scholarly journals Target Tracking Based on a Nonsingular Fast Terminal Sliding Mode Guidance Law by Fixed-Wing UAV

2017 ◽  
Vol 7 (4) ◽  
pp. 333 ◽  
Author(s):  
Kun Wu ◽  
Zhihao Cai ◽  
Jiang Zhao ◽  
Yingxun Wang
Keyword(s):  
Target Tracking ◽  
Sliding Mode ◽  
Terminal Sliding Mode ◽  
Guidance Law ◽  
Fast Terminal Sliding Mode

scholarly journals A Composite Guidance Law for Suppressing Measurement Noise of LOS Angular Rate

2019 ◽  
Vol 2019 ◽  
pp. 1-10
Author(s):  
Feng Chen ◽  
Guangjun He ◽  
Qifang He
Keyword(s):  
Sliding Mode Control ◽  
Finite Time ◽  
Disturbance Observer ◽  
Sliding Mode ◽  
Angular Rate ◽  
Measurement Noise ◽  
Terminal Sliding Mode ◽  
Guidance Law ◽  
Fast Terminal Sliding Mode ◽  
Low Altitude

To effectively intercept a low-altitude target in clutter background, a nonsingular fast terminal sliding mode guidance law is designed. The designed guidance law can fully exploit the fast convergence characteristics of linear sliding mode control and the finite-time-convergent characteristics of terminal sliding mode control to ensure that the line-of-sight (LOS) angle converges to a desired angle in a limited time at a faster rate. Utilizing the smooth switching characteristics of the hyperbolic tangent function similar to the saturation function, a finite-time-convergent differentiator is designed. Meanwhile, a new finite-time-convergent disturbance observer designed on the tracking differentiator can effectively track the ideal LOS angular rate, suppress the measurement noise, and make a smooth estimation of the target maneuvering acceleration in clutter background. Combining the estimated value of the disturbance observer, the sign function with switch coefficient is introduced to design a composite nonsingular fast terminal sliding mode guidance law. The simulation results show that the composite guidance law can not only effectively suppress the measurement noise of the LOS angular rate and improve the accuracy of low-altitude target intercepting, but also greatly reduce the energy consumption in the interception process.

scholarly journals Smooth Adaptive Finite Time Guidance Law with Impact Angle Constraints

2016 ◽  
Vol 2016 ◽  
pp. 1-19 ◽  
Author(s):  
Bin Zhao ◽  
Jun Zhou
Keyword(s):  
Finite Time ◽  
Sliding Mode ◽  
Impact Angle ◽  
Guidance System ◽  
Terminal Sliding Mode ◽  
Guidance Law ◽  
Adaptive Law ◽  
Target Acceleration ◽  
Control Scheme ◽  
Fast Terminal Sliding Mode

A smooth guidance law for intercepting a maneuvering target with impact angle constraints is documented based on the nonsingular fast terminal sliding mode control scheme and adaptive control scheme. Different from the traditional adaptive law which is used to estimate the unknown upper bound of the target acceleration, a new adaptive law is proposed to estimate the square of target acceleration bound, which avoids the use of the nonsmooth signum function and therefore ensures the smoothness of the guidance law. The finite time convergence of the guidance system is guaranteed based on the Lyapunov method and the finite time theory. Simulation results indicate that under the proposed guidance law the missile can intercept the target with a better accuracy at a desired impact angle in a shorter time with a completely smooth guidance command compared with the existing adaptive fast terminal sliding mode guidance laws, which shows the superiority of this method.

scholarly journals Adaptive Super-Twisting Algorithm-Based Nonsingular Terminal Sliding Mode Guidance Law

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Fang Yang ◽  
Kuanqiao Zhang ◽  
Lei Yu
Keyword(s):  
Finite Time ◽  
Sliding Mode ◽  
Fixed Time ◽  
Impact Angle ◽  
Terminal Sliding Mode ◽  
Finite Time Convergence ◽  
Guidance Law ◽  
Fast Terminal Sliding Mode ◽  
The Impact ◽  
Impact Angle Constraint

A nonsingular fast terminal sliding mode guidance law with an impact angle constraint is proposed to solve the problem of missile guidance accuracy and impact angle constraint for maneuvering targets. Aiming at the singularity problem of the terminal sliding mode, a fast terminal sliding mode surface with finite-time convergence and impact angle constraint is designed based on fixed-time convergence and piecewise sliding mode theory. To weaken chattering and suppress interference, a second-order sliding mode supertwisting algorithm is improved. By designing the parameter adaptive law, an adaptive smooth supertwisting algorithm is designed. This algorithm can effectively weaken chattering without knowing the upper bound information of interference, and it converges faster. Based on the proposed adaptive supertwisting algorithm and the sliding mode surface, a guidance law with the impact angle constraint is designed. The global finite-time convergence of the guidance law is proved by constructing the Lyapunov function. The simulation results verify the effectiveness of the proposed guidance law, and compared with the existing terminal sliding mode guidance laws, the proposed guidance law has higher guidance precision and angle constraint accuracy.

scholarly journals Fault-tolerant control for a class of n-order systems based on fast terminal sliding mode and extended state observer

2021 ◽  
pp. 002029402110286
Author(s):  
Pu Yang ◽  
Peng Liu ◽  
ChenWan Wen ◽  
Huilin Geng
Keyword(s):  
Fault Tolerant ◽  
Sliding Mode ◽  
Singular Control ◽  
Fault Tolerant Control ◽  
State Observer ◽  
Extended State Observer ◽  
Extended State ◽  
Terminal Sliding Mode ◽  
Fast Terminal Sliding Mode ◽  
Terminal Sliding Surface

This paper focuses on fast terminal sliding mode fault-tolerant control for a class of n-order nonlinear systems. Firstly, when the actuator fault occurs, the extended state observer (ESO) is used to estimate the lumped uncertainty and its derivative of the system, so that the fault boundary is not needed to know. The convergence of ESO is proved theoretically. Secondly, a new type of fast terminal sliding surface is designed to achieve global fast convergence, non-singular control law and chattering reduction, and the Lyapunov stability criterion is used to prove that the system states converge to the origin of the sliding mode surface in finite time, which ensures the stability of the closed-loop system. Finally, the effectiveness and superiority of the proposed algorithm are verified by two simulation experiments of different order systems.

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