tailieunhanh - Vibration Analysis and Control New Trends and Developments Part 6

Tham khảo tài liệu 'vibration analysis and control new trends and developments part 6', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | 6 A Semiactive Vibration Control Design for Suspension Systems with Mr Dampers Hamid Reza Karimi Department of Engineering Faculty of Engineering and Science University of Agder Norway 1. Introduction In an automotive system the vehicle suspension usually contributes to the vehicle s handling and braking for good active safety and driving pleasure and keeps the vehicle occupants comfortable and reasonably well isolated from road noise bumps and vibrations. The design of vehicle suspension systems is an active research field in automotive industry Du and Zhang 2007 Guglielmino et al. 2008 . Most conventional suspensions use passive springs to absorb impacts and shock absorbers to control spring motions. The shock absorbers damp out the motions of a vehicle up and down on its springs and also damp out much of the wheel bounce when the unsprung weight of a wheel hub axle and sometimes brakes and differential bounces up and down on the springiness of a tire. Semiactive suspension techniques Karkoub and Dhabi 2006 Shen et al. 2006 Zapateiro et al. 2009 promise a solution to the problem of vibration absorption with some comparatively better features than active and passive devices. Compared with passive dampers active and semiactive devices can be tuned due to their flexible structure. One of the drawbacks of active dampers is that they may become unstable if the controller fails. On the contrary semiactive devices are inherently stable because they cannot inject energy to the controlled system and will act as pure passive dampers in case of control failure. Among semiactive control devices magnetorheological MR dampers are particularly interesting because of the high damping force they can produce with low energy requirements being possible to operate with batteries simple mechanical design and low production costs. The damping force of MR dampers is produced when the MR fluid inside the device changes its rheological properties in the presence of a magnetic field. In .