Ferrous Shielded Sensor Assembly for Position Tracking
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing position sensing systems in devices with electromagnetic coils face inaccuracies due to magnetic field interference, making it difficult to accurately track the position of movable components like locking rings in differential systems.
Innovation Solution
A sensor assembly with a ferrous shield member that creates a shielded chamber to house a magnetic field sensor and a sensing magnet, shielding them from the electromagnetic coil's magnetic field, allowing for accurate detection of the movable component's position by monitoring the sensing magnet's magnetic field.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a magnetic sensor is placed within the electromagnetic coil's magnetic field to detect position, then the sensor can monitor the movable component's position, but the coil's magnetic field generates noise that interferes with the sensor's detection accuracy
Solution Approach 1:
The system divides the space into a shielded region (containing the sensor and sensing magnet) and an unshielded region (containing the electromagnetic coil). The shield member creates a distinct segmented zone that isolates the sensitive detection components from the interfering magnetic field, allowing both the coil and sensor to function in their respective zones without mutual interference.
Solution Approach 2:
The shield member acts as an intermediary element between the electromagnetic coil and the magnetic sensor. This ferrous material barrier intercepts and redirects the coil's magnetic field lines, preventing them from reaching the sensor. The shield member mediates the interaction by absorbing and channeling the magnetic flux around the protected detection zone.
2Measurement precision
If the magnetic sensor is moved farther away from the electromagnetic coil to reduce magnetic field interference, then the noise from the coil's magnetic field is reduced, but space constraints within the device casing prevent adequate separation
Solution Approach 1:
Instead of solving the interference problem by increasing linear distance (one-dimensional solution), the invention introduces a spatial dimension by creating a three-dimensional shielded chamber. The shield member forms an enclosed or partially enclosed volume that provides magnetic field protection while maintaining compact overall device dimensions, effectively adding a volumetric dimension to the problem solution.
Solution Approach 2:
The sensor assembly is nested within the device casing in a space-efficient manner. The shielded chamber containing the sensor and sensing magnet is integrated within the existing device volume, allowing the sensor system to be housed compactly without requiring additional external space. The nested configuration enables the sensor to remain close to the coil while maintaining detection accuracy through the shielded environment.
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 configuration significantly reduces electromagnetic interference, enhancing the accuracy and reliability of position sensing by isolating the sensor components from the coil's magnetic field, thereby improving the precision of tracking the movable component's position.
Implementation Method 1
The shield member is composed of a ferrous material to shield the magnetic field sensor and the sensing magnet from the first magnetic field generated by the electromagnetic coil
Implementation Method 2
The magnetic field sensor detects an electrical characteristic responsive to a second magnetic field produced by the sensing magnet to monitor a position of the movable component along the axis
Implementation Method 3
The electromagnetic coil is configured to generate a first magnetic field to move a movable component linearly along an axis between an advanced position and a retracted position relative to the electromagnetic coil based on a strength of the first magnetic field
Data Source
AI summary
A sensor assembly includes a housing, a shield member, a magnetic field sensor, and a sensing magnet. The housing is configured to be mounted at least proximate to an electromagnetic coil that generates a first magnetic field to cause a movable component to move linearly along an axis based on the strength of the first magnetic field. The sensing magnet is configured to be coupled to the movable component to move therewith. The magnetic field sensor and the sensing magnet are disposed within a shielded chamber defined by the shield member, which is ferrous to shield the magnetic field sensor and sensing magnet from the first magnetic field. The magnetic field sensor detects an electrical characteristic responsive to a second magnetic field produced by the sensing magnet to monitor a position of the movable component along the axis.