Vibration Analysis on Driver Seat for Small Cars 2011-26-0119

In India, small car segment is having maximum sale, which includes cars like Maruti 800, SUZUKI Swift, Maruti Alto, Tata Indica, etc. Driver seat is one of the main aspects to be considered while defining comfort in a moving vehicle. The current analysis concentrates on driver seat because driver comfort is of main concern since it is the most occupied seat in any vehicle and the occupancy is for longer duration. In addition to sitting, the driver's job is to manipulate different controls and concentrate parallely on many aspects. The research work aims at studying the vertical vibrations transferred to the human body via seat.

The work is an attempt towards studying dynamic characteristics of driver seat for comfort through objective evaluation. For objective evaluation, two tests were conducted; Seat Effective Amplitude Transmissibility (SEAT) test and Ride Comfort Index test under two different conditions, i.e., car level and seat level testing on Car "A" and Car "B." Both tests were carried out under controlled conditions.

Car level test was carried out on 4-Poster simulator, which can simulate exact road conditions in vertical direction whereas seat level testing is done on electro-dynamic shaker, which simulates sinusoidal signals. Results of experimentations, i.e., accelerations at seat base and seat mount were compared with reference standard ISO 2631-1(1997) which indicated average Root Mean Square (RMS) of Car "A" and Car "B" is 0.007 and 0.008 Km/s₂ respectively. Hence according to ISO 2631-1(1997), both cars fall into "fairly uncomfortable zone". SEAT Test revealed transmissibility in two different positions (front most and rearmost position). In front most position, transmissibility is 65.66% and 204% for Car "B" and Car "A" respectively, whereas transmissibility is 63.56% and 145% for Car "B" and Car "A" in rearmost position of seat.