Stereoscopic Camera-Sensor Model for the Development of Highly Automated Driving Functions within a Virtual Test Environment

The need for efficient and reproducible development processes for sensor and perception systems is growing with their increased use in modern vehicles. Such processes can be achieved by using virtual test environments and virtual sensor models. In the context of this, the present paper documents the development of a sensor model for depth estimation of virtual three-dimensional scenarios. For this purpose, the geometric and algorithmic principles of stereoscopic camera systems are recreated in a virtual form. The model is implemented as a subroutine in the Epic Games Unreal Engine, which is one of the most common Game Engines. Its architecture consists of several independent procedures that enable a local depth estimation, but also a reconstruction of a whole three-dimensional scenery. In addition, a separate programme for calibrating the model is presented. In addition to the basic principles, the architecture and the implementation, this work also documents the evaluation of the model created. It is shown that the model meets specifically defined requirements for real-time capability and the accuracy of the evaluation. Thus, it is suitable for the virtual testing of common algorithms and highly automated driving functions.

Methodical Approach to Integrate Human Movement Diversity in Real-Time into a Virtual Test Field for Highly Automated Vehicle Systems

Recently, virtual realities and simulations play important roles in the development of automated driving functionalities. By an appropriate abstraction, they help to design, investigate and communicate real traffic scenario complexity. Especially, for edge cases investigations of interactions between vulnerable road users (VRU) and highly automated driving functions, valid virtual models are essential for the quality of results. The aim of this study is to measure, process and integrate real human movement behaviour into a virtual test environment for highly automated vehicle functionalities. The overall system consists of a georeferenced virtual city model and a vehicle dynamics model, including probabilistic sensor descriptions. By motion capture hardware, real humanoid behaviour is applied to a virtual human avatar in the test environment. Through retargeting methods, which enable the independency of avatar and person under test (PuT) dimensions, the virtual avatar diversity is increased. To verify the biomechanical behaviour of the virtual avatars, a qualitative study is performed, which funds on a representative movement sequence. The results confirm the functionality of the used methodology and enable PuT independence control of the virtual avatars in real-time.

A Method for Modeling the Virtual Instrument Automatic Test System Based on the Petri Net

Virtual instrument is playing the important role in automatic test system. This paper introduces a composition of a virtual instrument automatic test system and takes the VXIbus based a test software platform which is developed by CAT lab of the UESTC as an example. Then a method to model this system based on Petri net is proposed. Through this method, we can analyze the test task scheduling to prevent the deadlock or resources conflict. At last, this paper analyzes the feasibility of this method.

The engine performance LabVIEW virtual instrument test system design

This paper adopts American National Instruments (NI) Company’s LabVIEW and LabVIEW RT virtual instrument softwareplatform and lots of things for this engine performance LabVIEW virtual instrument test system, such as the matched NI PCI dataCollection Card, NI SCXI signal-adjusting instrument and NI compact FieldPoint (cFP) distributed I/O real time system hardware.This system has realized multi performances’parallel test; and it can complete load, torsional moment, rotate speed, power, pressureand temperature’s real time monitoring automatically according to user’s setting; and finally through TCP/IP protocol it realizes testdata’s teleshare and telecontrol that user put on the test system. This system has such character as short development period, highuse efficiency and low cost, at the same time it has strong extensibility and reusability, so it has very high applied cost.

Virtual Thermal Test System Based on Simulink and Comsol Co-Simulation

A virtual thermal test system was built through the co-simulation using Simulink and Comsol to realize the complete virtualization of the thermal test.Using the co-simulation technology,comprehensive simulation analysis of the control system,electric field and thermal field was realized.The data state of each observation point could be directly observed at one time,including the output state information of the power amplifier,the output state information of the heater,and the thermal state information of the test unit.The virtual thermal test system has a predictive and guiding role for engineering thermal tests,and can realize thermal environment simulation beyond the existing thermal environment ground simulation capabilities,providing a basis for the development of future models.

Virtual rutting test of asphalt mixture using discrete element method

In order to investigate the permanent deformation behavior of asphalt mixtures from discontinuity, the virtual rutting test of asphalt mixtures is developed by the discrete element method （DEM）. A digital specimen generation procedure considering aggregate gradation and irregular shape is developed based on the probability theory and the Monte Carlo method. The virtual rutting test is then conducted based on the generated digital specimen. In addition, on the basis of the time-temperature superposition （TTS） principle, a calculation method is used to reduce the computation time of the virtual rutting test. The simulation results are compared with the laboratory measurements. The results show that the calculation method based on the TFS principle in the discrete element （DE） viscoelastic model can significantly reduce the computation time. The deformation law of asphalt mixtures in the virtual rutting test is similar to the laboratory measurements, and the deformation and the dynamic stability of the virtual rutting test are slightly greater than the laboratory measurements. The two-dimensional virtual rutting test can predict the permanent deformation performance of asphalt mixtures.

Virtual fracture test of asphalt mixture based on discrete element method

In order to study fracture behaviors of asphalt mixtures, virtual tests of the two-dimensional（2D） microstructure based on the discrete element method（ DEM） are designed. The virtual structure of the 2D digital specimen of asphalt mixture is generated based on a particle generation program, in which the gradation and the irregular shapes of aggregates are considered. With the 2D digital specimens, a DEM-based mixture model is established and center-point beam fracture simulation tests are conducted by the DEM. Meanwhile, a series of calibration tests are carried out in laboratory to evaluate the DEM model and validate the methods of virtual fracture tests. The test results indicate that the fracture intensity of asphalt mixtures predicted by the DEM matches very well with the intensity obtained in laboratory. It is concluded that the microstructural virtual tests can be used as a supplemental tool to evaluate fracture properties of asphalt mixtures.

Microstructure modeling and virtual test of asphalt mixture based on three-dimensional discrete element method

The objective of this work is to model the microstructure of asphalt mixture and build virtual test for asphalt mixture by using Particle Flow Code in three dimensions(PFC^(3D))based on three-dimensional discrete element method.A randomly generating algorithm was proposed to capture the three-dimensional irregular shape of coarse aggregate.And then,modeling algorithm and method for graded aggregates were built.Based on the combination of modeling of coarse aggregates,asphalt mastic and air voids,three-dimensional virtual sample of asphalt mixture was modeled by using PFC^(3D).Virtual tests for penetration test of aggregate and uniaxial creep test of asphalt mixture were built and conducted by using PFC^(3D).By comparison of the testing results between virtual tests and actual laboratory tests,the validity of the microstructure modeling and virtual test built in this study was verified.Additionally,compared with laboratory test,the virtual test is easier to conduct and has less variability.It is proved that microstructure modeling and virtual test based on three-dimensional discrete element method is a promising way to conduct research of asphalt mixture.

A virtual test of screening technology based on the AGEIA PhysX

The authors have created a virtual test of vibration particle-screening using Autodesk's 3ds Max software,the MAXScript scripting language and the AGEIA PhysX physics processing unit(PPU).The affect of various parameters on screening efficiency were modeled.The parameters included vibration amplitude,frequency and direction.The length and inclination of the vibrating surface were also varied.The virtual experiment is in basic agreement with results predicted from screening theory.This shows that the virtual screener can be used for preliminary investigations and the results used to evaluate screen design.In addition it can help with theoretical research.

Realization of Reconfigurable Virtual Environments for Virtual Testing

This paper presents the design and implementation of reconfigurable virtual environments (VEs) for virtual testing. It proposes a hybrid design approach that is derived from a so-called integration and composition of the reconfiguration strategy. The designing process has thus evolved from binding virtual objects using reconfiguration rules within the context of virtual testing scenarios. Therefore reconfigurable virtual environments are established with improved flexibility and scalability, tailored to a wide range of virtual testing applications. Those virtual environments integrate virtual testing scenarios, data acquisition, databases, rule mapping and application interfaces, which yield modular testing functions and an open-ended system architecture with a set of extensible interface tools to realize data exchange within reconfigurable VEs. This enables virtual testing scenarios to be reconfigured interactively based on real time data and communication between virtual environments and real environments. A virtual testing application has been implemented using reconfigurable VEs. Keywords Virtual environment - virtual testing - reconfigurable virtual reality Wenyan Wu graduated from Dalian University of Technology, China, with BSc and MSc in 1988 and 1991 respectively. She earned her PhD degree from University of Derby, UK, in 2002. She had taught and researched in Harbin Institute of Technology, China and De Montfort University, UK. She is currently a senior lecturer in simulation and virtual reality at Staffordshire University, UK. Her research interests include computer graphics, Virtual Reality and Augmented Reality system, advanced interface, modelling and simulation, distribution system.Zhengxu Zhao BSc, MSc, PhD, CEng, CITP, MBCS, full Professor in Applied Computing, Director of Virtual Reality Centre. He is also a Cheng Kong Scholar Project Professor in Virtual Reality Technology and Director of Virtual Reality Research Centre at the Southeast University, P R China. Professor Zhao’s research interests include computing graphics and VR systems, industrial process simulation, CIM and manufacturing management systems.

Modeling of Electromagnetic Wave Propagation and Its Applicationin Virtual Test

With the development of virtual test,the computation of the effect of different weather conditions on electromagnetic wave propagation is required in many simulation systems. Firstly,this paper presents a unique point of view for computing the electromagnetic wave attenuation ratio under different weather conditions by means of an independent electromagnetic wave propagation component that can be directly implemented in virtual test, and is easy to configure and easy to reuse. We present an analysis of the principles of electromagnetic wave propagation and the algorithms designed for realization of various propagation models within the electromagnetic wave propagation component. Secondly,this paper presents a use-case analysis and outlines the design of the component,verifies the developed models under various weather conditions,and obtains equivalent values as those obtained theoretically. Finally,we build a virtual test system,verify the system in different weather conditions,and again obtain equivalent values to those obtained theoretically. The algorithms in the electromagnetic wave propagation component are developed in the C language, which substantially improves the computational speed,and meets the real-time requirements of the virtual testing platform.

NUMERICAL MODELING OF MULTI-CYLINDER ELECTRO-HYDRAULIC SYSTEM AND CONTROLLER DESIGN FOR SHOCK TEST MACHINE

A high fidelity dynamic model of a high-energy hydraulically-actuated shock test machine for heavy weight devices is presented to satisfy the newly-built shock resistance standard and simulate the actual underwater explosion environments in laboratory as well as increase the testing capability of shock test machine. In order to produce the required negative shock pulse in the given time duration, four hydraulic actuators are utilized. The model is then used to formulate an advanced feedforward controller for the system to produce the required negative waveform and to address the motion synchronization of the four cylinders. The model provides a safe and easily controllable way to perform a ＂virtual testing＂ before starting potentially destructive tests on specimen and to predict performance of the system. Simulation results have demonstrated the effectiveness of the controller.

The Design and Implementation of Multi-user Data Sharing Platform for Remote Monitoring System Based on Virtual Instruments

Remote data monitoring system which adopts virtual instrument usually applies data sharing, acquisition and remote transmission technology via internet. It is able to finish concurrent data acquisition and processing for multi-user and multi-task and also build a personalized virtual testing environment for more people but with fewer instruments. In this paper, we＇ 11 elaborate on the design and implementation of information sharing platform through a typical example of how to build multi-user concurrent virtual testing environment based on the virtnal software LabVIEW.

Scheduling method based on virtual flattened architecture for Hierarchical system-on-chip

As the technology of IP-core-reused has been widely used, a lot of intellectual property （IP） cores have been embedded in different layers of system-on-chip （SOC）. Although the cycles of development and overhead are reduced by this method, it is a challenge to the SOC test. This paper proposes a scheduling method based on the virtual flattened architecture for hierarchical SOC, which breaks the hierarchical architecture to the virtual flattened one. Moreover, this method has more advantages compared with the traditional one, which tests the parent cores and child cores separately. Finally, the method is verified by the ITC＇02 benchmark, and gives good results that reduce the test time and overhead effectively.

灌木平茬机切割系统参数优化设计与验证

为分析圆盘锯式切割系统的切割机理,在Solidworks中建立单组圆盘锯及灌木枝条的简化模型,并在动力学分析软件ABAQUS中进行仿真分析,研究灌木切割过程中工作参数与圆锯片参数的关系。同时,以锯片转速、行进速度、枝径为影响因素,以锯切力为评价指标,对其影响的因素进行虚拟正交试验,并用Design Expert动态响应软件进行分析,得到响应面回归方程,得知当圆锯转速为2500r/min、前进速度为0.9m/s时平茬效果较好。用小型灌木平茬机上进行实地试验,结果表明破茬率和留茬高度均能满足农艺要求。

AFDX网络配置测试技术研究

终端系统作为AFDX网络数据传输的关键部分,其优劣决定着整个AFDX网络的通信性能。为了测试验证端系统功能,评估AFDX网络的传输性能,提出了一种AFDX网络配置测试方法。设计端系统的配置测试规范,建立端系统测试总体框架,对端系统的测试响应机制进行研究,规范化测试流程,生成的配置文件作为算法设计的输入信息。设计激励数据生成算法,建立激励数据生成框架,对数据发送的约束条件进行形式化定义,利用SMT求解器,生成激励数据发送时刻表。激励数据发送时刻表作为输入,利用TestCenter网络测试平台进行仿真实验,实验结果证明该方法能模拟当前AFDX网络配置在高负载数据流下的有效性。

虚拟仪器的电机测试系统设计研究

由于目前的微型计算机通用试验系统大都是使用Windows的多媒体软件,其计时精度和实时性都很差。本文提出利用虚拟仪器技术对电机测试试验系统进行仿真,并把软件工程学的概念引入到该试验系统的设计中,实现了各部分的功能相对的独立性,从而保证了该试验系统的可靠性。在此基础上,借助LabVIEW自身的特性,实现了基于操作系统的较为准确的计时工作,并具备了很强的移植能力。实践证明,此系统性能可靠、操作简便、实用方便,同时也减少了试验费用,能够很好地适应现场试验的需要。

机械振动测试系统设计中虚拟仪器的应用

LabVIEW具有直观的程序设计接口、方便的开发环境,已被广泛地用于测量、控制等方面。本文以基于虚拟仪器技术分析、系统软硬件设计及上下位机联合调试为手段,研制一种基于虚拟仪器技术的结构振动检测系统,并通过系统仿真试验与野外试验进行比较分析,以检验其实用性。本文对类似的软件的研发具有一定的参考价值。

信息化背景下综合设计性虚拟仿真实验评价系统构建

为对综合设计性虚拟仿真实验进行有效的评价建立实验评价系统。研究分析目前已有的在线开放课程评价体系和虚拟仿真实验的系统架构,把多元智能理论和学习结果分类理论应用于虚拟仿真实验评价系统中,构建包括理论知识维度、思维创新维度、实验技能测试维度和情感态度维度等多个维度的综合设计性虚拟仿真实验评价体系。