Ultrasonic Sensor Housing Ribs for Better Echo Detection
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Solution Overview
Problem
Existing ultrasonic sensors for motor vehicles experience structural vibrations that interfere with echo detection during signal emission, necessitating improved structural dynamics to enhance measurement accuracy and efficiency.
Innovation Solution
The ultrasonic sensor incorporates a decoupling element between the membrane assembly and the plastics housing, featuring ribs on the inner surface of the housing to reduce contact area and utilize a softer material for the decoupling element, ensuring minimal energy transfer and enhanced acoustic decoupling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a decoupling element is arranged between the membrane assembly and the plastics housing to reduce structural vibrations, then measurement precision is improved, but device complexity increases
Solution Approach 1:
A decoupling element made of softer material is introduced as an intermediary component between the membrane assembly and the plastics housing. This decoupling element reduces structural vibrations and improves echo detection precision by preventing direct mechanical coupling, while the ribs on the housing simplify the mounting structure and reduce the need for additional complex fastening mechanisms.
Solution Approach 2:
The contact interface between the housing and decoupling element is segmented into multiple discrete rib structures rather than a continuous contact surface. This segmentation reduces the bearing proportion to specific localized points, maintaining acoustic decoupling effectiveness while simplifying the overall structural design and reducing manufacturing complexity.
2Measurement precision
If the bearing proportion of the inner surface is reduced to improve acoustic decoupling, then measurement precision is improved, but manufacturing precision requirements increase
Solution Approach 1:
The rib structures are designed with specific local geometric characteristics (height, spacing, cross-sectional shape) that are optimized to provide effective acoustic decoupling at those specific locations. The softer material of the decoupling element compensates for variations in rib positioning, maintaining acoustic decoupling effectiveness without requiring extremely high manufacturing precision across the entire contact surface.
Solution Approach 2:
The bearing proportion parameter is changed from a continuous surface contact to a discrete point contact through the rib structures. This parameter change reduces the total contact area and improves acoustic decoupling, while the tolerance to manufacturing variations is increased due to the localized nature of the contact points and the compliance of the softer decoupling element material.
3Stability of the object's composition
If ribs are formed on the inner surface to reduce contact area, then structural dynamics are improved, but ease of manufacture decreases
Solution Approach 1:
The geometric parameters of the ribs (height, spacing, cross-sectional dimensions) are optimized to achieve the desired structural dynamics and acoustic decoupling effects. By carefully selecting these parameters, the ribs can be integrated into the housing molding process using standard manufacturing techniques, balancing the improvement in structural dynamics with the ease of manufacture.
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 design achieves improved acoustic decoupling and damping, allowing for better echo detection by reducing structural vibrations and facilitating easier mounting of the membrane assembly, thereby enhancing the sensor's measurement capabilities.
Implementation Method 1
transfer paths to structural elements that are able to store energy efficiently, such as the plastics housing and in particular the metallic contact elements arranged therein, should be eliminated as far as possible
Implementation Method 2
improve the structural dynamics of an ultrasonic sensor. In particular, transfer paths to structural elements that are able to store energy efficiently
Implementation Method 3
The ultrasonic membrane emits, excited by a sound transducer element attached thereto, energy in the form of an ultrasonic signal
Implementation Method 4
The sound transducer element then detects vibrations in the ultrasonic membrane which originate from an echo signal returning from the motor vehicle vicinity or the interior
Implementation Method 5
The sound transducer element then detects vibrations in the ultrasonic membrane which originate from an echo signal returning
Data Source
AI summary
The invention relates to an ultrasonic sensor (1) having an improved structural dynamic for a motor vehicle (20). The ultrasonic sensor (1) comprises: a plastic housing (2), a membrane assembly (3) arranged in a housing opening (4) of the plastic housing (2), the membrane assembly having an ultrasonic membrane (8), and a decoupling element (6) which is arranged between an inner surface (5) of the plastic housing (2) and the membrane assembly (3). A plurality of ribs (7, 71, 72) are formed at the inner surface (5) of the plastic housing (2), on which the decoupling element (6) rests against, and the ribs (7, 71, 72) are designed in such a way that the decoupling element (6) does not rest against the entire inner surface (5) of the plastic housing (2).