Vehicle Occupant Protection Pretensioner Control Logic
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Solution Overview
Problem
Existing occupant protection systems for vehicles face challenges in determining the appropriate activation of pretensioners during side collisions, as they fail to differentiate between local and dispersed load scenarios effectively, leading to inadequate clearance between the side door and the occupant, which can increase injury levels.
Innovation Solution
An occupant protection apparatus that includes a pretensioner, a door sensor to detect side door deformation, an occupant position detection sensor to determine the lumbar position, and a control unit that activates or prohibits pretensioner activation based on the collision scenario, ensuring optimal clearance and injury prevention.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the pretensioner is activated to instantaneously restrain the occupant, then the clearance between the occupant and impact area is maintained, but the injury level increases when the side door intrudes into the passenger compartment
Solution Approach 1:
The system changes the activation parameter of the pretensioner based on detected collision parameters. When a pole side collision is detected (local load with high intrusion risk), the pretensioner activation is prohibited. When an MDB side collision is detected (dispersed load with low intrusion risk), the pretensioner is activated. This dynamic parameter adjustment resolves the contradiction by adapting the restraint force to the specific collision scenario.
2Object-affected harmful factors
If the pretensioner is prohibited from activation to allow occupant movement, then clearance is maintained during intruding-object collision, but the occupant cannot be protected from inertial force during dispersed load collision
Solution Approach 1:
The system dynamically changes the pretensioner activation parameter based on collision type detection. For pole side collisions, activation is prohibited to maintain clearance. For MDB side collisions, activation is enabled to provide inertial protection. This resolves the contradiction by making the protection mechanism adaptive to different collision scenarios.
3Reliability
If existing occupant protection systems activate the pretensioner in all side collision scenarios, then inertial force protection is provided, but the clearance is compromised in local load collisions
Solution Approach 1:
The system changes the pretensioner activation parameter from a fixed state to a conditional state based on collision detection. By detecting whether the collision is a pole side collision or MDB side collision, the system selectively activates or prohibits the pretensioner, thereby maintaining clearance when needed while providing inertial protection when safe.
4Length of stationary object
If existing occupant protection systems prohibit pretensioner activation in all side collision scenarios, then clearance is maintained, but inertial force protection is lost in dispersed load collisions
Solution Approach 1:
The system dynamically adjusts the pretensioner activation parameter based on real-time collision detection. Instead of a fixed prohibition, the system enables activation for MDB side collisions where clearance is naturally maintained, while prohibiting activation for pole side collisions where intrusion risk exists. This resolves the contradiction by making protection both clearance-preserving and inertial-force-counteracting.
Data Source
AI summary
An occupant protection apparatus for a vehicle includes a door sensor that detects a defamation of a side door in a side collision and an occupant position detection sensor that detects a lumbar position of the occupant. A pretensioner is activated when it is determined from detection by the door sensor and the occupant position detection sensor that an intruding-object collision rear-end position in the side door is located in front of the lumbar position, and the pretensioner is prohibited from activation when it is determined that the intruding-object collision rear-end position is not located in front of the lumbar position. When there is a possibility that a clearance between the lumbar of the occupant and the deformed side door is insufficient, the pretensioner is prohibited from activation to allow the occupant to move at the early stage of a collision.