- 40 drivers participated in a study that tested the comfort of two different auto seat designs (Drive A and Drive B) over 2-hour highway drives.
- The seat tested in Drive B was modified from the production seat used in Drive A based on discomfort findings.
- Measurements of drivers in both drives found that the modified seat in Drive B resulted in drivers adopting a more neutral spinal posture compared to the slumped posture with the original seat.
4. 40 drivers from 25 to 76 years of age Mid-Size Sedan 2 hour highway drive in production seat Measurements in vehicle on highway Michigan State University research program Drive A
5. Drive B 18 drivers from original 40 in Drive A Same 2 hour highway drive in seat modified for Mid-Size Sedan
6. Subjective Comfort Measurements in DrivesA & B at Michigan State University. Pressure Distribution Position: 3D Video Measurements Seat Positions
11. 11 Driver changed from slumped in Drive A to neutral back posture in Drive B. Drive A Production Seat Drive B Modified Seat ERL Patents: US #6,840,125, US#7,047,831, US#7,347,114, US #7,797,138, EU #1019693 & Patents Pending
12. How do we know? Measurements in Drives Aand Band ERL model to understand the change.
13. In Drive B, Pelvis rotated 4.6º forward. Drive B Drive A
14. Pelvis rotated rearward in the slumped posture. Slumped Pelvis Position ERL Patents: US #6,840,125, US#7,047,831, US#7,347,114, US #7,797,138, EU #1019693 & Patents Pending
15. Pelvis rotates forward when posture changes from Slumped to Neutral Neutral Pelvis Position Slumped Pelvis Position ERL Patents: US #6,840,125, US#7,047,831, US#7,347,114, US #7,797,138, EU #1019693 & Patents Pending
16. In Drive B, drivers moved the seat 19mm forward for seat support. Neutral Seat Position Slumped Seat Position ERL Patents: US #6,840,125, US#7,047,831, US#7,347,114, US #7,797,138, EU #1019693 & Patents Pending
17. Driver selects fore/aft position for reach and low pressure on buttocks in seatback. Slumped Seat Position Buttocks ERL Patents: US #6,840,125, US#7,047,831, US#7,347,114, US #7,797,138, EU #1019693 & Patents Pending
18. Production (ID-Pt) Modified (ID-Pt) In Drive B, the highest pressure point (ID) under buttocks moved rearward.
19. ID is the highest pressure point under the pelvis. Slumped ID Position ERL Patents: US #6,840,125, US#7,047,831, US#7,347,114, US #7,797,138, EU #1019693 & Patents Pending
20. ID moves rearward on seat when posture changes from Slumped to Neutral. Neutral ID Position Slumped ID Position ERL Patents: US #6,840,125, US#7,047,831, US#7,347,114, US #7,797,138, EU #1019693 & Patents Pending
21. Eye height is a function of torso posture. Slumped Line of Sight ERL Patents: US #6,840,125, US#7,047,831, US#7,347,114, US #7,797,138, EU #1019693 & Patents Pending
22. In Drive B, the driver’s eye moved upwards 11mm and rearwards 17mm. Neutral Line of Sight Slumped Line of Sight ERL Patents: US #6,840,125, US#7,047,831, US#7,347,114, US #7,797,138, EU #1019693 & Patents Pending
23. In Drive B, drivers raised the steering wheel 3.6º. Drive A Drive B Drive B Neutral Posture Drive A Slumped Posture ERL Patents: US #6,840,125, US#7,047,831, US#7,347,114, US #7,797,138, EU #1019693 & Patents Pending
24. Drivers position steering wheel fortheir preferred arm and leg joint angles. ERL Patents: US #6,840,125, US#7,047,831, US#7,347,114, US #7,797,138, EU #1019693 & Patents Pending
25. ERL, LLC Eye and shoulder rise with change from slumped to erect postures. Eye Shoulder Erect Neutral Slumped ERL Patents: US #6,840,125, US#7,047,831, US#7,347,114, US #7,797,138, EU #1019693 & Patents Pending
26. Every time drivers adjusted the seat, position was recorded by computer. Seat Adjustments Fore/Aft Front Seat Height Rear
27. The longest time in one position is the Modal Period of seat position. Modal Period
29. Small and large drivers use back posture to meet different needs.
30. 30 Small women prefer Neutral & Erect back postures. Headliner 5th%tile Erect Line of Sight Neutral Slumped ERL Patents: US #6,840,125, US#7,047,831, US#7,347,114, US #7,797,138, EU #1019693 & Patents Pending
31. 31 Change in posture raises eye height for better downward vision. 5th%tile Headliner Erect Erect Line of Sight Slumped Line of Sight Slumped Neutral Erect Slumped ERL Patents: US #6,840,125, US#7,047,831, US#7,347,114, US #7,797,138, EU #1019693 & Patents Pending
32. 32 Preferred back posture is neutral which uses least muscle activity. 50th%tile Erect All spinal joints are in the middle of their range of motion. Neutral Slumped ERL Patents: US #6,840,125, US#7,047,831, US#7,347,114, US #7,797,138, EU #1019693 & Patents Pending
33. 33 Headliner too close for neutral posture in large male. 95th %tile Headliner Erect Neutral Slumped ERL Patents: US #6,840,125, US#7,047,831, US#7,347,114, US #7,797,138, EU #1019693 & Patents Pending
34. 34 Headliner often forces large male into slumped posture. 95th %tile Headliner Erect Neutral Slumped ERL Patents: US #6,840,125, US#7,047,831, US#7,347,114, US #7,797,138, EU #1019693 & Patents Pending
35. 35 Slumped posture needsadditional rearward travel. Headliner 95th %tile Erect Neutral Seat moves rearward. Slumped ERL Patents: US #6,840,125, US#7,047,831, US#7,347,114, US #7,797,138, EU #1019693 & Patents Pending
36. Why do the seat and package promote a slumped posture?
37. Head restraint position pushes head forward into slumped posture Can be modified for comfort and Federal regulations
38. Low seat back pushes buttocks forward into slumped posture. Can be modified for comfort and Federal regulations Can be comfortable with different design.
39. In new vehicles, seat still pushessmall woman into slumped posture.
40. Seat design must pass the H-point test and head restraint regulation.
41. Comfort is a development goal at supplier for seats that meet H-point and safety requirements!
42. Oscar back shape and body size define test requirements for interior. Oscar: 50th% Torso 95th% Legs
43. Oscar back shape does not represent a slumped posture. Oscar: 50th% Torso 95th% Legs ERL: 50th% Torso 50th% Legs Slumped posture in 50th %tile male
44. Oscar back shape does not represent a neutral posture. Oscar: 50th% Torso 95th% Legs ERL: 50th% Torso 50th% Legs Neutral posture in 50th %tile male
45. Oscar’s highest pressure point (ID) is posterior of the Medium Male Oscar: 50th% Torso 95th% Legs ERL: 50th% Torso 50th% Legs Neutral ID Position Oscar’s ID Position
46. 46 Seat designed first for “Oscar’s” unique back posture. “Oscar”
47. 47 Seat designed to pass H-point test. Unique Back Posture SAE Practice: “Slide the H-point machine rearward … until the seat pan contacts the seatback.”
48. 48 Seat designed to pass H-point and Head Restraint Tests. DOT Regulation requires head restraint within 55 mm of Oscar’s head. Unique Back Posture SAE Standard: “Slide the H-point machine rearward … until the seat pan contacts the seatback.”
50. The production seat in Drive A did not past the H-point test. H-point of Oscar Seating Reference Point (SgRP) Test requirement: H-point within ½” of SgRP
51. The ERL modified seat in Drive B passed the H-point test. H-point of Oscar Seating Reference Point (SgRP) Test requirement: H-point within ½” of SgRP
52. Do all drivers find cars that fit? “She said that when they went to look at new cars, she (she is about 5 ft 2 inch) never found a car that really fit her, but she accepted that, and chose cars by reliability, mileage, and color because she had no other choices!
53. How does seat design meet all requirements including comfort?
54. Driver needs to feel that the interior parts totally fit. Driver: Seat Pedal Steering Wheel Vision The passenger needs room for feet, knees and head! ERL Patents: US #6,840,125, US#7,047,831, US#7,347,114, US #7,797,138, EU #1019693 & Patents Pending
55. 55 HRMD J826 Optimize seating at beginning of design, not at the end of development. Erect Vision Neutral Comfort Space Slumped 5th 95th 50th ERL Patents: US #6,840,125, US#7,047,831, US#7,347,114, US #7,797,138, EU #1019693 & Patents Pending
56. ERL’s tools in this presentation used to explain the difference between Drive A and Drive B can be used for seat design to meet H-point test, safety test, and comfort tests at the beginning of vehicle development. Conclusion
57. Thanks for your time and interest. For more information, contact: ERL LLC reynolds@erlllc.com 517-256-3180