Steps to improving seat design and shape

Ahead of this presentation Automotive-IQ sat down with Dr. Reynolds to delve into some of these viewpoints which include:

• What has been done to improve seat shape design in the past few years.
• How this will help OEMs best accommodate driver seat positioning.
• The differences between pressure vs. load distribution in order to set a new standard for seat positioning.
• His unique approach to seat package variation, and what requirements/advancements that are being explored.

What has been done to improve seat shape design in the past few years?

“Seat shape has been an enigma. Shape has been confounded by appearance, defined in the styling domain, pressure distribution in engineering, and structures from suppliers that include foam, frames and adjusters for H-point travel and FMVSS 202a.

Recently, unoccupied seat shape has been described by statistical principal components analysis to define variability in production seats so that a measure of seat shape can be correlated with comfort, performance and safety for the occupant. The seat, however, supports driver’s body weight in a position of static equilibrium to operate the car.

The position of landmarks that represent the distribution of body weight forces varies with body size and back posture. A model of this support was developed at Michigan State University to define optimal seat shape for drivers in position to operate the car. The model uses the load deflection properties of the seat relative to positions of landmarks representing the distribution of forces from body weight acting on the seat. Thus, optimal seat shape can be defined for styling to create an appearance that is visually appealing and suppliers to develop structures that support driver comfort, performance and safety.”

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How will this help OEMs best accommodate driver seat positioning?

“Since seat shape represents the position of the surfaces that support the distribution of forces in seated drivers, positions of the seat will be more accurately defined by taking into consideration seat support. In a driver comfort study at Michigan State University, a production seat was modified by changing the shape of the seat back. In a blinded study, drivers adjusted the seat forward an average of 19mm and re-positioned their eye upwards and rearwards because of the change in posture.

In addition, drivers of different body sizes use different back postures for comfort and fit. Thus, the use of seat shape and representative digital human body models in different back postures provides a more comprehensive driver seat positioning tool.”

List some of the differences between pressure vs. load distribution in order to set a new standard for seat positioning?

“Pressure distribution is a detailed analysis of load distribution in the seat for a specific body size and back posture. The advantage of using force distribution is the capability to optimize seat shape constraints for different postures used by different size drivers to operate the car. The resulting shape will be defined to optimize seat support for all drivers in their preferred position to drive the car.”

Where do you see the future of automotive seating in the next 2-5 years?

“Automotive seating will continue to be developed for cars and trucks driven by seated drivers. In association with the traditional driver’s seat, more attention will be devoted to autonomous cars and the freedom of the driver to perform other tasks while being driven in the car. Thus, a driver/passenger seat will be needed that will provide support for the driver to interact with a wider range of activities than driving.”

Explain what’s unique about your approach to seat package variation, and what requirements/advancements are you exploring?

“Seat shape is an integral part of the support required by the driver in different back postures. The most unique characteristics of the ERL approach are consideration of the effects of back posture on seat position, eye position, and reach to controls when designing optimal seat shape for the layout of the vehicle interior.

Including the occupied seat to define the unoccupied seat shape provides a set of constraints that the stylists use to create seat appearance and seat suppliers use to develop structures (foam and metal) and adjusters that optimize comfort while reducing iterative expenses of traditional seat design.”