Torque Steering Angle Sensor Offset Correction
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Solution Overview
Problem
Conventional torque steering angle sensors experience measurement errors due to interference between the steering torque and steering angle measuring mechanisms, leading to reduced detection accuracy.
Innovation Solution
A torque steering angle sensor system comprising a circular ring magnet, magnetic path forming members, magnetic flux collecting rings, and magnetic field detecting elements, along with a slide magnet and slide mechanism, which allows for the detection of steering torque and angle with enhanced accuracy by correcting magnetic field offsets and amplitudes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a torque steering angle sensor uses both steering torque measuring mechanism and steering angle measuring mechanism with shared magnetic components, then the device complexity is reduced, but measurement precision deteriorates due to mutual interference between the two measuring mechanisms
Solution Approach 1:
The patent divides the magnetic field detection into two independent measurement systems: one for torque measurement using magnetic flux density changes, and another for angle measurement using magnetic field direction changes. This segmentation allows each measurement to be processed independently, eliminating mutual interference while sharing the same ring magnet structure, thus reducing device complexity without sacrificing measurement precision.
Solution Approach 2:
The patent introduces separate magnetic field detecting elements for each measurement function: first detecting elements for torque measurement and second detecting elements for angle measurement. These intermediary sensors act as mediators that independently convert different aspects of the magnetic field into measurable signals, preventing cross-interference between torque and angle measurements while maintaining a unified magnetic component structure.
2Ease of manufacture
If the torque sensor and steering angle sensor share the same magnetic components, then manufacturing cost is reduced, but detection accuracy deteriorates due to measurement errors from mutual interference
Solution Approach 1:
The patent makes the ring magnet a universal component that serves dual functions: generating magnetic flux for torque measurement and providing magnetic field direction information for angle measurement. This multi-functionality allows a single magnetic component to replace what would traditionally require separate magnets, reducing manufacturing cost while the independent detection systems ensure that detection accuracy is maintained for both measurements.
Solution Approach 2:
The patent segments the detection function into independent torque detection and angle detection pathways, each with its own processing algorithm. This segmentation allows the shared magnetic components to be utilized for both measurements without the measurements interfering with each other, thereby maintaining high detection accuracy while reducing manufacturing costs through component sharing.
3Device complexity
If magnetic field detecting elements are arranged to detect both torque and steering angle, then the device structure is simplified, but measurement errors increase due to interference between measuring mechanisms
Solution Approach 1:
The patent segments the magnetic field detection into two independent measurement systems: one for torque measurement using magnetic flux density changes, and another for angle measurement using magnetic field direction changes. This segmentation allows each measurement to be processed independently, eliminating mutual interference while sharing the same ring magnet structure, thus reducing device complexity without sacrificing measurement precision.
Solution Approach 2:
The patent employs multiple magnetic field detecting elements (more than minimally required) to independently detect different aspects of the magnetic field. By using excessive detection elements with dedicated functions, the system ensures that each measurement has sufficient independent data, preventing interference errors while maintaining a relatively simple overall structure through the shared magnetic component.
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 system achieves improved detection accuracy for both steering torque and angle by minimizing measurement errors through offset and amplitude correction, ensuring precise calculations of steering wheel parameters.
Implementation Method 1
magnetic path forming members that are configured so as to vary a relative angle between a ring magnet depending on the twist of the torsion bar and vary a transmitting magnetic flux by varying a positional relation with the magnetic poles
Implementation Method 2
a magnetic field detecting element is arranged opposite the ring magnet of the input shaft
Data Source
AI summary
A torque steering angle sensor includes a ring magnet that rotates together with the first rotary member, a second magnetic field detecting element arranged opposite an outer peripheral surface of the ring magnet, a slide magnet arranged opposite the second magnetic field detecting element in the axial direction, and a slide mechanism moving the slide magnet in the axial direction depending on a rotation of the first rotary member; and wherein the steering angle computing portion includes a slide magnet distance computing portion calculating a migration length from a reference position of the slide magnet; and a steering angle correcting portion correcting an offset of the magnetic field strength in the radial direction based on the migration length and configures so as to compute the steering angle of the steering wheel using a magnetic field strength in the radial direction corrected by the steering angle correcting portion.