Pressure sensing and control of an aircraft passenger seat

The premise of this work is to address aircraft seat comfort. This thesis presents the development of an automatic morphing backrest used to reduce pressure experienced by the passenger from the seat. Uncomfortable, high surface pressure zones on the backrest can be alleviated by decentralizing the occupant’s weight. The improved pressure distribution is intended to decrease discomfort during flight while taking different comfort/discomfort models into consideration. Pressure distribution data from the embedded sensor mat is used to compute the seat’s cushion deflection and corresponding backrest contour caused by the passenger’s weight. The surfaces of interest - the passenger’s back and the seat, are modelled and discretized. The discretized surface contact pressure is integrated into the hyperelastic contact model to determine the loading profile. From this, the current pressure distribution and the cushion’s surface change are computed and used in the control system to create the corresponding actuation of the surface.

Zone-based active noise control for an aircraft passenger seat

The goal of this research is to improve zone-based local active noise control for an aircraft passenger seat using head tracking and virtual sensing methods. Broadband diffuse sound fields are analyzed in order to determine the level of attenuation around the passenger’s ears. The virtual sensing methods which were evaluated from literature include the virtual microphone technique, the forward difference prediction technique, and the adaptive LMS moving virtual microphone techniques. In addition to virtual sensing, a new methodology for integrating zone-based technologies with existing local ANC techniques has been developed. The virtual sensing simulation and head tracking measurements can be used to verify this methodology.

Pressure sensing and control of an aircraft passenger seat

The premise of this work is to address aircraft seat comfort. This thesis presents the development of an automatic morphing backrest used to reduce pressure experienced by the passenger from the seat. Uncomfortable, high surface pressure zones on the backrest can be alleviated by decentralizing the occupant’s weight. The improved pressure distribution is intended to decrease discomfort during flight while taking different comfort/discomfort models into consideration. Pressure distribution data from the embedded sensor mat is used to compute the seat’s cushion deflection and corresponding backrest contour caused by the passenger’s weight. The surfaces of interest - the passenger’s back and the seat, are modelled and discretized. The discretized surface contact pressure is integrated into the hyperelastic contact model to determine the loading profile. From this, the current pressure distribution and the cushion’s surface change are computed and used in the control system to create the corresponding actuation of the surface.

Zone-based active noise control for an aircraft passenger seat

The goal of this research is to improve zone-based local active noise control for an aircraft passenger seat using head tracking and virtual sensing methods. Broadband diffuse sound fields are analyzed in order to determine the level of attenuation around the passenger’s ears. The virtual sensing methods which were evaluated from literature include the virtual microphone technique, the forward difference prediction technique, and the adaptive LMS moving virtual microphone techniques. In addition to virtual sensing, a new methodology for integrating zone-based technologies with existing local ANC techniques has been developed. The virtual sensing simulation and head tracking measurements can be used to verify this methodology.

Optimum structural design of seat frames for commercial vehicles

Seat frames in commercial vehicles generally consist of components such as foot brackets, seats, back, head restraints and fasteners. In addition to mechanical properties, comfort is another important parameter. This study aims to reduce the cost of a commercial vehicle by means of alternative materials and design changes in the passenger seat frame. For this purpose, three different methods were used to optimize seat back pipes: reducing the cross-section, using thinner sections in the seat frame via alternative material and making design changes in the foot brackets. In the methods applied, mitigation and cost reductions were achieved. The suitability of the design changes in the seat through geometric changes was confirmed by international ECE R14 test results and finite element method analyses.

A multifactorial approach to specify comfortable rail seats

BACKGROUND: A robust rail seat comfort assessment can inform the GB rail industry when procuring new seats and identify areas for comfort improvement in the refurbishment of existing seats, improving the customer experience. OBJECTIVE: To take a multifactorial approach to measuring comfort and to create a robust seat comfort assessment method for the GB rail industry. METHODS: Seat comfort assessment scores were developed by identifying seat dimensions (e.g. Seat height, seat width, seat depth), seat pad thickness and hardness requirements, seat accessories and seat attractiveness components. Scores for each seat feature were verified by conducting a fitting trial and asking 7 participants to rank dimensions through a range of adjustment. The combined scoring of features was verified by asking 14 participants to rank seats in three configurations (<minimum comfort; minimum comfort;>minimum comfort). The seat comfort dimensions scores were then validated by ranking seven existing rail seats using the assessment method and comparing the ranks with subjective comfort ranks of 12 participants. RESULTS: The validation testing resulted in a moderate positive correlation, indicating an alignment between the seat comfort assessment method and subjective comfort scores. CONCLUSIONS: A multifactorial seat comfort assessment has been shown to be a good indicator of passenger seat comfort.