Vehicle Seat Occupancy Sensor Insert to Prevent Foam Preload
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Solution Overview
Problem
Existing occupant detection systems (ODS) integrated into vehicle seats face challenges such as reduced sensitivity and reliability due to the foam-in-place manufacturing process, which can lead to foam creeping over sensor pads and preload issues.
Innovation Solution
The proposed solution involves embedding the ODS between the seat foam and the seat outer membrane, and manufacturing the seat using a foam-in-place process where a plug or insert with the ODS is embedded in a recess of the seat, creating a gap that helps maintain sensor reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the ODS is integrated into the vehicle seat using the foam-in-place manufacturing process, then the seat can be manufactured efficiently, but the reliability of ODS readings deteriorates due to foam creeping over sensor pads and preload issues
Solution Approach 1:
The seat is divided into multiple components: an outer membrane, foam material, and a separate insert component. The ODS is integrated into the insert rather than being embedded directly in the foam, allowing the insert to be placed into a recess in the seat base. This segmentation prevents foam from contacting the sensor pads while maintaining manufacturing efficiency.
Solution Approach 2:
The insert acts as an intermediary component between the foam and the ODS. The insert includes a top surface that defines a gap with the bottom surface of the seat, and the sensor pads are positioned on this surface. The foam contacts the insert rather than the sensors directly, preventing foam creep from affecting sensor reliability.
2Ease of manufacture
If the ODS is embedded directly in the foam, then the manufacturing process is simplified, but the sensitivity and reliability of the ODS deteriorate due to foam preload on sensor pads
Solution Approach 1:
The ODS is separated from the foam by placing it in an insert component rather than embedding it directly in the foam. This segmentation maintains manufacturing simplicity while preventing foam preload from affecting sensor performance.
Solution Approach 2:
The insert serves as a mediator between the foam and the ODS. The foam is contained by the insert structure, and the sensor pads are positioned on the insert's top surface, which defines a gap with the seat bottom surface. This prevents direct foam contact with the sensors, eliminating preload issues while keeping the manufacturing process straightforward.
3Reliability
If a gap is created between the plug/insert and the seat surface, then the reliability of ODS readings improves by preventing foam contact, but the device complexity increases
Solution Approach 1:
The insert component serves multiple functions: it provides a mounting structure for the ODS, creates the necessary gap to prevent foam contact, and acts as a barrier to contain the foam. This multi-functionality reduces the need for additional components, thereby limiting the increase in device complexity.
Solution Approach 2:
The ODS mounting structure and the gap-creating feature are merged into a single insert component. The insert is placed into a recess in the seat base, and its top surface automatically defines the gap with the bottom surface of the seat. This merging simplifies the overall structure compared to using separate components for each function.
Data Source
AI summary
A vehicle seat with an embedded occupancy detector system and manufacturing method for same, and an occupant protection system including an occupancy detector system embedded in a vehicle seat as described herein. Examples include a molded vehicle seat with one or more inserts including an occupant detection system with one or more sensor pads. A gap housing one or more sensor pads of an occupant detection system may be provided between a surface of an insert and a recessed surface of the molded vehicle seat.