Active Disturbance Rejection Controller Implemented Using S-Function Blocks

Active Disturbance Rejection Controller (ADRC) represents an advanced control algorithm capable of effectively handling system uncertainties and external disturbances. Implementing ADRC through S-function modules in MATLAB environment fully leverages its flexibility and computational efficiency.

The core concept of ADRC involves estimating total system disturbances through an extended state observer (ESO) and compensating for them within the control law. This design grants the controller strong robustness against system parameter variations and external disturbances.

For MATLAB implementation, three crucial S-function programs are typically required: Main Controller Program: Contains the primary logic of ADRC algorithm, responsible for computing control output using discrete-time state equations and nonlinear feedback mechanisms. State Observer Program: Implements extended state observer functionality through difference equations to estimate system states and total disturbances in real-time. Disturbance Compensation Program: Performs feedforward compensation based on observer-estimated disturbances using disturbance rejection techniques to enhance system robustness.

This implementation approach exhibits excellent modular characteristics, facilitating reuse and parameter adjustments across different control systems. Through S-function's sample time configuration, it can flexibly adapt to various real-time control requirements. Simulation results demonstrate that the S-function-based ADRC maintains superior control performance under diverse disturbance conditions, validated through stability analysis and frequency response tests.