Selective Knee Airbag Deployment for Post-Collision Vision
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Solution Overview
Problem
Existing occupant restraint systems inflate both knee and upper-body airbags in low-speed collisions, causing the upper-body airbag to obstruct the occupant's vision, making it difficult to drive after the collision.
Innovation Solution
An occupant restraint system with a control mechanism that inflates only the knee airbag for impact loads between predetermined values and both airbags for higher impact loads, using sensors to determine the appropriate response based on impact load, seat belt usage, occupant weight, and seat position.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If both knee airbag and upper-body airbag are inflated in low-speed collisions, then occupant protection is improved, but the upper-body airbag obstructs the occupant's vision, making driving after collision difficult
Solution Approach 1:
The system changes the operational parameters of the airbag system by introducing multiple impact load thresholds (first predetermined value and second predetermined value). Based on the detected impact load magnitude, the system selectively activates different airbag configurations: only knee airbag for moderate impacts, both knee and upper-body airbags for severe impacts. This parameter-based differentiation resolves the contradiction by providing appropriate protection levels without unnecessary vision obstruction.
Solution Approach 2:
The airbag protection system is segmented into two independent components: knee airbag and upper-body airbag. The control system can selectively activate these segments based on impact severity. For low-speed collisions, only the knee airbag segment is activated, providing necessary protection without the upper-body airbag obstructing vision. This segmentation allows the system to provide tailored protection that balances safety with post-collision drivability.
2Reliability
If both knee airbag and upper-body airbag are inflated every time impact load is applied, then comprehensive occupant protection is achieved, but unnecessary airbag inflation occurs in low-speed collisions where seat belt is sufficient
Solution Approach 1:
The system implements parameter-based control by establishing two impact load thresholds. The control means compares the detected impact load against these thresholds to determine the appropriate airbag activation strategy. This parameter differentiation enables the system to avoid unnecessary energy consumption by not inflating airbags when the impact load is below the first predetermined value, where seat belt protection alone is sufficient.
Solution Approach 2:
The system applies partial action by selectively activating only the necessary airbag components based on impact severity. For low-speed collisions below the first threshold, no airbag action is taken. For moderate collisions between the two thresholds, only partial activation of the knee airbag occurs. This partial action principle prevents excessive airbag inflation and the associated energy waste while maintaining adequate protection.
3Ease of operation
If control mechanism selectively inflates only knee airbag for moderate impact loads, then proper protection is provided without vision obstruction, but system complexity increases
Solution Approach 1:
The control means serves multiple functions: it detects impact load, compares the load against predetermined thresholds, determines the appropriate airbag activation strategy, and controls the inflation of different airbag combinations. This multi-functionality consolidates what could be multiple separate systems into a single control unit, managing the complexity while achieving the desired selective airbag deployment for unobstructed vision in moderate collisions.
Data Source
AI summary
An occupant restraint system having a knee airbag and an upper-body airbag. The control unit inflates only the knee airbag if the impact load applied to the vehicle due to a collision or the like is equal to or greater than the first predetermined value and less than the second predetermined value that is set larger than the first predetermined value, and inflates both the knee airbag and the upper-body airbag if the impact load is equal to or greater than the second predetermined value.