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Development of Actuator-Amplifier Systems for Active Vibration Control of Gearboxes

Okda, Sherif (2024)
Development of Actuator-Amplifier Systems for Active Vibration Control of Gearboxes.
Technische Universität Darmstadt
doi: 10.26083/tuprints-00027879
Ph.D. Thesis, Primary publication, Publisher's Version

Abstract

Reducing carbon emissions stands as a paramount goal in the global effort to combat climate change. Reducing a vehicle’s weight enhances efficiency and reduces emissions significantly. However, this approach presents a challenge as lighter vehicles experience higher vibrations and noise emission levels. As a result, vehicle manufacturers are investing in addressing these issues to maintain passenger comfort standards and comply with regulatory requirements. This study presents the development and evaluation of an active vibration control system designed to minimize the transmission of vibrations to the car cabin, by actively countering vibrations in the gearbox housing and effectively limiting their transfer through the transmission mounts. The system is designed to specifically address the high-frequency vibrations that occur at the meshing frequency of the transmission and its harmonics, with an emphasis on cost-effectiveness, lightweight construction, and compact design tailored for automotive applications. The research focuses on the comprehensive development of both the actuator and power amplifier components of the active vibration control system, ensuring an integrated approach to improve vehicle comfort and performance. An inertial mass actuator is developed to counteract the housing vibrations, utilizing a piezoelectric stack selected as the active element, due to its superior performance and reliability at high frequencies. The actuator design, validated through Simulink modeling and experimental testing, achieves a remarkable balance of generated force, efficiency, lightweight construction, and compact dimensions. Additionally, a switching amplifier is developed, through the modification of a bidirectional buck-boost converter for efficient DC/AC conversion through the manipulation of its feedback loop. This design demonstrates high efficiency and compact dimensions, making it well-suited for automotive applications. An innovative test-rig is constructed to accurately replicate gearbox vibration phenomena, offering an economical alternative to complex setups. The developed test-rig is excited by a piezo stack actuator at the input shaft. Rigorous testing on the newly developed rig demonstrates significant vibration reduction across a broad frequency spectrum, particularly notable above 2500 Hz. However, there are some difficulties in controlling vibrations at certain frequencies. An average reduction of approximately 8.5 dB is achieved between 1000 Hz and 1500 Hz, an average reduction of approximately 14 dB is obtained between 1500 and 2500 Hz, and an average reduction of 10.8 dB is achieved between 2500 and 5000 Hz. The active vibration control system is also tested on an operational gearbox showing its ability to reduce the highest acceleration peak at the mounting point by approximately 40 dB. Subsequent to the validation of the active vibration control system, a novel concept of integrating piezoelectric shear actuators into the gearbox housing is introduced, presenting advantages such as reduced weight, lower power consumption, and improved accommodation. Two designs are developed utilizing single and double-shear actuators. Simulation and experimental validation on a simple plate structure effectively demonstrate the effectiveness of the shear actuators in vibration suppression. The single shear actuator design demonstrated reductions in vibration levels equivalent to approximately 34 dB when targeting the first local bending mode, While the double shear actuator design targeting the first and second local bending modes achieved a reduction equivalent to approximately 36 dB at steady state when targeting the first bending mode and approximately 41 dB is achieved at steady state by targeting the second bending mode.

Item Type: Ph.D. Thesis
Erschienen: 2024
Creators: Okda, Sherif
Type of entry: Primary publication
Title: Development of Actuator-Amplifier Systems for Active Vibration Control of Gearboxes
Language: English
Referees: Melz, Prof. Dr. Tobias ; Rinderknecht, Prof. Dr. Stephan
Date: 20 August 2024
Place of Publication: Darmstadt
Collation: xvii, 122 Seiten
Refereed: 17 July 2024
DOI: 10.26083/tuprints-00027879
URL / URN: https://tuprints.ulb.tu-darmstadt.de/27879
Abstract:

Reducing carbon emissions stands as a paramount goal in the global effort to combat climate change. Reducing a vehicle’s weight enhances efficiency and reduces emissions significantly. However, this approach presents a challenge as lighter vehicles experience higher vibrations and noise emission levels. As a result, vehicle manufacturers are investing in addressing these issues to maintain passenger comfort standards and comply with regulatory requirements. This study presents the development and evaluation of an active vibration control system designed to minimize the transmission of vibrations to the car cabin, by actively countering vibrations in the gearbox housing and effectively limiting their transfer through the transmission mounts. The system is designed to specifically address the high-frequency vibrations that occur at the meshing frequency of the transmission and its harmonics, with an emphasis on cost-effectiveness, lightweight construction, and compact design tailored for automotive applications. The research focuses on the comprehensive development of both the actuator and power amplifier components of the active vibration control system, ensuring an integrated approach to improve vehicle comfort and performance. An inertial mass actuator is developed to counteract the housing vibrations, utilizing a piezoelectric stack selected as the active element, due to its superior performance and reliability at high frequencies. The actuator design, validated through Simulink modeling and experimental testing, achieves a remarkable balance of generated force, efficiency, lightweight construction, and compact dimensions. Additionally, a switching amplifier is developed, through the modification of a bidirectional buck-boost converter for efficient DC/AC conversion through the manipulation of its feedback loop. This design demonstrates high efficiency and compact dimensions, making it well-suited for automotive applications. An innovative test-rig is constructed to accurately replicate gearbox vibration phenomena, offering an economical alternative to complex setups. The developed test-rig is excited by a piezo stack actuator at the input shaft. Rigorous testing on the newly developed rig demonstrates significant vibration reduction across a broad frequency spectrum, particularly notable above 2500 Hz. However, there are some difficulties in controlling vibrations at certain frequencies. An average reduction of approximately 8.5 dB is achieved between 1000 Hz and 1500 Hz, an average reduction of approximately 14 dB is obtained between 1500 and 2500 Hz, and an average reduction of 10.8 dB is achieved between 2500 and 5000 Hz. The active vibration control system is also tested on an operational gearbox showing its ability to reduce the highest acceleration peak at the mounting point by approximately 40 dB. Subsequent to the validation of the active vibration control system, a novel concept of integrating piezoelectric shear actuators into the gearbox housing is introduced, presenting advantages such as reduced weight, lower power consumption, and improved accommodation. Two designs are developed utilizing single and double-shear actuators. Simulation and experimental validation on a simple plate structure effectively demonstrate the effectiveness of the shear actuators in vibration suppression. The single shear actuator design demonstrated reductions in vibration levels equivalent to approximately 34 dB when targeting the first local bending mode, While the double shear actuator design targeting the first and second local bending modes achieved a reduction equivalent to approximately 36 dB at steady state when targeting the first bending mode and approximately 41 dB is achieved at steady state by targeting the second bending mode.

Alternative Abstract:
Alternative abstract Language

Die Reduktion von Treibhausgasen ist ein vorrangiges Ziel bei den weltweiten Bemühungen zur Bekämpfung des Klimawandels. Die Verringerung des Fahrzeuggewichts steigert die Effizienz und verringert die Emissionen erheblich. Dieser Ansatz stellt jedoch eine Herausforderung dar, da leichtere Fahrzeuge oft mit höheren Vibrationen und Geräuschemissionen verbunden sind. Aus diesem Grund investieren die Fahrzeughersteller in die Lösung dieser Probleme, um den Komfort für die Fahrgäste aufrechtzuerhalten und die gesetzlichen Anforderungen zu erfüllen. In dieser Arbeit wird die Entwicklung und Bewertung eines aktiven Schwingungsregelungssystems vorgestellt, das die Schwingungen in Getriebegehäuse von Fahrzeugen mindern soll. Ziel des Schwingungsdämpfungssystems ist es, die Schwingungen an den Befestigungspunkten zu minimieren. Dadurch wird verhindert, dass diese Schwingungen in den Fahrzeuginnenraum übertragen werden, und der Fahrkomfort wird insgesamt verbessert. Das System wurde speziell für hochfrequente Schwingungen entwickelt, die an Zahneingriffsfrequenz und deren Oberwellen auftreten. Mit dem Schwerpunkt auf Kosteneffizienz, geringem Gewicht und kompaktem Design, das auf Automobilanwendungen zugeschnitten ist, konzentriert sich die Forschung auf die umfassende Entwicklung sowohl der Aktuator- als auch der Leistungsverstärkerkomponenten. Um den Gehäuseschwingungen entgegenzuwirken, wird ein Trägheitsmassenaktuator entwickelt, der piezoelektrische Stapel als aktive Elemente verwendet, die aufgrund ihrer überlegenen Leistung und Zuverlässigkeit bei hohen Frequenzen ausgewählt wurden. Das Design des Aktuators, das durch eine Simulink-Modellierung und experimentelle Tests validiert wurde, bietet ein bemerkenswertes Gleichgewicht zwischen Leichtbau und kompakten Abmessungen. Darüber hinaus wird ein Schaltverstärker entwickelt, der die Modifikation eines bidirektionalen Abwärts/Aufwärts-Wandlers für eine effiziente Gleichstrom/Wechselstrom-Wandlung durch die Manipulation seiner Rückkopplungsschleife nutzt und sich durch hohe Effizienz und kompakte Designmerkmale auszeichnet. Ein innovativer Prüfstand wurde konstruiert, um die Schwingungsphänomene von Getrieben genau nachzubilden und bietet eine wirtschaftliche Alternative zu komplexen Rotationsaufbauten. Der entwickelte Prüfstand wird durch einen Piezo-Stapelaktor an der Eingangswelle angeregt. Rigorose Tests mit dem neu entwickelten Prüfstand zeigen eine signifikante Schwingungsreduzierung über ein breites Frequenzspektrum, besonders deutlich oberhalb von 2500 Hz. Zwischen 1000 Hz und 1500 Hz wird eine durchschnittliche Reduktion von etwa 8,5 dB erreicht, zwischen 1500 und 2000 Hz eine durchschnittliche Reduktion von etwa 14 dB und zwischen 2500 und 5000 Hz eine durchschnittliche Reduktion von 10,8 dB. Das aktive Schwingungsdämpfungssystem wurde auch an einem in Betrieb befindlichen Getriebe getestet. Dabei zeigte sich, dass es in der Lage ist, die höchste Beschleunigungsspitze am Montagepunkt um etwa 40 dB zu reduzieren. Im Anschluss an die Validierung des aktive Schwingungsdämpfungssystems wird ein neuartiges Konzept zur Integration piezoelektrischer Scheraktoren in Getriebegehäuse vorgestellt, das Vorteile wie geringeres Gewicht, niedrigeren Stromverbrauch und bessere Integration bietet. Es wurden zwei Entwürfe mit Einzel- und Doppelscherenaktoren entwickelt. Simulation und experimentelle Validierung an einer einfachen Plattenstruktur zeigen die Wirksamkeit der Scheraktoren bei der Schwingungsunterdrückung. Der Entwurf mit einem Scheraktuator zeigte eine Verringerung der Schwingungspegel um ca. 34 dB, wenn er auf den lokalen Biegemodus abzielt, während der Entwurf mit zwei Scheraktuatoren, der auf zwei lokale Biegemodi abzielt, eine Verringerung um ca. 36 dB im stationären Zustand erreicht, wenn er auf den ersten Biegemodus abzielt, und ca. 41 dB im stationären Zustand, wenn er auf den zweiten Biegemodus abzielt.

German
Uncontrolled Keywords: Active vibration control, Smart structures, Adaptronics, Piezoelectric, Inertial mass actuator, Gearbox, Housing
Status: Publisher's Version
URN: urn:nbn:de:tuda-tuprints-278793
Classification DDC: 600 Technology, medicine, applied sciences > 620 Engineering and machine engineering
Divisions: 16 Department of Mechanical Engineering
16 Department of Mechanical Engineering > Research group System Reliability, Adaptive Structures, and Machine Acoustics (SAM)
16 Department of Mechanical Engineering > Research group System Reliability, Adaptive Structures, and Machine Acoustics (SAM) > Development, modelling, evaluation, and use of smart structure components and systems
Date Deposited: 20 Aug 2024 13:08
Last Modified: 21 Aug 2024 05:17
PPN:
Referees: Melz, Prof. Dr. Tobias ; Rinderknecht, Prof. Dr. Stephan
Refereed / Verteidigung / mdl. Prüfung: 17 July 2024
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