Investigation and development of a Digital Twin for the Maeslant barrier: Exploring the application of digital twins in the maintenance and operation of storm surge barriers

A Digital twin, a digital replica of a physical entity or system, encapsulated in a software model, represents a promising technology that has demonstrated its effectiveness for asset management in various industries. Rijkswaterstaat has gained interest in investigating the possibilities for digital twin integration in the asset management of...

Searching for Meiji-Tokyo: Heterogeneous Visual Media and the Turn to Global Urban History, Digitalization, and Deep Learning

Security economics in the HTTPS value chain

Even though we increasingly rely on HTTPS to secure Internet communications, several landmark incidents in recent years have illustrated that its security is deeply flawed. We present an extensive multi-disciplinary analysis that examines how the systemic vulnerabilities of the HTTPS authentication model could be addressed. We conceptualize the...

Realisation of a knowledge platform for theme 1 "soil and construction"

Data of Simona population for MDHMS application: Collecting and deriving data for human modelling sotware to use in Flight Simulator Design

For the interior design of a flight simulator, the ergonomic software MDHMS has been used to test different interior layout issues. The MDHMS program includes an accommodation analysis capability, which generates a digital sample of the specific target group. This report shows the data required for this analysis. Since there are just a few...

The real-time Hermes robot arm simulator: HSF-P

The Hermes manipulation system (HERA) is a sophisticated space manipulator system, which has to perform tasks ranging from berthing to tool operation in various operational modes from fully automatic to purely manual. The HERA system main contractor is Fokker Space & Systems B.V. (FSS). Development and qualification of such a space-based...

The generation of a random process with a spectrum with fractional power

A method is described to generate a random Gaussian process with a power spectrum with fractional power, for example the von Karman spectrum for atmospheric turbulence. The method uses digital filtering of a white noise process and it is based on the use of fractional derivatives. An algorithm to generate the process is presented.

Frequency response analysis of hybrid systems

Current design methods for digital control systems to be operated in a continuous environment do not always result in the most efficient use of digital computing hardware. To improve this situation, a dedicated frequency response analysis method was developed for hybrid systems. For practical use of the method, it has been expanded to an...

A modular and versatile acquisition, recording and preprocessing system for airborne remote sensing

The National Aerospace Laboratory "NLR" is the operator of an aircraft which can be equipped with either a SLAK, a multl spectral scanner or a TVbased scanner. The airborne recording equipment la designed to accommodate these various sensors. The general airborne system setup is: the sensor, a dedicated digitizing unit and an Interface to a High...

Towards digital computer simulation of the dynamics of flexible spacecraft

Software design for digital computer simulation of the dynamics of flexible spacecraft equipped with actuators and sensors, should take into account two properties of the overall system: (i) s.ampled-data control of the spacecraft leads to discontinuous inputs (forcing functions) in the differential equations of motion, thereby requiring...

Reliability aspects of software for digital avionics

Modern commercial transport aircraft contain digital avionics systems for more and more safety critical functions. The reliability and safety of those new systems depend on the hardware reliability and on the reliability of the embedded software. In this report, an overview is given of available methods and techniques to develop reliable...

Application of model following control and estimation techniques to attitude control of manoeuvring spacecraft Part II: Simulation software description

This document describes two computer programs developed during a study of the application of modern control techniques in the area of spacecraft attitude control. Theory and simulation results are described in part I of this report. In part II a general overview of the tasks of the simulation program is presented, and program design aspects are...

Experimental and system study of Reaction Wheels. Part II: System study on wheel state feedback

The increasing power of on-board processors allows more freedom in the design and operation of reaction wheel control systems. This report discusses several performance and implementation aspects of the operation of wheel systems which have their own internal feedback control system. A model following control concept is found to be superior. The...

Trends in airline avionics

Modern avionics are an integral part of the aircraft. They provide the functions of communication, navigation, energy management, identification, weather, terrain, and collision avoidance, the presentation of flight and warning data as well as aircraft guidance and stabilization. New developments in micro-electronics and display technology...

Digital large scale restitution and map compilation

For the effective performance of its work, the Rijkswaterstaat, which has a staff of about 12.000, consists of 25 Directorates with different duties. One of them is the Meetkundige Dienst (Survey Department) with a staff of about 500, which is charged with the geodetic support of the Rijkswaterstaat. Part of this support is the preparation of...

Digital filtering methods, with applications to satellite attitude determination in the presence of modelling errors. Part I: theory

The report reviews a number of digital filtering methods and gives examples of their application. The methods include batch processing methods and rec\irsive methods, not only in the classical formulations but also in square-root formulations. The latter formulations have the purpose to prevent certain numerical inconveniences. Much attention is...

In-orbit experiment with an attitude control algorithm for ANS based on modern control principles

The existing fine attitude system of the Astronomical Netherlands Satellite was designed on the basis of conventional digital control techniques. The possibility of a more advanced approach is presented in this report. As an example, an alternative control algorithm for the scan mode has been developed with the use of state estimation and state...