# A CPO-Optimized Enhanced Linear Active Disturbance Rejection Control for Rotor Vibration Suppression in Magnetic Bearing Systems

## TL;DR

This paper introduces a new control strategy combining a bio-inspired optimizer with a disturbance rejection framework to significantly reduce rotor vibrations in magnetic bearing systems.

## Contribution

The novel integration of the crested porcupine optimizer (CPO) with ELADRC for adaptive tuning in vibration suppression is presented.

## Key findings

- The CPO-ELADRC scheme reduces regulation time by 66.7% and peak displacement by 86.8% under step disturbances.
- It achieves a 79.8% improvement in adjustment speed and an 86.4% reduction in peak control current under sinusoidal excitation.
- The strategy improves dynamic stability and prevents current saturation across diverse operating scenarios.

## Abstract

To mitigate rotor vibrations in magnetic bearing systems arising from mass imbalance, this study proposes a novel suppression strategy that integrates the crested porcupine optimizer (CPO) with an enhanced linear active disturbance rejection control (ELADRC) framework. The approach introduces a disturbance estimation and compensation scheme based on a linear extended state observer (LESO), wherein both the LESO bandwidth ω0 and the LADRC controller parameter ωc are adaptively tuned using the CPO algorithm to enable decoupled control and real-time disturbance rejection in complex multi-degree-of-freedom (DOF) systems. Drawing inspiration from the crested porcupine’s layered defensive behavior, the CPO algorithm constructs a state-space model incorporating rotor displacement, rotational speed, and control current, while leveraging a reward function that balances vibration suppression performance against control energy consumption. The optimized parameters guide a real-time LESO-based compensation model, achieving accurate disturbance cancelation via amplitude-phase coordination between the generated electromagnetic force and the total disturbance. Concurrently, the LADRC feedback structure adjusts the system’s stiffness and damping matrices to improve closed-loop robustness under time-varying operating conditions. Simulation studies over a wide speed range (0~45,000 rpm) reveal that the proposed CPO-ELADRC scheme significantly outperforms conventional control methods: it shortens regulation time by 66.7% and reduces peak displacement by 86.8% under step disturbances, while achieving a 79.8% improvement in adjustment speed and an 86.4% reduction in peak control current under sinusoidal excitation. Overall, the strategy offers enhanced vibration attenuation, prevents current saturation, and improves dynamic stability across diverse operating scenarios.