Graph SLAM-Based 2.5D LIDAR Mapping Module for Autonomous Vehicles

This paper proposes a unique Graph SLAM framework to generate precise 2.5D LIDAR maps in an XYZ plane. A node strategy was invented to divide the road into a set of nodes. The LIDAR point clouds are smoothly accumulated in intensity and elevation images in each node. The optimization process is decomposed into applying Graph SLAM on nodes’ intensity images for eliminating the ghosting effects of the road surface in the XY plane. This step ensures true loop-closure events between nodes and precise common area estimations in the real world. Accordingly, another Graph SLAM framework was designed to bring the nodes’ elevation images into the same Z-level by making the altitudinal errors in the common areas as small as possible. A robust cost function is detailed to properly constitute the relationships between nodes and generate the map in the Absolute Coordinate System. The framework is tested against an accurate GNSS/INS-RTK system in a very challenging environment of high buildings, dense trees and longitudinal railway bridges. The experimental results verified the robustness, reliability and efficiency of the proposed framework to generate accurate 2.5D maps with eliminating the relative and global position errors in XY and Z planes. Therefore, the generated maps significantly contribute to increasing the safety of autonomous driving regardless of the road structures and environmental factors.

Dynamic Performance of Vehicle–Guideway Bridge Systems for Low–Medium-Speed Maglev Trains Under Earthquakes

This paper developed a numerical model for predicting the seismic responses of vehicle–guideway bridge systems for low–medium-speed (LMS) maglev trains. Each vehicle was characterized as a multi-rigid-body with 50 degree of freedoms (DOFs), and the guideway bridge was modeled by the finite element method. The actively controlled electromagnetic forces were considered in simulating the vehicle–guideway interaction relationship. Subsequently, the equations of motion for the vehicle–guideway coupled system under earthquake were, respectively, established in relative and absolute coordinate systems to quantify the effect of structural pseudo-static components, so that the seismic effect can be taken into account. Case study was then conducted to thoroughly discuss the seismic responses of the vehicle–guideway coupled system in both time and frequency domains. Furthermore, parametric study was carried out to determine the effect of key parameters (i.e. vehicle speed, stiffness of guideway) on the system’s responses. The results show that the conventional seismic analysis method relative motion method (RMM) (ignoring the structural pseudo-static component) will considerably underestimate the seismic responses of the coupled system, especially of the vehicle. It is suggested that the formulation be established in the absolute coordinate system (i.e. using direct solution method, DSM) for more actual prediction. The frequency responses indicate that the vibrations of vehicle–guideway coupled system under earthquake relate significantly to the natural frequencies of vehicle and bridge, while the same is not true for the vehicle-induced excitation.

Relative differential equations from water treatment Leukocytes with self-operating computer

Conventional differentiation has many problems, they are no smoothness, singularity, and non simultaneous.The origin of those problems is:1. Since the differentiation value of conventional differentiation has the infinitesimal real number (include the 10 problem of direction) direction), simultaneous equations are impossible rotation, vibration, and instability Moreover , it generates singularity.2. The problem concerning the existence of minus, There is no apple of a minus piece.A minus piece (a minus time and a minus space) does not exist in the macro world , although it is able to exist in the world of the uncertainty principle. Therefore , don't use the number of minuses absolutely . It is defined as an absolute arithmetic. Relatively the number of minuses should be used. It is defined as a relative arithmetic (operation).In this study, relative differential equation (RDE) by Zai Pair which elementized Nature World solves those problems. Concretely, RDE is able to obtain smoothness by Str Zai, obtain the solution from the singularity by Zai Pair, obtain Kyoku without the infinitesimal real number by Zai Pair and obtain independent from the conventional absolute coordinate system. Moreover, the RDE has self-operating computing, the RDE self-operating computer (SOC) is not model, and the RDE SOC is solution itself and the graph itself. In an example, inflammation itself is RDE SOC itself.

Relative differential equations from water treatment Leukocytes with self-operating computer

Conventional differentiation has many problems, they are no-smoothness, singularity, and non-simultaneous. The origin of those problems is:1. Since the differentiation value of conventional differentiation has the infinitesimal real number (include the problem of direction), simultaneous equations are impossible (rotation, vibration, and instability). Moreover, it generates singularity. 2. The problem concerning the existence of minus, There is no apple of a minus piece. A minus piece (a minus time and a minus space) does not exist in the macro world, although it is able to exist in the world of the uncertainty principle. Therefore, don't use the number of minuses absolutely. It is defined as an absolute arithmetic. Relatively, the number of minuses should be used. It is defined as a relative arithmetic (operation). In this study, relative differential equation (RDE) by Zai Pair which element-ized Nature World solves those problems. Concretely, RDE is able to obtain smoothness by Str Zai, obtain the solution from the singularity by Zai Pair, obtain Kyoku without the infinitesimal real number by Zai Pair and obtain independent from the conventional absolute coordinate system. Moreover, the RDE has self-operating computing, the RDE self-operating computer (SOC) is not model, and the RDE SOC is solution itself and the graph itself. In an example, inflammation itself is RDE SOC itself.

Generalized algorithms for the identification of seismic ground excitations to building structures based on generalized Kalman filtering under unknown input

The exact information of seismic excitation and structural state is a prerequisite for structural seismic safety assessment and vibration control. When the seismic excitation to a structure is not measured, the seismic excitation can be identified as an inversed problem from measured structural responses. Although some relevant approaches have been developed, there are certain limitations or drawbacks in the existing approaches. To circumvent these problems, two generalized algorithms are proposed for the identification of seismic ground excitation to multi-story and tall buildings, respectively. When the seismic ground excitation to a structure is not measured, the data measured by a structural health monitoring system are structural absolute responses. So the structural motion equation in the absolute coordinate system is derived, in which the unknown seismic ground excitation is treated as unknown external force acting on the structure. First, the identification of unknown seismic excitations to multi-story building structures is studied. A generalized Kalman filtering under unknown input is proposed for the identification of structural state and unknown seismic excitation without the observation of structural absolute acceleration responses at the location of unknown external force. The derivation of the proposed generalized Kalman filtering under unknown input is based on the classical Kalman filter, but is more general than the existing identification approaches based on Kalman filter with unknown input in the deployments of accelerometers in the building structure. Then, it is extended to explore the identification of unknown seismic excitations to tall building structures. To avoid substructural identification from the top to bottom in a sequential manner, the motion equation in absolute coordinate system is reduced by modal expansion. Moreover, instead of the identification of unknown modal forces in previous approaches, the seismic excitation is directly identified without increasing the number of unknown forces. To demonstrate the proposed algorithms, numerical examples of identifying seismic excitations to a 6-story shear building and an 18-story tall building are investigated.

THREE-DIMENSIONAL DIGITAL DOCUMENTATION OF HERITAGE SITES USING TERRESTRIAL LASER SCANNING AND UNMANNED AERIAL VEHICLE PHOTOGRAMMETRY

Three-dimensional digital documentation is an important technique for the maintenance and monitoring of cultural heritage sites. This study focuses on the three-dimensional digital documentation of the Magoksa Temple, Republic of Korea, using a combination of terrestrial laser scanning and unmanned aerial vehicle (UAV) photogrammetry. Terrestrial laser scanning mostly acquired the vertical geometry of the buildings. In addition, the digital orthoimage produced by UAV photogrammetry had higher horizontal data acquisition rate than that produced by terrestrial laser scanning. Thus, the scanning and UAV photogrammetry were merged by matching 20 corresponding points and an absolute coordinate system was established using seven ground control points. The final, complete threedimensional shape had perfect horizontal and vertical geometries. This study demonstrates the potential of integrating terrestrial laser scanning and UAV photogrammetry for three-dimensional digital documentation. This new technique is expected to contribute to the three-dimensional digital documentation and spatial analysis of cultural heritage sites.

Study on Elastic Dynamic Model for the Clamping Mechanism of High-Speed Precision Injection Molding Machine

This work centered on the double-toggle clamping mechanism with diagonal-five points for the high-speed precise plastic injection machine. Based on Lagrange equations, the differential equations of motion for the beam elements are established, in a rotating coordinate system and an absolute coordinate system, respectively. 43 generalized coordinates and a model matrix for the mechanism are created and some coordinate matrices are derived. By coupling the coordinate transformation and matrix manipulation, a high nonlinear and strong time-variant elastic dynamic model is obtained. Based on the dynamic model, a Kineto-Elasto Dynamics (KED) analysis and a Kineto-Elasto Static (KES) analysis are carried out, respectively. By comparing and analyzing the simulation results of KED and KES, the regularity of elastic vibration of the clamping mechanism in high-speed clamping process has been revealed.

A Modular Design Method Based on Control-Model

In order to solve problems concerning the complex module replacement and positioning difficulties in the modular design process, the control-model which reflects the main structure of product is established. Control-model bases itself on the product’s absolute coordinate system, and by establishing datum plane and sketches it reflects the main structure of products. According to the relationship between modules, modules can be partitioned into main-modules and attached-modules. The main- and attached-modules established by using control-model as seed file contain relevant information of the control-model, therefore the method of modules’ rapid positioning by comparison and updating as well as module change strategies can be used to realize modular design process without assembly constraints. Finally, taking a certain type of tank semi-trailer as an example, this paper makes detailed explanation about the modular design method based on control-model.

A Relative Method for Finite Element Nonlinear Structural Analysis

Nodal displacements are referred to the initial configuration in the total Lagrangian formulation and to the last converged configuration in the updated Lagrangian formulation. This research proposes a relative nodal displacement method to represent the position and orientation for a node in truss structures. Since the proposed method measures the relative nodal displacements relative to its adjacent nodal reference frame, they are still small for a truss structure undergoing large deformations for the small size elements. As a consequence, element formulations developed under the small deformation assumption are still valid for structures undergoing large deformations, which significantly simplifies the equations of equilibrium. A structural system is represented by a graph to systematically develop the governing equations of equilibrium for general systems. A node and an element are represented by a node and an edge in graph representation, respectively. Closed loops are opened to form a spanning tree by cutting edges. Two computational sequences are defined in the graph representation. One is the forward path sequence that is used to recover the Cartesian nodal displacements from relative nodal displacements and traverses a graph from the base node towards the terminal nodes. The other is the backward path sequence that is used to recover the nodal forces in the relative coordinate system from the known nodal forces in the absolute coordinate system and traverses from the terminal nodes towards the base node. One closed loop structure undergoing large deformations is analyzed to demonstrate the efficiency and validity of the proposed method.