Dual sensor crash sensing system
First Claim
1. A method of activating a safety device for vehicular passenger protection in the passenger compartment of a vehicle having a forward direction of travel in which it is susceptible to a frontal crash, said vehicle having a centrally located acceleration sensor forward of said compartment producing acceleration signals (Ac), an acceleration sensor in said passenger compartment producing acceleration signals (As), and a computer for continually processing acceleration signals from said sensors during vehicle operation to detect a frontal crash and, thereafter, further processing said acceleration signals, said method comprising;
- pre-identifying at least two different modes of frontal crashes that produce different patterns of velocity/time values and displacement/time values for each of said acceleration sensors as they experience a frontal crash in such modes of crash;
pre-determining safety device activation threshold velocity/time values and threshold displacement/time values, said time values commencing with the detection of a said crash for each of said sensors in each of said pre-identified modes, and by using said computer upon the detection of a frontal crash;
integrating each of said acceleration signals, Ac and As, over time to determine a current sequence of velocity values, Vc and Vs, for each of said sensor locations, and continually obtaining a maximum value of Vc as Vcm;
integrating said Vs and Vcm velocity values over time to determine current displacement values, Ss and Sc, for said sensor locations;
calculating a displacement value, Scad, for said centrally located sensor based on absolute values of Ac in accordance with the following equation;
Scad=∫
(max(∫
|Ac|·
dt)−
Vcm)·
dt;
comparing selected of said Vs and Vcm velocity values and Ss, Sc and Scad displacement values with said predetermined corresponding velocity and displacement threshold values as a basis for determining whether any of said frontal crash modes requires safety device activation and;
if any one of said mode comparisons requires activation, activating said device.
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Accused Products
Abstract
A computer based method for activating a vehicular safety device for passenger protection is disclosed. The method uses a centrally located front-end acceleration sensor and a passenger compartment sensor. When a crash situation is sensed, current acceleration data is integrated to produce velocity values for both sensor locations. Actual displacement values for the front-end sensor are calculated as well as displacement values based on absolute values of acceleration of that sensor. The velocity and displacement values are selectively used in at least three vehicle crash mode analyses. Examples of such crash modes are full frontal-like modes, pole-like modes and angle-like modes. When appropriate threshold values are exceeded, device activation for one or more activation stages is initiated.
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Citations
20 Claims
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1. A method of activating a safety device for vehicular passenger protection in the passenger compartment of a vehicle having a forward direction of travel in which it is susceptible to a frontal crash, said vehicle having a centrally located acceleration sensor forward of said compartment producing acceleration signals (Ac), an acceleration sensor in said passenger compartment producing acceleration signals (As), and a computer for continually processing acceleration signals from said sensors during vehicle operation to detect a frontal crash and, thereafter, further processing said acceleration signals, said method comprising;
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pre-identifying at least two different modes of frontal crashes that produce different patterns of velocity/time values and displacement/time values for each of said acceleration sensors as they experience a frontal crash in such modes of crash;
pre-determining safety device activation threshold velocity/time values and threshold displacement/time values, said time values commencing with the detection of a said crash for each of said sensors in each of said pre-identified modes, and by using said computer upon the detection of a frontal crash;
integrating each of said acceleration signals, Ac and As, over time to determine a current sequence of velocity values, Vc and Vs, for each of said sensor locations, and continually obtaining a maximum value of Vc as Vcm;
integrating said Vs and Vcm velocity values over time to determine current displacement values, Ss and Sc, for said sensor locations;
calculating a displacement value, Scad, for said centrally located sensor based on absolute values of Ac in accordance with the following equation;
Scad=∫
(max(∫
|Ac|·
dt)−
Vcm)·
dt;
comparing selected of said Vs and Vcm velocity values and Ss, Sc and Scad displacement values with said predetermined corresponding velocity and displacement threshold values as a basis for determining whether any of said frontal crash modes requires safety device activation and;
if any one of said mode comparisons requires activation,activating said device. - View Dependent Claims (2, 3, 4, 5, 8, 12, 15, 19)
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6. A method of activating a safety device for vehicular passenger protection in the passenger compartment of a vehicle having a forward direction of travel in which it is susceptible to crash situations in a full frontal direction mode, a pole-like frontal mode and in an angular direction mode, said vehicle having a centrally located acceleration sensor forward of said compartment producing acceleration signals (Ac), an acceleration sensor in said passenger compartment producing acceleration signals (As), and a computer for continually processing acceleration signals from said sensors during vehicle operation, said method being executed on said computer during a crash situation and comprising
integrating each of said acceleration signals, Ac and As, over time to determine a current sequence of velocity values, Vc and Vs, for each of said sensor locations, and continually obtaining a maximum value of Vc as Vcm; -
integrating said Vcm velocity values over time to determine current displacement values, Sc, for said central sensor location;
calculating a displacement value, Scad, for said centrally located sensor based on absolute values of Ac in accordance with the following equation;
Scad=∫
(max(∫
|Ac|·
dt)−
Vcm)·
dt;
comparing said Vs and Vcm velocity values with predetermined threshold velocity values for said sensor locations as a basis for determining whether a full frontal mode crash situation requires safety device actuation;
comparing selected of said Vs and Vcm velocity values and Sc and Scad displacement values with predetermined corresponding velocity and displacement threshold values as a basis for determining whether an angular mode or pole-like frontal crash situation requires safety device activation and;
if any one of said frontal or angular crash mode comparisons requires activation,activating said device. - View Dependent Claims (7, 9, 10, 11, 13, 14, 16, 17, 18, 20)
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Specification