# adrc_quadrotor

**Repository Path**: libin971204/adrc_quadrotor

## Basic Information

- **Project Name**: adrc_quadrotor
- **Description**: ADRC uses an Extended state observer to linearize the Quadrotor's Nonlinear dynamics (similar to Feedback linearization). This makes it capable of eliminating disturbances (robustness).
- **Primary Language**: Unknown
- **License**: Not specified
- **Default Branch**: master
- **Homepage**: None
- **GVP Project**: No

## Statistics

- **Stars**: 4
- **Forks**: 5
- **Created**: 2020-03-25
- **Last Updated**: 2026-04-07

## Categories & Tags

**Categories**: Uncategorized

**Tags**: None

## README

# Active Disturbance Rejection Controller

## Introduction  
<p style="text-align: justify"> ADRC uses an Extended state observer to linearize the Quadrotor's Nonlinear dynamics (similar to Feedback linearization). This makes it capable of eliminating disturbances (robustness).</p>


## Description  
![](InkedQuadModel425284_LI.jpg)  
Disturbance observers are known for their use in the estimation of unmeasurable dynamics in a plant. An ADRC controller as the name implies actively cancels disturbances and unwanted dynamics. It is based on the concept of an extended state observer (ESO). An extended state observer is a type of disturbance observer that estimates combined or total disturbances in a plant by introducing a fictitious state (also known as the extended state) that represents the unknown or unwanted dynamics. After estimation of the unknown dynamics, a feedback linearization-type operation is used to cancel out the total disturbance from the plant dynamics. This implies that the control affine plant transforms to a linear feedback integrator system. As a result, linear control theory can be applied. It is thus intuitive that the performance of the controller is dependent on the accuracy, speed and performance of the ESO.  
![](formula4.png)   
![](Figure2.PNG)  
  
  
## Results  
![](figure1.PNG)