---
_id: '51518'
abstract:
- lang: eng
  text: In applications of piezoelectric actuators and sensors, the dependability
    and particularly the reliability throughout their lifetime are vital to manufacturers
    and end-users and are enabled through condition-monitoring approaches. Existing
    approaches often utilize impedance measurements over a range of frequencies or
    velocity measurements and require additional equipment or sensors, such as a laser
    Doppler vibrometer. Furthermore, the non-negligible effects of varying operating
    conditions are often unconsidered. To minimize the need for additional sensors
    while maintaining the dependability of piezoelectric bending actuators irrespective
    of varying operating conditions, an online diagnostics approach is proposed. To
    this end, time- and frequency-domain features are extracted from monitored current
    signals to reflect hairline crack development in bending actuators. For validation
    of applicability, the presented analysis method was evaluated on piezoelectric
    bending actuators subjected to accelerated lifetime tests at varying voltage amplitudes
    and under external damping conditions. In the presence of a crack and due to a
    diminished stiffness, the resonance frequency decreases and the root-mean-square
    amplitude of the current signal simultaneously abruptly drops during the lifetime
    tests. Furthermore, the piezoelectric crack surfaces clapping is reflected in
    higher harmonics of the current signal. Thus, time-domain features and harmonics
    of the current signals are sufficient to diagnose hairline cracks in the actuators.
article_number: '521'
article_type: original
author:
- first_name: Osarenren Kennedy
  full_name: Aimiyekagbon, Osarenren Kennedy
  id: '9557'
  last_name: Aimiyekagbon
- first_name: Amelie
  full_name: Bender, Amelie
  id: '54290'
  last_name: Bender
- first_name: Tobias
  full_name: Hemsel, Tobias
  id: '210'
  last_name: Hemsel
- first_name: Walter
  full_name: Sextro, Walter
  id: '21220'
  last_name: Sextro
citation:
  ama: Aimiyekagbon OK, Bender A, Hemsel T, Sextro W. Diagnostics of Piezoelectric
    Bending Actuators Subjected to Varying Operating Conditions. <i>Electronics</i>.
    2024;13(3). doi:<a href="https://doi.org/10.3390/electronics13030521">10.3390/electronics13030521</a>
  apa: Aimiyekagbon, O. K., Bender, A., Hemsel, T., &#38; Sextro, W. (2024). Diagnostics
    of Piezoelectric Bending Actuators Subjected to Varying Operating Conditions.
    <i>Electronics</i>, <i>13</i>(3), Article 521. <a href="https://doi.org/10.3390/electronics13030521">https://doi.org/10.3390/electronics13030521</a>
  bibtex: '@article{Aimiyekagbon_Bender_Hemsel_Sextro_2024, title={Diagnostics of
    Piezoelectric Bending Actuators Subjected to Varying Operating Conditions}, volume={13},
    DOI={<a href="https://doi.org/10.3390/electronics13030521">10.3390/electronics13030521</a>},
    number={3521}, journal={Electronics}, publisher={MDPI AG}, author={Aimiyekagbon,
    Osarenren Kennedy and Bender, Amelie and Hemsel, Tobias and Sextro, Walter}, year={2024}
    }'
  chicago: Aimiyekagbon, Osarenren Kennedy, Amelie Bender, Tobias Hemsel, and Walter
    Sextro. “Diagnostics of Piezoelectric Bending Actuators Subjected to Varying Operating
    Conditions.” <i>Electronics</i> 13, no. 3 (2024). <a href="https://doi.org/10.3390/electronics13030521">https://doi.org/10.3390/electronics13030521</a>.
  ieee: 'O. K. Aimiyekagbon, A. Bender, T. Hemsel, and W. Sextro, “Diagnostics of
    Piezoelectric Bending Actuators Subjected to Varying Operating Conditions,” <i>Electronics</i>,
    vol. 13, no. 3, Art. no. 521, 2024, doi: <a href="https://doi.org/10.3390/electronics13030521">10.3390/electronics13030521</a>.'
  mla: Aimiyekagbon, Osarenren Kennedy, et al. “Diagnostics of Piezoelectric Bending
    Actuators Subjected to Varying Operating Conditions.” <i>Electronics</i>, vol.
    13, no. 3, 521, MDPI AG, 2024, doi:<a href="https://doi.org/10.3390/electronics13030521">10.3390/electronics13030521</a>.
  short: O.K. Aimiyekagbon, A. Bender, T. Hemsel, W. Sextro, Electronics 13 (2024).
date_created: 2024-02-20T06:46:43Z
date_updated: 2024-03-15T16:15:56Z
department:
- _id: '151'
doi: 10.3390/electronics13030521
funded_apc: '1'
intvolume: '        13'
issue: '3'
keyword:
- piezoelectric transducer
- self-sensing
- fault detection
- diagnostics
- hairline crack
- condition monitoring
language:
- iso: eng
publication: Electronics
publication_identifier:
  issn:
  - 2079-9292
publication_status: published
publisher: MDPI AG
quality_controlled: '1'
status: public
title: Diagnostics of Piezoelectric Bending Actuators Subjected to Varying Operating
  Conditions
type: journal_article
user_id: '9557'
volume: 13
year: '2024'
...
---
_id: '22507'
abstract:
- lang: eng
  text: Several methods, including order analysis, wavelet analysis and empirical
    mode decomposition have been proposed and successfully employed for the health
    state estimation of technical systems operating under varying conditions. However,
    where information such as the speed of rotating machinery, component specifications
    or other domain-specific information is unavailable, such methods are often infeasible.
    Thus, this paper investigates the application of classical time-domain features,
    features from the medical field and novel features from the highly comparative
    time-series analysis (HCTSA) package, for the health state estimation of rotating
    machinery operating under varying conditions. Furthermore, several feature selection
    methods are investigated to identify features as viable health indicators for
    the diagnostics and prognostics of technical systems. As a case study, the presented
    methods are evaluated on real-world and experimentally acquired vibration data
    of bearings operating under varying speed. The results show that the selected
    features can successfully be employed as health indicators for technical systems
    operating under varying conditions.
author:
- first_name: Osarenren Kennedy
  full_name: Aimiyekagbon, Osarenren Kennedy
  id: '9557'
  last_name: Aimiyekagbon
- first_name: Amelie
  full_name: Bender, Amelie
  id: '54290'
  last_name: Bender
- first_name: Walter
  full_name: Sextro, Walter
  id: '21220'
  last_name: Sextro
citation:
  ama: 'Aimiyekagbon OK, Bender A, Sextro W. On the applicability of time series features
    as health indicators for technical systems operating under varying conditions.
    In: <i>Proceedings of the Seventeenth International Conference on Condition Monitoring
    and Asset Management (CM 2021)</i>.'
  apa: Aimiyekagbon, O. K., Bender, A., &#38; Sextro, W. (n.d.). On the applicability
    of time series features as health indicators for technical systems operating under
    varying conditions. <i>Proceedings of the Seventeenth International Conference
    on Condition Monitoring and Asset Management (CM 2021)</i>. Seventeenth International
    Conference on Condition Monitoring and Asset Management (CM 2021).
  bibtex: '@inproceedings{Aimiyekagbon_Bender_Sextro, title={On the applicability
    of time series features as health indicators for technical systems operating under
    varying conditions}, booktitle={Proceedings of the Seventeenth International Conference
    on Condition Monitoring and Asset Management (CM 2021)}, author={Aimiyekagbon,
    Osarenren Kennedy and Bender, Amelie and Sextro, Walter} }'
  chicago: Aimiyekagbon, Osarenren Kennedy, Amelie Bender, and Walter Sextro. “On
    the Applicability of Time Series Features as Health Indicators for Technical Systems
    Operating under Varying Conditions.” In <i>Proceedings of the Seventeenth International
    Conference on Condition Monitoring and Asset Management (CM 2021)</i>, n.d.
  ieee: O. K. Aimiyekagbon, A. Bender, and W. Sextro, “On the applicability of time
    series features as health indicators for technical systems operating under varying
    conditions,” presented at the Seventeenth International Conference on Condition
    Monitoring and Asset Management (CM 2021).
  mla: Aimiyekagbon, Osarenren Kennedy, et al. “On the Applicability of Time Series
    Features as Health Indicators for Technical Systems Operating under Varying Conditions.”
    <i>Proceedings of the Seventeenth International Conference on Condition Monitoring
    and Asset Management (CM 2021)</i>.
  short: 'O.K. Aimiyekagbon, A. Bender, W. Sextro, in: Proceedings of the Seventeenth
    International Conference on Condition Monitoring and Asset Management (CM 2021),
    n.d.'
conference:
  end_date: 2021-06-18
  name: Seventeenth International Conference on Condition Monitoring and Asset Management
    (CM 2021)
  start_date: 2021-06-14
date_created: 2021-06-23T05:24:39Z
date_updated: 2023-09-22T08:10:34Z
ddc:
- '620'
department:
- _id: '151'
file:
- access_level: open_access
  content_type: application/pdf
  creator: kennedy
  date_created: 2021-06-23T06:43:44Z
  date_updated: 2021-06-23T06:50:07Z
  description: 'This is a post-print version of the article presented at the Seventeenth
    International Con-ference on Condition Monitoring and Asset Management (CM 2021).
    The event websiteis available at:  https://www.bindt.org/events/CM-2021/ and the
    abstract is available at:https://www.bindt.org/events/CM-2021/abstract-9a7/.'
  file_id: '22508'
  file_name: Aimiyekagbon_et_al_2021_On_the_applicability_of_time_series_features_as_health_indicators_postPrint.pdf
  file_size: 1875572
  relation: main_file
  title: On the applicability of time series features as health indicators for technical
    systems operating under varying conditions
file_date_updated: 2021-06-23T06:50:07Z
has_accepted_license: '1'
keyword:
- Wind turbine diagnostics
- bearing diagnostics
- non-stationary operating conditions
- varying operating conditions
- feature extraction
- feature selection
- fault detection
- failure detection
language:
- iso: eng
oa: '1'
publication: Proceedings of the Seventeenth International Conference on Condition
  Monitoring and Asset Management (CM 2021)
publication_status: inpress
quality_controlled: '1'
status: public
title: On the applicability of time series features as health indicators for technical
  systems operating under varying conditions
type: conference
user_id: '9557'
year: '2021'
...
---
_id: '37002'
abstract:
- lang: eng
  text: HDL-mutation based fault injection and analysis is considered as an important
    coverage metric for measuring the quality of design simulation processes [20,
    3, 1, 2]. In this work, we try to solve the problem of automatic simulation data
    generation targeting HDL mutation faults. We follow a search based approach and
    eliminate the need for symbolic execution and mathematical constraint solving
    from existing work. An objective cost function is defined on the test input space
    and serves the guidance of search for fault-detecting test data. This is done
    by first mapping the simulation traces under a test onto a control and data flow
    graph structure which is extracted from the design. Then the progress of fault
    detection can be measured quantitatively on this graph to be the cost value. By
    minimizing this cost we approach the target test data. The effectiveness of the
    cost function is investigated under an example neighborhood search scheme. Case
    study with a floating point arithmetic IP design has shown that the cost function
    is able to guide effectively the search procedure towards a fault-detecting test.
    The cost calculation time as the search overhead was also observed to be minor
    compared to the actual design simulation time.
author:
- first_name: Tao
  full_name: Xie, Tao
  last_name: Xie
- first_name: Wolfgang
  full_name: Müller, Wolfgang
  id: '16243'
  last_name: Müller
- first_name: Florian
  full_name: Letombe, Florian
  last_name: Letombe
citation:
  ama: 'Xie T, Müller W, Letombe F. HDL-Mutation Based Simulation Data Generation
    by Propagation Guided Search. In: <i>Proceedings of Euromicro DSD 2011</i>. IEEE;
    2011. doi:<a href="https://doi.org/10.1109/DSD.2011.83">10.1109/DSD.2011.83</a>'
  apa: Xie, T., Müller, W., &#38; Letombe, F. (2011). HDL-Mutation Based Simulation
    Data Generation by Propagation Guided Search. <i>Proceedings of Euromicro DSD
    2011</i>. <a href="https://doi.org/10.1109/DSD.2011.83">https://doi.org/10.1109/DSD.2011.83</a>
  bibtex: '@inproceedings{Xie_Müller_Letombe_2011, place={Oulu, Finnland}, title={HDL-Mutation
    Based Simulation Data Generation by Propagation Guided Search}, DOI={<a href="https://doi.org/10.1109/DSD.2011.83">10.1109/DSD.2011.83</a>},
    booktitle={Proceedings of Euromicro DSD 2011}, publisher={IEEE}, author={Xie,
    Tao and Müller, Wolfgang and Letombe, Florian}, year={2011} }'
  chicago: 'Xie, Tao, Wolfgang Müller, and Florian Letombe. “HDL-Mutation Based Simulation
    Data Generation by Propagation Guided Search.” In <i>Proceedings of Euromicro
    DSD 2011</i>. Oulu, Finnland: IEEE, 2011. <a href="https://doi.org/10.1109/DSD.2011.83">https://doi.org/10.1109/DSD.2011.83</a>.'
  ieee: 'T. Xie, W. Müller, and F. Letombe, “HDL-Mutation Based Simulation Data Generation
    by Propagation Guided Search,” 2011, doi: <a href="https://doi.org/10.1109/DSD.2011.83">10.1109/DSD.2011.83</a>.'
  mla: Xie, Tao, et al. “HDL-Mutation Based Simulation Data Generation by Propagation
    Guided Search.” <i>Proceedings of Euromicro DSD 2011</i>, IEEE, 2011, doi:<a href="https://doi.org/10.1109/DSD.2011.83">10.1109/DSD.2011.83</a>.
  short: 'T. Xie, W. Müller, F. Letombe, in: Proceedings of Euromicro DSD 2011, IEEE,
    Oulu, Finnland, 2011.'
date_created: 2023-01-17T09:02:48Z
date_updated: 2025-02-26T14:44:15Z
department:
- _id: '672'
doi: 10.1109/DSD.2011.83
keyword:
- Hardware design languages
- Cost function
- Computational modeling
- Fault detection
- Data models
- Analytical models
- Testing
language:
- iso: eng
place: Oulu, Finnland
publication: Proceedings of Euromicro DSD 2011
publication_identifier:
  isbn:
  - 978-1-4577-1048-3
publisher: IEEE
status: public
title: HDL-Mutation Based Simulation Data Generation by Propagation Guided Search
type: conference
user_id: '5786'
year: '2011'
...