Vehicle Occupant Build Detection Under Twisted Posture
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Solution Overview
Problem
Conventional occupant build determination systems in vehicles fail to accurately assess the build of occupants in twisted postures, leading to false determinations due to variations in shoulder joint positions, which can affect the setting of airbag operating conditions.
Innovation Solution
An on-board system that includes an imager, seat-belt sensor, and sitting-surface sensor, using image processing and posture analysis to determine occupant build levels by calculating shoulder-joint information and occupant-area data, distinguishing between adult and child builds, and adjusting airbag settings accordingly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If image processing is used to determine occupant build, then airbag operating conditions can be set based on occupant weight, but false determination occurs when occupant is in twisted posture
Solution Approach 1:
The patent applies local quality by selectively weighting different body parts in the image processing. Specifically, it gives higher weight to lower body parts (legs, feet) and lower weight to upper body parts (shoulders, arms) when the occupant is detected in a twisted posture. This localized adjustment of measurement quality resolves the contradiction by maintaining accurate build determination for the lower body while accommodating the distortion in the upper body caused by twisting.
Solution Approach 2:
The patent changes the parameter of body part weight coefficients based on the detected posture. When a twisted posture is detected, the system dynamically adjusts the weight parameters assigned to different body parts in the build calculation algorithm. This parameter change allows the system to compensate for posture-induced distortions and maintain reliable build determination across various occupant positions.
2Ease of operation
If shoulder joint position is used to calculate occupant build, then build determination is straightforward, but twisted posture causes variation in shoulder joint position leading to false determination
Solution Approach 1:
The patent segments the occupant's body into multiple parts and assigns different weights to each segment based on posture. Instead of relying solely on shoulder joint positions, the system divides the body into upper and lower segments, with the lower segment (legs, feet) given higher weight when twisting is detected. This segmentation resolves the contradiction by maintaining calculation simplicity while improving measurement precision through selective emphasis on unaffected body segments.
Solution Approach 2:
The patent introduces posture detection as an intermediary step between image capture and build calculation. The posture detection mechanism acts as a mediator that determines whether to apply standard or adjusted weight coefficients to different body parts. This intermediary layer enables the system to maintain straightforward calculation procedures while compensating for shoulder joint position variations caused by twisted postures.
Data Source
AI summary
In an apparatus for determining a build of an occupant sitting in a seat within a cabin of a vehicle, an image acquirer is configured to acquire an image of the occupant. A position-information calculator is configured to calculate shoulder-joint information that is information representing positions of left and right shoulder joints of the occupant in the image. A twisted-posture determiner is configured to determine whether the occupant is in a twisted posture based on the shoulder-joint information. An occupant-build determiner is configured to determine a build of the occupant based on the shoulder-joint information. The occupant-build determiner is further configured to, in response to the twisted-posture determiner determining that the occupant is in the twisted posture, cancel making a determination of the build of the occupant based on shoulder-joint information that was used to determine that the occupant is in the twisted posture.