Ultrasonic Sensor Thin Plate Lamb Wave Detection
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Solution Overview
Problem
Conventional ultrasonic sensors with high directivity reduce detectable range and increase manufacturing costs, causing exterior design deterioration when multiple sensors are required for object detection, especially near vehicle doors.
Innovation Solution
An ultrasonic sensor system that transmits pulse-shaped waves to a thin plate, using Lamb waves for object detection, allowing for reduced sensor placement and minimizing exterior design impact by using a single set of sensors with low directivity ultrasonic waves radiating from the plate, which cover the entire surface, eliminating the need for multiple sensors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If ultrasonic waves with high directivity are used for object detection, then detection accuracy is improved, but the detectable range is reduced
Solution Approach 1:
The detection space is segmented into two distinct wave paths: direct waves traveling through the thin plate and reflected waves that radiate outward and return. This segmentation allows the system to process different wave types separately, enabling broad coverage while maintaining detection accuracy through time-difference analysis.
Solution Approach 2:
The thin plate serves as an intermediary medium that guides ultrasonic waves. By using the plate as a waveguide, the system achieves both broad coverage (through plate propagation) and directional control (through controlled radiation points), resolving the contradiction between range and precision.
2Area of stationary object
If multiple ultrasonic sensors are arranged two-dimensionally to expand detection coverage, then detectable range is improved, but manufacturing cost increases
Solution Approach 1:
A single ultrasonic sensor performs multiple functions: it transmits waves through the thin plate, receives direct waves, and receives reflected waves from multiple directions. The thin plate itself acts as a waveguide that distributes energy across the detection area, making one sensor equivalent to multiple sensors in terms of coverage.
Solution Approach 2:
The invention merges the functions of multiple sensors into a single sensor system by utilizing the thin plate as a shared transmission and reception medium. The plate conducts ultrasonic waves from one sensor to multiple detection points, combining what would require multiple independent sensors into one integrated system.
3Area of stationary object
If multiple ultrasonic sensors are arranged to improve detection coverage, then detectable range is improved, but exterior design deteriorates
Solution Approach 1:
The ultrasonic sensor is extracted from the traditional exposed mounting configuration and integrated behind the thin plate. The plate is positioned in front of the sensor, allowing the sensor to be hidden while still performing detection functions through the plate medium, thus preserving exterior design while maintaining detection coverage.
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
This approach enables effective object detection near vehicle doors without compromising exterior design aesthetics and reduces manufacturing costs by allowing a single set of sensors to cover the necessary area, improving detection accuracy and reducing sensor visibility.
Implementation Method 1
an ultrasonic transmitter that transmits pulse-shaped ultrasonic waves to a thin plate to excite the thin plate
Implementation Method 2
an ultrasonic receiver that receives direct waves and reflected waves among the ultrasonic waves propagating in the thin plate excited by the pulse-shaped ultrasonic waves, the direct waves propagating in only the thin plate, and the reflected waves radiating outward, then reflected by an object, and returning to the thin plate
Implementation Method 3
a detector that detects the object present near the thin plate on the basis of a difference between a time at which the ultrasonic receiver receives the direct waves and a time at which the ultrasonic receiver receives the reflected waves
Data Source
AI summary
An ultrasonic sensor in the invention includes an ultrasonic transmitter, an ultrasonic receiver, and a detector. The ultrasonic transmitter transmits pulse-shaped ultrasonic waves to a thin plate to excite the thin plate. The ultrasonic receiver receives direct waves and reflected waves among the ultrasonic waves propagating in the thin plate excited by the pulse-shaped ultrasonic waves, the direct waves propagating only in the thin plate, and the reflected waves radiating outward, then reflected by the object, and returning to the thin plate. The detector detects the object present near the thin plate on the basis of a difference between a time at which the ultrasonic receiver receives the direct waves and a time at which the ultrasonic receiver receives the reflected waves.