Vehicle Bumper Radar Assembly for False-Trigger-Free Liftgate Sensing
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Solution Overview
Problem
Existing vehicle liftgate systems require manual operation or complex foot-activated sensors that can lead to false triggers due to objects outside a predetermined region, posing challenges for users carrying loads and complicating operation.
Innovation Solution
A radar sensor system with a steerable antenna and adjustable bracket is integrated into the vehicle bumper to project RF energy within a controlled field of view, preventing extension beyond the vehicle footprint and minimizing debris intrusion, using a radar housing with a vent filter and seal to enhance accuracy and reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Extent of automation
If sensors are mounted under the rear bumper to detect objects for liftgate operation, then automatic opening capability is improved, but false triggers occur due to objects outside the predetermined region
Solution Approach 1:
The antenna is configured with a specific radiation pattern that concentrates RF energy within a predetermined region corresponding to the vehicle footprint. This creates a localized detection zone with high signal intensity inside the footprint and rapidly decreasing intensity outside, enabling the sensor to distinguish between relevant objects within the region and irrelevant objects outside the region, thereby reducing false triggers while maintaining automatic opening capability
Solution Approach 2:
The system dynamically adjusts the detection sensitivity based on the spatial distribution of reflected RF energy. By evaluating the strength and pattern of returned signals, the system can adaptively determine whether a detected object falls within the intended detection zone, allowing reliable automatic operation while filtering out false triggers from objects outside the predetermined region
2Adaptability or versatility
If the field of view extends beyond the vehicle footprint to detect more objects, then detection coverage is improved, but false triggers increase due to objects outside the predetermined region
Solution Approach 1:
The antenna radiation pattern is specifically designed to create a concentrated beam within the vehicle footprint rather than omnidirectional coverage. This localized quality ensures that detection sensitivity is high within the predetermined region while naturally attenuating signals from outside this region, achieving effective detection coverage where needed while minimizing false triggers from peripheral objects
3Reliability
If manual operation is required for liftgate opening, then false triggers are prevented, but user convenience deteriorates when hands are occupied
Solution Approach 1:
The system replaces manual mechanical operation with automated radar-based detection. The antenna transmits RF energy and the sensor processes reflected signals to automatically determine when the liftgate should be opened, eliminating the need for manual intervention while maintaining reliability through spatially-selective detection that prevents false triggers
Solution Approach 2:
The system enables the vehicle to detect and respond to user intent automatically without requiring manual input. By monitoring the predetermined region for objects indicating user presence or intent (such as a foot positioned for kicking or a hand gesture), the system self-activates the liftgate opening sequence, providing hands-free convenience while maintaining reliability through the spatially-constrained detection zone
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
The system accurately detects gestures or objects within the vehicle perimeter, reducing false triggers and ensuring seamless operation without manual intervention, while maintaining sensor integrity and preventing debris ingress.
Implementation Method 1
an antenna disposed within the radar housing and which is configured to project radio frequency (RF) energy through a field of view (FOV) to detect an object or a gesture within a footprint of the motor vehicle
Implementation Method 2
The vent filter is impermeable to liquids and permeable to air
Data Source
AI summary
A non-contact object and/or gesture detection system includes at least one sensor configured to sense an object or motion within a field of view (FOV) using radio frequency radiation. Various sensor and brackets are provided which may allow a position and/or tilt of the sensor to be adjusted for controlling the FOV. A sensor housing includes a vent filter that breathable but impermeable to liquids. Various antenna designs are provided to provide desired FOV sizes and shapes, particularly for optimizing a radiation pattern that is relatively wide and shallow. A steerable antenna layout is also provided for controlling the location of the FOV without an adjustable bracket. A sensor housing including a projector mount for an icon projector is provided. A seal prevents debris from entering between the antenna and the bumper.