Vehicle Liftgate Sensor Layout to Avoid Coating Interference
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Solution Overview
Problem
Existing sensor units for contactlessly actuating vehicle elements, such as liftgates, face interference from vehicle coatings like chrome, which can impede the functionality of capacitive proximity sensors by being impenetrable, limiting their placement and effectiveness.
Innovation Solution
A sensor unit design featuring two radar sensor devices with overlapping capturing areas, where one is positioned closer to the floor and extends further back in the forward direction, allowing the unit to be mounted below coatings and ensuring reliable detection of leg movements despite coatings, using a carrier element that can be attached to the vehicle independently of its parts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If capacitive proximity sensors are used for contactless actuation, then the sensors can detect leg movements, but the vehicle coatings like chrome impede the sensor functionality by being impenetrable
Solution Approach 1:
The sensor unit is divided into multiple sensor devices (first sensor device 220 and second sensor device 230) with different capturing areas. This segmentation allows the system to use at least one sensor that is not blocked by the coating, ensuring reliable detection despite the presence of impenetrable vehicle coatings.
Solution Approach 2:
The patent positions sensor devices at different vertical heights relative to the vehicle floor. The first sensor device 220 is positioned at a first height and the second sensor device 230 at a second height, creating a vertical dimension that allows at least one sensor to operate below the coating's interference zone.
2Ease of operation
If the sensor unit is positioned higher on the vehicle, then it can be easily mounted on vehicle parts, but it becomes blocked by coatings and cannot detect leg movements reliably
Solution Approach 1:
The patent introduces vertical positioning with at least two different heights for sensor devices. This allows the sensor unit to be mounted on vehicle parts while extending at least one sensor below the coating level, simultaneously achieving ease of mounting and reliable detection.
Solution Approach 2:
Different sensor devices are assigned different vertical positions and capturing areas. The first sensor device 220 and second sensor device 230 have different height positions, allowing each to operate in its optimal zone - some above, some below the coating - ensuring overall system reliability while maintaining mounting flexibility.
3Device complexity
If a single sensor device is used, then the device complexity is reduced, but the capturing area is limited and cannot reliably detect leg movements from different positions
Solution Approach 1:
Multiple sensor devices with different capturing areas are merged into a single sensor unit 200. The first capturing area 226 and second capturing area 236 work together to provide comprehensive coverage, reliably detecting leg movements from various positions while maintaining a unified mounting structure.
Solution Approach 2:
The sensor unit 200 is designed as a multi-functional assembly that can be mounted on various vehicle parts while providing reliable detection across different positions. The combination of multiple sensor devices with different capturing areas gives the unit universal applicability and enhanced detection capability.
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
Enables the sensor unit to be arranged lower on the vehicle, avoiding coating interference and ensuring correct operation, allowing for reliable contactless actuation of vehicle elements like liftgates even with coatings present.
Implementation Method 1
the first sensor device (220) has a radar sensor for sending and receiving a first radar signal, and/or the second sensor device (230) has a radar sensor for sending and receiving a second radar signal
Data Source
AI summary
Various embodiments of the teachings herein include a sensor unit for a contactless actuator of an adjustable vehicle element. The sensor unit may include: a carrier element for mounting to a vehicle; a first sensor device attached to the carrier element and having a first capturing area; and a second sensor device attached to the carrier element and having a second capturing area. When mounted on the vehicle, the first sensor device is arranged closer to a floor of the vehicle than the second sensor device; and the first capturing area extends further back with respect to a forward direction of travel of the vehicle than the second capturing area.