Impact Angle Guidance Law via Controlling Line-of-Sight Dynamics

2018 ◽  
Author(s):  
Ulas H. Ates
Keyword(s):  
Impact Angle ◽  
Line Of Sight ◽  
Guidance Law

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.

Impact angle control based on integral sliding mode manifold and extended state observer

2018 ◽  
Vol 233 (6) ◽  
pp. 2131-2140
Author(s):  
Xiaojian Zhang ◽  
Mingyong Liu ◽  
Yang Li ◽  
Feihu Zhang
Keyword(s):  
Sliding Mode ◽  
Impact Angle ◽  
State Observer ◽  
Extended State Observer ◽  
Line Of Sight ◽  
Extended State ◽  
Integral Sliding Mode ◽  
Guidance Law ◽  
Switched Nonlinear System ◽  
The Impact

This paper discusses the issue of impact angle control over guidance in scenarios of an interceptor against the maneuvering targets. Inspired by switched nonlinear system, an integral sliding mode manifold is first developed. Then, the impact angle control over guidance is derived by using the integral sliding mode manifold with finite time control. To obtain precise guidance effect, the second-order of extended state observer is proposed in the case of unknown target acceleration. Finally, composited impact angle control over guidance based on extended state observer is developed. The stability analysis of the proposed guidance law is demonstrated by using Lyapunov function, and theoretical proof that the line-of-sight angle and line-of-sight angular rate can converge to the desired value in finite steps, respectively. Numerical simulation results are illustrated to validate the performance of the proposed guidance law.

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 Suboptimal Midcourse Guidance with Terminal-Angle Constraint for Hypersonic Target Interception

2019 ◽  
Vol 2019 ◽  
pp. 1-13
Author(s):  
Shizheng Wan ◽  
Xiaofei Chang ◽  
Quancheng Li ◽  
Jie Yan
Keyword(s):  
Impact Angle ◽  
Line Of Sight ◽  
Load Factor ◽  
Control Sequence ◽  
Air Breathing ◽  
Kinematics Model ◽  
Guidance Law ◽  
Target Interception ◽  
Midcourse Guidance ◽  
Terminal Angle Constraint

For the problem of hypersonic target interception, a novel midcourse guidance method with terminal-angle constraint is proposed. Referring to the air-breathing and the boost-gliding hypersonic targets, flight characteristics and difficulties of interception are analyzed, respectively. The requirements of midcourse guidance for interceptors are provided additionally. The kinematics model of adversaries is established concerning line-of-sight coupling in longitudinal and lateral planes. Suboptimal guidance law with terminal-angle constraint, specifically the final line-of-sight angle or impact angle, is presented by means of model predictive static programming. The trajectory is optimized and the load factor would finally converge after penalizing control sequence and output deviations. The realization of terminal angle is firstly verified with a constant speed target. A full interception scenario is further simulated focusing on a typical boost-gliding target, which flies along a skipping trajectory. Results show the success of providing handover conditions for intercepting hypersonic targets.

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.

Sliding mode–based simultaneous control of impact angle and impact time

2021 ◽  
pp. 095441002110298
Author(s):  
Kakoli Majumder ◽  
Shashi Ranjan Kumar
Keyword(s):  
Sliding Mode ◽  
Impact Angle ◽  
Line Of Sight ◽  
Impact Time ◽  
Guidance Law ◽  
Simultaneous Control ◽  
Terminal Constraints ◽  
Time Requirements ◽  
Target Interception ◽  
The Impact

In this article, a sliding mode control–based nonlinear guidance scheme for controlling both impact angle and impact time simultaneously is proposed. The problem of impact angle control is first transformed to that of controlling line-of-sight angle and its rate, while the requirement of impact time is achieved by tracking the desired time-to-go. The chosen time-to-go estimate accounts for the curvature required to meet the impact angle requirements toward the target interception. In order to satisfy both of these terminal constraints, the sliding surface is defined as a combination of impact time error and the variable pertaining to the errors in line-of-sight angle and its rate, with appropriate gains assigned to them. The interceptor first performs necessary maneuvers to meet the impact time requirements and then steers its course to achieve the target interception at a desired impact angle. The guidance law is initially derived using nonlinear engagement kinematics against stationary targets and then extended to cater to constant velocity targets using the concept of predicted interception point. Numerical simulations are performed to validate the efficacy of the proposed guidance scheme for various initial engagement geometries. The performance of the proposed guidance scheme is also compared with those of the existing guidance laws and shown to be superior.

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.

Impact-angle-constrained reentry guidance law guaranteeing convergence before attainment of desired line-of-sight range

2018 ◽  
Vol 233 (8) ◽  
pp. 2783-2791
Author(s):  
Chunwang Jiang ◽  
Guofeng Zhou ◽  
Rui Lv ◽  
Haifeng Tu ◽  
Fengjun Yang ◽  
...  
Keyword(s):  
Angular Rate ◽  
Impact Angle ◽  
Line Of Sight ◽  
The Novel ◽  
Proportional Navigation ◽  
Stationary Target ◽  
Guidance Law ◽  
Ground Impact ◽  
Impact Angle Constraint ◽  
Guidance Model

For reentry vehicle attacking a stationary target on the ground, impact-angle-constrained guidance law guaranteeing convergence before attainment of desired line-of-sight range is studied in this paper. Initially, a novel guidance model is established, in which line-of-sight range is treated as an independent variable, describing the relative motion between the vehicle and the target. Subsequently, a guidance law with impact angle constraint is designed based on the guidance model, which is presented in the form of normal overload. Compared with traditional guidance laws, the proposed one guarantees line-of-sight angular rate converges to zero and line-of-sight angle converges to the commanding impact angle before line-of-sight range decreases to the desired value. Finally, comparisons among proportional navigation guidance, optimal navigation guidance, and the proposed guidance are carried out by numerical simulation, which demonstrate the correctness and advantage of the novel guidance model and guidance law. The guidance model and guidance law proposed in this paper provide a new way for the design of fast convergent guidance law with impact angle constraint.

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.

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