1. Technical Field
One or more embodiments of the present application relate to a crash sensor system and method that may be used to determine when a vehicle is involved in a frontal impact crash.
2. Background Art
In 1978 the U.S. National Highway Traffic Safety Administration (NHTSA) began crash-testing vehicles sold throughout the United States. The crash-test protocol involved running the vehicles head-on into a fixed barrier at 35 M.P.H. Under the New Car Assessment Program (NCAP), the results of these crash-tests were published for consumers to review under what is commonly referred to as the NHTSA star rating scale. The NHTSA star rating scale informs a consumer as to how the vehicle performed using a five star scale. For example, a NHTSA five (5) star rating would be recommended if the test-results indicated that an occupant of the vehicle had less than a ten percent (10%) chance of suffering a life-threatening injury. Conversely, a NHTSA one (1) star rating would be recommended if the test-results indicated that the occupant of the vehicle had more than a forty-five percent (45%) chance of suffering a life-threatening injury.
As such, consumers have been increasingly basing a portion of their vehicle purchase upon the published NHTSA star rating scale. The consumers may tend to avoid vehicles that fall within the lower star rating (e.g., 1-2 stars) and may base a purchase on a vehicle with a high star rating (e.g., 3-4 stars).
In response to the NHTSA star rating scale, vehicle manufacturers have continually worked to improve the crash sensing technologies (i.e., crash sensor systems). These crash sensor systems operate to continually monitor and generate vehicle crash signals. A controller receiving the crash signals makes a determination whether the vehicle has been involved in a front impact, side impact or roll-over crash. Based upon the type of crash, the controller signals that a particular safety restraint system be deployed.
For example, based upon the crash signals received, if the controller determines that the vehicle has been involved in a frontal impact crash, a pair of frontal air bags may be deployed. Likewise, if the controller determines the vehicle has been involved in a side impact crash, a pair of side curtain air bags may be deployed. However, current frontal crash sensor systems typically include some latent time delay between the occurrence of the frontal impact crash and the deployment of the frontal safety restraint system.
According to a non-limiting embodiment of the present application, a crash sensor system and method may be provided that includes at least one pressure sensor coupled to a vehicle frame member. The vehicle frame member having a cavity and the at least one pressure sensor being configured to generate a pressure signal indicative of a pressure change within the cavity. The crash sensor system further including a controller configured to compare the received pressure signal against a predetermined pressure threshold. The controller also being configured to determine that a frontal impact crash has occurred when the pressure signal exceeds the predetermined pressure threshold.
With reference to
The crash sensors 11 included within the vehicle 10 may be assigned to monitor and transmit crash signals pertaining to a particular crash scenario. For example, the frontal longitudinal accelerometers (12, 14) may monitor and transmit acceleration signals pertaining to frontal impact crashes. The controller 28 may receive the acceleration signals transmitted by the frontal longitudinal accelerometer sensors (12, 14) and determine whether the vehicle 10 has been involved in a frontal impact crash. If the controller 28 determines that the acceleration signals received from the frontal longitudinal accelerometer sensors (12, 14) indicate that a frontal impact crash has occurred, then the controller 28 may confirm the occurrence of the frontal impact crash by monitoring the acceleration signals transmitted by the central longitudinal accelerometer sensor 24. If the frontal longitudinal accelerometer sensors (12, 14) indicate, and the central longitudinal accelerometer sensor 24 confirms, that the vehicle 10 has been involved in a frontal impact collision, then the controller 28 may deploy a front safety restraint system that includes, but is not limited to, a pair of frontal airbags (30, 32).
As noted above in connection with
To begin, the acceleration signal illustrated in
In addition, when the vehicle 10 is involved in a frontal impact crash at a lower speed (e.g., less than 12 M.P.H.) the front-end engine compartment 40 may absorb much of the energy of the frontal impact crash. As such, the acceleration crash signal generated by the pair of frontal longitudinal acceleration sensors (12, 14) may not indicate that a frontal impact crash has occurred. Thus, the controller 28 may not be able to determine that a frontal impact crash has occurred and the controller 28 may not deploy the frontal safety restraint systems.
As is further illustrated in
As stated, the pressure sensor 66 may be coupled to the front bumper 48. More particularly, the pressure sensor 66 may be coupled to the inner wall 72 of the front bumper 48. The front bumper 48 may also be designed so that the cavity 68 is open at both ends. By having an opening at both ends of the front bumper 48, the cavity 68 may be substantially sealed thereby allowing a path for pressurized air to escape during a frontal impact crash. However, it is also contemplated that the front bumper 48 may also be completely sealed at both ends. As such, no path may exist for the pressurized air generated during a frontal impact crash to escape.
When the vehicle 10 is involved in a frontal impact crash, the pressure sensor 66 may generate a pressure signal indicative of a pressure change within the cavity 68. In turn, the controller 28 may receive and determine if the pressure signal exceeds a predetermined pressure threshold. If the pressure signal exceeds the predetermined pressure threshold, then the controller 28 may determine that the vehicle 10 is involved in a frontal impact crash. However, if the pressure signal does not exceed the predetermined pressure threshold, then the controller 28 may determine that the vehicle 10 is not involved in a frontal impact crash.
As shown in
For example, the first pressure sensor 74 may be coupled to a driver side of the front bumper 48. Moreover, the second pressure sensor 76 may be coupled to a passenger side of the front bumper 48. If the vehicle 10 is involved in a frontal impact crash, then the first pressure sensor 74 may generate a first pressure signal indicative of the pressure change within the cavity 68 located on the driver side of the front bumper 48. In addition, the second pressure sensor 76 may generate a second pressure signal indicative of the pressure change within the cavity 68 located on the passenger side of the front bumper 48.
The controller 28 may receive the first and second pressure signals and determine if the difference between the first and second pressure signals exceeds a predetermined pressure threshold. If so, the controller 28 may determine that the vehicle is involved in a frontal impact crash. The controller 28 may further compare the first and second pressure signals to a crash severity threshold in order to determine whether the frontal impact crash occurred on the driver or passenger side of the vehicle 10. For example, if the first pressure signal exceeds the crash severity threshold, the controller 28 may determine the vehicle is involved in a frontal impact crash occurring on the driver side of the vehicle. However, if the second pressure signal exceeds the crash severity threshold, then the controller 28 may determine the vehicle 10 is involved in a frontal impact crash occurring on the passenger side of the vehicle 10. One or more embodiments of the present application further contemplate that if the difference between the first and second pressure signals do not exceed the predetermined pressure threshold, and both the first and second pressure signals exceed the crash severity threshold, then the controller 28 may determine that the vehicle 10 is involved in frontal impact crash occurring on a central portion of the vehicle 10 (e.g., a full frontal impact crash). It is noted that any number of pressure sensors may be positioned on the front bumper 48 and that the number of pressure sensors positioned thereon may vary based on the desired criteria of a particular implementation.
As shown in
The controller 28 may receive the first and second pressure signals and determine if the difference between the first and second pressure signals exceeds a predetermined pressure threshold. If so, the controller 28 may determine the vehicle is involved in a frontal impact crash. The controller may further compare the first and second pressure signals to a crash severity threshold in order to determine whether the frontal impact crash occurred on the driver or passenger side of the vehicle 10. If the first pressure signal exceeds the crash severity threshold, then the controller 28 may determine the vehicle is involved in a frontal impact crash occurring on the driver side of the vehicle. If on the other hand, the second pressure signal exceeds the crash severity threshold, then the controller 28 may determine the vehicle is involved in a frontal impact crash occurring on the passenger side of the vehicle. One or more embodiments of the present application further contemplate that if the difference between the first and second pressure signals do not exceed the predetermined pressure threshold, and both the first and second pressure signals exceed the crash severity threshold, then the controller 28 may determine that the vehicle 10 is involved in frontal impact crash occurring on a central portion of the vehicle 10 (e.g., a full frontal impact crash).
It is also generally contemplated that the pressure sensors 66 may generate a pressure signal indicative of the location on the front bumper 40 upon which the frontal impact crash occurs. For example, if the vehicle 10 is involved in a frontal impact crash occurring along the driver side portion of the vehicle 10, an increase in pressure may occur in one or more of the sealed chambers 90 located on the driver's side of the vehicle 10. In turn, the attached pressure sensors 66 may generate and transmit pressure signals indicative of the increased pressure change. The controller 28 may receive these pressure signals and may determine that the vehicle 10 has been involved in a frontal impact crash occurring on the driver's side of the vehicle 10.
It is generally contemplated that the one or more sealed chambers 90 may also be included within the pair of frontal side rails (44, 46). It is also noted that any number of pressure sensors (74, 76) may be coupled to the one or more sealed chambers 90 and may operate to generate and transmit pressure signals indicative of pressure changes within the one or more sealed chambers 90.
The pressure signal 94 may include a start time 100 and a pressure time delay 102. The pressure signal 94 may further include a time 104 indicative of the occurrence of a frontal impact crash. As illustrated, the pressure time delay 102 may be smaller than the acceleration time delay 60 illustrated in the acceleration graph 52. As such, the pressure signal 94 may be generated at a time closer to the actual occurrence of the frontal impact crash. By incorporating pressure sensors into the front bumper 48 or into the pair of frontal side rails (44, 46), the pressure signal generated during the occurrence of a frontal impact crash may be more responsive than the acceleration signal generated by the frontal longitudinal acceleration sensors (12, 14). Thus, the controller 28 may deploy the frontal restraint safety system at a time closer to the actual occurrence of the frontal impact crash.
With reference back to the drawings,
In operation 204, the controller 28 may determine if the pressure signal exceeds a predetermined pressure threshold. If the pressure signal does not exceed the predetermined pressure threshold, then the flow diagram 200 may return back to operation 202. However, if the pressure signal does exceed the predetermined pressure threshold, the flow diagram 200 may proceed to operation 206.
In operation 206, the controller 28 may confirm whether the vehicle 10 has been involved in a frontal impact crash. The controller 28 may confirm the occurrence of the frontal impact crash by determining if the acceleration signal exceeds a predetermined acceleration threshold. If the acceleration signal does not exceed the predetermined acceleration threshold, then the flow diagram 200 proceeds back to operation 202. However, if the acceleration signal does exceed the predetermined acceleration threshold, then the flow diagram 200 proceeds to operation 208.
In operation 208, the controller 28 may control one or more frontal safety restraint systems. More particularly, the controller 28 may be configured to control and deploy the pair of frontal airbags (30, 32) when it is determined that the vehicle 10 is involved in a frontal impact crash.
While embodiments of the present application may have been illustrated and the described is not intended those embodiments illustrate and describe the only embodiments of the present application. Rather, the words used in the above application are words of description rather than limitations and it should be understood that changes may be made to the above description without departing from the spirit and scope of the application. As such, specifically details disclosed are merely representative basis for teaching one skilled in the art to practice the present application.