scholarly journals A Two-Phased Guidance Law for Impact Angle Control with Seeker’s Field-of-View Limit

2018 ◽  
Vol 2018 ◽  
pp. 1-13 ◽  
Author(s):  
Haoqiang Zhang ◽  
Shengjing Tang ◽  
Jie Guo ◽  
Wan Zhang
Keyword(s):  
Impact Angle ◽  
Quadratic Equation ◽  
Field Of View ◽  
Line Of Sight ◽  
Guidance Law ◽  
Physical Limit ◽  
The Look ◽  
The One ◽  
The Impact ◽  
Impact Angle Constraint

A two-phased guidance problem with terminal impact angle constraints and seeker’s field-of-view limit is addressed in this paper for a missile against a nonmaneuvering incoming target. From the conventional PN guidance without any constraints, it is found that satisfying the impact angle constraint causes a more curved missile trajectory requiring a large look angle. To avoid the look angle exceeding the seeker’s physical limit, a two-phased look angle control guidance scheme with the terminal constraint is introduced. The PN-typed guidance law is designed for each guidance phase with a specific switching condition of line-of-sight. The proposed guidance law is comprised of two types of acceleration commands: the one in the initial phase which aims at controlling the missile’s look angle to reach the limit and the other for final phase which is produced by switching the navigation gain. The monotonicity of the line-of-sight angle and look angle is analyzed and proved to support the proposed method. To evaluate the specific navigation gains for both initial and final phases, the scaling coefficient between them is discussed by solving a quadratic equation with respect to the initial navigation gain. To avoid a great abrupt acceleration change at the switching instant, a minimum coefficient is chosen. Extensive simulations are performed to validate the efficiency of the proposed approach.

Impact angle guidance law to prevent the detection degradation of a seeker

2021 ◽  
pp. 095441002110440
Author(s):  
Jun-Yong Lee ◽  
H Jin Kim
Keyword(s):  
Rapid Change ◽  
Image Plane ◽  
Impact Angle ◽  
Motion Blur ◽  
Stationary Target ◽  
Guidance Law ◽  
The Look ◽  
Low Sensitivity ◽  
The Impact ◽  
Impact Angle Constraint

An impact angle control guidance (IACG) law applicable to a homing missile equipped with a strapdown imaging seeker is investigated against a stationary target. Given an impact angle constraint, usually a detour is generated and the change of the look angle is inevitable. A rapid change of the look angle can cause a fast relative target motion in the seeker’s image plane, which can lead to a motion blur effect. The main contribution of the paper is that an IACG law is designed to minimize the look angle rate to prevent the loss of the target signal. Based on the variational approach, the optimal look angle rate that satisfies the impact angle constraint is derived, and the guidance law is designed to follow the optimal look angle rate. Using various weighting functions, a guidance law that has low sensitivity to the initial condition is also developed. Numerical simulation supports the performance of the guidance law. The result illustrates that the proposed guidance law reduces the rate of look angle in comparison with other IACG laws.

scholarly journals Time-Varying Biased Proportional Guidance with Seeker’s Field-of-View Limit

2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Zhe Yang ◽  
Hui Wang ◽  
Defu Lin
Keyword(s):  
Impact Angle ◽  
Field Of View ◽  
Line Of Sight ◽  
Terminal Phase ◽  
Time Varying ◽  
Guidance Law ◽  
Homing Missiles ◽  
Guidance Laws ◽  
Bias Terms ◽  
Impact Angle Constraint

Traditional guidance laws with range-to-go information or time-to-go estimation may not be implemented in passive homing missiles since passive seekers cannot measure relative range directly. A time-varying biased proportional guidance law, which only uses line-of-sight (LOS) rate and look angle information, is proposed to satisfy both impact angle constraint and seeker’s field-of-view (FOV) limit. In the proposed guidance law, two time-varying bias terms are applied to divide the trajectory into initial phase and terminal phase. The initial bias is designed as a function of LOS rate and look angle to maintain the seeker’s lock-on while the final bias eliminates the deviation between the integral value of angle control bias and the expected bias amount. A switching logic is adopted to change the biases continuously so that there is no abrupt acceleration change during the engagement. Extensive simulations considering both kinematic and realistic missile models are performed to illustrate the efficiency of the proposed method.

Trajectory shaping guidance law design using constraint-combining multiplier

2021 ◽  
pp. 095441002098637
Author(s):  
Min-Guk Seo ◽  
Chang-Hun Lee ◽  
Tae-Hun Kim
Keyword(s):  
Design Method ◽  
Impact Angle ◽  
State Variables ◽  
Flight Trajectory ◽  
Potential Significance ◽  
Guidance Law ◽  
Terminal Constraints ◽  
The Impact ◽  
Guidance Laws ◽  
Impact Angle Constraint

A new design method for trajectory shaping guidance laws with the impact angle constraint is proposed in this study. The basic idea is that the multiplier introduced to combine the equations for the terminal constraints is used to shape a flight trajectory as desired. To this end, the general form of impact angle control guidance (IACG) is first derived as a function of an arbitrary constraint-combining multiplier using the optimal control. We reveal that the constraint-combining multiplier satisfying the kinematics can be expressed as a function of state variables. From this result, the constraint-combining multiplier to achieve a desired trajectory can be obtained. Accordingly, when the desired trajectory is designed to satisfy the terminal constraints, the proposed method directly can provide a closed form of IACG laws that can achieve the desired trajectory. The potential significance of the proposed result is that various trajectory shaping IACG laws that can cope with various guidance goals can be readily determined compared to existing approaches. In this study, several examples are shown to validate the proposed method. The results also indicate that previous IACG laws belong to the subset of the proposed result. Finally, the characteristics of the proposed guidance laws are analyzed through numerical simulations.

scholarly journals Two-Phase Optimal Guidance Law considering Impact Angle Constraint with Bearings-Only Measurements

2017 ◽  
Vol 2017 ◽  
pp. 1-12 ◽  
Author(s):  
Tianning Wang ◽  
Shengjing Tang ◽  
Jie Guo ◽  
Haoqiang Zhang
Keyword(s):  
Sliding Mode ◽  
Information Matrix ◽  
Impact Angle ◽  
Estimation Accuracy ◽  
Two Phase ◽  
Terminal Sliding Mode ◽  
Guidance Law ◽  
Optimal Guidance ◽  
The Impact ◽  
Impact Angle Constraint

The implementation of advanced guidance laws with bearings-only measurements requires estimation of the range information. To improve estimation accuracy and satisfy the impact angle constraint, this paper proposes a two-phase optimal guidance law consisting of an observing phase and an attacking phase. In the observing phase, the determinant of Fisher information matrix is maximized to achieve the optimal observability and a suboptimal solution expressed by leading angle is derived analytically. Then, a terminal sliding-mode guidance law is designed to track the desired leading angle. In the followed attacking phase, an optimal guidance law is integrated with a switching term to satisfy both the impact angle constraint and the field-of-view constraint. Finally, comparison studies of the proposed guidance law and a traditional optimal guidance law are conducted on stationary targets and maneuvering targets cases. Simulation results demonstrate that the proposed guidance law is able to improve the range observability and achieve better terminal performances including impact angle accuracy and miss distance.

Fixed-time three-dimensional guidance law with input constraint and actuator faults

2020 ◽  
pp. 095441002097197
Author(s):  
Peng Li ◽  
Qi Liu ◽  
Chen-Yu He ◽  
Xiao-Qing Liu
Keyword(s):  
Fault Tolerant ◽  
Sliding Mode ◽  
Input Saturation ◽  
Three Dimensional ◽  
Impact Angle ◽  
Actuator Faults ◽  
Input Constraint ◽  
Guidance Law ◽  
The Impact ◽  
Impact Angle Constraint

This paper investigates the three-dimensional guidance with the impact angle constraint, actuator faults and input constraint. Firstly, an adaptive three-dimensional guidance law with impact angle constraint is designed by using the terminal sliding mode control and nonhomogeneous disturbance observer. Then, in order to solve the problem of the input saturation and actuator faults, an adaptive anti-saturation fault-tolerant three-dimensional law is proposed by using the hyperbolic tangent function based on the passive fault-tolerant control. Finally, the effectiveness of the designed guidance laws is verified by using the Lyapunov function and simulation.

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.

Study on Autopilot Dynamics with Robust Guidance Law and Terminal Constraint in Mechanical Engineering

2013 ◽  
Vol 644 ◽  
pp. 77-80
Author(s):  
Zhi Ping Li ◽  
Jun Zhou ◽  
Jian Guo Guo
Keyword(s):  
Mechanical Engineering ◽  
Tracking Error ◽  
Vertical Plane ◽  
Lyapunov Stability Theory ◽  
Mathematic Model ◽  
Impact Angle ◽  
Guidance System ◽  
Guidance Law ◽  
The One ◽  
The Impact

A new nonlinear robust guidance law was proposed by considering autopilot dynamics. Firstly, the mathematic model was built according to relationship between target and missile in vertical plane, by introducing the one-order dynamics of autopilot in Mechanical Engineering. Secondly, the nonlinear terminal guidance was obtained by applying the H∞ control theory under the performance index of minimizing the terminal angular constraint tracking error and control energy, and the asymptotic stability of guidance system was strictly proven by Lyapunov stability theory avoiding the estimation of the time-to-go. Finally, an illustrative example was given to show that the guidance law was more robust and both the impact angle and guidance precision were met in the case of no any target information.

scholarly journals Generalized Guidance Formulation for Impact Angle Interception with Physical Constraints

Aerospace ◽  
2021 ◽  
Vol 8 (10) ◽  
pp. 307
Author(s):  
Hyeong-Geun Kim ◽  
Jun-Yong Lee
Keyword(s):  
Impact Angle ◽  
Field Of View ◽  
Line Of Sight ◽  
Physical Constraints ◽  
Guidance Law ◽  
Optimal Guidance ◽  
Rate Profile ◽  
Homing Missiles ◽  
Impact Angles ◽  
General Guidance

This paper proposes an optimal impact angle control guidance law for homing missiles with a narrow field-of-view of the seekers. As groundwork for designing a guidance law, we first present a general guidance structure that can achieve any terminal constraint of the line-of-sight rate based on the optimal control theory. We configure the desired profile of the line-of-sight rate using a saturation function whose exact form is determined to satisfy the required boundary conditions. By combining the line-of-sight rate profile with the optimal guidance structure, we develop a guidance law that achieves an impact angle interception with the field-of-view constraint. Herein, as the entire guidance structure is derived based on exact kinematics without any approximation, the proposed law ensures the accurate impact angle interception for various engagement scenarios. This precise consideration of the engagement kinematics also accurately ensures the energy optimality of preventing the excessive use of control inputs when homing. To evaluate the performance of the proposed method, numerical simulations with various engagement scenarios are conducted, and the results demonstrate that the proposed law allows missiles to accurately intercept their targets with the desired impact angles and without violating the prescribed field-of-view constraint.

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.

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