EP0444866A1
Expired / Lapsed
EP
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Control system for vehicle safety device
Assignee: Airbag Systems Co Ltd
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Filing: 1991-02-26
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Granted: —
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Expires: 2011-02-26
Abstract
Abstract A control system for a vehicle safety device includes a pair of acceleration sensing circuits (10a, 10b). The outputs of the acceleration sensing circuits correspond to a deceleration of the vehicle in a direction of running of the vehicle, and are in opposite phase with each other. A differential calculation device (20a, 20b, 130a, 130b) effects calculation in accordance with the difference between the outputs of the acceleration sensing circuits, so as to cause noises, applied to the acceleration sensing circuits, to cancel each other, thereby preventing an inadvertent activation of the vehicle safety device due to such noises. According to another alternative construction, in order to prevent the inadvertent activation of the vehicle safety device due to the noises, the opposite-phase outputs of the pair of acceleration sensing circuits (10a, 10b) are integrated by a pair of integrating circuits (30a, 30b), and a pair of collision judgment circuits (40a, 40b) compare the outputs of the integrating circuits with respective threshold levels so as to judge whether a collision has occurred. A drive circuit (70) activates the vehicle safety device when the pair of collision judgment circuits both judge that the collision has occurred.
Inventors
- 👤 Masami C/O Zexel Corporation Okano
- 👤 Kunihiro C/O Zexel Corporation Takeuchi
- 👤 Hideyuki C/O Zexel Corporation Kaneko
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-26 09:32
CPC Classifications
B; B60; B60R; B60R21/00; B60R21/01; B60R21/013; B60R21/0132; B60R21/0133; G; G01; G01P; G01P21/00
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
155 words
A control system for a vehicle safety device comprising: (a) a pair of first and second acceleration sensing circuits each having an acceleration sensor, outputs of said acceleration sensing circuits corresponding to a deceleration of a vehicle in a direction of running of the vehicle; (b) collision judgment means for judging whether or not a collision of the vehicle has occurred; and (c) a drive circuit responsive to the collision judgment made by said collision judgment means so as to activate the vehicle safety device; CHARACTERIZED in that: the outputs (V1a, V1b) of said acceleration sensing circuits (10a, 10b) are in opposite phase with each other; there is provided differential calculation means (20a, 20b, 130a, 130b) for effecting calculation in accordance with the outputs of said pair of acceleration sensing circuits; and said collision judgment means (40a, 40b) effects the collision judgment in accordance with a differential calculation value calculated by said differential calculating means.
Claim 2
Dependent Claim
37 words
A control system according to claim 1, in which said differential calculation means includes differential amplifier means (20a, 20b) for amplifying the difference between the outputs (V1a, V1b) of said pair of acceleration sensing circuits (10a, 10b).
Claim 3
Dependent Claim
109 words
A control system according to claim 2, in which said differential amplifier means comprises a pair of first and second differential amplifier circuits (20a, 20b), the outputs (V1a, V1b) of said first and second acceleration sensing circuits (10a, 10b) being fed respectively to a non-inverting input terminal and an inverting input terminal of said first differential amplifier circuit (20a), and the outputs of said first and second acceleration sensing circuits being fed respectively to an inverting input terminal and a non-inverting input terminal of said second differential amplifier circuit (20b), whereby the outputs (V2a, V2b) of said pair of differential amplifier circuits are in opposite phase with each other.
Claim 4
Dependent Claim
131 words
A control system according to claim 3, in which said differential amplifier means further comprises a pair of integrating circuits (30a, 30b), said collision judgment means comprising a pair of collision judgment circuits (40a, 40b), said pair of integrating circuits respectively receiving and integrating the outputs of said pair of differential amplifier circuits whereby the integral outputs (V3a, V3b) of said pair of integrating circuits are in opposite phase with each other, each of said collision judgment circuits comparing a respective one of said integral output with a threshold level, and outputting a collision judgment signal when said integral output exceeds said threshold level, and said drive circuit (70), when receiving said collision judgment signals from said pair of collision judgment circuits at the same time, activating the vehicle safety device.
Claim 5
Dependent Claim
33 words
A control system according to claim 3, in which said differential calculation means further comprises differential integrating means (130a, 130b) for integrating the outputs of said pair of differential amplifier circuits (20a, 20b).
Claim 6
Dependent Claim
180 words
A control system according to claim 5, in which said differential integrating means comprises a pair of first and second differential integrating circuits (130a, 130b), said collision judgment means comprising a pair of collision judgment circuits (40a, 40b), the outputs (V2a, V2b) of said first and second differential amplifier circuits (20a, 20b) being fed respectively-to an inverting input terminal and a non-inverting input terminal of said first differential integrating circuit, the outputs of said first and second differential amplifier circuits being fed respectively to a non-inverting input terminal and an inverting input terminal of said second differential integrating circuit whereby the outputs of said pair of differential integrating circuits are in opposite phase with each other, each of said collision judgment circuits (40a, 40b) comparing the output of a corresponding one of said differential integrating circuits with a threshold level, and outputting a collision judgment signal when said output exceeds said threshold level, and said drive circuit (70), when receiving said collision judgment signals from said pair of collision judgment circuits at the same time, activating the vehicle safety device.
Claim 7
Dependent Claim
35 words
A control system according to claim 1, in which said differential calculation means comprises differential integrating means (130a, 130b) for integrating the difference between the outputs of said pair of acceleration sensing circuits (10a, 10b).
Claim 8
Dependent Claim
194 words
A control system according to claim 7, in which said differential calculation means comprises a pair of first and second amplifier circuits (120a, 120b) and a pair of first and second differential integrating circuits (130a, 130b) serving as said differential integrating means, said collision judgment means comprising a pair of first and second collision judgment circuits (40a, 40b), the outputs of said first and second amplifier circuits being fed respectively to an inverting input terminal and a non-inverting input terminal of said first differential integrating circuit, the outputs of said first and second amplifier circuits being fed respectively to a non-inverting input terminal and an inverting terminal of said second differential integrating circuit whereby the outputs of said pair of differential integrating circuits are in opposite phase with each other, each of said collision judgment circuits (40a, 40b) comparing the output of a corresponding one of said differential integrating circuits with a threshold level, and outputting a collision judgment signal when said output exceeds said threshold level, and said drive circuit (70), when receiving said collision judgment signals from said pair of collision judgment circuits at the same time, activating the vehicle safety device.
Claim 9
Dependent Claim
160 words
A control system for a vehicle safety device comprising: (a) a pair of acceleration sensing circuits each having an acceleration sensor, outputs of said acceleration sensing circuits corresponding to a deceleration of a vehicle in a direction of running of the vehicle; (b) a pair of integrating means for integrating the outputs of said pair of acceleration sensing circuits; (c) a pair of collision judgment means for respectively comparing the integral values, obtained by said pair of integrating means, with threshold levels so as to judge whether or not a collision of the vehicle has occurred; and (d) a drive circuit for activating the vehicle safety device when said pair of collision judgment means both judges that the collision has occurred; CHARACTERIZED in that: the outputs (V1a, V1b) of said acceleration sensing circuits (10a, 10b) are in opposite phase with each other; and integral values of said pair of integrating means (130a, 130b) are in opposite phase with each other;
Claim 10
Dependent Claim
72 words
A control system according to claim 1 or claim 9, in which there is provided malfunction judgment means (50) for adding the outputs of said pair of acceleration sensing circuits, and for comparing this added value with two different threshold levels, and for judging that a malfunction has occurred in one of said pair of acceleration sensing circuits when said added value is outside of the range between said two threshold levels.
Claim 11
Dependent Claim
38 words
A control system according to claim 10, in which there is provided activation inhibition means (60) responsive to the malfunction judgment by said malfunction judgment means (50) so as to inhibit the activation of the vehicle safety device.
Claim 12
Dependent Claim
34 words
A control system according to claim 1 or claim 9, in which said pair of acceleration sensors (11a, 11b; 111a, 111b) are mounted on a common base member (12; 101) mounted on the vehicle.
Claim 13
Dependent Claim
54 words
A control system according to claim 12, in which said base member comprises a rigid plate (12) whose plane is disposed perpendicular to the direction of running of the vehicle, said pair of acceleration sensors comprising piezoelectric elements (11a, 11b), respectively, which are mounted on front and rear surfaces of said rigid plate, respectively.
Claim 14
Dependent Claim
53 words
A control system according to claim 12, in which said base member comprises a leaf spring (101) whose plane is disposed perpendicular to the direction of running of the vehicle, said pair of acceleration sensors comprising strain gauges (111a, 111b), respectively, which are mounted on front and rear surfaces of leaf spring, respectively.
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