Envelope detector useful in crash discrimination

• US 5,563,791 A
• Filed: 10/25/1994
• Issued: 10/08/1996
• Est. Priority Date: 10/25/1994
• Status: Expired due to Fees

• Current Assignee: Automotive Systems Laboratory, Incorporated (Ningbo Junsheng Investment Group Co., Ltd.)
• Original Assignee: Automotive Systems Laboratory, Incorporated (Ningbo Junsheng Investment Group Co., Ltd.)
• Inventors: Gioutsos, Tony, Tabar, Daniel N., Gillis, Edward J.
• Primary Examiner(s): Teska, Kevin J.
• Assistant Examiner(s): Walker, Tyrone V.
• Application Number:
  US08/329,080
• Time in Patent Office: 714 Days
• Field of Search: 364/424.05, 307/10.1, 340/436, 340/669, 280/734, 280/735, 180/274, 180/282
• US Class Current: 701/45
• CPC Class Codes: B60R 21/0132 responsive to vehicle motion parameters , e.g. to vehicle longitudinal or transversal deceleration or speed value
• CPC Class Codes: B60R 21/01332 by frequency or waveform analysis

Abstract

A system (10) and method for detecting an envelope of received vehicle acceleration information (a(t)) useful in controlling actuation of a vehicle passenger safety device, wherein consecutive values for received vehicle acceleration information (a(t)) are stored and rank-ordered in a pair of rank-order filters (14, 16) to provide a highest-ranked value (a_H) from among the most-recent half of the stored values, and a highest-ranked value (a_H '"'"') from among the least-recent half of the stored values. The absolute value of the highest-ranked least-current value is taken and subtracted from the highest-ranked most-recent value to obtain a modified jerk measure (j_H *). The absolute value of the thus-generated modified jerk value is taken to obtain a measure (m₁) which tracks the envelope of the received acceleration information and, hence, is useful as an envelope detector when evaluating a crash waveform for purposes of controlling actuation of the safety device.

Claims

1. A system for detecting an envelope of vehicle acceleration information received over successive sampling periods comprising:

means for storing consecutive values for said received information during each sampling period to provide a plurality of stored values;

means for selecting the most-recent half of said stored values to obtain a first set of values;

means for rank-ordering the values in said first set to obtain the highest-ranked value in said first set;

means for selecting the least-recent half of said stored values to obtain a second set of values;

means for rank-ordering the values in said second set to obtain the highest-ranked value in said second set;

means for generating the absolute value of the highest-ranked value in said second set;

means for subtracting said generated absolute value from the highest-ranked value in said first set to obtain a modified jerk measure; and

means for generating the absolute value of said modified jerk measure, wherein said absolute value of said modified jerk measure is representative of an envelope value.

2. A method for detecting an envelope of received vehicle acceleration information comprising the steps of:

storing said received information over time to obtain a plurality of stored values for said received information;

selecting the most-recent half of said stored values to obtain a first set of values;

rank-ordering the values in said first set to obtain the highest-ranked value in said first set;

selecting the least-recent half of said stored values to obtain a second set of values;

rank-ordering the values in said second set to obtain the highest-ranked value in said second set;

generating the absolute value of the highest-ranked value in said second set;

subtracting said generated value from the highest-ranked value in said first set to obtain a modified jerk measure; and

generating the absolute value of said modified jerk measure, wherein said absolute value of said modified jerk measure is representative of an envelope value.

3. A method of tracking trends in transitory information generated by a vehicle acceleration sensor comprising the steps of:

generating a signal representative of an envelope of said generated transitory acceleration information; and

outputing said signal to a vehicle crash discrimination system for analysis, wherein said step of generating a signal representative of an envelope further comprises the steps of;

storing said transitory information generated over a sampling period to obtain a plurality of stored values for said transitory information;

selecting the most-recent half of said stored values to obtain a first set of values;

rank-ordering the values in said first set to obtain the highest-ranked value in said first set;

selecting the least-recent half of said stored values to obtain a second set of values;

rank-ordering the values in said second set to obtain the highest-ranked value in said second set;

generating the absolute value of the highest-ranked value in said second set;

subtracting said generated value from the highest-ranked value in said first set to obtain a modified jerk measure; and

generating the absolute value of said modified jerk to produce said signal representative of the envelope.