Pressure sensing and control of an aircraft passenger seat

Abstract

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.

Contact Pressure Based Passenger Following Seat Motion Control

“…Furthermore, this result from [17], if for every two degrees of recline of the backrest, there is 2 degrees recline of the seat-pan, we can completely eliminate shear and avoid the sliding of the passenger from the seat since as reported in [17], sliding from the seat makes passengers uncomfortable. A 2:1 synchro-tilt ratio between backrest and seat-pan is also mentioned in [18].…”

“…When a force is applied on a piezoelectric sensor, it releases a current and by measuring that current, the force on the sensor can be calculated. The process of calibration and calculation of force from the current being sensed is shown in [18]. Dividing the force measured by a sensor, by the linearized area of that sensor, we measure the pressure the force on that sensor.…”

“…Dividing the force measured by a sensor, by the linearized area of that sensor, we measure the pressure the force on that sensor. Furthermore, to calculate the linearized area, we once again have from [18], Figure 3-33.…”

“…Figure 3-33: Sensor node effective area [18] Here the area of the sensor is given as a product of le and he, le is 4cm and he = 2le. Thus, we have an area, Ae = 32cm 2 or 0.0032m 2 .…”

“…When a force is applied on a piezoelectric sensor, it releases a current and by measuring that current, the force on the sensor can be calculated. The process of calibration and calculation of force from the current being sensed is shown in [18].…”