A synthetic position decoding technology for rotary transformers based rotor position measurement system

Area of Science:

• Electrical Engineering
• Control Systems
• Robotics

Background:

• Rotary transformers are crucial for position sensing in motor drives.
• Traditional decoding methods often rely on specialized, costly integrated circuits.
• Integrating diverse motor drive platforms requires flexible position decoding solutions.

Purpose of the Study:

• To propose a software-based rotary transformer position decoding scheme.
• To eliminate the need for dedicated decoding chips in motor drive control.
• To enable compatibility with various motor drive control platforms through a novel signal conversion method.

Main Methods:

• Designed a simple analog excitation and signal conditioning circuit.
• Utilized software demodulation and a phase-locked loop (PLL) for position signal decoding.
• Developed a single-cycle partition average method for converting angle position to A/B/Z encoder-like signals.

Main Results:

• The proposed scheme successfully decoded rotary transformer signals without specialized chips.
• Experimental validation on an STM32F407 platform confirmed the scheme's effectiveness and accuracy.
• The software-based approach demonstrated comparable results to traditional chip-based decoding.

Conclusions:

• The rotary transformer position decoding scheme offers a cost-effective and flexible alternative.
• The method is suitable for various motor drive control applications.
• Software-based decoding enhances adaptability across different hardware platforms.