Car seat impact on driver’s sitting behavior and perceived discomfort during prolonged real driving on varied road types

Abstract

Prolonged driving under real conditions can entail discomfort linked to driving posture, seat design features, and road properties like whole-body vibrations (WBV). This study evaluated the effect of three different seats (S1 = soft; S2 = firm; S3 = soft with suspension system) on driver’s sitting behavior and perceived discomfort on different road types in real driving conditions. Twenty-one participants drove the same 195 km itinerary alternating highway, city, country, and mountain segments. Throughout the driving sessions, Contact Pressure (CP), Contact Surface (CS), Seat Pressure Distribution Percentage (SPD%) and Repositioning Movements (RM) were recorded via two pressure mats installed on seat cushion and backrest. Moreover every 20 minutes, participants rated their whole-body and local discomfort. While the same increase in whole-body discomfort with driving time was observed for all three seats, S3 limited local perceived discomfort, especially in buttocks, thighs, neck, and upper back. The pressure profiles of the three seats were similar for CP, CS and RM on the backrest but differed on the seat cushion. The soft seats (S1 & S3) showed better pressure distribution, with lower SPD% than the firm seat (S2). All three showed highest CP and CS under the thighs. Road type also affected both CP and CS of all three seats, with significant differences appearing between early city, highway and country segments. In the light of these results, automotive manufacturers could enhance seat design for reduced driver discomfort by combining a soft seat cushion to reduce pressure peaks, a firm backrest to support the trunk, and a suspension system to minimize vibrations.

Perceived discomfort and neuromuscular fatigue during long-duration real driving with different car seats

“…The physical description of the three seats tested in our experiment as well as their softness characterization tests performed by CTAG (Automotive Technology Center of Galicia, Spain),) are already well detailed in the article of Lantoine et al, [ 35 ]. These tests consisted of measuring the maximum displacements of cushion and backrest foams under an identical force applied by a robotic dummy (Force vs Displacement tests—FvsD).…”

“…Concerning cushions, the foam displacement was highest for S 3 (suspended seat), followed by S 1 and finally S 2 , thereby defining S 3 and S 1 as soft seats and S 2 as a firm seat. For more details, see Lantoine et al, [ 35 ]. It is important to notice that due to confidential and patented data, we are unable to provide more details regarding seat features.…”

Urethane-Foam-Embedded Silicon Pressure Sensors including Stress-Concentration Packaging Structure for Driver Posture Monitoring

“…Driver-monitoring sensors that detect the health and cognitive status of car drivers have gained much attention for future automotive safety technology, enabling cars to request emergency responses up to level 3 automated driving and to give an alert to drivers who are distracted, fatigued, and drowsy [1][2][3][4][5][6][7][8]. Methods for monitoring driver inattentive states that lead to road accidents [2,[9][10][11] involve detecting driver behavior with cameras [6,[11][12][13], detecting driver fatigue and drowsiness with vitals sensors [6,7,14,15], and measuring body pressure distribution with pressure-sensor matrices in the seats [16][17][18]. Driver monitoring must meet the following requirements for commercial applications [2,6,9]:…”

“…However, there is much information that cannot be obtained with cameras due to changes in brightness inside the car, ambient light, and the driver's clothing [19]. Therefore, a method of measuring pressure distribution by integrating pressure sensors [16,18] into car seats, which have the advantage of direct contact with the body, is attracting attention when used in combination with a camera.…”

Parametric Modelling of Pedal Pressing Activities During Road Traffic Delay

“…The advantages of a proper driving position are clear, which are better visibility, better comfort and quicker response times [4][5]. In contract, an achy back, a stiff neck, a painful shoulder due to constant shaking, rattling, and rolling of everyday commuting will wear drivers out [6].…”