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

2019 ◽  
Vol 2019 ◽  
pp. 1-15 ◽  
Author(s):  
Xing Fang ◽  
Yujia Shang

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.

Author(s):  
Yohan Díaz-Méndez ◽  
Leandro Diniz de Jesus ◽  
Marcelo Santiago de Sousa ◽  
Sebastião Simões Cunha ◽  
Alexandre Brandão Ramos

Sliding mode control (SMC) is a widely used control law for quadrotor regulation and tracking control problems. The purpose of this article is to solve the tracking problem of quadrotors using a relatively novel nonlinear control law based on SMC that makes use of a conditional integrator. It is demonstrated by a motivation example that the proposed control law can improve the transient response and chattering shortcomings of the previous approaches of similar SMC based controllers. The adopted Newton–Euler model of quadrotor dynamics and controller design is treated separately in two subsystems: attitude and position control loops. The stability of the control technique is demonstrated by Lyapunov’s analysis and the effectiveness and performance of the proposed method are compared with a similar integral law, also based on SMC, and validated by tracking control problems using numerical simulations. Simulations were developed in the presence of external disturbances in order to evaluate the controller robustness. The effectiveness of the proposed controller was verified by performance indexes, demonstrating less accumulated tracking errors and control activity and improvement in the transient response and disturbance rejection when compared to a conventional integrator sliding mode controller.


2019 ◽  
Vol 2019 ◽  
pp. 1-10
Author(s):  
Tian Dong ◽  
Changjian Zhao ◽  
Zhiguo Song

In this paper, an autopilot design method for a compound control small-scale solid rocket is proposed. The rocket has multiple actuators, including a flexible nozzle for pitching and yawing channels, aerodynamic fins for rolling channel, and lateral thrusters which work in on-off mode for all three channels. In order to keep the aircraft steady in the initial stage of launch when the dynamic pressure is low, the autopilot is aimed at optimizing the cooperation among the actuators. Firstly, without considering the discontinuous lateral thrust, the control law for flexible nozzle and aerodynamic fins is achieved via the sliding mode control approach. On this basis, an object to be controlled with choiceness is obtained for the lateral thrusters controlled loop. Secondly, the operation logic of lateral thrusters is programmed, regarding rolling moment as priority. Thirdly, after a continuous controller is obtained, a discretization method for the lateral thrusters control law is designed combining the characteristics of sliding mode control and Lyapunov’s stableness theorem. Finally, the fundamental cause why compound control improves the system stability is given theoretically. Simulation results validate the improved response performance and robustness against uncertainties and disturbance of the autopilot.


2017 ◽  
Vol 55 (1) ◽  
pp. 116 ◽  
Author(s):  
Le Xuan Hai ◽  
Thai Huu Nguyen ◽  
Tran Gia Khanh ◽  
Nguyen Tien Thanh ◽  
Bui Trong Duong ◽  
...  

The paper presents a PID – Fuzzy Sliding Mode control (PID-FSMC) algorithm for overhead crane system to guarantee anti-sway trajectory tracking of the nominal plant. The proposed PID-FSMC law guarantees the closed-loop asymptotical stability as well as improveS the transient response of the load sway dynamics when the trolley is moving. The simulation results confirm the propriety of the proposed controller and show great promise of the controller application in practice.


2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Shuo Wang ◽  
Ju Jiang ◽  
Chaojun Yu

In this paper, a controller combining backstepping and adaptive supertwisting sliding mode control method is proposed for altitude and velocity tracking control of air-breathing hypersonic vehicles (AHVs). Firstly, the nonlinear longitudinal model of AHV is introduced and transformed into a strict feedback form, to which the backstepping method can be applied. Considering the longitudinal trajectory tracking control problem (altitude control and velocity control), the altitude tracking control system is decomposed to several one-order subsystems based on the backstepping method, and an adaptive supertwisting sliding mode controller is designed for each subsystem, in order to obtain the virtual control variables and actual control input. Secondly, the overall stability of the closed-loop system is proved by the Lyapunov stability theory. At last, the simulation is carried out on an AHV model. The results show that the proposed controller has good control performances and good robustness in the parameter perturbation case.


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