METHOD FOR ESTIMATING SURFACE TEMPERATURE OF VENTILATED SEAT
A method for estimating a surface temperature of a ventilated seat. A heat transfer rate to or from a material layer is determined based on a temperature applied to the material layer by convective air. A temperature of the material layer is estimated based on the heat transfer rate to or from the material layer. A heat transfer rate to or from a trim layer is determined based on the temperature of the material layer, which is applied to the trim layer. A change rate of the surface temperature is calculated based on the heat transfer rate to or from the trim layer. A surface temperature is estimated based on the change rate of the surface temperature.
1 . A method for estimating a surface temperature of a ventilated seat, the method comprising:
determining a heat transfer rate to or from a material layer based on a temperature applied to the material layer by convective air;
estimating a temperature of the material layer based on the heat transfer rate to or from the material layer;
determining a heat transfer rate to or from a trim layer based on the temperature of the material layer, which is applied to the trim layer;
calculating a change rate of the surface temperature based on the heat transfer rate to or from the trim layer; and
updating an estimated surface temperature of the trim layer from a prior program cycle based on the change rate of the surface temperature and the estimated surface temperature of the trim layer from the prior program cycle.
2 . The method according to claim 1 , wherein the convective air flows through one or more vents formed in the material layer and/or a porosity of the material layer.
3 . The method according to claim 2 , wherein the convective air is drawn from a cabin of a vehicle.
4 . The method according to claim 3 , wherein the convective air is free from thermal conditioning by a heating device and/or a cooling device.
5 . The method according to claim 1 , wherein the material layer is a spacer layer disposed between the trim layer and a fluid distribution device.
6 . The method according to claim 1 , wherein the method further comprises determining a second heat transfer rate to or from the trim layer based on a second temperature applied to the trim layer.
7 . The method according to claim 6 , wherein the second temperature is applied by cabin air; optionally wherein the cabin air is located above the trim layer.
8 . The method according to claim 1 , wherein the method further comprises determining a third heat transfer rate to or from the trim layer based on a third temperature applied to the trim layer.
9 . The method according to claim 8 , wherein the third temperature is applied by an occupant.
10 . The method according to claim 1 , wherein the change rate of the surface temperature is additionally based on the second heat transfer rate and/or the third heat transfer rate.
11 . The method according to claim 10 , wherein the method further comprises determining an occupancy status of the ventilated seat.
12 . The method according to claim 11 , wherein for an occupied seat, the change rate of the surface temperature is additionally based on the second heat transfer rate and the third heat transfer rate.
13 . The method according to claim 12 , wherein for an unoccupied seat, the change rate of the surface temperature is additionally based on the second heat transfer rate.
14 . The method according to claim 1 , wherein the heat transfer rates to or from the material layer and the trim layer are influenced respectively by a thermal resistance of the material layer and a thermal resistance of the trim layer; and wherein the thermal resistances of the material layer and the trim layer are selected based upon if the ventilated seat is occupied or not.
15 . The method according to claim 14 , wherein the heat transfer rate to or from the material layer is influenced by a surface area across which the first temperature is applied; and wherein the surface area is selected based on if the ventilated seat is occupied or not.
16 . The method according to claim 15 , wherein the temperature estimated for the material layer and/or the change rate of the surface temperature are based on one or more additional heat transfer rates.
17 . The method according to claim 16 , wherein the one or more additional heat transfer rates relative to the material layer includes a heat transfer rate between a fluid distribution device and the material layer.
18 . The method according to claim 1 , wherein the first temperature is sensed by a sensor local to the cabin of the vehicle in which the ventilated seat is located.
19 . The method according to claim 1 , further comprising controlling a blower including:
receiving the surface temperature;
receiving a cabin air temperature;
optionally receiving a relative humidity; and
regulating a duty cycle of the blower based on the surface temperature, the cabin air temperature, the relative humidity, or any combination thereof.
20 . A system for performing the method according to claim 19 , the system comprising:
a blower operating in either push or pull mode;
a fluid distribution device (e.g., in the form of a bag), a portion thereof that is oriented toward a seat surface being air permeable;
a temperature sensor (e.g., located on-board the blower); and
a relative humidity sensor (e.g., located proximate to the seat surface).