Patent Application
20080319697
A vehicle system has been developed that monitors a pressure on a vehicle seat to determine whether a passenger on the vehicle seat is an adult or a child.
A drawback associated with the existing vehicle system is that the system may not be able to determine a pressure exerted on the vehicle seat by a passenger as accurately as desired since the measured pressure is not compensated for temperature, an applied seat belt tension, vehicle seat aging, and vehicle seat compression.
Accordingly, the inventors herein have recognized a need for a system and a method that accurately determines a pressure exerted on a vehicle seat by a passenger, compensating for temperature, an applied seat belt tension, vehicle seat aging and vehicle seat compression.
A method for determining an amount of pressure applied by an occupant on a vehicle seat in a vehicle in accordance with an exemplary embodiment is provided. The method includes receiving a first signal from a pressure transducer in the vehicle seat at a microprocessor. The first signal is indicative of a pressure measured by the pressure transducer. The method further includes determining a pressure value based on the first signal, utilizing the microprocessor. The method further includes receiving a second signal from a temperature sensor at the microprocessor. The second signal indicates a temperature proximate the vehicle seat. The method further includes determining a temperature value based on the second signal, utilizing the microprocessor. The method further includes receiving a third signal from a belt tension sensor at the microprocessor. The third signal indicates an amount of tension on a seat belt associated with die vehicle seat. The method further includes determining a belt tension value based on the third signal, utilizing the microprocessor. The method further includes determining a compensated pressure value indicative of the amount of pressure applied to the vehicle seat based on the pressure value, the temperature value, and the belt tension value, utilizing the microprocessor. The method further includes storing the compensated pressure value indicative of the amount of pressure applied to the vehicle seat in a memory device, utilizing the microprocessor. The method may additionally include determining a classification of the occupant based on the amount of pressure applied to the vehicle seat.
A system for determining an amount of pressure applied by an occupant on a vehicle seat in a vehicle in accordance with another exemplary embodiment is provided. The system includes a pressure transducer disposed in the vehicle seat. The pressure transducer is configured to generate a first signal indicative of a pressure measured by the pressure transducer. The system further includes a temperature sensor disposed proximate the vehicle seat. The temperature sensor is configured to generate a second signal indicating a temperature proximate the vehicle seat. The system further includes a belt tension sensor coupled to a seat belt associated with the vehicle seat. The belt tension sensor is configured to generate a third signal indicating an amount of tension applied to a seat belt associated with the vehicle seat. The system further includes a microprocessor operably communicating with the pressure transducer and the temperature sensor and the belt tension sensor. The microprocessor is configured to determine a pressure value based on the first signal. The microprocessor is further configured to determine a temperature value based on the second signal. The microprocessor is further configured to determine a belt tension value based or; the third signal. The microprocessor is further configured to determine a compensated pressure value indicative of the amount of pressure applied to the vehicle seat based on the pressure value, the temperature value, and the belt tension value. The microprocessor is further configured to store the compensated pressure value indicative of the amount of pressure applied to the vehicle seat in a memory device. The microprocessor may be additionally configured to determine a classification of the occupant based on the amount of pressure applied to the vehicle seat.
Referring to
The vehicle seat 20 is provided to hold a vehicle occupant thereon. The seat 20 includes a frame 50, foam cushions 52, 54 and a bladder 56. The frame 50 is fixedly coupled to a portion of a vehicle frame (not shown). The foam cushions 52, 54 are disposed on the frame 50. Further, in one exemplary embodiment the bladder 56 is disposed under the foam cushion 52. In an alternative exemplary embodiment, the bladder 56 is disposed in the foam cushion 52. The bladder 56 includes a fluid such as silicon for example, which is non-corrosive, and not subject to freezing at extreme ambient temperatures. In addition, a semi-rigid backplane may be placed under the bladder 56 to provide a suitable reaction surface, as disclosed for example in U.S. Pat. No. 6,490,936, filed May 14, 1999, assigned to the assignee of the present invention and incorporated herein by reference. Alternatively, the bladder 56 may be placed between two semi rigid backplanes to provide reaction services on both sides of the bladder 56.
The system 32 is provided to determine an amount of pressure applied by occupant on the vehicle seat 20. Further, the system 32 is provided to determine a seat occupant classification based upon the amount of pressure applied by the occupant on the vehicle seat 20. The system 32 includes a pressure transducer 70, a temperature sensor 72, a belt tension sensor 74, an ignition system 75, a microprocessor 76, and a memory device 78.
The pressure transducer 70 is configured to generate a signal indicative of an amount of pressure in the bladder 56, that is received by the microprocessor 76. The pressure transducer 70 is operably coupled to the bladder 56 and is electrically coupled to the microprocessor 76.
The temperature sensor 72 is configured to generate a signal indicative of a temperature level proximate the seat 20, that is received by the microprocessor 76. In one exemplary embodiment, the temperature sensor 72 is disposed within the foam cushion 52 and is electrically coupled to the microprocessor 76. Of course, the temperature sensor 72 could be disposed in alternate locations outside of the vehicle seat 20.
The belt tension sensor 74 is configured to generate a signal indicative of an amount of tension applied to the seat belt 24 by an occupant, that is received by the microprocessor 76. In one exemplary embodiment, the belt tension sensor 74 is disposed on the buckle 30 associated with the vehicle seat 20. As shown, the belt extends through an anchor member 28 and has a clip 26 configured to be received by the buckle 34 for securing an occupant in the vehicle seat 20.
The ignition system 75 is provided to activate an engine (not shown) of the vehicle 10. During operation, the ignition system 75 is configured to generate a signal indicating activation of the engine that is received by the microprocessor 76.
The microprocessor 76 is configured to determine an amount of pressure applied by an occupant on the vehicle seat 20 in response to signals received from the pressure transducer 70, the temperature sensor 72, the belt tension sensor 74, and the ignition system 75, as will be described in greater detail below. Further, the microprocessor 76 is configured to determine a seat occupant classification based upon the amount of pressure applied by the occupant on the vehicle seat 20, as will be described in greater detail below.
Referring to
At step 100, the pressure transducer 70 operably communicating with the bladder 56 in the vehicle seat 20 generates a first signal indicative of a pressure measured by the pressure transducer 70.
At step 102, the microprocessor 76 receives the first signal and determines a pressure value based on the first signal.
At step 104, the temperature sensor 72 generates a second signal indicating a temperature proximate the vehicle seat 20.
At step 106, the microprocessor 76 receives the second signal and determines a temperature value based on the second signal.
At step 108, the belt tension sensor 74 generates a third signal indicating an amount, of tension on the seat belt 24 associated with the vehicle seat 20.
At step 110, the microprocessor 76 receives the third signal and determines a belt tension value based on the third signal.
At step 112, the microprocessor 76 determines a compensated pressure value based on the pressure value, the temperature value, and the belt tension value. In particular, the microprocessor can determine the compensated pressure value utilizing the following equation:
Compensated pressure value=F(pressure value,temperature value,belt tension value), wherein the term F corresponds to a mathematical function.
At step 114, the microprocessor 76 monitors the ignition system 75 to determine a cumulative time interval value corresponding to a cumulative amount of time that the vehicle 10 has been operated over a vehicle life.
At step 116, the microprocessor 76 determines a time-based seat aging compensation value based on the cumulative time interval value. Referring to
Referring again to
At step 120, the microprocessor 76 determines a condition-based seat aging compensation value based on the change in pressure associated with the bladder 56 over the vehicle life. Referring to
At step 122, the microprocessor 76 monitors the ignition system 75 to determine a first time interval value corresponding to a time interval that the vehicle 10 has been operated since activation of the ignition system 75.
At step 124, the microprocessor 76 determines a seat compression compensation value based on the first time interval value. Referring to
At step 126, the microprocessor 76 determines a final pressure value indicative of the amount of pressure applied to the vehicle seat 20 based on the compensated pressure value, the time-based seat aging compensation value, the condition-based seat aging compensation value, and the seat compression compensation value. In particular, the final pressure value can be obtained by summing together the compensated pressure value, the time-based seat aging compensation value, the condition-based seat aging compensation value, and the seat compression compensation value.
At step 128, the microprocessor 76 stores the final pressure value in the memory device 78.
At step 130, the microprocessor 76 makes a determination as to whether the final pressure value is greater than a threshold value. It the value of step 130 equals “yes”, the method advances to step 132. Otherwise, the method advances to step 134.
At step 132, the microprocessor 76 sets a first seat occupant classification flag equal to a first predetermined value indicating the occupant of the vehicle seat 20 corresponds to a first classification of vehicle occupant, and stores the first seat occupant classification flag in the memory device 78. After step 132, the method is exited.
At step 134, the microprocessor 76 sets a second seat occupant classification flag equal to a second predetermined value indicating the occupant of the vehicle seat 20 corresponds to a second classification of vehicle occupant, and stores the second seat occupant classification flag in the memory device 78. After step 134, the method is exited.
The above-described method can be embodied in the form of computer-implemented software algorithms and apparatuses for practicing those processes. In an exemplary embodiment, the method is embodied in computer program code executed by one or more elements. The present method may be embodied in the form of computer program code containing instructions stored in tangible media, such as floppy diskettes, CD-ROMs, hard drives, flash memory, or any other computer-readable storage medium, wherein, when the computer program code is loaded into and executed by a microprocessor, the microprocessor becomes an apparatus for practicing the invention.
The inventive system and method for determining art amount of pressure applied by an occupant on a vehicle seat represents a substantial improvement over other systems and methods. In particular, the inventive system and method provide a technical effect of determining the amount of pressure applied by the occupant on the vehicle seat based on signals from a pressure transducer, a temperature sensor, and a belt tension sensor to more accurately determine the amount of pressure applied by the occupant on the vehicle seat.
While the invention has been described with reference to exemplary embodiments, it will be understood by those skilled in the art that various changes may be made and equivalent elements may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiments disclosed for carrying out this invention, but that the invention will include all embodiments falling within the scope of the appended claims. Moreover, the use of the terms first, second, etc. do not denote any order or importance, but rather the terms first, second, etc. are used to distinguish one element from another. Further, the use of the terms a, an, etc. do not denote a limitation of quantity, but rather denote the presence of at least one of the referenced item.
