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.

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.

Polynomial guidance law for impact angle control with a seeker look angle limit

2019 ◽  
Vol 234 (3) ◽  
pp. 857-870
Author(s):  
Zhou Zhiming ◽  
Xiaoxian Yao
Keyword(s):  
Impact Angle ◽  
Line Of Sight ◽  
Time Varying ◽  
Proportional Navigation ◽  
Guidance Law ◽  
Maneuvering Targets ◽  
Nonlinear Simulations ◽  
Impact Angles ◽  
The Impact ◽  
Guidance Laws

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.

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.

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.

Generalized optimal impact-angle-control guidance with terminal acceleration response constraint

2017 ◽  
Vol 231 (14) ◽  
pp. 2515-2536 ◽  
Author(s):  
Hui Wang ◽  
Jiang Wang ◽  
Defu Lin
Keyword(s):  
General Expression ◽  
Impact Angle ◽  
Acceleration Response ◽  
Proportional Navigation ◽  
Guidance Law ◽  
Optimal Guidance ◽  
Terminal Constraints ◽  
Miss Distance ◽  
Guidance Laws ◽  
Impact Angle Constraint

To study the optimal impact-angle-control guidance problem with multiple terminal constraints, a generalized optimal impact-angle-control guidance law with terminal acceleration response constraint (GOIACGL-TARC) is proposed. In the deriving, a time-to-go − nth power weighted object function is adopted to derived the GOIACGL-TARC and a general expression of GOIACGL-TARC is presented. Based on the general expression of GOIACGL-TARC, three guidance laws, GOIACGL-TARC1/TACC0/TACC1 are proposed and the inheritance relationship between GOIACGL-TACC0/TACC1/TARC1 and the conventional optimal guidance law with impact angle constraint is demonstrated. Performance analysis of the proposed guidance laws shows that in the case of GOIACGL-TACC0, the terminal acceleration is not zero at n = 0 and only as n > 0, the terminal acceleration converges to zero; in the case of GOIACGL-TACC1 and GOIACGL-TARC1, GOIACGL-TARC1 can guarantee the acceleration response to reach the exactly zero value but GOIACGL-TACC1 cannot, which can only guarantee the acceleration command to reach the exactly zero value. It is pointed out that compared with the biased proportional navigation guidance law, GOIACGL-TARC1 has an outstanding guidance performance in acceleration response, miss distance, and terminal impact angle error.

Field-of-view-constrained impact angle control guidance with error convergence before interception considering speed changes

2020 ◽  
pp. 095441002094201
Author(s):  
Jinrae Kim ◽  
Namhoon Cho ◽  
Youdan Kim
Keyword(s):  
Impact Angle ◽  
Field Of View ◽  
Time Varying ◽  
Angle Error ◽  
Proportional Navigation ◽  
Stationary Target ◽  
Guidance Law ◽  
Independent Variable ◽  
Angle Interval ◽  
The Impact

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.

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