ISO26262-Compliant Inductive Long-Stroke Linear-Position Sensors as an Alternative to Hall-Based Sensors for...

Area of Science:

• Automotive Engineering
• Sensor Technology
• Electromagnetics

Background:

• Vehicle safety relies on accurate position sensors resistant to harsh automotive environments.
• Existing Hall-based sensors, including 3D Hall sensors, struggle with external magnetic fields (EXMFs) and long-stroke (LS) positions.
• A need exists for robust, accurate position sensing solutions compliant with automotive safety standards like ISO26262.

Purpose of the Study:

• To propose and evaluate an ISO26262-compliant inductive position sensor (IPS) as a safer alternative to Hall-based sensors.
• To assess the IPS's performance regarding accuracy, robustness to EXMFs, and functionality at LS positions.
• To compare the IPS against existing 3D Hall sensors in critical automotive application scenarios.

Main Methods:

• An inductive position sensor (IPS) utilizing a 3.5 MHz-induced magnetic field source was developed.
• The IPS was tested for accuracy at varying airgaps (1.5-2.5 mm) and LS distances up to 12 mm.
• Immunity tests were conducted against external magnetic fields (EXMFs) per ISO11452-8 and a 0.1 T field.

Main Results:

• The IPS demonstrated stable accuracy within ±0.85% across different airgaps and was unaffected by LS positions.
• Unlike Hall-based sensors, the IPS showed minimal B field degradation at LS.
• The IPS exhibited robustness against EXMFs due to its high excitation frequency, passing immunity tests.

Conclusions:

• The proposed inductive position sensor (IPS) offers a superior alternative to Hall-based sensors for automotive safety applications.
• The IPS provides reliable and accurate position sensing, overcoming limitations of existing technologies in harsh environments and at long-stroke distances.
• The IPS meets ISO26262 compliance, ensuring enhanced safety and performance in vehicles.