scholarly journals Nonsingular Continuous Finite-Time Convergent Guidance Law with Impact Angle Constraints

2019 ◽  
Vol 2019 ◽  
pp. 1-13
Author(s):  
Luyao Zang ◽  
Defu Lin ◽  
Yi Ji
Keyword(s):  
Finite Time ◽  
Sliding Mode ◽  
Angular Rate ◽  
Impact Angle ◽  
Second Order ◽  
Terminal Sliding Mode ◽  
Guidance Law ◽  
The Stability ◽  
Twisting Algorithm ◽  
Guidance Laws

This paper documents a novel nonsingular continuous guidance which can drive the line-of-sight (LOS) angular rate to converge to zero in finite time in the presence of impact angle constraints. More specifically, based on the second-order sliding mode control (SMC) theory, a second-order observer (2-OB) is presented to estimate the unknown target maneuvers, while a super twisting algorithm- (STA-) based guidance law is presented to restrict the LOS angle and angular rate. Compared with other terminal sliding mode guidance laws, the proposed guidance law absorbs the merits of the conventional linear sliding mode (LSM) and terminal sliding mode (TSM) and uses switching technique to avoid singularity. In order to verify the stability of the proposed guidance law, a finite-time bounded (FTB) function is invited to prove the boundedness of the proposed observer-controller system and a Lyapunov approach is presented to prove the finite-time convergence (FTC) of the proposed sliding system. Rigorous theoretical analysis and numerical simulations demonstrate the mentioned properties.

scholarly journals Second-Order Sliding Mode Guidance Law considering Second-Order Dynamics of Autopilot

2019 ◽  
Vol 2019 ◽  
pp. 1-11
Author(s):  
Kuanqiao Zhang ◽  
Suochang Yang
Keyword(s):  
Dynamic Characteristics ◽  
Finite Time ◽  
Sliding Mode ◽  
Impact Angle ◽  
Second Order ◽  
Terminal Sliding Mode ◽  
Finite Time Convergence ◽  
Guidance Law ◽  
Impact Angle Constraint ◽  
Second Order Sliding Mode

Aiming at the requirement that some missiles need to meet certain impact angles when attacking targets, we consider the second-order dynamic characteristics of autopilot, thereby proposing a second-order sliding mode guidance law with impact angle constraint. Firstly, based on the terminal sliding mode control, we design a fast nonsingular terminal sliding mode guidance law with impact angle constraint. Based on the second-order sliding mode control, a second-order sliding mode guidance law with impact angle constraint is proposed. We have proved its finite time convergence characteristics and presented the specific convergence time expression. Subsequently, the dynamic characteristics of the autopilot are approximated to the second-order link. Combined with the dynamic surface control theory, we proposed a second-order sliding mode guidance law considering the second-order dynamic characteristics of the autopilot and proved its finite-time convergence characteristics. Finally, the effectiveness and superiority of the proposed guidance law are verified by comparative simulation experiments.

Robust impact angle constraints guidance law with autopilot lag and acceleration saturation consideration

2018 ◽  
Vol 41 (1) ◽  
pp. 182-192 ◽  
Author(s):  
Junhong Song ◽  
Shenmin Song
Keyword(s):  
Upper Bound ◽  
Finite Time ◽  
Sliding Mode ◽  
Three Dimensional ◽  
Impact Angle ◽  
Guidance System ◽  
Control Technique ◽  
Backstepping Method ◽  
Terminal Sliding Mode ◽  
Guidance Law

In this paper, for the three-dimensional terminal guidance problem of a missile intercepting a manoeuvring target, a robust continuous guidance law with impact angle constraints in the presence of both an acceleration saturation constraint and a second-order-lag autopilot is developed. First, based on non-singular fast terminal sliding mode and adaptive control, a step-by-step backstepping method is used to design the guidance law. In the process of guidance law design, with the use of a finite-time control technique, virtual control laws are developed, a tracking differentiator is used to eliminate the ‘explosion of complexity’ problem inherent in the traditional backstepping method, and an additional system is constructed to deal with the acceleration saturation problem; its states are used for guidance law design and stability analysis. Moreover, the target acceleration is considered bounded disturbance, but the upper bound is not required to be known in advance, whereas the upper bound is estimated online by a designed adaptive law. Next, finite-time stability of the guidance system is strictly proved by using a Lyapunov method. Finally, numerical simulations are presented to demonstrate the excellent guidance performances of the proposed guidance law in terms of accuracy and efficiency.

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.

A novel adaptive second-order nonsingular terminal sliding mode guidance law design

2020 ◽  
Vol 234 (16) ◽  
pp. 2263-2273
Author(s):  
Shuai Xu ◽  
Min Gao ◽  
Dan Fang ◽  
Yi Wang ◽  
Baochen Li
Keyword(s):  
Finite Time ◽  
Sliding Mode ◽  
Initial Conditions ◽  
Dynamic Control ◽  
Small Neighborhood ◽  
Lyapunov Stability Theory ◽  
Second Order ◽  
Terminal Sliding Mode ◽  
Guidance Law ◽  
Nonsingular Terminal Sliding Mode

Aiming at the problem of missile attacking ground target in pitch plane, combined with a composite fast nonsingular terminal sliding mode, a new adaptive finite-time stable guidance law with attack angle constraint is designed based on the second-order sliding mode control. The improved extended state observer is used to estimate the uncertainties and compensate the control quantity, and the dynamic control gains are designed to avoid the problem about “excessive estimation” of the parameter upper limit. According to the Lyapunov stability theory, it is proved that the system states can converge into a small neighborhood near the equilibrium point in a finite time. Monte Carlo simulation is carried out by randomly generating initial conditions, which proves that the guidance law has strong adaptability to different initial conditions and has good guidance precision.

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.

Continuous reaching law based three-dimensional finite-time guidance law against maneuvering targets

2018 ◽  
Vol 41 (2) ◽  
pp. 321-339 ◽  
Author(s):  
Yu-Jie Si ◽  
Shen-Min Song
Keyword(s):  
Finite Time ◽  
Sliding Mode ◽  
Traditional Approach ◽  
Three Dimensional ◽  
Terminal Sliding Mode ◽  
Reaching Law ◽  
Closed Loop Systems ◽  
Guidance Law ◽  
Effective Performance ◽  
Guidance Laws

Three-dimensional finite-time guidance laws are proposed in this paper. Differing from the traditional approach that considers homing guidance problems as two identical and perpendicular channels, guidance laws proposed in this paper employ the coupled three-dimensional engagement dynamics to improve the guidance precision. A new reaching law is adopted to guarantee guidance laws continuous, which eliminates the chattering phenomenon caused by discontinuous terms. Moreover, the guidance law accelerates the convergence rate of closed-loop systems and avoids the singularity. Afterwards, the paper discusses the problem that the upper bound of the lumped uncertainty including the target information is unavailable. Therefore, to deal with this problem, another adaptive guidance law is presented, which can also guarantee the finite-time convergence of guidance systems. Numerical simulations have demonstrated that the two guidance laws have effective performance and outperform traditional terminal sliding mode guidance laws.

Cooperative guidance law for intercepting a hypersonic target with impact angle constraint

2022 ◽  
pp. 1-19
Author(s):  
S. Liu ◽  
B. Yan ◽  
R. Liu ◽  
P. Dai ◽  
J. Yan ◽  
...  
Keyword(s):  
Measurement Errors ◽  
Sliding Mode ◽  
Impact Angle ◽  
Terminal Sliding Mode ◽  
Guidance Law ◽  
Cooperative Guidance ◽  
Simulation Results ◽  
Twisting Algorithm ◽  
The Impact ◽  
Impact Angle Constraint

Abstract The cooperative guidance problem of multiple inferior missiles intercepting a hypersonic target with the specific impact angle constraint in the two-dimensional plane is addressed in this paper, taking into consideration variations in a missile’s speed. The guidance law is designed with two subsystems: the direction of line-of-sight (LOS) and the direction of normal to LOS. In the direction of LOS, by applying the algebraic graph theory and the consensus theory, the guidance command is designed to make the system convergent in a finite time to satisfy the goal of cooperative interception. In the direction of normal to LOS, the impact angle is constrained to transform into the LOS angle at the time of interception. In view of the difficulty of measuring unknown target acceleration information in real scenarios, the guidance command is designed by utilising a super-twisting algorithm based on a nonsingular fast-terminal sliding mode (NFTSM) surface. Numerical simulation results manifest that the proposed guidance law performs efficiently and the guidance commands are free of chattering. In addition, the overall performance of this guidance law is assessed with Monte Carlo runs in the presence of measurement errors. The simulation results demonstrate that the robustness can be guaranteed, and that overall efficiency and accuracy in intercepting the hypersonic target are achieved.

scholarly journals Design of Second-Order Sliding Mode Guidance Law Based on the Nonhomogeneous Disturbance Observer

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Huibo Zhou ◽  
Shenmin Song ◽  
Junhong Song ◽  
Jing Niu
Keyword(s):  
Dynamic Characteristics ◽  
Finite Time ◽  
Disturbance Observer ◽  
Sliding Mode ◽  
Time Estimation ◽  
Variable Structure ◽  
Terminal Sliding Mode ◽  
Guidance Law ◽  
Power Rate ◽  
Guidance Laws

Considering the guidance problem of relative motion of missile target without the dynamic characteristics of missile autopilot in the interception planar, non-homogeneous disturbance observer is applied for finite-time estimation with respect to the target maneuvering affecting the guidance performance. Two guidance laws with finite-time convergence are designed by using a fast power rate reaching law and the prescribed sliding variable dynamics. The nonsingular terminal sliding mode surface is selected to improve dynamic characteristics of missile autopilot. Furthermore, the finite-time guidance law with dynamic delay characteristics is designed for the target maneuvering through adopting variable structure dynamic compensation. The simulation results demonstrate that, for different target maneuvering, the proposed guidance laws can restrain the sliding mode chattering problem effectively and make the missile hit the maneuvering target quickly and accurately with condition of corresponding assumptions.

scholarly journals Multivariable Adaptive Super-Twisting Guidance Law Based on Barrier Function

2021 ◽  
Vol 11 (23) ◽  
pp. 11178
Author(s):  
Yukuan Liu ◽  
Guanglin He ◽  
Yanan Du ◽  
Yulong Zhang ◽  
Zenghui Qiao
Keyword(s):  
Sliding Mode Control ◽  
Barrier Function ◽  
Sliding Mode ◽  
Mode Control ◽  
Guidance Law ◽  
Target Acceleration ◽  
The Stability ◽  
The One ◽  
Twisting Algorithm ◽  
Guidance Laws

For tactical missiles, sliding mode control and super-twisting algorithms have been widely studied in the area of guidance law design. However, these methods require the information of the target accelerations and the target acceleration derivatives, which is always unknown in practice. In addition, guidance laws utilizing these tools always have chattering phenomena and large acceleration commands. To solve these problems, this article introduces a barrier function based super twisting controller and expands the controller to a multivariable adaptive form. Consequently, a multivariable adaptive super-twisting guidance law based on barrier function is proposed. Moreover, the stability of the guidance law is analyzed, and the effectiveness and the robustness are demonstrated by three simulation examples. Compared with previous guidance laws using sliding mode control or super-twisting algorithm, the one proposed in this paper does not require the information of target accelerations, nor target acceleration derivatives; it has smaller super-twisting gains so that has smaller acceleration commands; it can increase and decrease the gains to follow the target accelerations and maintain the sliding mode, and it does not chatter.

Distributed synergetic guidance law for multiple missiles with angle-of-attack constraint

2020 ◽  
Vol 124 (1274) ◽  
pp. 533-548
Author(s):  
H. You ◽  
F.-J. Zhao
Keyword(s):  
Control Theory ◽  
Finite Time ◽  
Cooperative Control ◽  
Sliding Mode ◽  
Angle Of Attack ◽  
Impact Angle ◽  
Normal Direction ◽  
Guidance Law ◽  
Multiple Missiles ◽  
Twisting Algorithm

AbstractBased on the missiles with adjustable thrust, a distributed synergetic guidance law for multiple missiles with angle-of-attack constraint is designed to achieve a cooperative attack by multiple missiles on a moving target. Divide the guidance law into two parts: the line of sight (LOS) direction and the normal direction of LOS. The guidance law is designed in LOS direction based on the multi-agent system cooperative control theory and super-twisting algorithm, which can control missiles’ time-to-go converging in finite time. In the normal direction of LOS, the other guidance law is designed to control missiles hitting the target with impact angle constraint based on zeroing LOS rate thought and finite-time sliding mode control theory. The two non-homogeneous disturbance observers are designed to estimate the target manoeuvring information in the two parts of the guidance law. The simulation results show that the guidance law designed by this paper can complete the cooperative attack task while suppressing the chattering phenomenon effectively.

Sign in / Sign up

Export Citation Format

Share Document