Method of determining optimal seat surface contours and seat having an optimized seat surface contour

1. An aircraft passenger seat having a plurality of seat surfaces configured for a target population of varying anthropometry, the aircraft passenger seat comprising:

a seat back produced with contours derived from

i) obtaining first quantitative definitions of back surfaces of a sample of individuals relative to a seat back surface reference,

ii) adjusting a first mathematical summary of the quantitative definitions of the back surfaces of the sample of individuals by

a) a fore-aft mathematical function of a summary statistic of the of back surfaces of the sample of individuals on a fore and aft axis of the seat back surface reference, and

b) a side-side mathematical function of a summary statistic of the back surfaces of the sample of individuals on a side-to-side axis of the seat back surface reference; and

a seat bottom produced with contours derived from

iii) obtaining second quantitative definitions of buttock and under thigh surfaces of the sample of individuals relative to a seat bottom surface reference, and

iv) adjusting a second mathematical summary of the quantitative definitions of the buttock and under thigh surfaces of the sample of individuals by a mathematical function of a summary statistic of the buttock and under thigh surfaces of the sample of individuals.

2. The aircraft passenger seat according to claim 1 , wherein adjusting the second mathematical summary of the quantitative definitions of the buttock and under thigh surfaces of the sample of individuals comprises adjusting the second mathematical summary of the quantitative definitions of the buttock and under thigh surfaces of the sample of individuals by:

a) a second fore-aft mathematical function of a summary statistic of the buttock and under thigh surfaces of the sample of individuals on a fore and aft axis of the seat bottom surface reference; and

b) a second side-side mathematical function of a summary statistic of the buttock and under thigh surfaces of the sample of individuals on a side-to-side axis of the seat bottom surface reference.

3. The aircraft passenger seat according to claim 1 , wherein obtaining first quantitative definitions of back surfaces comprises obtaining first quantitative definitions of back, back of head, back of neck and back of buttock surfaces of the sample of individuals.

4. The aircraft passenger seat according to claim 1 , wherein the seat back surface reference is defined using an x-axis as a centerline of a back of a reference seat and a y-axis parallel to a spine angle of the reference seat parallel to a pre-defined reference plane.

5. A method of producing an aircraft passenger seat by a process comprising:

determining quantitative definitions of back, buttock and under-thigh surfaces of a sample of individuals;

determining an improved bottom surface contour by adjusting a mathematical summary of the buttock and under-thigh surfaces of the sample of individuals by

i) applying a first mathematical function of a summary statistic of the buttock and under-thigh surfaces of the sample of individuals on a fore and aft axis of a seat bottom surface reference, and

ii) applying a second, different mathematical function of a summary statistic of the buttock and under-thigh surfaces of the sample of individuals on a side-to-side axis of the seat bottom surface reference;

determining an improved back surface contour by adjusting a mathematical summary of the back surfaces of the sample of individuals by applying a third mathematical function of a summary statistic of the back surfaces of the sample of individuals;

conforming a seat bottom of the aircraft passenger seat to the improved bottom surface contour; and

conforming a seat back of the aircraft passenger seat to the improved back surface contour.

6. The method of claim 5 , wherein determining the improved back surface contour comprises applying the third mathematical function of a summary statistic of the back surfaces of the sample of individuals on a fore and aft axis of a seat back surface reference, and a fourth, different mathematical function of a summary statistic of the back surfaces of the sample of individuals on a side-to-side axis of the seat back surface reference.

7. The method of claim 6 , wherein the third mathematical function comprises defining a mean spine support profile by identifying the minimum z-value for all values of x at each value of y in a matrix of mean z values for the back surface reference.

8. The method of claim 7 , wherein the fourth mathematical function comprises defining a two-dimensional, in x and z, adjusted back transverse support rib profiles for each value of y on the back surface reference by multiplying each mean z-value by a scaling coefficient or function.

9. The method of claim 8 , wherein determining the improved back surface contour further comprises:

defining zeroed back transverse support rib profiles for every value of y in the back surface by subtracting the minimum z value identified in each adjusted back transverse support rib profile from all z-values of that same adjusted transverse support rib profile; and

adding the z-value of the mean spine support profile to all z-values of each zeroed back transverse support rib at the corresponding value of y.

10. The method of claim 5 , further comprising obtaining a plurality of measurements from impressions in soft material of a test seat by the sample of individuals, wherein determining the quantitative definitions of back, buttock and under-thigh surfaces of the sample of individuals comprises creating matrices of z-values from the plurality of measurements.

11. The method of claim 5 , wherein the first mathematical function comprises defining a mean bottom support profile by identifying the minimum z-value for all values of x at each value of y in a matrix of mean z values for the bottom surface reference.

12. The method of claim 11 , further comprising determining an adjusted bottom support profile by subtracting from or adding to each z-value of the mean bottom support profile a function of a summary statistic for the value of x at which the minimum value of z was found for the relevant value of y.

13. The method of claim 11 , wherein the mean z-values are weighted to reflect the frequency of occurrence of the anthropometry of each individual sample subject in the target population where the distribution of anthropometry in the sample does not adequately correspond to the distribution of anthropometry in the target population.

14. The method of claim 5 , wherein the second mathematical function comprises defining a two-dimensional, in x and z, adjusted bottom transverse profile for each value of y on the bottom surface reference.

15. The method of claim 5 , wherein the seat back surface reference is defined using an x-axis as a centerline of a back of a reference seat and a y-axis parallel to a spine angle of the reference seat parallel to a pre-defined reference plane.

16. The method of claim 15 , wherein the seat bottom surface reference is defined using an x-axis as a side-to-side plane parallel to the pre-defined reference plane and a z-axis perpendicular to the pre-defined reference plane.

17. A method of producing an aircraft passenger seat by a process comprising:

determining quantitative definitions of back, buttock and under-thigh surfaces of a sample of individuals;

determining an improved bottom surface contour by adjusting a mathematical summary of buttock and bottom thigh surfaces of a sample of individuals by applying a first mathematical function of a summary statistic of the buttock and bottom thigh surfaces of the sample of individuals;

determining an improved back surface contour by

applying a second mathematical function of a summary statistic of the back surfaces of the sample of individuals on a fore and aft axis of a seat back surface reference, and

applying a third, different mathematical function of a summary statistic of the back surfaces of the sample of individuals on a side-to-side axis of the seat back surface reference;

conforming a seat bottom of the aircraft passenger seat to the improved bottom surface contour; and

conforming a seat back of the aircraft passenger seat to the improved back surface contour.

18. The method of claim 17 , wherein:

the first mathematical function is applied on a fore and aft axis of a seat bottom surface reference; and

determining the improved bottom surface contour further comprises applying a second, different mathematical function of a summary statistic of the buttock and under-thigh surfaces of the sample of individuals on a side-to-side axis of the seat bottom surface reference.

19. The method of claim 17 , wherein determining the quantitative definitions further comprises determining quantitative definitions from back of head, back of neck and back of buttock surfaces of the sample of individuals.

20. The method of claim 17 , wherein determining the quantitative definitions further comprises weighting the quantitative definitions, for each individual of the sample of individuals, to reflect a frequency of occurrence of anthropometry of the respective individual in the target population.