Patent Application
20070125589
The present invention relates generally to pedestrian safety systems for motor vehicles and, more particularly, to a situationally dependent vehicle structure which is configured to be modified in response to a detected vehicle condition.
When a moving vehicle strikes an obstacle, the obstacle often first hits the front bumper of the vehicle and then travels up over the bumper and lands on the hood. As such, the obstacle impacts both the bumper and the hood of the vehicle.
It is known in the art to provide impact sensing systems configured to detect an imminent impact and modify the bumper and/or hood of a vehicle to reduce the potential injury to a struck pedestrian. More particularly, the structure of the bumper may be modified in response to a detected imminent impact with an object. It is also known to raise the vehicle hood to provide a gap between the hood and the engine compartment thereby increasing the cushioning effect of the hood when imminent impact with an object is detected.
Bumpers have also been developed with additional cushion to reduce damaging impact with pedestrians. One problem with such a modified bumper design is that it tends to increase the repair costs resulting from low speed impacts. In general, a vehicle structure that is more pedestrian friendly often conflicts with other customer requirements, such as styling, high speed aerodynamics, and increase bumper durability.
According to an illustrative embodiment of the present disclosure, a pedestrian safety system for a motor vehicle includes a bumper positioned in front of an engine compartment, and a hood positioned above the engine compartment. A bumper actuator is operably coupled to the bumper and is configured to modify the stiffness of the bumper. A hood actuator is operably coupled to the hood and is configured to vertically move the hood relative to the engine compartment. A vehicle condition sensor is configured to detect a vehicle condition. A controller is in communication with the bumper actuator, the hood actuator, and the sensor. The controller is configured to control the bumper actuator and the hood actuator in response to the detected vehicle condition.
According to a further illustrative embodiment of the present disclosure, a pedestrian safety system for a motor vehicle includes a hood covering an engine compartment, and an actuator operably coupled to the hood and configured to raise and lower the hood. A sensor is configured to detect a vehicle condition including at least one of vehicle speed and vehicle location. A controller is in communication with the sensor and is configured to cause the actuator to move the hood in response to the detected condition.
According to yet another illustrative embodiment of the present disclosure, a pedestrian safety system for a motor vehicle includes a situationally dependent structure, and a sensor configured to detect the location of the vehicle. A controller is in communication with the sensor and is configured to cause selected modification of the situationally dependent structure in response to the detected vehicle location.
According to a further illustrative embodiment of the present disclosure, a method of modifying a situationally dependent vehicle structure includes the steps of providing a situationally dependent vehicle structure, and detecting the location of the vehicle. The method further includes the steps of determining whether the detected location is within a high pedestrian contact zone, and modifying the situationally dependent vehicle structure if the detected location is within the high pedestrian contact zone.
The above-mentioned and other features and objects of this invention, and the manner of attaining them, will become more apparent and the invention itself will be better understood by reference to the following description of embodiments of the invention taken in conjunction with the accompanying drawings, wherein:
Corresponding reference characters indicate corresponding parts throughout the several views. Although the drawings represent embodiments of the present invention, the drawings are not necessarily to scale and certain features may be exaggerated in order to better illustrate and explain the present invention. The exemplifications set out herein illustrate embodiments of the invention in several forms and such exemplification is not to be construed as limiting the scope of the invention in any manner.
The embodiments discussed below are not intended to be exhaustive or limit the invention to the precise forms disclosed in the following detailed description. Rather, the embodiments are chosen and described so that others skilled in the art may utilize their teachings.
Referring initially to
With reference to
With further reference to
The external condition sensor 48 may be used to detect objects 51 (
The controller 34 is configured to control operation of the hood actuators 22 and the bumper actuator 32 in response to the detected vehicle conditions of location and speed, as indicated by the input signals 36 and 38. In one illustrative embodiment, the location detector 40 provides input of vehicle location to the controller 34 which, in turn, determines the likelihood of pedestrian contact. For example, the controller 34 will determine whether the vehicle location is in a high pedestrian contact zone. Such a high pedestrian contact zone may be stored within a memory 52 and supplied to the controller 34. Illustratively, such a high pedestrian contact zone may be a neighbourhood where there is increased pedestrian traffic. In contrast, a remote highway would be given a lower likelihood of contact and not classified as a high pedestrian contact zone. Based upon the level of pedestrian contact anticipated, the controller 34 will make a decision as to whether to deploy, or enable a structural modification of, the hood 16 or bumper 24.
In a further illustrative embodiment, vehicle speed may also be considered in the deployment decision. At low speeds, illustratively less than eight miles per hour, and at high speeds, illustratively greater than twenty-five miles per hour, no changes in structure would be required by the controller 34. Average speed over a relatively short period of time is used by the controller 34 in its decision making process. In some areas, for example large areas within cities, the system 10 could be locked into a pedestrian friendly configuration. In other words, the controller 34 would maintain the structures 16 and 24 in rest modes.
By activating the hood actuators 22, the vehicle hood 16 is raised, illustratively by approximately two inches. This implementation allows for styling requirements which are primary concerns at low speeds, and for aerodynamic requirements which are primary concerns at higher speeds. At intermediate speeds, the hood 22 is elevated above the engine compartment 14 to provide additional cushioning effect for the pedestrian. In the illustrative embodiment, the controller actuates the actuators 22 to raise the hood 16 only when the detected speed is between 8 and 25 miles per hour. It may be appreciated that this speed range may vary depending upon structural details and environmental conditions.
In order to minimize pedestrian leg injuries, several options are available to stiffen or soften the contact surface of the bumper 24. Utilizing magnetically or mechanically activated bi-stable devices, the structure of the bumper 24 can be made more rigid. As shown in
As shown in
With reference now to
At optional block 116, the controller 34 determines whether the external conditions meet predetermined criteria. For example, the external condition may be the distance to object 51 in front of the vehicle 12. Illustratively, based upon the detected speed and the distance to a leading vehicle, the controller 34 may determine that it is unlikely the pedestrian would get between the vehicles. As such, if the predetermined criteria is not met (for example, the distance is less than a predetermined amount), then the process continues to block 106 where the hood 16 is in its lowered position, and to block 108 where the bumper 24 is in its rigid mode. If the predetermined condition is met, then the process continues to block 118, where the hood 16 is raised or deployed, and to block 120 where the bumper 24 is deployed to its spring mode of operation. The process then returns to block 102 where the vehicle location is detected and the steps continue in the manner identified above.
While this invention has been described as having an exemplary design, the present invention may be further modified within the spirit and scope of this disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains.
