scholarly journals A Decentralized Low-Chattering Sliding Mode Formation Flight Controller for a Swarm of UAVs

Sensors ◽  
2020 ◽  
Vol 20 (11) ◽  
pp. 3094 ◽  
Author(s):  
Thiago F. K. Cordeiro ◽  
João Y. Ishihara ◽  
Henrique C. Ferreira
Keyword(s):  
Sliding Mode ◽  
Formation Flight ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Control Objective ◽  
Low Pass ◽  
Local Controller ◽  
Chattering Effect ◽  
Virtual Leader ◽  
Decentralized Architecture

In this paper, a nonlinear robust formation flight controller for a swarm of unmanned aerial vehicles (UAVs) is presented. It is based on the virtual leader approach and is capable of achieving and maintaining a formation with time-varying shape. By using a decentralized architecture, the local controller in each UAV uses information only from the UAV itself, its neighbors, and from the virtual leader. Also, a synchronization control objective provides a mechanism to weight between the fleet achieving the desired formation shape, that is, achieving the desired relative position between the UAVs, and each UAV achieving its desired absolute position. The use of a combination of a sliding mode controller and a low pass filter reduces the usual chattering effect, providing a smooth control signal while maintaining robustness. Simulation results show the effectiveness of the proposed decentralized controller.

scholarly journals Trajectory tracking control for chain-series robot manipulator: Robust adaptive fuzzy terminal sliding mode control with low-pass filter

2020 ◽  
Vol 17 (3) ◽  
pp. 172988142091698 ◽  
Author(s):  
Pengcheng Wang ◽  
Dengfeng Zhang ◽  
Baochun Lu
Keyword(s):  
Trajectory Tracking ◽  
Sliding Mode ◽  
Sliding Mode Controller ◽  
Continuous Control ◽  
Terminal Sliding Mode ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Adaptive Fuzzy ◽  
Low Pass ◽  
Robust Adaptive

This article investigates a difficult problem which focuses on the external disturbance and dynamic uncertainty in the process of trajectory tracking. This article presents a robust adaptive fuzzy terminal sliding mode controller with low-pass filter. The low-pass filter can provide smooth position and speed signals. The fuzzy terminal sliding mode controller can achieve fast convergence and desirable tracking precision. Chattering is eliminated with continuous control law, due to high-frequency switching terms contained in the first derivative of actual control signals. Ignoring the prior knowledge upper bound, the controller can reduce the influence of the uncertain kinematics and dynamics in the actual situation. Finally, the experiment is carried out and the results show the performance of the proposed controller.

Chatter alleviation for a class of second-order under-actuated mechanical systems with matched and mismatched disturbances

2016 ◽  
Vol 23 (3) ◽  
pp. 458-468
Author(s):  
Jinjin Shi ◽  
Jinxiang Wang ◽  
Fangfa Fu
Keyword(s):  
Sliding Mode ◽  
Mechanical Systems ◽  
Design Procedure ◽  
Second Order ◽  
Control Input ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Sliding Surfaces ◽  
Low Pass ◽  
Mismatched Disturbances

The chattering phenomenon and a system with both matched and mismatched disturbances are the major difficulties in sliding mode control design. This paper presents an effective design procedure to alleviate these two difficulties for a class of second-order under-actuated mechanical systems. In the proposed design, new hierarchical sliding surfaces are designed and a modified disturbance observer is utilized to estimate the lumped disturbance which is a linear combination of the matched and mismatched disturbances. The chatter in control input is filtered out by an integrator, which acts as a low-pass filter. The asymptotic stabilities of the entire sliding surfaces are guaranteed. A design study considering lateral control of a vehicle with matched and mismatched disturbances demonstrates the effectiveness of the proposed design.

scholarly journals Higher-Order Sliding Mode Observer for Speed and Position Estimation in PMSM

2014 ◽  
Vol 2014 ◽  
pp. 1-12 ◽  
Author(s):  
Suneel K. Kommuri ◽  
Kalyana C. Veluvolu ◽  
M. Defoort ◽  
Yeng C. Soh
Keyword(s):  
Sliding Mode ◽  
Permanent Magnet Synchronous Motor ◽  
Estimation Method ◽  
Higher Order ◽  
Position Estimation ◽  
Accurate Estimation ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Three Phase ◽  
Low Pass

This paper presents a speed and position estimation method for the permanent magnet synchronous motor (PMSM) based on higher-order sliding mode (HOSM) observer. The back electromotive forces (EMFs) in the PMSM are treated as unknown inputs and are estimated with the HOSM observer without the need of low-pass filter and phase compensation modules. With the estimation of back EMFs, an accurate estimation of speed and rotor position can be obtained. Further, the proposed method completely eliminates chattering. Experimental results with a 26 W three-phase PMSM demonstrate the effectiveness of the proposed method.

Adaptive back-stepping sliding mode guidance laws with autopilot dynamics and acceleration saturation consideration

2019 ◽  
Vol 233 (13) ◽  
pp. 4853-4863 ◽  
Author(s):  
Sheng-Tao Geng ◽  
Jie Zhang ◽  
Jing-Guang Sun
Keyword(s):  
Sliding Mode ◽  
Lyapunov Theory ◽  
Guidance System ◽  
Terminal Sliding Mode ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Guidance Law ◽  
Mode Method ◽  
Low Pass ◽  
Constraint Model

This paper studies the guidance scheme for the terminal guidance problem subject to input constraints, attack angle constraints, and second-order dynamics of missile autopilot. Firstly, the guidance system model with the above multi-constraint model is given. Secondly, an anti-saturation back-stepping guidance law which makes use of the low-pass filter to avoid the differential of the virtual control signals is designed based on the terminal sliding mode method, auxiliary system, and adaptive technique. Finally, Lyapunov theory and numerical simulations are utilized to prove that the states of the system under the proposed guidance law are uniformly ultimately bounded.

Two time-scale observer-based robust motion controller design and realization of a linear actuator

2016 ◽  
Vol 40 (11) ◽  
pp. 3241-3251 ◽  
Author(s):  
Nan Wang ◽  
Weiyang Lin ◽  
Jinyong Yu ◽  
An Zhang ◽  
Chao Ye
Keyword(s):  
Time Scale ◽  
Controller Design ◽  
Sliding Mode ◽  
Adaptive Robust Control ◽  
Velocity Signal ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Signal Tracking ◽  
Time Scale Separation ◽  
Low Pass

In this paper, an observer-based sliding mode controller is proposed for a high-accuracy motion plant to suppress the disturbances and improve the tracking performance. In particular, a two time-scale separation technology, which can recover the disturbance state in a faster time scale, is utilized to compensate the disturbances and improve the system robustness. The parameter identification is carried out to obtain the model coefficients with a high fitting rate. Such an identified model can allow the engineers to tune the controller’s gains highly enough when the system suffers from the measurement noises. Instead of the traditional low-pass filter, a differentiator is introduced for the velocity signal prediction and its discrete-time version is provided to attenuate the noises effect. To verify the effectiveness of the proposed approach, an adaptive robust control law is compared with the proposed one in terms of dynamic positioning error, robustness and rapid signal tracking, and the superiority and advantages can be illustrated by the experimental results.

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