recognition algorithm such as a neural network an accurate location of the driver 39 s head can be found even when the driver 39 s head is partially obscured by a hat coat or hairdo this also provides at least one other identification morphological characteristic which can be used to further identify the occupant namely the diameter of the driver 39 s head with a knowledge of the weight of an occupant additional improvements can be made to automobile and truck seat designs in particular the stiffness of the seat can be adjusted so as to provide the same level of comfort for light and for heavy occupants the damping of occupant motions which heretofore has been largely neglected can also be readily adjusted as shown on fig5 which is a view of the seat of fig1 showing one of several possible arrangements for changing the stiffness and the damping of the seat in the seat bottom 520 there is a container 515 the conventional foam and spring design has been replaced by an inflated rectangular container very much like an air mattress which contains a cylindrical inner container 518 which is filled with an open cell urethane foam an adjustable orifice 525 connects the.