Crash sensing via piezoelectric sensors
View Patent ↗A system and method for characterizing piezoelectric sensor responses for automotive vehicle crash analysis, is disclosed. The method employs Daubechies wavelet analysis ( 1006 ) to plot signal response amplitudes ( 1008 ) in three-dimensional space of at least one piezoelectric sensor. A cluster, signifying a combination of Daubechies amplitudes of the at least one piezoelectric sensor in three-dimensional space, is compared to reference clusters ( 1010 ) stored in the automotive vehicle. Based on results from comparing the cluster to the reference clusters, instructions are transmitted to an occupant restraint control system ( 1013 ) in the vehicle to deploy a specific airbag at a specific power level.
1. A method for characterizing piezoelectric sensor signal responses for automotive vehicle crash analysis, said method comprising:
providing at least one piezoelectric sensor mounted at a predetermined locations on the automotive vehicle;
sampling a response from the piezoelectric sensor for a predetermined period of time;
subjecting the response from the piezoelectric sensor to a wavelet analysis and obtaining signal amplitudes;
plotting the signal amplitudes in three-dimensional space and forming a cluster of signal amplitudes;
comparing a most recent cluster to reference clusters that are indicative of both crash and non-crash events; and
providing instructions to an occupant restraint control system in the automotive vehicle.
2. The method of claim 1 , further comprising providing three polyvinylidene fluoride piezoelectric sensors mounted at predetermined locations on a transparency product of the automotive vehicle.
3. The method of claim 2 , wherein the transparency product is a windshield.
4. The method of claim 3 , comprising applying a Daubechies transfer function in the wavelet analysis.
5. A method for characterizing piezoelectric sensor signal responses for automobile crash analysis, said method comprising:
providing at least three polyvinylidene fluoride piezoelectric sensors;
mounting the three polyvinylidene fluoride piezoelectric sensors on a windshield of the automobile;
sampling responses from the three polyvinylidene fluoride piezoelectric sensors to a Daubechies wavelet analysis and obtaining Daubechies amplitudes for each polyvinylidene fluoride piezoelectric sensor;
aggregating the Daubechies amplitudes from the three polyvinylidene fluoride piezoelectric sensors and plotting the intersection of the Daubechies amplitudes and forming a cluster of the Daubechies amplitudes.
6. The method of claim 5 , comprising providing a fourth polyvinylidene fluoride piezoelectric sensor.
7. The method of claim 5 , comprising incorporating the fourth polyvinylidene fluoride piezoelectric sensor into a rear-view mirror mounting button of the automobile.
8. The method of claim 5 , further comprising using orthogonal single-axis polyvinylidene fluoride piezoelectric sensors.
9. The method of claim 5 , further comprising using a dual signal path integrated circuit for sampling responses from the polyvinylidene fluoride piezoelectric sensors.
10. The method of claim 5 , wherein at least one application-specific integrated circuit controls the method.
11. The method of claim 10 , further comprising locating the at least one application-specific integrated circuit in at least one piezoelectric sensor.
12. The method of claim 10 , further comprising locating the at least one application-specific integrated circuit within the occupant restraint control system.
13. The method of claim 1 , further comprising:
combining the signal amplitudes and plotting a commonality point of the signal amplitudes in three-dimensional space;
comparing commonality points of most recent signal amplitudes to a library including a memory of reference commonality points of signal amplitudes; and
instructing deployment of at least one airbag using results from comparing the most recent commonality points of signal amplitudes to the reference commonality points of signal amplitudes.
14. A method for characterizing a response from a sensor used for automotive vehicle crash analysis, said method comprising:
providing at least one sensor mounted at a predetermined location on the automotive vehicle;
sampling a response from the sensor for a predetermined period of time;
subjecting the response from the sensor to a wavelet analysis and obtaining signal amplitudes;
plotting the signal amplitudes in three-dimensional space and forming a cluster of signal amplitudes;
comparing a most recent cluster to reference clusters that are indicative of both crash and non-crash events; and
providing instructions to an occupant restraint control system in the automotive vehicle.
15. The method of claim 14 , wherein the sensor is a piezoelectric sensor.