Search results

Filters

  • Journals
  • Authors
  • Keywords
  • Date
  • Type

Search results

Number of results: 3
items per page: 25 50 75
Sort by:
Download PDF Download RIS Download Bibtex

Abstract

Among the full-field optical measurement methods, the Digital Image Correlation (DIC) is one of the techniques which has been given particular attention. Technically, the DIC technique refers to a non-contact strain measurement method that mathematically compares the grey intensity changes of the images captured at two different states: before and after deformation. The measurement can be performed by numerically calculating the displacement of speckles which are deposited on the top of object’s surface. In this paper, the Two-Dimensional Digital Image Correlation (2D-DIC) is presented and its fundamental concepts are discussed. Next, the development of the 2D-DIC algorithms in the past 33 years is reviewed systematically. The improvement of 2DDIC algorithms is presented with respect to two distinct aspects: their computation efficiency and measurement accuracy. Furthermore, analysis of the 2D-DIC accuracy is included, followed by a review of the DIC applications for two-dimensional measurements.

Go to article

Authors and Affiliations

Sze-Wei Khoo
Saravanan Karuppanan
Ching-Seong Tan
Download PDF Download RIS Download Bibtex

Abstract

This contribution deals with the modelling of a selected part of a new automotive communication standard called FlexRay. In particular, it focuses on the mechanism ensuring the start-up of a FlexRay network. The model has been created with the use of timed automata and verified. For this purpose the UPPAAL software tool has been used that allows the modelling of discrete event systems with the use of timed automata, and subsequently the verification of the model with the use of suitable queries compiled in the so called computation tree logic. This model can be used to look for incorrect settings of time parameters of communication nodes in the network that prevent network start-up and subsequently the start of the car. The existence of this model also opens the way for finding possible errors in the standard. On the basis of the model, the work gives a case study of the start-up mechanism behaviour verification in a FlexRay network consisting of three communication nodes.

Go to article

Authors and Affiliations

Jan Malinský
Jiří Novák
Download PDF Download RIS Download Bibtex

Abstract

Geospatial data obtained using Unmanned Aerial Vehicles (UAVs) and Unmanned Surface Vehicles (USVs) are increasingly used to model the terrain in the coastal zone, in particular in shallow waterbodies (with a depth of up to 1 m). In order to generate a terrain relief, it is important to choose a method for modelling that will allow it to be accurately projected. Therefore, the aim of this article is to present a method for accuracy assessment of topo-bathymetric surface models based on geospatial data recorded by UAV and USV vehicles. Bathymetric and photogrammetric measurements were carried out on the waterbody adjacent to the public beach in Gdynia (Poland) in 2022 using a DJI Phantom 4 RTK UAV and an AutoDron USV. The geospatial data integration process was performed in the Surfer software. As a result, Digital Terrain Models (DTMs) in the coastal zone were developed using the following terrain modelling methods: Inverse Distance to a Power (IDP), Inverse Distance Weighted (IDW), kriging, the Modified Shepard’s Method (MSM) and Natural Neighbour Interpolation (NNI). The conducted study does not clearly indicate any of the methods, as the selection of the method is also affected by the visualization of the generated model. However, having compared the accuracy measures of the charts and models obtained, it was concluded that for this type of data, the kriging (linear model) method was the best. Very good results were also obtained for the NNI method. The lowest value of the Root Mean Square Error (RMSE) (0.030 m) and the lowest value of the Mean Absolute Error (MAE) (0.011 m) were noted for the GRID model interpolated with the kriging (linear model) method. Moreover, the NNI and kriging (linear model) methods obtained the highest coefficient of determination value (0.999). The NNI method has the lowest value of the R68 measure (0.009 m), while the lowest value of the R95 measure (0.033 m) was noted for the kriging (linear model) method.
Go to article

Authors and Affiliations

Oktawia Lewicka
1 2

  1. Department of Geodesy and Oceanography, Gdynia Maritime University, ul. Morska 81-87, 81-225 Gdynia, Poland
  2. Marine Technology Ltd., ul. Wiktora Roszczynialskiego 4-6, 81-521 Gdynia, Poland

This page uses 'cookies'. Learn more