Method of characterizing a vehicle crash event based on shear waves in the vehicle frame
First Claim
1. A method of characterizing an impact to a vehicle, comprising the steps of:
- sensing acoustic emission wave energy in a frame of the vehicle;
isolating shear wave components of the sensed acoustic emission wave energy;
characterizing a transmission of the isolated shear wave components through the frame to determine a direction of the impact;
sensing the acoustic emission wave energy at first, second and third distributed locations on the frame;
isolating the shear wave components of the sensed acoustic emission wave energy at each of the first, second and third locations;
characterizing the transmission of the isolated shear wave components through the frame by identifying at time-of-arrival of the shear wave components at the first, second and third locations;
determining the direction of the impact based on the identified times-of arrival;
evaluating the identified times-of-arrival for plausibility; and
issuing a diagnostic error report if the evaluation reveals that identified times-of-arrival are implausible.
5 Assignments
0 Petitions
Accused Products
Abstract
A vehicle crash event is detected and characterized based on the transmission of acoustical shear waves through the vehicle frame. At least three, and preferably four or more, acoustical emission sensors longitudinally and laterally distributed on the vehicle frame produce acoustical signals that are processed to extract the shear wave energy due to impacts. Since shear waves are non-dispersive and travel through the vehicle frame at a known velocity, they can be detected in any part of the frame. The extracted shear wave signals are used not only to judge the severity of the impact, but also to characterize the type of crash and determine the direction of the impact based on when the shear wave is detected by each of the acoustical emission sensors.
-
Citations
15 Claims
-
1. A method of characterizing an impact to a vehicle, comprising the steps of:
-
sensing acoustic emission wave energy in a frame of the vehicle; isolating shear wave components of the sensed acoustic emission wave energy; characterizing a transmission of the isolated shear wave components through the frame to determine a direction of the impact; sensing the acoustic emission wave energy at first, second and third distributed locations on the frame; isolating the shear wave components of the sensed acoustic emission wave energy at each of the first, second and third locations; characterizing the transmission of the isolated shear wave components through the frame by identifying at time-of-arrival of the shear wave components at the first, second and third locations; determining the direction of the impact based on the identified times-of arrival; evaluating the identified times-of-arrival for plausibility; and issuing a diagnostic error report if the evaluation reveals that identified times-of-arrival are implausible. - View Dependent Claims (9, 14)
-
-
2. A method of characterizing an impact to a vehicle, comprising the steps of:
-
sensing acoustic emission wave energy in a frame of the vehicle; isolating shear wave components of the sensed acoustic emission wave energy; characterizing a transmission of the isolated shear wave components through the frame to determine a direction of the impact; sensing the acoustic emission wave energy at first, second and third distributed locations on the frame; isolating the shear wave components of the sensed acoustic emission wave energy at each of the first, second and third locations; characterizing the transmission of the isolated shear wave components through the frame by identifying at time-of-arrival of the shear wave components at the first, second and third locations; determining the direction of the impact based on the identified times-of-arrival; storing a table of shear wave times-of-arrival vs. impact direction; and determining the impact direction by indexing the stored table based on the identified times-of-arrival. - View Dependent Claims (10, 15)
-
-
3. A method of characterizing an impact to a vehicle, comprising the steps of:
-
sensing acoustic emission wave energy in a frame of the vehicle; isolating shear wave components of the sensed acoustic emission wave energy; characterizing a transmission of the isolated shear wave components through the frame to determine a direction of the impact; sensing the acoustic emission wave energy at first, second and third distributed locations on the frame, wherein the first, second, and third locations define a sensing plane that is substantially parallel to a road surface on which the vehicle is supported; isolating the shear wave components of the sensed acoustic emission wave energy at each of the first, second and third locations; characterizing the transmission of the isolated shear wave components through the frame by identifying at time-of-arrival of the shear wave components at the first, second and third locations; determining the direction of the impact based on the identified times-of-arrival; sensing the acoustic emission wave energy at a fourth location on the frame that is vertically displaced from the sensing plane defined by the first, second and third locations; isolating the shear wave components of the sensed acoustic emission wave energy at the fourth location; characterizing the transmission of the isolated shear wave components through the frame by identifying at time-of-arrival of the shear wave components at the first, second, third and fourth locations; and determining the direction of the impact based on the identified times-of-arrival. - View Dependent Claims (11)
-
-
4. A method of characterizing an impact to a vehicle, comprising the steps of:
-
sensing acoustic emission wave energy in a frame of the vehicle; isolating shear wave components of the sensed acoustic emission wave energy; characterizing a transmission of the isolated shear wave components through the frame to determine a direction of the impact; performing a time-domain correlation of the isolated shear wave components with a library of stored shear wave signatures for different test crashes; and if the correlation reveals a sufficiently close match between the isolated shear wave components and the stored shear wave signatures for a given test crash, classifying the impact based on a classification of the given test crash. - View Dependent Claims (5, 12)
-
-
6. A method of characterizing an impact to a vehicle, comprising the steps of:
-
sensing acoustic emission wave energy in a frame of the vehicle; isolating shear wave components of the sensed acoustic emission wave energy; characterizing a transmission of the isolated shear wave components through the frame to determine a direction of the impact; sensing the acoustic emission wave energy with a plurality of piezoelectric acoustic emission sensors mounted on the frame; and applying an electrical pulse to a selected piezoelectric acoustic emission sensor to create a test acoustic emission, and monitoring signals produced by the other piezoelectric acoustic emission sensors to diagnostically test such other sensors. - View Dependent Claims (7, 8, 13)
-
Specification