Sinteza inertera pomoću povratne veze po vibracijskom ubrzanju

undergraduate thesis

• Title (english): The synthesis of the inerter using acceleration feedback
• Author: Stipe Turalija
• Mentor: Neven Alujević (mentor)
• Granter: University of Zagreb; Faculty of Mechanical Engineering and Naval Architecture; Zagreb
• Defense date and country: 2023-03-01, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Mechanical Engineering

Abstract

U ovom radu razmatra se realizacija inertera pomoću negativne povratne veze po relativnom vibracijskom ubrzanju. U prvom dijelu rada prikazan je kratki osvrt na modeliranje vibracijskih sustava, načine suzbijanja vibracija te princip rada inertera uz primjere postojećih izvedbi uređaja. Izveden je matematički model s dva stupnja slobode gibanja (SSG) mehaničkog sustava koji je proširen dinamikom mjernih i pogonskih članova. Promatran je utjecaj dinamike mjernih i pogonskih članova na stabilnost povratne veze. Pokazano je da je sustav bezuvjetno stabilan ako se zanemari dinamika mjernih i pogonskih članova, a ukoliko se ona uzme u obzir, sustav je uvjetno stabilan. Izveden je i numerički model metodom konačnih elemenata sa 100 SSG sa i bez dinamike pogonskih i mjernih članova. Provedena je analiza glavnih formi vibriranja pomoću koje su određene prijenosne funkcije potrebne za usporedbu. Matematički model s dva SSG uspoređen je s numeričkim modelom dobivenim metodom konačnih elemenata. Matematički modeli su verificirani i eksperimentalno.Eksperimentalni postav izrađen je tehnologijom 3D ispisa i opremljen akcelerometrima i elektromehaničkim aktuatorima. Provedena su mjerenja prijenosnih funkcija zatvorenog regulacijskog kruga za određivanje maksimalno postizive inertancije te otvorenog kruga za vrednovanje stabilnosti povratne veze. Mjerenja pokazuju da je stabilnost povratne veze vrlo osjetljiva na dinamičko ponašanje pogonskih i mjernih instrumenata.

Abstract (english)

This thesis deals with the realisation of the inerter using a negative acceleration feedback loop. The first part of the thesis presents a short review of modelling of vibration systems, passive vibration control techniques and the working principle of the inerter with examples of
the existing realisations of the device. A mathematical model with two mechanical degrees of freedom (DOF) is derived and expanded to include the dynamics of both sensors and actuators. The impact of the sensor-actuator dynamics on the stability of the feedback loop is studied. It is shown that the active control system is unconditionally stable if the dynamic behaviour of the sensors and the actuators is neglected and that the system becomes conditionally stable if these dynamics are taken into consideration. A numerical model using
the finite element method with 100 DOF is also developed both neglecting and considering the sensor-actuator dynamics. Modal analysis is conducted using this model and its results are used to calculate transfer functions needed for the comparison. Mathematical model with 2 DOF is compared to the finite element method model with 100 DOF. Both mathematical models are also validated experimentally. The experimental setup is fabricated using a fused deposition modelling (FDM) technology and is equipped with accelerometers and electrodynamic (voice coil) actuators. Closed loop transfer functions are measured in order to determine the maximum achievable inertance. Open loop transfer functions were also measured for the evaluation of the stability of the feedback loop. The measurements reveal that the stability of the feedback loop is very sensitive to the dynamic behaviour of the sensor/actuator transducers.

• Keywords: vibracije; izolacija vibracija; inerter; automatska regulacija vibracija; stabilnost regulacijskih sustava; performanse regulacijskih sustava
• Keywords (english): vibrations; vibration isolation; inerter; active vibration control; stability of active control systems; performance of active control systems
• Language: croatian
• URN:NBN: urn:nbn:hr:235:122926
• Project: Number: IP-2019-04-5402; Title: Dinamika Aktivnih i Rotirajućih KONstrukcija; Title: Dynamics of Active and Rotating Structures; Acronym: DARS; Leader: Neven Alujević; Jurisdiction: Croatia; Funder: HRZZ; Funding stream: IP
• Study programme: Title: Mechanical Engineering; Study programme type: university; Study level: undergraduate; Academic / professional title: sveučilišni/a prvostupnik/ prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka strojarstva (sveučilišni/a prvostupnik/ prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka strojarstva)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Embargoed access; Embargo expiration date: 2025-02-23
• Created on: 2023-02-24 10:24:32