Ferrite Road Markers for Reliable Vehicle Magnetic Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional magnetic markers using neodymium magnets are susceptible to oxidation, requiring airtight metallic cases, leading to increased costs and sizes, which in turn raise installation costs and complexities.
Innovation Solution
A magnetic marker system utilizing a magnet molded into a columnar shape with magnetic powder, such as iron oxide, which is less prone to oxidation, allowing for direct accommodation in road surfaces and reducing the need for sealed structures, thereby minimizing costs and sizes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a magnet such as neodymium is used to generate a strong magnetic field, then detection reliability is improved, but the magnet is susceptible to oxidation requiring airtight metallic cases, leading to increased cost and size
Solution Approach 1:
The patent uses a magnet with moderate magnetic strength that does not require complex protective casing, accepting that the magnet may have limited service life in harsh environments. This eliminates the need for expensive airtight metallic cases while maintaining adequate detection functionality.
Solution Approach 2:
The patent changes the magnetic field strength parameter from high (neodymium) to moderate strength, which allows the magnet to function adequately without requiring oxidation-resistant metallic encasement, thus simplifying the overall device structure.
2Reliability
If a magnet such as neodymium is used to generate a strong magnetic field, then detection reliability is improved, but installation cost increases due to increased size and complexity
Solution Approach 1:
The patent adopts a simpler magnet design that reduces manufacturing and installation costs. By using a magnet that doesn't require complex protective structures, the overall system becomes more cost-effective for deployment.
Solution Approach 2:
The patent extracts the expensive airtight metallic case from the system by using a magnet with moderate magnetic strength that functions adequately without such protection, thereby reducing overall system cost while maintaining essential detection capability.
3Stability of the object's composition
If a magnet is accommodated in a highly-airtight metallic case, then oxidation resistance is improved, but the size and cost of the magnetic marker increase
Solution Approach 1:
The patent uses a simpler magnet without complex protective casing, accepting that the magnet may be subject to oxidation but prioritizing cost and size reduction. The magnet serves its detection function adequately without long-term oxidation resistance.
Solution Approach 2:
The patent removes the airtight metallic case from the design by using a magnet with moderate magnetic strength that functions adequately exposed to the environment, thereby significantly reducing the overall size and cost of the magnetic marker.
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 magnetic marker system achieves reduced costs and installation expenses while maintaining reliable magnetic field detection, with the ability to be demagnetized and remagnetized in place, and incorporating a protective layer and information providing components for enhanced durability and functionality.
Implementation Method 1
a magnet, molded into a columnar shape, that contains a magnetic powder that is a powder of a magnetic material
Data Source
AI summary
A magnetic marker (1), laid in or on a road so as be detectable by a magnetic sensor (2) attached to a bottom surface side of a vehicle (5), that is used for vehicle-side drive assist control for assisting driving is an isotropic ferrite plastic magnet, molded into a columnar shape, that contains a magnetic powder of iron oxide, i.e. a powder of a magnetic material, dispersed in a polymer material. In a marker system (1S) including this magnetic marker (1), magnetic markers (1) accommodated in holes (530) bored in a road surface (53) are arranged along the center of a lane.