Angular position error compensation based on multi-sensor phase modulation

Angular position measurement accuracy is a critical factor limiting the positioning and control performance of high-end equipment, and systematic errors further restrict its improvement. Existing compensation methods either rely on external references that are difficult to deploy on-site, or they fail to identify specific harmonics due to sensor layout constraints, making it challenging to achieve a balance among accuracy, cost, and practicality. This paper proposes an angular position error compensation method based on multi-sensor phase modulation. By collaboratively configuring two sets of uniformly distributed readheads and leveraging their complementary harmonic suppression characteristics, the method reconstructs the error spectrum through phase modulation, enabling high-integrity estimation of full-circle systematic errors without the need for external reference devices. Theoretical analysis shows that this method can effectively suppress all harmonic components except the 12th order and its integer multiples. Experimental results demonstrate that after applying phase modulation compensation to a three-head uniformly distributed self-calibration system, the peak-to-peak error is reduced from 15.44 ′ ′ −3.64 ′ ′ , and the root mean square error decreases from 4.13 ′ ′ −1.04 ′ ′ . The proposed method achieves high-precision error compensation with only a few sensors, offering the advantages of a simple structure, low cost, and suitability for on-site real-time calibration, thereby providing what we believe to be a new approach for high-precision angular position measurement.