SEAT CONTOUR CONTROL SYSTEM AND METHOD

Abstract

A seat with an adjusting mechanism for selectively changing a contour and firmness of the seat. A force/pressure sensor is arranged between the contour of the seat which is in contact with the occupant, and the adjusting mechanism. The force/pressure sensor measures the actual force/pressure with which the occupant presses upon the seat, and which force/pressure is adjustable by the respective adjusting mechanism. A control unit stores a desired force/pressure value for the seat, and controls the adjusting mechanism to drive the actual force/pressure towards the desired force/pressure. The seat also has an operator interface which receives input from an operator. The control unit has a manual mode where the adjusting mechanism is only controlled by the operator interface. The control unit in the automatic mode records the actual value from the force/pressure sensor when the operator adjusts the seat through the interface. The control unit then sets the desired force/pressure to the present value of the force/pressure sensor. Once the operator is finished changing the adjusting mechanism, the control unit continues in automatic mode and performs any changes to the adjusting mechanism to drive the actual force/pressure from the force/pressure sensor for the value of the new desired force/pressure.

Claims

1. A seat comprising: a cushion having a surface configured to support an occupant of the seat; an adjusting mechanism arranged in said cushion, said adjusting mechanism selectively adjusting a contour and firmness of said surface; a force sensor arranged on one of said surface, and between said surface and said adjusting mechanism, said force sensor measuring an actual force applied by the occupant to said cushion; and a control unit receiving an actual force value from said force sensor, said control unit also having a predetermined desired force value, said control unit having an automatic mode comparing the actual force value with the desired force value, said control unit controlling said adjusting mechanism to drive the actual pressure value toward the desired force value in said automatic mode.

2. A seat in accordance with claim 1, wherein: said adjusting mechanism includes a pneumatic bladder; said force sensor is arranged between said surface of said cushion and a surface of said pneumatic bladder.

3. A seat in accordance with claim 1, further comprising: a plurality of said adjusting mechanisms being arranged in said cushion, each said adjusting mechanism selectively adjusting a contour and firmness of a different portion of the seat; a plurality of said force sensors, each of said portions of the seat having one of said plurality of force sensors, said each sensor measuring an actual force applied by the occupant to a respective said portion of the seat; said control unit controlling each of said adjusting mechanisms to drive an actual force value from a respective said force sensor toward a desired force value for a respective said portion of the seat.

4. A seat in accordance with claim 1, further comprising: an operator interface receiving input from an operator; said control unit controlling said adjusting mechanism as a function of the input received by said operator interface in a manual mode, said control unit recording the actual force value from the force sensor when said control unit controls said adjusting mechanism as a function of the input, said control unit setting the desired force value to the actual force value when said control unit controls said adjusting mechanism as a function of the input.

5. A seat in accordance with claim 4, wherein: said control unit switches between said automatic mode and said manual mode as a function of the input received by said operator interface.

6. A seat in accordance with claim 5, wherein: said control unit switches from said automatic mode to said manual mode upon receiving input from said operator interface indicating a change in one of shape and firmness of the seat.

7. A seat in accordance with claim 6, wherein: said control unit switches from said manual mode to said automatic mode upon receiving no input from said operator interface indicating a change in one of shape and firmness of the seat.

8. A seat in accordance with claim 1, wherein: said adjusting mechanism includes a cable with a tension device adjusting a tension in said cable; said force sensor is arranged between said surface of said cushion and said cable.

9. A seat in accordance with claim 8, wherein: said tension device is an electric motor.

10. A seat in accordance with claim 8, wherein: said tension device is an electric solenoid.

11. A seat in accordance with claim 1, wherein: said adjusting mechanism includes a spring with a tension device adjusting a tension in said spring; said force sensor is arranged between said surface of said cushion and said spring.

12. A seat in accordance with claim 11, wherein: said tension device is an electric motor.

13. A seat in accordance with claim 11, wherein: said tension device is an electric solenoid.

14. A seat in accordance with claim 1, wherein: said force sensor is a piezoresistive sensor.

15. A seat in accordance with claim 1, wherein: said force sensor is one of a resistive, capacitive or inductive sensor.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0024] FIG. 1 is a view of a portion of seat of the present invention;

[0025] FIG. 2 is a view of a pressure sensor;

[0026] FIG. 3 is a cross sectional schematic view of a portion of the seat of the present invention with bladders as adjusting mechanisms;

[0027] FIG. 4 is a flowchart showing the steps for adjusting the seat in the automatic mode;

[0028] FIG. 5 is a continuation of the flowchart of FIG. 4;

[0029] FIG. 6 is an example of the pneumatic connections and wiring diagram of the present invention; and

[0030] FIG. 7 is a cross sectional schematic view of a portion of the seat of the present invention with cables and/or springs as adjusting mechanisms.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0031] Referring to the drawings in particular, FIG. 1 shows a seat 10 which has a seat base 12 and a seat back 14. In the seat base 12 is shown a plurality of adjusting mechanisms 16. The adjusting mechanisms 16 change the shape/contour of a portion of the seat, as well as the firmness of that portion of the seat. The adjusting mechanisms 16 can include pneumatic bladders that are selectively inflatable and deflatable. A single adjusting mechanisms 16 can have one pneumatic bladder or a set of pneumatic bladders to adjust the contour and/or the firmness of the respective portion of the seat. FIG. 1 shows adjusting mechanisms 16 in the seat base 12. It is also possible for adjusting mechanisms 16 to be incorporated into the seat back 14, and any other portions of a seat 10 where the contour and/or firmness of that portion of the seat is desired to be adjustable.

[0032] In between the adjusting mechanism 16 and the occupant of the seat, there are pressure sensors 20. These pressure sensors 20 measure the pressure or force that the occupant places against the respective portion of the seat. The force that the occupant presses onto the seat portion and associated force/pressure sensor can be measured in newtons or any other force unit. While the force that the occupant presses on to the seat can be considered a pressure, that force/pressure is not necessarily the gas pressure inside a respective bladder. The force that the sensors 20 measure is a force that is in a different location than the force from the gas pressure in the respective bladder.

[0033] Each force/pressure sensor 20 is preferably associated with at least one of the adjusting mechanisms 16, and it is possible for more than one force/pressure sensor 20 to be associated with a single adjusting mechanism 16. The force/pressure sensors 20 can be placed on the exterior of the adjusting mechanisms 16. If the adjusting mechanisms 16 is a pneumatic bladder, the associated force/pressure sensor 20 can be placed between the outer surface 26 of the pneumatic bladder and the surface 24 of the associated portion of the seat, as shown in FIG. 3.

[0034] In one embodiment, as shown in FIG. 4, of the present invention, the actual contour force/pressure value Pa is read at step 30 from the force/pressure sensor 20. This actual contour force/pressure value Pa is compared 32 with a desired/target force/pressure value Pd that has been predetermined. If the actual contour force/pressure value Pa is less than the desired force/pressure value Pd then a control unit 40 in step 34 moves the adjusting mechanism 16 toward the occupant. If the actual contour force/pressure value Pa is greater than the desired force/pressure value Pd then a control unit 40 in step 36 moves the adjusting mechanism 16 away from the occupant. The present invention then returns back to step 30 to read the actual contour force/pressure value Pa from the force/pressure sensor 20, and the process starts over again.

[0035] In the embodiment of FIG. 6, the adjusting mechanism 16 includes a pneumatic bladder 42, a valve controller 44 and a pump 46. The control unit 40 receives the actual contour force/pressure value Pa from the pressure sensor 20 over a signal line/wire. The control unit 40 moves the pneumatic bladder 42 by controlling the valve controller 44 and the pump 46 over the signal lines/wires. In particular, when the adjusting mechanism 16/bladder 42 is to move a portion of the seat 10 toward the occupant, or make that portion firmer, the pump is operated to supply gas via the pneumatic line to the valve controller 44, and the valve controller 44 is operated to use the gas from the pump 46 to inflate the bladder 42 in another pneumatic line. When it is desired to move the portion of the seat 10 away from the occupant, or to make that portion less firm, the pump 46 can stop operation if it is not needed for any other purposes, such as inflating other bladders, and the valve controller 44 is operated to discharge gas from the bladder 42.

[0036] Another valve controller 48 can also be controlled by the control unit 40 to control other pneumatic bladders for other portions of the seat 10. There could be even more valve controllers than 44 and 48 as shown in FIG. 6 which control many more pneumatic bladders, depending on the number of portions of the seat that are to be adjustable.

[0037] The present invention also has an operator interface 18 where the operator can adjust the shape and firmness of the portions of the seat that have adjusting mechanisms. The operator interface 18 is connected to the control unit 40. If there is no input from the operator, then the control unit operates as shown in FIG. 4 to control the adjusting mechanisms to make in the actual contour force/pressure similar to the desired contour force/pressure.

[0038] As shown in FIGS. 4 and 5, if the operator desires to change the shape or firmness of the portion of the seat, the operator indicates this on the operator interface 18, and this information is sent to the control unit 40 which then controls in step 50 the adjusting mechanism 16 accordingly. While, or after, the adjusting mechanism 16 is being controlled by the operator, the actual contour force/pressure measured by the force/pressure sensor 20 is being recorded 52. The desired contour pressure can then be set at step 54 to the value of this recorded actual contour force/pressure. The process then starts again from step 28 of checking for input from the operator, as shown back again in FIG. 4. If the operator continues to adjust the seat 10, then the process goes back to operating as per FIG. 5. If the operator is no longer adjusting the seat, then step 28 proceeds to step 30 and the control unit 40 controls the adjusting mechanism 16 to make the actual contour force/pressure from the force/pressure sensors 20 be similar to the desired contour force/pressure as recorded in step 52 of FIG. 5. In this way, the operator adjusts the shape and/or firmness of the respective portion of the seat 10 to a desired value, and then the control unit keeps that portion of the seat at the desired shape and/or firmness. If the occupant of the seat changes his/her position, or the driving conditions change, the shape and/or firmness of a portion of the seat may also change, which may change the force/pressure measured by the force/pressure sensor 20. In the automatic mode, the control unit 40 controls the adjusting mechanism to try to keep the actual force/pressure similar to the desired force/pressure so that the occupant feels that the respective portion of the seat always has a similar shape and/or firmness as last adjusted by the operator through the operator interface 18.

[0039] The force/pressure sensors 20 measure the force that the occupant applies to the surface 24 and that force is transmitted through the seat in the direction of the adjusting mechanism 16. The placement of the force/pressure sensor 20 between the surface 24 of the seat and the adjusting mechanism 16 is advantageous in that the force/pressure sensor at this location measures the force differently than a pressure sensor which measures gas pressure inside a pneumatic bladder. Also the size of the force/pressure sensor 20 can be smaller than an effective surface area of the adjusting mechanism 16, and therefore the force/pressure sensor 20 can measure more local and specific forces than a sensor which measures gas pressure inside a pneumatic bladder. The location and size of the force/pressure sensors 20 therefore allow more specific measuring of the force that an occupant applies to the seat, and adjustments to the size and firmness of portions of the seat is therefore also more specific.

[0040] FIG. 7 shows an embodiment using a cable arrangement 27 for the adjusting mechanism 16. The cable arrangement 27 has a cable 29 and a motor 25. By rotating the motor 25, the cable 29 can be made tighter or looser which makes the corresponding portion of the seat firmer or softer. FIG. 7 also shows using a spring arrangement 23 for the adjusting mechanism 16. The spring arrangement 23 has a spring 21 and a solenoid 19 to adjust the tension in the spring 21. The solenoid 19 is connected to the spring 21, and a solenoid 19 has a mobile portion which can be selectively moved to adjust the length of the spring 21, which then controls how firm or soft is the corresponding portion of the seat.

[0041] While specific embodiments of the invention have been shown and described in detail to illustrate the application of the principles of the invention, it will be understood that the invention may be embodied otherwise without departing from such principles.