Guidance law for mimicking short-range ballistic trajectories

Author(s):  
Yash Raj Sharma ◽  
Ashwini Ratnoo

This paper considers the problem of mimicking short-range ballistic trajectories and presents a feedback guidance law addressing that. Analysis of the ideal ballistic trajectory is carried out and closed-form expressions are derived for the heading error and its derivative. Satisfying the launch angle, the impact angle, and the initial heading error rate of the ballistic trajectory, a guidance law is proposed using bearings-only information of the impact point. Analysis of the proposed guidance law is carried out evaluating the variation in guidance gains, the maximum look-angle, and the capturability. Analyzing the time-varying effective navigation gain, boundedness of the lateral acceleration is also ascertained. Simulations are carried out mimicking the ideal and realistic ballistic trajectories. Robustness of the proposed guidance method is verified against wind disturbances and error in modeling drag coefficient.

Author(s):  
Jinrae Kim ◽  
Namhoon Cho ◽  
Youdan Kim

An impact angle control guidance law is proposed for stationary target interception considering missile's field-of-view limit and speed changes. The proposed impact angle control guidance law is structured as a biased proportional navigation with a time-varying bias. The proposed guidance law does not involve any switching logic for maintaining lock-on; hence, the guidance command is continuous during the entire engagement. Unlike the most existing studies, the proposed method guarantees that the impact angle error converges to zero before interception without the constant-speed assumption. To realize these desirable properties, the positive invariance of the bounded look angle interval and the change of independent variable are utilized. Numerical simulations are conducted to demonstrate the performance of the proposed guidance law.


Author(s):  
Zhou Zhiming ◽  
Xiaoxian Yao

In this paper, the impact angle control problem is investigated by applying the polynomial shaping method. By shaping the light-of-sight angle with relative range, a guidance law called range polynomial guidance is proposed, and the coefficients are determined by boundary conditions. The range polynomial guidance law can be applied to maneuvering targets. By profiling the seeker look angle with the light-of-sight angle, a guidance law called line-of-sight polynomial guidance is developed for impact angle control under a limitation on the seeker look angle. The line-of-sight polynomial guidance law is also effective in intercepting a non-maneuvering moving target at the desired impact angle. Guidance laws with different gain sets are discussed in this paper. The proposed guidance laws take the form of proportional navigation with a time-varying navigation gain. Nonlinear simulations are performed to validate the efficacy of the proposed guidance laws in various engagement conditions. Comparison with other studies demonstrates the practicality and flexibility of the proposed guidance laws in the design of desired impact angles and maximum look angles.


2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Libing Hou ◽  
Jihong Zhu ◽  
Minchi Kuang ◽  
Heng Shi

To solve the problem regarding the impact angle of the missile, this paper proposes a novel guidance law, which can control the missile to hit the target at the desired angle. The key of the guidance law is selecting a moving point on the collision line as the virtual target, and the tactical requirements can be fulfilled by the missile directly pursuing the virtual target. The Lyapunov stable theory is used to prove the convergence of the proposed guidance law. The guidance command is generated by a PID controller to make the missile towards the virtual target. The proposed guidance law makes the lateral acceleration of the missile converge to zero, which leads the angle of attack to zero, and it theoretically guarantees the flight path angle equals the attitude angle. Numerical simulations demonstrate this impact angle control guidance law is very accurate and robust. Regardless of whether the initial heading error is large or small, the missile which employs the proposed guidance law can always hit the target from the preset direction and the guidance process is smooth.


Author(s):  
Ronggang Wang ◽  
Shuo Tang

To intercept a higher-speed target in the terminal guidance phase, this paper proposes a generalized relative biased proportional navigation (BPN) law. In order to enlarge the capture domain of the classical proportional navigation (PN) law and make full use of the maneuverability of a missile, the paper designs time-varying navigation coefficients; thus the modified PN guidance law integrates the advantages of the PN guidance law with those of the retro-PN guidance law. In order to intercept high-speed targets with impact angle constraints, the relative BPN law is introduced, and the impact angle is achieved by controlling the relative flight-path angle. In order to improve the performance of the guidance law for intercepting higher-speed maneuvering targets, some compensation measures are designed for guidance commands. Extensive simulations are conducted to verify the design features of the proportional navigation law.


Author(s):  
Min-Guk Seo ◽  
Chang-Hun Lee ◽  
Tae-Hun Kim

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.


2017 ◽  
Vol 2017 ◽  
pp. 1-12 ◽  
Author(s):  
Tianning Wang ◽  
Shengjing Tang ◽  
Jie Guo ◽  
Haoqiang Zhang

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.


Author(s):  
Peng Li ◽  
Qi Liu ◽  
Chen-Yu He ◽  
Xiao-Qing Liu

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.


2016 ◽  
Vol 2016 ◽  
pp. 1-14 ◽  
Author(s):  
Zhe Yang ◽  
Hui Wang ◽  
Defu Lin ◽  
Luyao Zang

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.


2009 ◽  
Vol 42 (2) ◽  
pp. 321-325 ◽  
Author(s):  
Chang-Kyung Ryoo ◽  
H. Jin Kim ◽  
Min-Jea Tahk ◽  
Jin-Ik Lee

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