scholarly journals Impact Time Guidance Law Considering Autopilot Dynamics Based on Variable Coefficients Strategy for Maneuvering Target

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Wei Shang ◽  
Jie Guo ◽  
Shengjing Tang ◽  
Yueyue Ma ◽  
Yao Zhang
Keyword(s):  
Finite Time ◽  
Sliding Mode ◽  
Variable Coefficients ◽  
Guidance System ◽  
Impact Time ◽  
Maneuvering Target ◽  
Guidance Law ◽  
Convergence Control ◽  
Unknown Disturbance ◽  
The Impact

This paper investigates the terminal guidance problem for the missile intercepting a maneuvering target with impact time constraint. An impact time guidance law based on finite time convergence control theory is developed regarding the target motion as an unknown disturbance. To further improve the performance of the guidance law, an autopilot dynamics which is considered as a first-order lag is taken into consideration. In the proposed method, the coefficients change with the relative distance between missile and target. This variable coefficient strategy ensures that the missile impacts the target at the desired time with little final miss distance. Then it is proved that states of the guidance system converge to sliding mode in finite time under the proposed guidance law. Numerical simulations are presented to demonstrate the effectiveness of the impact time guidance law with autopilot dynamics (ITGAD).

Finite Time Convergence Guidance Law Accounting for Missile Autopilot

2015 ◽  
Vol 137 (5) ◽  
Author(s):  
Pingping Qu ◽  
Chuntao Shao ◽  
Di Zhou
Keyword(s):  
Finite Time ◽  
Control Method ◽  
Sliding Mode ◽  
Line Of Sight ◽  
Practical Applications ◽  
Maneuvering Target ◽  
Finite Time Convergence ◽  
Guidance Law ◽  
Convergence Control ◽  
Derivatives Of

A guidance law with finite time convergence is designed using the sliding mode control method and finite time convergence control theory, accounting for the missile autopilot as second-order dynamics. The high-order derivatives of the line of sight (LOS) angle are avoided in the expression of guidance law such that it can be implemented in practical applications. The designed guidance law is effective in compensating the bad influence of the autopilot dynamics on guidance accuracy. In simulations of intercepting a non maneuvering target or a maneuvering target, respectively, the designed guidance law is compared with the adaptive sliding mode guidance (ASMG) law in the presence of missile autopilot lag. Simulation results show that the designed guidance law is able to guide a missile to accurately intercept a nonmaneuvering target or a maneuvering target with finite time, even if it escapes in a great and fast maneuver and the autopilot has a relatively large lag.

Three-dimensional cooperative interception guidance law with impact time constraint

2021 ◽  
pp. 095441002110105
Author(s):  
Li Hongxia ◽  
Deng Yifan ◽  
Yuanli Cai
Keyword(s):  
Finite Time ◽  
Control Method ◽  
Three Dimensional ◽  
Time Constraint ◽  
Lyapunov Theory ◽  
Guidance System ◽  
Consensus Protocol ◽  
Impact Time ◽  
Guidance Law ◽  
The Impact

This article proposes a new terminal cooperative guidance law with impact time constraint in three-dimensional (3D) engagement. Two parts are comprised by this guidance scheme to control the impact time and fulfill the interception. The guidance law along the line-of-sight (LOS) direction is first designed based on finite time consensus protocol to share time-to-go values among missiles and reach the consensus. Meanwhile, the guidance law on the LOS normal direction is developed based on the fast finite time control method to achieve the interception. The stability analysis of the proposed guidance law based on the Lyapunov theory is also demonstrated in detail. Moreover, the maneuvering target can be intercepted successfully under the presented control algorithm, and the guidance system can fulfill stability within finite time. Additionally, the effectiveness and applicability of the proposed guidance scheme are explicitly verified through simulation tests.

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 New Impact Time and Angle Control Guidance Law for Stationary and Nonmaneuvering Targets

2016 ◽  
Vol 2016 ◽  
pp. 1-14 ◽  
Author(s):  
Zhe Yang ◽  
Hui Wang ◽  
Defu Lin ◽  
Luyao Zang
Keyword(s):  
Sliding Mode Control ◽  
Sliding Mode ◽  
Impact Angle ◽  
Accurate Solution ◽  
Control Surface ◽  
Impact Time ◽  
Tuning Parameters ◽  
Mode Control ◽  
Guidance Law ◽  
The Impact

A guidance problem for impact time and angle control applicable to cooperative attack is considered based on the sliding mode control. In order to satisfy the impact angle constraint, a line-of-sight rate polynomial function is introduced with four tuning parameters. And the time-to-go derivative with respect to a downrange orientation is derived to minimize the impact time error. Then the sliding mode control surface with impact time and angle constraints is constructed using nonlinear engagement dynamics to provide an accurate solution. The proposed guidance law is easily extended to a nonmaneuvering target using the predicted interception point. Numerical simulations are performed to verify the effectiveness of the proposed guidance law for different engagement scenarios.

Super-twisting integral-sliding-mode guidance law considering autopilot dynamics

2017 ◽  
Vol 232 (9) ◽  
pp. 1787-1799 ◽  
Author(s):  
Kezi Meng ◽  
Di Zhou
Keyword(s):  
Finite Time ◽  
Disturbance Observer ◽  
Sliding Mode ◽  
Lyapunov Stability Theory ◽  
Guidance System ◽  
Integral Sliding Mode ◽  
Finite Time Stability ◽  
Guidance Law ◽  
Chattering Free ◽  
Twisting Algorithm

A new guidance law considering missile autopilot dynamics is established via integrating a smooth super-twisting algorithm with nonlinear integral sliding mode. In this guidance law, a finite-time disturbance observer is introduced to estimate mismatched and matched disturbances resulting from target maneuvers. Based on Lyapunov stability theory, the finite-time stability of the closed-loop guidance system under this law is analyzed using a finite-time bounded function. The super-twisting algorithm guarantees that the proposed guidance law is chattering-free and the disturbance observer does not depend on the prior knowledge of target acceleration. So the proposed guidance law is easy to be implemented in practice. The finite-time convergence and robustness of the proposed guidance law are demonstrated via numerical simulations accounting for missile autopilot dynamics.

Impact Time Control Guidance Law Considering Seeker's Field-of-View Constraint Without Time-to-Go Information

2016 ◽  
Vol 20 (3) ◽  
pp. 412-417
Author(s):  
Zhe Yang ◽  
◽  
Defu Lin ◽  
Luyao Zang
Keyword(s):  
Sliding Mode ◽  
Field Of View ◽  
Impact Time ◽  
Time Control ◽  
Guidance Law ◽  
Heading Angle ◽  
One And Many ◽  
The Look ◽  
The Impact ◽  
Guidance Laws

Accurate time-to-go estimation with large heading angle error is difficult for homing guidance laws, especially for the impact time control. Considering this, a new cooperative guidance law which requires no time-to-go estimation is investigated. First, the impact time control problem is transformed to the look angle command tracking problem. The look angle command guarantees that the range-to-go error converges to zero asymptotically. Then the proposed guidance law considering the seeker's field-of-view constraint is derived using sliding mode control to track the desired look angle signal. Numerical simulations are performed to verify the effectiveness of the proposed guidance law for one-to-one and many-to-one engagement scenarios.

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.

Sliding mode guidance for impact time and angle constraints

2017 ◽  
Vol 232 (16) ◽  
pp. 2961-2977 ◽  
Author(s):  
Shashi Ranjan Kumar ◽  
Debasish Ghose
Keyword(s):  
Constant Velocity ◽  
Sliding Mode ◽  
Impact Angle ◽  
Time Error ◽  
Impact Time ◽  
Guidance Law ◽  
Terminal Constraints ◽  
Noisy Measurements ◽  
The Impact ◽  
Guidance Laws

This paper proposes a guidance strategy, which caters to both impact angle and impact time terminal constraints. This guidance scheme is based on switching between impact time and impact angle guidance laws. Unlike the existing impact time guidance laws, the proposed guidance strategy takes into account the curvature of the trajectory due to requirement of impact angle. The guidance law is derived using sliding mode control theory with the switching surface based on impact time error. The interceptor first corrects its course to nullify the impact time error and then aims to achieve interception with desired impact angle. In order to reduce transitions between the two guidance laws, a novel hysteresis loop is introduced in the switching conditions. The guidance law is initially designed for stationary targets, and later it is extended to constant velocity targets using the notion of predicted interception point. In order to validate the efficacy of the proposed guidance strategy, simulation results are presented with constant as well as realistic time-varying speed interceptor models for different engagement scenarios against stationary and constant velocity targets. The performance of the guidance law is evaluated under noisy measurements and the presence of system lag and its performance is compared with other existing guidance laws.

scholarly journals Field-of-View Constrained Impact Time Control Guidance via Time-Varying Sliding Mode Control

Aerospace ◽  
2021 ◽  
Vol 8 (9) ◽  
pp. 251
Author(s):  
Shuai Ma ◽  
Xugang Wang ◽  
Zhongyuan Wang
Keyword(s):  
Sliding Mode Control ◽  
Sliding Mode ◽  
Field Of View ◽  
Time Varying ◽  
Sliding Surface ◽  
Impact Time ◽  
Mode Control ◽  
Time Control ◽  
Guidance Law ◽  
The Impact

The problem of impact time control guidance with field-of-view constraint is addressed based on time-varying sliding mode control. The kinematic conditions that satisfy the impact time control with field-of-view constraint are defined, and then a novel time-varying sliding surface is constructed to achieve the defined conditions. The sliding surface contains two unknown coefficients: one is tuned to achieve the global sliding surface to satisfy the impact time constraint and zero miss distance, and the other is tuned to guarantee the field-of-view constraint. The guidance law is designed to ensure the realization of the global sliding mode. On this basis, the guidance law is modified to a closed-loop structure, and the maximum detection capability of the seeker is utilized to a greater extent. Under the proposed guidance law, neither the small angle assumption nor time-to-go estimation is needed. The guidance command is continuous and converges to 0 at the desired impact time. Simulation results demonstrate the effectiveness and superiority of the proposed guidance law.

Three-dimensional finite-time guidance law based on sliding mode adaptive RBF neural network against a highly manoeuvering target

2022 ◽  
pp. 1-20
Author(s):  
G. Wu ◽  
K. Zhang ◽  
Z. Han
Keyword(s):  
Neural Network ◽  
Finite Time ◽  
Sliding Mode ◽  
Rbf Neural Network ◽  
Three Dimensional ◽  
Lyapunov Theory ◽  
Guidance System ◽  
Guidance Law ◽  
Target Acceleration ◽  
Terminal Guidance

Abstract In order to intercept a highly manoeuvering target with an ideal impact angle in the three-dimensional space, this paper promises to probe into the problem of three-dimensional terminal guidance. With the goal of the highly target acceleration and short terminal guidance time, a guidance law, based on the advanced fast non-singular terminal sliding mode theory, is designed to quickly converge the line-of-sight (LOS) angle and the LOS angular rate within a finite time. In the design process, the target acceleration is regarded as an unknown boundary external disturbance of the guidance system, and the RBF neural network is used to estimate it. In order to improve the estimation accuracy of RBF neural network and accelerate its convergence, the parameters of RBF neural network are adjusted online in real time. At the same time, an adaptive law is designed to compensate the estimation error of the RBF neural network, which improves the convergence speed of the guidance system. Theoretical analysis demonstrates that the state and the sliding manifold of the guidance system converge in finite time. According to Lyapunov theory, the stability of the system can be guaranteed by online adjusting the parameters of RBF neural network and adaptive parameters. The numerical simulation results verify the effectiveness and superiority of the proposed guidance law.

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