a closed-loop ...configuration together with measurements from a laser scanner and an inertial measurement unit (IMU). In this approach, the fine-alignment phase of the registration is integrated with the filter innovation step for estimation correction, while the filter estimate propagation provides the coarse alignment needed to find the corresponding points at the beginning of ICP iteration cycle. The convergence of the ICP point matching is monitored by a fault-detection logic, and the covariance associated with the ICP alignment error is estimated by a recursive algorithm. This ICP enhancement has proven to improve robustness and accuracy of the pose-tracking performance and to automatically recover correct alignment whenever the tracking is lost. The Kalman filter estimator is designed so as to identify the required parameters such as IMU biases and location of the spacecraft center of mass. The robustness and accuracy of the relative navigation algorithm is demonstrated through a hardware-in-the loop simulation setting, in which actual vision data for the relative navigation are generated by a laser range finder scanning a spacecraft mockup attached to a robotic motion simulator.
In this article a new offline method for correcting non-linear drift in all three dimensions (3D) is presented. Using this method, a sample region is measured in multiple sub-measurements, each with ...increased sampling distance and thus reduced measurement time. The datasets of the sub-measurements are aligned using a point-to-plane iterative closest point algorithm to reconstruct and correct the 3D drift. Afterwards, the corrected datasets are fused into a single dataset. Compared to conventional drift-correction methods, the new method has the advantages of drift correction in full 3D with higher temporal resolution, less extra measurement time and data redundancy, as well as high application flexibility (e.g. compatibility to non-raster sampling). However, the resulting dataset might have slightly decreased resolution. If a high-resolution low-drift dataset is required, the method can be applied in an extended way, where an additional high-resolution measurement is taken whose drift can be corrected by the aforementioned dataset generated by data fusion. Two experimental measurements and a simulation study have been carried out in a new low-noise 3D atomic force microscope, showing great application potential of the proposed method.
PDF
