Redesigning and improving work vehicle seats



Driving a bus or operating heavy equipment on a daily basis can be pernicious: the vibrations generated by work vehicles are like a slow poison that gradually affects the vehicle operator's digestive system and spinal column. This has been shown by the work of Subhash Rakheja, a professor in the Department of Mechanical, Industrial and Aerospace Engineering at Concordia University. Indeed, prolonged exposure to these vibrations is recognized as an occupational injury and is compensated in Québec and several European countries.

To protect bus drivers, he established a standard aimed at limiting the stretching and compression of the spine to less than five times per second. 

Work vehicles are equipped with suspension seats to protect drivers. However, these are far from optimal, as they are rarely specific to the type of vehicle and are not adjusted to the driver's height and weight.

To improve the design of suspension seats, Professor Rakheja, in collaboration with the Institut de recherche Robert-Sauvé en santé et en sécurité du travail and the CNESST, developed a driver's workstation simulator to test suspension effectiveness and the impact of various adjustments – seat, backrest, headrest – on 58 drivers. Unique in Canada, this tool is linked to software that generates the actual vibrations felt when operating different types of work vehicles. Subhash Rakheja used sensors placed on either side of the spine to measure the level of vibration transferred to drivers and determine their impact on the body. To protect bus drivers, he established a standard aimed at limiting the stretching and compression of the spine to less than five times per second by reducing the vibrations transmitted by the seat.

The researcher is currently in discussion with various work vehicle manufacturers in Québec, Europe and the United States who are interested in using his finding to improve the design of their seat suspension.