THÈSE - Bibliothèque Ecole Centrale Lyon - École Centrale de Lyon

AbstractThis work deals with the study, the design and the realization on an active car seatsuspension. It starts from the actual theoretical knowledge of active control of vibrations.In our case, we have applied an "active solution" to improve the comfort of car passenger.The comfort criteria (statical, postural, dynamical) which are now taken into accountin the design of actual car seats, have been firstly reviewed. On this basis, we have chosento develop an optimized suspension to solve the spécifie problem of vibratory isolation ofthe passenger.Three points have been mainly developped:• The first is devoted to a theoretical study of passive, semi-active and active suspensions.Through the use of a simple model, the ability of seat suspension to improve thepassenger comfort has been investigated. An analysis performed on the sensitivity of thedesign parameters has demonstrated the limitation of passive suspensions compared tosemi-active ones.» The second point concerns the modelization and the numerical simulation of the dynamicalbehaviour of the "controlled seat". We have applied an electromechanical actuator,presenting a reversibility property, permitting the use of two laws of control: the first oneis dissipative and is based on the classical principal of the skyhook semi-active damper.The second is active and original. It uses an imcomplete state feed-back loop. Numericalsimulations have shown the efficiency of those laws for the global isolation of the seat. Themodelling has also been used as a major design tool to optimize the différent parts of theprototype.e The last point deals with the design and the realization of the prototype of the activeseat suspension and more specifically, the kinematic guide, the stiffness mechanism, theelectromechanical actuator and his electronic control. The system has been fulhy characterizedon a test-rig and the performances concerning the isolation and comfort are presentedregarding différent excitations: stationnary and transitory.Key words: Seat, Comfort, Active suspension, Active control, Isolation, Electrical actuator,Design, Prototype, Cellulary materials, Modélisation, Viscoelastic models.