Vehicle Seat Occupancy Sensing With Door-Based RF Mode Switching
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Solution Overview
Problem
Existing vehicle seat occupancy sensors face challenges in accurately distinguishing between occupants, particularly when they are sitting close together or in multiple rows, and require multiple sensors, which can be expensive.
Innovation Solution
A seat occupancy sensor system using RF sensors operates in two modes: a first mode for tracking occupant entry/exit based on occupant count, and a second mode for detecting and distinguishing occupants within the cabin, adjusting sensor settings like range and angular resolution to enhance accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If pressure sensors or capacitive sensors are used for each seat to detect occupancy, then occupancy detection accuracy is improved, but system cost increases due to requiring separate sensors for each seat
Solution Approach 1:
The patent combines multiple sensor functions into a single ultrasonic sensor that can detect occupancy across multiple seats simultaneously. The ultrasonic sensor emits sound waves and measures reflections to determine occupancy status of front and rear seats without requiring separate sensors for each seat, thereby reducing system cost while maintaining detection capability.
Solution Approach 2:
The ultrasonic sensor is designed to perform multiple functions: detecting occupancy in the front seat, detecting occupancy in the rear seat, and distinguishing between different occupancy scenarios (front only, rear only, both occupied). This multi-functional approach eliminates the need for dedicated sensors for each seating position.
2Device complexity
If a single ultrasonic sensor is used to detect movements around multiple seats, then system cost is reduced, but measurement precision deteriorates when occupants are sitting close together or in multiple rows
Solution Approach 1:
The patent implements a dynamic switching mechanism that changes the sensor's operational mode based on vehicle door status. When doors are open, the sensor operates in first operational mode for general occupancy detection. When doors are closed, it switches to second operational mode with adjusted parameters for enhanced resolution to distinguish between occupants sitting close together or in multiple rows.
Solution Approach 2:
The system dynamically adjusts ultrasonic sensor parameters including pulse frequency, pulse duration, and gain settings based on door status and detected occupancy patterns. These parameter changes enable the single sensor to achieve high measurement precision in distinguishing multiple occupants without requiring multiple sensors, thus maintaining cost-effectiveness.
3Measurement precision
If the sensor operates in high resolution mode to distinguish occupants sitting close together, then measurement precision is improved, but energy consumption increases
Solution Approach 1:
The patent employs periodic switching between different operational modes based on door status. The sensor operates in lower energy first operational mode when doors are open, and only switches to higher energy second operational mode with enhanced resolution when doors are closed and occupant distinction is critical. This periodic switching reduces overall energy consumption while maintaining precision when needed.
Solution Approach 2:
The system applies high resolution detection partially - only when door status indicates it is necessary (doors closed). During other times when doors are open, the system uses standard detection mode. This partial application of high resolution mode reduces energy consumption while still providing accurate occupant distinction when required by the operational context.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Improves accuracy in detecting and distinguishing vehicle occupants by optimizing sensor settings based on vehicle door status, reducing false detections and misdetections.
Implementation Method 1
at least one seat occupancy sensor configured to receive radio frequency (RF) signals within a passenger cabin of the vehicle
Data Source
AI summary
A seat occupancy sensor system and method that use radio frequency (RF) sensors to detect and distinguish vehicle occupants in a passenger cabin of a vehicle. The system may include one or more seat occupancy sensor(s) and a seat occupancy control module and can operate according to different operational modes based on the state of the vehicle doors. When one or more door(s) are open, the system and method may operate according to a first operational mode that keeps track of vehicle occupants entering and/or exiting the passenger cabin; and when there are no doors open, the system and method may operate according to a second operational mode that detects and distinguishes vehicle occupants in the passenger cabin, with the occupant count from the first mode being used as an input. These different operational modes can help improve the accuracy and/or performance of seat occupancy sensor system.