scholarly journals Automotive Lidar Modelling Approach Based on Material Properties and Lidar Capabilities

Sensors ◽  
2020 ◽  
Vol 20 (11) ◽  
pp. 3309 ◽  
Author(s):  
Stefan Muckenhuber ◽  
Hannes Holzer ◽  
Zrinka Bockaj
Keyword(s):  
Infrared Spectrum ◽  
Material Properties ◽  
Incidence Angle ◽  
Lidar Measurement ◽  
Automated Driving ◽  
Measurement Device ◽  
Test Environment ◽  
Physical Test ◽  
Virtual Test ◽  
Modelling Approach

Development and validation of reliable environment perception systems for automated driving functions requires the extension of conventional physical test drives with simulations in virtual test environments. In such a virtual test environment, a perception sensor is replaced by a sensor model. A major challenge for state-of-the-art sensor models is to represent the large variety of material properties of the surrounding objects in a realistic manner. Since lidar sensors are considered to play an essential role for upcoming automated vehicles, this paper presents a new lidar modelling approach that takes material properties and corresponding lidar capabilities into account. The considered material property is the incidence angle dependent reflectance of the illuminated material in the infrared spectrum and the considered lidar property its capability to detect a material with a certain reflectance up to a certain range. A new material classification for lidar modelling in the automotive context is suggested, distinguishing between 7 material classes and 23 subclasses. To measure angle dependent reflectance in the infrared spectrum, a new measurement device based on a time of flight camera is introduced and calibrated using Lambertian targets with defined reflectance values at 10 % , 50 % , and 95 % . Reflectance measurements of 9 material subclasses are presented and 488 spectra from the NASA ECOSTRESS library are considered to evaluate the new measurement device. The parametrisation of the lidar capabilities is illustrated by presenting a lidar measurement campaign with a new Infineon lidar prototype and relevant data from 12 common lidar types.

Enhancement of acoustic absorption of a rigidly backed poroelastic plate with periodic elliptic inclusions

2019 ◽  
Vol 33 (30) ◽  
pp. 1950367
Author(s):  
Hongbo Zhang ◽  
Bilong Liu
Keyword(s):  
Material Properties ◽  
Composite Plate ◽  
Incidence Angle ◽  
Major Axis ◽  
Acoustic Energy ◽  
Absorption Peak ◽  
Acoustic Absorption ◽  
The Finite Element Method ◽  
Solid Materials ◽  
Low Frequencies

Perfect acoustic absorption is an important issue for a lot of applications. In this paper, a rigidly backed poroelastic plate with periodic elliptic inclusions is proposed to achieve perfect acoustic absorption at low frequencies by using the finite element method (FEM) with the porous material considered as fluid and solid materials. The absorption of the acoustic energy in such a composite plate resulting from viscous and thermal losses is enhanced by the resonances of the inclusions and energy trapping between the upper part of the poroelastic plate and the inclusion at low frequencies. The influence of the geometry, the incidence angle and the material properties on the absorption coefficient are investigated in detail. Our results show that increasing the major axis of the inclusion, the first absorption peak is pushed to lower frequencies and its value is first increased upto one and then it is decreased. The major axis is the most important parameter to tune the absorption peak, when the thickness is not changed. Once the major axis is determined, perfect acoustic absorption persists even if other parameters are changed. The reported results pave the way for the design of absorption devices which could be used to solve the major issue of noise control.

Virtual Test Environment for Self-Optimizing Systems

2013 ◽  
Author(s):  
Jörg Stöcklein ◽  
Daniel Baldin ◽  
Wolfgang Müller ◽  
Tao Xie
Keyword(s):  
Operating System ◽  
Real Time ◽  
Virtual Prototype ◽  
Test Cases ◽  
Test Environment ◽  
Dead Code ◽  
Real Time Operating System ◽  
The Real ◽  
Code Coverage ◽  
Virtual Test

In our paper we present a virtual test environment for self-optimizing systems based on mutant based testing to validate user tasks of a real-time operating system. This allows the efficient validation of the code coverage of the test cases and therefore helps to detect errors in order to improving the reliability of the system software. Technically we are able to run and test the software on both systems. By writing application software and setting up the virtual test environment properly, we define our test cases. To validate the code coverage for our test cases, we use the approach of mutant based testing. By running this mutated code on our virtual prototype in the virtual test environment, we are able to efficiently validate the code coverage and are able to detect bugs in the application code or detect dead code that is not executed. Finding non-executing code leads to redefinition of our test cases by either changing the test environment or the application code in the case of dead code. We implemented the virtual test environment on top of the third party low cost VR system Unity 3D, which is frequently used in entertainment and education. We demonstrate our concepts by the example of our BeBot robot vehicles. The implementation is based on our self-optimizing real-time operating system ORCOS and we used the tool CERTITUDE(TM) for generating the mutations in our application code. Our BeBot virtual prototype in our virtual test environment implements the same low-level interface to the underlying hardware as the real BeBot. This allows a redirection of commands in ORCOS to either the real or the virtual BeBot in order to provide a VR based platform for early software development as well as ensures comparable conditions under both environments. Our example applies a virtual BeBot that drives through a labyrinth utilizing its IR sensors for navigation. The mutant based testing checks if all situations implemented by the software to navigate through the labyrinth are covered by our tests.

Virtual Test of Automated Driving Functions

ATZ worldwide ◽  
2020 ◽  
Vol 122 (5) ◽  
pp. 16-21
Author(s):  
Torsten Butz ◽  
Simon Paleduhn ◽  
Alexander Merkel ◽  
Christian Bohner
Keyword(s):  
Automated Driving ◽  
Virtual Test

A Multi-Station Rolling/Sliding Tribotester for Knee Bearing Materials

2004 ◽  
Vol 126 (2) ◽  
pp. 380-385 ◽  
Author(s):  
Douglas W. Van Citters ◽  
Francis E. Kennedy ◽  
John H. Currier ◽  
John P. Collier ◽  
Thomas D. Nichols
Keyword(s):  
Material Properties ◽  
Normal Load ◽  
Fatigue Behavior ◽  
Water Environment ◽  
Fatigue Tests ◽  
Test Environment ◽  
Normal Contact ◽  
Bearing Materials ◽  
Number Of Cycles

Total joint replacements traditionally employ ultra high molecular weight polyethylene (UHMWPE) as a bearing material due to its desirable material properties and biocompatibility. Failure of these polyethylene bearings can lead to expensive and risky revision surgery, necessitating a better understanding of UHMWPE’s tribological properties. A six-station rolling/sliding machine was developed to study the behavior of accelerated-aged UHMWPE in cylinder-on-cylinder contact. The normal load and sliding/rolling ratio in the oscillatory contacts can be controlled separately for each test station, as can the liquid test environment. Fatigue tests were run on the machine with UHMWPE versus cobalt-chrome cylinders in a distilled water environment at normal contact pressures of approximately 20 MPa. All specimens failed by subsurface cracking during tribotesting on the machine, and the failures were similar to those that occur in-vivo. The fatigue behavior of the polymer was analyzed to determine its relationship to oxidation and stress state in the rolling/sliding cylinder. At the 20 MPa test load, the number of cycles to fatigue failure by subsurface cracking was inversely proportional to the oxidation level. Analysis of the stress levels through the bulk of the polyethylene specimens and their relationship to the material properties provide insight as to why cracks initiate and propagate subsurface.

Material properties of the cornea and sclera: A modelling approach to test experimental analysis

2011 ◽  
Vol 44 (3) ◽  
pp. 543-546 ◽  
Author(s):  
M. Asejczyk-Widlicka ◽  
W. Śródka ◽  
R.A. Schachar ◽  
B.K. Pierścionek
Keyword(s):  
Material Properties ◽  
Experimental Analysis ◽  
Modelling Approach

Determination of local material properties of OSB sample by coupling advanced imaging techniques and morphology-based FEM simulation

Holzforschung ◽  
2011 ◽  
Vol 65 (6) ◽  
pp. 811-818 ◽  
Author(s):  
Vaclav Sebera ◽  
Lech Muszyński
Keyword(s):  
Compression Test ◽  
Material Properties ◽  
Spatial Information ◽  
Oriented Strand Board ◽  
Imaging Techniques ◽  
Image Correlation ◽  
Fe Model ◽  
Physical Test ◽  
Local Material ◽  
Local Material Properties

Abstract The goal was to determine local mechanical properties inside of oriented strand board (OSB) based on a realistic morphology-based finite element (FE) model and data acquired from a physical test performed on the same material. The spatial information and local grayscale intensity from CT-scans obtained from small OSB sample was transformed into a 2D regular morphology-based FE mesh with corresponding material properties. The model was then used to simulate the actual compression test performed on the specimen using simplified boundary conditions. The simulated strain fields from the model were compared with the actual strain field measured on the specimen surface during the compression test by means of a full-field optical method, named digital image correlation (DIC). Finally, the original set of material properties was adjusted by an iterative procedure to minimize the difference between the simulated and the measured strain data. The results show that the developed procedure is useful to find local material properties as well as for morphological modeling without the need of segmentation of the image data. The achieved results serve as a prerequisite for full 3D analyses of the complex materials.

Virtual 3D Model Simulation for Design and Implementation of Automated Processes

2010 ◽  
Author(s):  
Richard Y. Chiou ◽  
Yongjin James Kwon ◽  
Sang C. Park ◽  
Robin Kizirian ◽  
Yueh-Ting Yang ◽  
...  
Keyword(s):  
Process Development ◽  
Production Systems ◽  
Model Simulation ◽  
Substantial Reduction ◽  
Systems Design ◽  
Design Tool ◽  
Test Environment ◽  
Physical Test ◽  
Simulation Tools ◽  
Automated Processes

This paper presents the integration and implementation of automated processes, based on the sequence control specifications and requirements of PLC (Programmable Logic Controller) systems to create a virtual test environment using a software simulation tool, PLCStudio. In order to meet the demands of the new manufacturing paradigm, PLCStudio is being designed as a next generation tool for digital production. This production solution set represents an integrated suite that provides manufacturing process design, tool and fixture design, factory and production systems design, visualization, and automation through 3D virtual simulation tools. The significant effect and benefit for the manufacturer from such a suite of tools would be a substantial reduction to the manufacturing lifecycle. This includes reduction of the assembly time and cut-down on the cost for a process development through the virtual validation and commissioning of production systems. In this paper, a process with quantifiable goals and efficiencies utilizing a robot and other devices is developed. PLCStudio is used to model the process. PLC logic control is developed to control the system and tested virtually using PLCStudio before it is used in a full scale physical test.

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