The engineering team that developed the 2013 Nissan Altima’s front seats relied on research data from NASA as a start point in designing innovative “zero gravity” seats.
“Designing seats to simulate an occupant in a weightless environment is intended to minimize the muscular loading of the occupant’s back, pelvis, and torso. This is accomplished by developing the seat’s shape and support system to put the occupant’s spine in its natural position,” Jason Harsant, Manager of Seat Engineering at the Nissan Technical Center North America Inc. in Farmington Hills, MI, explained to SAE Magazines.
The seatback shape and its patented structure provides varying levels of support in the lumbar, midback, and shoulder regions to position the occupant’s spine in its natural position. According to NASA seating and posture research, a seat design that correlates to low occupant fatigue is a design that mimics a body-neutral posture—essentially the relaxed position the human body assumes in a weightless environment.
Previous Nissan vehicle seat designs, including the 2012 Altima, were primarily focused on continuous occupant loading with adjustable lumbar support offered on select models. But the “zero gravity” six-way adjustable driver seat and the four-way adjustable front passenger standard bucket seat essentially react to occupant loads by holding the person in the desired, neutral position.
“The result is that the occupant requires substantially less muscle support during driving, which minimizes driving fatigue,” said Harsant.
Nissan seat engineers used a unique seat simulator to measure the natural position and loading of an occupant at 14 different locations along the seatback from the pelvis to the upper back. (Details of the early phase of this study are described in SAE technical papers 2006-01-1302 and 2007-01-0348.)
“Using the study’s shape and support loading targets, Nissan worked with suppliers to design the seat structure, foam, and trim to match the ideal condition as much as possible,” Harsant said.
Components for the new Nissan Altima front seats are being supplied by Japan’s FNK Spring Co. Ltd., which is a joint venture between Faurecia and NHK. Johnson Controls’ workers are assembling the seats for Altima sedans produced from Nissan’s Smyrna, TN, plant, while Faurecia workers are assembling the seats for the Altima sedans manufactured at Nissan’s Canton, MS, facility.
The hip point on the 2013 Altima front seats is 520 mm (20.5 in) from the ground in the z-direction. Cushion length is 382 mm (15.0 in). The seatback height is 608 mm (23.9 in) along the torso. Overall seat cushion width is 501 mm (19.7 in), while the seatback’s overall width is 526 mm (20.7 in).
Altima is the first Nissan vehicle to feature the NASA-inspired seats. “We plan to roll out these innovative zero gravity seats on upcoming all-new Nissan models,” said Vishnu Jayamohan, Nissan product planner.
http://articles.sae.org/11073/
