Variable Resistance Conductive Rubber Sensor for Vehicle Safety
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional pinch sensors for vehicles have limited activation angles, are complex and costly to construct, and can experience false activations due to routing issues, while Hall effect sensors are expensive and struggle to meet safety standards for vehicle window applications.
Innovation Solution
A variable resistance conductive rubber sensor body that is formable, moldable, and extrudable, with a microcontroller connected to detect changes in resistance or temperature, allowing for a wide range of applications including vehicle windows, seats, and closure systems, offering increased activation angles and reduced complexity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional pinch sensors with conductive wires embedded in rubber strip are used, then the sensor can detect object contact through resistance drop, but the activation angle is limited to about 35 degrees and false activations occur due to routing issues
Solution Approach 1:
The patent replaces the mechanical wire contact system with a capacitive sensing system. Instead of relying on physical wire contact that requires precise alignment and head-on impact, the invention uses capacitive changes detected by a microcontroller to sense object presence. This substitution eliminates the 35-degree activation angle limitation and false activations caused by wire routing, as capacitive sensing can detect objects from multiple angles without mechanical contact.
Solution Approach 2:
The patent changes the detection parameter from electrical resistance (requiring wire contact) to capacitance (detecting object proximity). By monitoring capacitive changes in the rubber strip material itself rather than wire-to-wire resistance, the system achieves broader activation angles and improved reliability. The microcontroller detects capacitive variations caused by nearby objects, enabling detection beyond the limited mechanical contact angle.
2Reliability
If conventional pinch sensors with complex extrusion and crimping processes are used, then the sensor can detect contact, but the construction becomes complex and costly
Solution Approach 1:
The patent extracts and eliminates the complex wire embedding, extrusion, and crimping processes from the sensor construction. By removing the conductive wires and their associated manufacturing steps, the invention simplifies the construction to a basic rubber strip with embedded capacitive sensing capability. The microcontroller directly monitors capacitive changes in the simplified structure, eliminating the need for complex assembly processes while maintaining detection functionality.
Solution Approach 2:
The patent makes the rubber strip material itself serve multiple functions: it provides the structural base, acts as the capacitive sensing element, and eliminates the need for separate wire components. This multi-functionality reduces construction complexity by integrating sensing capability into the base material rather than requiring additional wires and complex assembly processes.
3Reliability
If Hall effect sensors are used for vehicle window applications, then the sensor can detect object presence, but the cost increases and meeting DOT safety standards becomes challenging due to lag time
Solution Approach 1:
The patent replaces Hall effect sensors with a capacitive sensing system using the rubber strip and microcontroller. This substitution reduces cost by eliminating expensive Hall effect components while achieving faster response times. The capacitive sensing system detects object proximity through dielectric changes in the rubber material, providing immediate detection without the lag time that prevents meeting DOT safety standards for power window applications.
Solution Approach 2:
The patent changes the detection parameter from magnetic field (Hall effect) to capacitance (dielectric properties). By monitoring capacitive changes in the rubber strip caused by nearby objects, the system achieves faster response times compared to Hall effect sensors. The microcontroller continuously monitors capacitive variations, enabling immediate detection and response to objects in the window path, thus meeting stringent safety standards.
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 solution provides a cost-effective, flexible, and reliable sensor system capable of detecting pressure and temperature changes across a broader activation angle, enhancing safety and reducing false activations, while meeting stringent vehicle safety standards.
Implementation Method 1
the sensor body being elastically deformed when acted upon by an applied force resulting from an external contact
Implementation Method 2
the conductive material of the sensor body exhibits an increase in electrical resistance
Implementation Method 3
the microcontroller being configured to detect the presence of external contact to the sensor body as a result of an increase in electrical resistance in response to an increase in temperature resulting from the external contact
Data Source
AI summary
A variable resistance conductive rubber sensor and method of detecting an object/human touch therewith is provided. The sensor has a sensor body constructed from electrically conductive rubber. The sensor body extends between opposite first and second ends. A first wire is operably connected to the first end and a second wire may be operably connected to the second end, with the first and second wires being brought into electrical communication with one another by the intermediately extending electrically conductive rubber of the sensor body. A microcontroller is operably connected to the sensor body to detect the presence of an applied force or human touch on the sensor body.