Steering Angle Sensor Magnetic Shielding for Torque Interference
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Solution Overview
Problem
Combined sensor devices for motor vehicles face challenges in preventing mutual interference between the magnetic fields of torque sensor units and steering angle sensor units, which affects sensor accuracy.
Innovation Solution
A sensor device design featuring a secondary rotor assembly with a magnetic shielding unit, where at least one flat magnetic shielding element is attached for conjoint rotation to the secondary rotor, effectively shielding the torque sensor magnetic field from the steering angle sensor magnetic field, reducing interference and allowing for a more compact and accurate sensor arrangement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If magnetic shielding elements are added to prevent mutual interference between torque sensor and steering angle sensor magnetic fields, then sensor accuracy is improved, but device complexity increases
Solution Approach 1:
A magnetic shielding element is introduced as an intermediary component between the torque sensor magnetic unit and the steering angle sensor magnetic unit. This shielding element acts as a mediator that blocks mutual interference between the two magnetic fields, allowing both sensors to operate accurately in close proximity without requiring separate isolated housing structures.
Solution Approach 2:
The magnetic shielding element is integrated into the existing sensor device structure by attaching it to the secondary rotor, effectively nesting the shielding function within the existing mechanical assembly. This allows the shielding to be incorporated without adding a completely separate structural system, thereby limiting the increase in device complexity.
2Volume of moving object
If the sensor device is designed to be compact, then installation space is reduced, but magnetic interference between sensor units increases
Solution Approach 1:
The magnetic shielding element serves as a mediator that enables compact placement of the sensor units by blocking magnetic interference. This allows the torque sensor and steering angle sensor to be positioned close together in a compact arrangement while preventing harmful magnetic coupling between them.
Solution Approach 2:
The magnetic shielding element is strategically positioned only in the specific region where magnetic interference occurs - between the two magnetic units. This localized approach provides effective interference blocking without requiring a complete enclosure or significant increase in overall device volume.
3Measurement precision
If magnetic shielding elements are attached to the secondary rotor for conjoint rotation, then interference is reduced, but manufacturing complexity increases
Solution Approach 1:
The magnetic shielding element is combined with the secondary rotor assembly, attaching it directly to the secondary rotor. This merging of components simplifies the overall structure compared to separate mounting arrangements and allows the shielding to rotate conjointly with the secondary rotor, maintaining consistent positioning during operation.
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 reduced magnetic interference, enabling a more compact and accurate sensor device with improved steering angle detection and increased stability of the steering angle magnetic unit against demagnetization or aging, while maintaining high torque sensor accuracy.
Implementation Method 1
a magnetic shielding unit with at least one flat first magnetic shielding element, which extends in a plane perpendicular to the first axis of rotation, in order to shield the torque sensor magnetic field of the torque sensor unit and the first steering angle magnetic field of the steering angle sensor unit at least partially from one another
Implementation Method 2
has at least one torque sensor magnetic unit to generate a torque sensor magnetic field and at least one torque magnetic sensor to generate a torque sensor signal as a function of a torque applied to the shaft
Implementation Method 3
a first steering angle magnetic unit which is assigned to the first secondary rotor to generate a first steering angle magnetic field
Implementation Method 4
the generated signal can be evaluated to determine the applied torque... the magnetic flux density in the stator elements changes, which can be detected by means of the torque magnetic sensor
Implementation Method 5
a first steering angle magnetic sensor which is assigned to the first secondary rotor to generate at least one first sensor signal as a function of a rotary angle of the main rotor
Data Source
AI summary
A sensor device is disclosed. The sensor device includes a torque sensor unit and a steering angle sensor unit for a motor vehicle. The torque sensor unit is configured to detect a torque which is applied to a steering shaft, rotatable about a main axis of rotation. The torque sensor unit includes at least one torque sensor magnetic unit to generate a torque sensor magnetic field and at least one torque magnetic sensor to generate a torque sensor signal as a function of a torque applied to the shaft. The steering angle sensor unit is configured to detect a rotary angle of the shaft. The steering angle sensor unit includes a main rotor, a first secondary rotor, and a first steering angle magnetic sensor.