Mechanical transfer function cancellation
An apparatus includes one or more sensors and a control unit. The one or more sensors may be configured to generate signals in response to movement of a vehicle. The control unit generally comprises (i) an interface configured to receive the signals from the sensors and (ii) a filter configured to reduce an effect that a mechanical transfer function of a housing of at least one of the sensors has on at least one of the signals. The filter may be configured to utilize a variable frequency band digital representation of the mechanical transfer function to negate the effect of the mechanical transfer function of the housing on the at least one of the signals.
1. An apparatus comprising:
one or more sensors configured to generate sensor signals in response to mechanical signals received from a vehicle; and
a control unit comprising (i) an interface configured to receive the sensor signals from the sensors and (ii) a filter configured to reduce an effect that a mechanical transfer function of a housing of at least one of the sensors has on at least one of the sensor signals, wherein the filter is configured to utilize a variable frequency band digital representation of the mechanical transfer function to negate the effect of the mechanical transfer function of the housing on the at least one of the sensor signals, and the control unit is configured to update the variable frequency band digital representation of the mechanical transfer function over a lifetime of the vehicle.
2. The apparatus according to claim 1 , wherein said sensors comprise at least one of a single-axis sensor, a dual-axis sensor, or a tri-axial sensor.
3. The apparatus according to claim 1 , wherein said variable frequency band digital representation of said mechanical transfer function is stored in memory.
4. The apparatus according to claim 1 , wherein said variable frequency band digital representation of said mechanical transfer function is embodied in one or more lookup tables.
5. The apparatus according to claim 1 , wherein said variable frequency band digital representation of said mechanical transfer function comprises a plurality of multiplication factors corresponding to a plurality of frequency bands and a plurality of signal magnitudes.
6. The apparatus according to claim 1 , wherein said filter is configured to amplify or attenuate a particular frequency band based upon a corresponding signal magnitude.
7. The apparatus according to claim 1 , wherein said one or more sensors are part of a passive restraint system of the vehicle.
8. The apparatus according to claim 7 , wherein said control unit is further configured to make a deployment decision for one or more safety devices based upon an output of said filter.
9. The apparatus according to claim 8 , further comprising one or more airbags and one or more seatbelt pretensioners, wherein said control unit is further configured to control at least one of air bag deployment and seat belt pretensioning in response to inertial sensor data, impact sensor data, proximity sensor data or a combination thereof received from the one or more sensors.
10. The apparatus according to claim 1 , wherein the variable frequency band digital representation of the mechanical transfer function is updated periodically in response to a door of the vehicle being opened and closed.
11. A method of mechanical transfer function cancellation comprising:
receiving sensor signals from one or more sensors configured to generate the sensor signals in response to mechanical signals received from a vehicle;
filtering the sensor signals to reduce an effect that a mechanical transfer function of a housing of at least one of the sensors has on at least one of the sensor signals, wherein the filtering utilizes a variable frequency band digital representation of the mechanical transfer function of the housing of the at least one of the sensors to negate the effect of the mechanical transfer function of the housing on the at least one of the sensor signals and the variable frequency band digital representation of the mechanical transfer function of the housing of the at least one of the sensors is updated over a lifetime of the vehicle; and
making a deployment decision for one or more safety systems of the vehicle based on the filtered sensor signals.
12. The method according to claim 11 , wherein said sensors comprise at least one of a single-axis sensor, a dual-axis sensor, or a tri-axial sensor.
13. The method according to claim 11 , wherein said variable frequency band digital representation of said mechanical transfer function is stored in a memory of an electronic control unit of the vehicle.
14. The method according to claim 11 , wherein said variable frequency band digital representation of said mechanical transfer function is embodied in one or more lookup tables.
15. The method according to claim 11 , wherein said variable frequency band digital representation of said mechanical transfer function comprises a plurality of multiplication factors corresponding to a plurality of frequency bands and a plurality of signal magnitudes.
16. The method according to claim 11 , wherein said filtering comprises amplifying or attenuating a particular frequency band based upon a corresponding signal magnitude.
17. The method according to claim 11 , wherein said one or more sensors are part of a passive restraint system of the vehicle.
18. The method according to claim 17 , wherein said deployment decision is related to one or more safety devices.
19. The method according to claim 18 , wherein said deployment decision controls at least one of air bag deployment and seat belt pretensioning in response to inertial sensor data, impact sensor data, proximity sensor data or a combination thereof received from the one or more sensors.
20. The method according to claim 11 , further comprising updating the variable frequency band digital representation of the mechanical transfer function periodically in response to a door of the vehicle being opened and closed.