Trajectory Tracking Control for Small-Scale Unmanned Helicopters with Mismatched Disturbances Based on a Continuous Sliding Mode Approach

Xing Fang,Yujia Shang

doi:10.1155/2019/6235862

Abstract

A novel continuous sliding mode control (CSMC) strategy based on the finite-time disturbance observer (FTDO) is proposed for the small-scale unmanned helicopters in the presence of both matched and mismatched disturbances. First, a novel sliding surface is designed based on the estimates of the mismatched disturbances and their derivatives obtained by the FTDO. Then, a continuous sliding mode control law is developed, which does not lead to any chattering phenomenon. Furthermore, the closed-loop helicopter system is proved to be asymptotically stable. Finally, the excellent hovering and tracking performance, as well as the powerful disturbance rejection capability of the proposed novel CSMC method, is validated by the simulation results.

Highlights

With the prominent capabilities of vertical take-off and landing and hovering and high levels of maneuverability, smallscale unmanned helicopters have become the most popular unmanned aerial vehicles (UAVs)
The objective of this paper is to develop a novel continuous sliding mode controller for the small-scale unmanned helicopter to track the predefined trajectory asymptotically despite the presence of both matched and mismatched disturbances
In order to evaluate the superiority of the proposed continuous sliding mode control (CSMC) method, both the traditional sliding mode control (SMC) and ENDO-SMC [28] are employed as comparative methods

Summary

Introduction

With the prominent capabilities of vertical take-off and landing and hovering and high levels of maneuverability, smallscale unmanned helicopters have become the most popular unmanned aerial vehicles (UAVs). Some disturbances enter the unmanned helicopter systems via different channels with control inputs, which are known as mismatched disturbances. It has become a quite attractive and challenging task to design high-performance control strategies for unmanned helicopters [1,2,3,4]. Some flight controllers are designed based on the linear model of the unmanned helicopters, including PID [5], LQR [6], and H∞ [7]. With the unique disturbance suppression capability, sliding mode control (SMC) methods have been proposed to attenuate the model uncertainties and external disturbances of the unmanned helicopters [11].

Objectives

Results

Conclusion