Vehicle Door Sensor Layout for Accurate Foot Gesture Detection
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Solution Overview
Problem
Current sensor units for contactless vehicle door actuation, such as tailgate opening, often incorrectly trigger due to inability to reliably distinguish between specific foot movements intended for door opening and other foot movements, leading to unwanted trunk openings.
Innovation Solution
A sensor unit comprising two proximity sensors with elongated detection fields, where one field protrudes beyond the other, allowing for precise differentiation between movements in different directions, coupled with a control unit that evaluates signal time offsets to determine the intent to open the door, and is integrated with a fully automatic door locking system for enhanced security.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single proximity sensor is used to detect foot movements for door opening, then the device complexity is reduced, but the measurement precision deteriorates leading to incorrect triggering
Solution Approach 1:
The detection task is segmented into two independent proximity sensors instead of using a single sensor. Each sensor has an elongated detection field oriented in the longitudinal direction, allowing them to independently detect movements in different spatial zones. This segmentation enables the system to distinguish between longitudinal kicking movements and transverse walking movements by analyzing which sensor is triggered and the timing of triggers.
Solution Approach 2:
The solution adds a spatial dimension to the detection system by arranging two sensors with elongated fields in the longitudinal direction. This dimensional arrangement allows the system to differentiate movement types based on spatial location and temporal sequence, transforming a single-point detection problem into a multi-point spatial detection system that can identify movement direction and intent.
2Device complexity
If the detection fields of two proximity sensors are positioned close together, then the device complexity is reduced, but the measurement precision deteriorates making it difficult to distinguish movement directions
Solution Approach 1:
Each proximity sensor is given a distinct local quality through its elongated detection field geometry, oriented specifically in the longitudinal direction. This local differentiation in field shape and orientation allows each sensor to be sensitive to movements in its specific spatial zone, enabling the system to distinguish between longitudinal kicking movements (affecting one sensor primarily) and transverse walking movements (affecting sensors in sequence or differently).
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 sensor unit effectively differentiates between kicking and sideways movements, reducing false triggers and ensuring accurate door operation, while the integration with a fully automatic locking system prevents unauthorized access.
Implementation Method 1
the or each detection field is expediently a flat electrode via which - in the manner typical for capacitive sensors - an electric field is radiated into the surrounding space, this electric field being measurable through the body tissue when a vehicle user approaches being affected
Implementation Method 2
an electric field is radiated into the surrounding space, this electric field being measurable through the body tissue
Data Source
Figure 1
Figure 2~4
AI summary
The invention relates to a sensor unit (2) which is not susceptible to errors for contactlessly actuating a vehicle door (3). The sensor unit (2) comprises a first proximity sensor (20) and a second proximity sensor (22). Each of the two proximity sensors (20, 22) has an elongate detection field (21, 23) extending substantially in a Y direction (9). The detection fields (21, 23) of the two proximity sensors (21, 23) are spaced from one another in a direction perpendicular to the Y direction (9). In addition, the detection field (21) of the first proximity sensor (20) projects beyond the detection field (29) of the second proximity sensor (22) in the Y direction at least on one side by a projecting length (A).