Please use this identifier to cite or link to this item: http://buratest.brunel.ac.uk/handle/2438/13624
Title: Application of active controllers to suppress engine vibrations
Authors: Dayyani, Keyvan
Advisors: Esat, I
Chen, J
Keywords: Active vibration cancellation;Engine vibration;Vibration cancelation of the engine transmitted to the class's;Active engine mount
Issue Date: 2016
Publisher: Brunel University London
Abstract: Researchers are trying to find a solution for reducing the vibration of the engine with minimum changes to the engine mounts. Several researches and main giant car companies have presented valuable effort in these areas but still new research is needed to improve the control system. The present research carried out a comprehensive study of the state of art methods to suppress unwanted vibration from the engine to the passenger cars. This research was designed based on the objective of the Trelleborg Company to investigate the influence of Active Vibration Control (AVC) on the real engine. Therefore, this thesis tried to challenge the vibration problem with practical engineering approach by implementing different types of controllers experimentally and applying them on the real petrol engine. Inversing controlling technique and PID controller tuned with different methods (Ziegler Nichols and tyreus-luyben) have been tested here on two separate platforms; unbalanced DC motor and petrol engine. In addition, as a requirement of the study, the resonance frequency and related mode shapes of the system was investigated experimentally. It is also shown that using suitable filters can help elimination of high frequency noises in the control signals. This study experimentally tests PID controller with mentioned tuned methods on a real engine with this specific setup for the first time. A new scheme was developed with "mode shapes specific controller system", according to which the shaker position and the controller parameters were specified according to the system mode shapes. The result of applying controllers shows that both control methods have a similar effect on vibration reduction. A 33% - 37% reduction on DC motor achieved in different frequencies (20Hz, 37.5Hz and 46.2Hz) with different control methods, and about 10% reduction on petrol engine at resonance frequency while the shaker IV40 (with max 30N force) was placed on the chassis. For reducing the vibration transmitted from the engine to the chassis, for the first time the shaker was placed on the engine (unlike in previous studies where the shaker was placed on the chassis). Using shaker IV40 placed on the engine results in a 20% reduction in vibration transmission, which is a significant improvement in comparison with having the shaker on the chassis. The optimum result was achieved using shaker IV45 (Max 50N force), which yielded a vibration reduction of 33%.
Description: This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University London.
URI: http://bura.brunel.ac.uk/handle/2438/13624
Appears in Collections:Mechanical and Aerospace Engineering
Dept of Mechanical Aerospace and Civil Engineering Theses

Files in This Item:
File Description SizeFormat 
FulltextThesis.pdfFile embargoed until 18/6/20198.67 MBAdobe PDFView/Open    Request a copy


Items in BURA are protected by copyright, with all rights reserved, unless otherwise indicated.