Apparatus for and method of controlling activation of passive restraint

• US 5,961,562 A
• Filed: 11/01/1996
• Issued: 10/05/1999
• Est. Priority Date: 11/06/1995
• Status: Expired due to Fees

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Iyoda, Motomi
• Primary Examiner(s): Cuchlinski, Jr., William A.
• Assistant Examiner(s): PIPALA, EDWARD J
• Application Number:
  US08/742,874
• Time in Patent Office: 1,068 Days
• Field of Search: 701/45, 701/46, 307/10.1, 180/271, 180/282, 280/734, 280/735
• US Class Current: 701/45
• CPC Class Codes: B60R 21/013 including means for detecting collisions, impending collisions or roll-over
• CPC Class Codes: B60R 21/01336 using filtering

Abstract

A CPU 30 first receives data of accelerations Gx and Gy applied respectively along a longitudinal axis and a lateral axis of a vehicle (S20). The CPU 30 then calculates an arithmetic value fx from the acceleration Gx in the longitudinal direction according to specified arithmetic operations, and calculates an arithmetic value fy from the acceleration Gy in the lateral direction according to specified arithmetic operations (S22). The CPU 30 subsequently projects vectors based on the arithmetic values fx and fy in a preset direction a to yield projective components of the vectors, and determines a sum fa of the projective components (S24). The CPU 30 compares the projective component fa with a threshold value fth(a) previously set for the direction a, and determines whether or not the projective component fa is greater than the threshold value fth(a) (S26). When determining that the projective component fa is greater than the threshold value fth(a), the CPU 30 generates an activation signal to activate air bag units 60 to 66 (S28). The structure of the present invention does not require the calculation of the magnitude or the direction of a composite vector, thereby being free from complicated and time-consuming arithmetic operations. No division is included in the required arithmetic operations, so that the result of calculation does not diverge.

Claims

1. An activation control apparatus for controlling activation of a passive restraint mounted on a vehicle, said apparatus comprising:

acceleration measuring means for measuring a first acceleration acting in a first direction of said vehicle and a second acceleration acting in a second direction of said vehicle, which is different from said first direction;

first arithmetic and logic means for calculating a first arithmetic value from said first acceleration according to a specified arithmetic operation;

second arithmetic and logic means for calculating a second arithmetic value from said second acceleration according to a specified arithmetic operation;

projective component deriving means for setting a first vector that is along said first direction and based on said first arithmetic value and a second vector that is along said second direction and based on said second arithmetic value, deriving projective components of said first vector and said second vector in a specified projecting direction in a plane including said first vector and said second vector, and summing up the projective components thus derived; and

activation means for activating said passive restraint based on the sum of the projective components.

2. An activation control apparatus in accordance with claim 1, wherein said projective component deriving means presets a plurality of projecting directions, derives projective components of said first vector and said second vector in each of said projecting directions, and sums up the projective components for said each projecting direction,

said activation means activating said passive restraint based on any one of the sums of the projective components obtained for the respective projecting directions.

3. An activation control apparatus in accordance with either one of claims 1 and 2, wherein at least one of said first arithmetic and logic means, said second arithmetic and logic means, and said projective component deriving means further comprises means for varying a ratio of said first arithmetic value to said second arithmetic value to relatively vary an effect said first arithmetic value and said second arithmetic value have on the sum of said projective components.

4. An activation control apparatus for controlling activation of a passive restraint mounted on a vehicle, said apparatus comprising:

acceleration measuring means for measuring a first acceleration acting in a first direction of said vehicle, a second acceleration acting in a second direction of said vehicle, and a third acceleration acting in a third direction of said vehicle, said first direction, said second direction, and said third direction being different from one another;

first arithmetic and logic means for calculating a first arithmetic value from said first acceleration according to a specified arithmetic operation;

second arithmetic and logic means for calculating a second arithmetic value from said second acceleration according to a specified arithmetic operation;

third arithmetic and logic means for calculating a third arithmetic value from said third acceleration according to a specified arithmetic operation;

first projective component deriving means for setting a first vector that is along said first direction and based on said first arithmetic value and a second vector that is along said second direction and based on said second arithmetic value, deriving projective components of said first vector and said second vector in a specified first projecting direction in a plane including said first vector and said second vector, and summing up the projective components thus derived to yield a fourth arithmetic value;

second projective component deriving means for setting a third vector that is along said third direction and based on said third arithmetic value and a fourth vector that is along said first projecting direction and based on said fourth arithmetic value, deriving projective components of said third vector and said fourth vector in a specified second projecting direction in a plane including said third vector and said fourth vector, and summing up the projective components thus derived; and

activation means for activating said passive restraint based on the sum of the projective components given by said second projective component deriving means.

5. An activation control apparatus in accordance with claim 4, wherein said first projective component deriving means presets a plurality of first projecting directions, derives projective components of said first vector and said second vector in each of said first projecting directions, and sums up the projective components to yield a fourth arithmetic value for said each first projecting direction,

said second projective component deriving means presets a plurality of second projecting directions, derives projective components of said third vector and said fourth vector in each of said second projecting directions, and sums up the projective components for said each second projecting direction,

said activation means activating said passive restraint based on any one of the sums of the projective components obtained for the respective second projecting directions.

6. A method of controlling activation of a passive restraint mounted on a vehicle, said method comprising the steps of:

(a) measuring a first acceleration acting in a first direction of said vehicle and a second acceleration acting in a second direction of said vehicle, which is different from said first direction;

(b) calculating a first arithmetic value from said first acceleration according to a specified arithmetic operation, and calculating a second arithmetic value from said second acceleration according to a specified arithmetic operation;

(c) setting a first vector that is along said first direction and based on said first arithmetic value and a second vector that is along said second direction and based on said second arithmetic value, deriving projective components of said first vector and said second vector in a specified projecting direction in a plane including said first vector and said second vector, and summing up the projective components thus derived; and

(d) activating said passive restraint based on the sum of the projective components.

7. A method in accordance with claim 6, wherein said step (c) further comprises the steps of:

presetting a plurality of projecting directions, deriving projective components of said first vector and said second vector in each of said projecting directions, and summing up the projective components for said each projecting direction,

said step (d) further comprising the step of;

activating said passive restraint based on any one of the sums of the projective components obtained for the respective projecting directions.

8. A method in accordance with either one of claims 6 and 7, wherein at least one of said steps (b) and (c) further comprises the step of:

varying a ratio of said first arithmetic value to said second arithmetic value to relatively vary an effect said first arithmetic value and said second arithmetic value have on the sum of said projective components.

9. A method of controlling activation of a passive restraint mounted on a vehicle, said method comprising the steps of:

(a) measuring a first acceleration acting in a first direction of said vehicle, a second acceleration acting in a second direction of said vehicle, and a third acceleration acting in a third direction of said vehicle, said first direction, said second direction, and said third direction being different from one another;

(b) calculating a first arithmetic value from said first acceleration according to a specified arithmetic operation, calculating a second arithmetic value from said second acceleration according to a specified arithmetic operation, and calculating a third arithmetic value from said third acceleration according to a specified arithmetic operation;

(c) setting a first vector that is along said first direction and based on said first arithmetic value and a second vector that is along said second direction and based on said second arithmetic value, deriving projective components of said first vector and said second vector in a specified first projecting direction in a plane including said first vector and said second vector, and summing up the projective components thus derived to yield a fourth arithmetic value;

(d) setting a third vector that is along said third direction and based on said third arithmetic value and a fourth vector that is along said first projecting direction and based on said fourth arithmetic value, deriving projective components of said third vector and said fourth vector in a specified second projecting direction in a plane including said third vector and said fourth vector, and summing up the projective components thus derived; and

(e) activating said passive restraint based on the sum of the projective components given in said step (d).

10. A method in accordance with claim 9, wherein said step (c) further comprises the steps of:

presetting a plurality of first projecting directions, deriving projective components of said first vector and said second vector in each of said first projecting directions, and summing up the projective components to yield a fourth arithmetic value for said each first projecting direction,

said step (d) further comprising the steps of;

presetting a plurality of second projecting directions, deriving projective components of said third vector and said fourth vector in each of said second projecting directions, and summing up the projective components for said each second projecting direction,

said step (e) further comprising the step of;

activating said passive restraint based on any one of the sums of the projective components obtained for the respective second projecting directions.