Fully online calibration-compensation method for rotary table positioning error

Abstract

The precision rotary table is an angular positioning generator commonly used in the industry. Ensuring its long-term stability of positioning accuracy is a key concern. Researchers have conducted extensive studies on the online calibration and real-time compensation of rotary table positioning errors. However, existing research often involves some offline processing throughout the calibration and compensation stages. Currently, there is very little research on methods in which the entire process of calibrating and compensating rotary table positioning errors is fully online. Therefore, this paper proposes a fully online calibration-compensation method for rotary table positioning errors and develops a rotary table positioning error calibration-compensation system. Based on the Fourier self-calibration principle and the harmonic compensation principle, this method implements online calibration and real-time compensation of positioning errors using a heterogeneous processor. Throughout the entre process, data processing is guaranteed to be online. The experimental results show that the positioning accuracy of the rotary table improved from [−150.0′′, 137.9′′] to [−1.3′′, 1.6′′], effectively improving its precision. The proposed method is highly suitable for compact or cost-sensitive precision rotary tables, while also being applicable for spindle condition monitoring.