Servizio Comunitario di Informazione in materia di Ricerca e Sviluppo - CORDIS

Seat vibration control in road and rail vehicles

Active control systems dedicated to seat vibration control are being developed to reduce both physiological and psychological discomfort experienced by drivers and passengers. An effective way to reduce vibrations experienced by drivers and passengers during transportation, consists of using an active control system with an actuator located under the seat.

Results of the comfort index study showed that very low frequencies (down to 3 to 4 Hz) were to be taken into account. Processing of the in situ recordings aboard cars, trucks and buses, leads to the conclusion that displacements of the actuator had to be much larger than thought initially. A robust control algorithm, capable of dealing with saturation of the actuator, has been developed in order to get best performance of the actuator. Theoretical and experimental work on actuators led to the choice of actuator technology and the final system was manufactured and the related simulation tool was developed. The active control system (made available in a 24 V version) was first tested in a laboratory and then aboard a truck. Data were processed and analysed both in terms of vibration reduction and comfort enhancement. High comfort enhancement was obtained on roads corresponding to high frequency excitation. Good performance in terms of comfort improvement was obtained during laboratory experiments especially for recordings corresponding to the car. Despite performance of the final system is greatly above initial specifications, the displacement of the actuator (6 mm peak-to-peak) appears to be still too limited in case of a truck on a road with very low frequency excitation. Nevertheless, due to the developed simulation tool and to the experience acquired, the actuator can be quickly adapted to future user specifications.

Reported by

Thomson Marconi Sonar SAS
525 Routes des Dolines
06903 Sophia Antipolis