THE DESIGN AND ANALYSIS OF EXPERIMENTS. By Oscar Kempthorne. New York, John Wiley and Sons, Inc., 1952. 631 pp. $8.50. This book by a teacher of statistics (as well as a consultant for \"experimenters\") is a comprehensive study of the philosophical background for the statistical design of experiment. It is necessary to have some facility with algebraic notation and manipulation to be able to use the volume intelligently. The problems are presented from the theoretical point of view, without such practical examples as would be helpful for those not acquainted with mathematics. The mathematical justification for the techniques is given. As a somewhat advanced treatment of the design and analysis of experiments, this volume will be interesting and helpful for many who approach statistics theoretically as well as practically. With emphasis on the \"why,\" and with description given broadly, the author relates the subject matter to the general theory of statistics and to the general problem of experimental inference. MARGARET J. ROBERTSON

The Design and Analysis of Experiments

Fault detection, isolation, and reconfiguration (FDIR) is an important and challenging problem in many engineering applications and continues to be an active area of research in the control community. This paper presents a survey of the various model-based FDIR methods developed in the last decade. In the paper, the FDIR problem is divided into the fault detection and isolation (FDI) step, and the controller reconfiguration step. For FDI, we discuss various model-based techniques to generate residuals that are robust to noise, unknown disturbance, and model uncertainties, as well as various statistical techniques of testing the residuals for abrupt changes (or faults). We then discuss various techniques of implementing reconfigurable control strategy in response to faults.

A Survey of Fault Detection, Isolation, and Reconfiguration Methods

Past, present and future of nonlinear system identification in structural dynamics

Technology developments in structural health monitoring of large-scale bridges

https://people.duke.edu/~hpgavin/SystemID/References/Markovsky+VanHuffel-SP-2007.pdf

Overview of total least-squares methods

Engineering approach for robust vibro-acoustic design optimization

Operational Modal Analysis (OMA) allows the structural identification of systems in working conditions, moving from output data only. External forces remain not measured. Basically some fundamental assumptions have to be satisfied: (i) the not known loads acting on the system need to have the form of white noise sequences, (ii) in the case of multi-point excitation the external inputs are required to be strictly uncorrelated. In the field of vehicle dynamics, OMA can be utilised to assess the performance of different suspension systems equipping the same type of vehicle. The output data recorded at the different sensor locations during vehicle road tests are affected by a certain correlation among the road forces acting on the wheels, mainly that loading the front and the rear axle, even if inputs on wheels belonging to the left and the right side could be also in some way correlated. In this paper the correlation between the road inputs acting on the front and the rear axle of a passenger car has been investigated with the aim of obtaining a novel OMA formulation moving from the expressions of the modal decomposition of the output power spectral densities that hold in this case.

Operational Modal Analysis of passenger cars: Effect of the correlation between front and rear inputs

An impedance approach to vibro-acoustic modeling

Switched reluctance machines (SRMs) benefit from major advantages, such as cheap and robust construction and electrical fault tolerance, but also suffer from noise, vibration and harshness (NVH) issues. The present paper focuses on the NVH influence of the current hysteresis controller, which is generally used in SRM drives. The impact of changes in the controller sampling time is experimentally investigated on an 8/6 15 kW (30 kW peak) SRM. In practice the initial hysteresis controller, implemented on a dSPACE platform running at 10 kHz, is compared with an improved version running twenty times faster on external microcontrollers. Tests are performed in the form of run-ups, in order to study the drive in transient conditions and investigate a continuous speed range, while vibration, current and sound pressure waves are measured. Current waveforms are also simulated using AMESim software to compare with experimental measurements. Both controller implementations are modelled and both run-up and constant speed conditions are considered. To identify the frequency content related to the switching process, those simulation results are also analysed before and after having removed the current ripple due to switching through signal processing. Run-up results are plotted as waterfall diagrams, which both give a global overview of the frequency content for the considered speed range and allow distinguishing speed-order related harmonics and resonance frequencies. It is observed that the improved controller generates a shift of the spectrum towards higher frequencies with a global reduction of vibration and noise amplitude. Furthermore, the excitation of the dominating first ovalization mode of the SRM is considerably reduced.

Noise and vibrations of switched reluctance machine drives - influence of the current hysteresis control

While the digital twin has become an intrinsic part of the product creation process, its true power lies in the connectivity of the digital representation with its physical counterpart. Data acquired on the physical asset can validate, update and enrich the digital twin. The knowledge contained in the digital representation brings value to the physical asset itself. When a dedicated encapsulation is extracted from the digital twin to model a specific set of behaviors in a specific context, delivering a stand-alone executable representation, such instantiated and self-contained model is referred to as an Executable Digital Twin. In this contribution, key building blocks such as model order reduction, real-time models, state estimation and co-simulation are reviewed, and a number of characteristic use cases are presented. These include virtual sensing, hybrid testing and hardware-in-the loop, model-based control and model-based diagnostics.

Herman Van der Auweraer

Papers

Engineering approach for robust vibro-acoustic design optimization

Operational Modal Analysis of passenger cars: Effect of the correlation between front and rear inputs

An impedance approach to vibro-acoustic modeling

Noise and vibrations of switched reluctance machine drives - influence of the current hysteresis control

The Executable Digital Twin: merging the digital and the physics worlds