scholarly journals A Geometry-Based Guidance Law to Control Impact Time and Angle under Variable Speeds

Mathematics ◽  
2020 ◽  
Vol 8 (6) ◽  
pp. 1029
Author(s):  
Xinghui Yan ◽  
Minchi Kuang ◽  
Jihong Zhu
Keyword(s):  
Inverse Dynamics ◽  
Impact Angle ◽  
Generation Process ◽  
Impact Time ◽  
End Point ◽  
Guidance Law ◽  
Trajectory Length ◽  
Aerial Vehicle ◽  
Adjustable Range ◽  
The Impact

To provide a feasible solution for a variable speed unmanned aerial vehicle (UAV) to home on a target with impact time and angle constraints, this paper presents a novel geometry-based guidance law composed of trajectory reshaping and tracking. A trajectory generation process using Bezier curves is introduced to satisfy the impact time and angle constraints under time-varying speed. The impact angle is satisfied by driving the UAV along a specified ending line. The impact time is satisfied by controlling the trajectory length, which is realized through adjusting one Bezier curve end point along the ending line. The adjustable range of this end point, along with the maximum trajectory curvature, is analyzed to ensure that the trajectory is flyable. Guidance command is generated using inverse dynamics. Numerical simulations under various scenarios are demonstrated to illustrate the performance and validate the effectiveness of the proposed method.

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.

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.

Design of Guidance Law with Impact Angle and Impact Time Constraints

2014 ◽  
Vol 945-949 ◽  
pp. 1493-1499 ◽  
Author(s):  
Lin Ping Feng ◽  
Zuo E Fan ◽  
You Gen Zhang
Keyword(s):  
Control Theory ◽  
State Feedback ◽  
Impact Angle ◽  
The State ◽  
Guidance System ◽  
Time Constraints ◽  
Impact Time ◽  
Guidance Law ◽  
Optimal Guidance ◽  
The Impact

In order to achieve the tactical mission of cooperative attack for multi-missiles, in a predetermined direction at a predetermined time, this paper studies the design of guidance law with impact angle and impact time constraints. Firstly, using the optimal control theory, the optimal guidance law is designed to control the impact angle, based the relative motion between missile and target. Then the state feedback guidance law is designed to control the arrival impact time, with the application of feedback linearization control theory. Finally, reference the design idea of two-stage guidance system, the anti-ship missile use two different guidance laws in the process of attacking the target. During the first stage, the state feedback guidance law is used to accurately control the impact time and coarsely control the impact angle. During the second stage, the optimal guidance law is used to accurately control the impact angle. And the correctness and effectiveness of the design method is verified by simulation.

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.

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 Three-Dimensional Fixed-Time Cooperative Guidance Law With Impact Angle Constraint and Prespecified Impact Time

IEEE Access ◽  
2021 ◽  
Vol 9 ◽  
pp. 29755-29763
Author(s):  
Mu Lin ◽  
Xiangjun Ding ◽  
Chunyan Wang ◽  
Li Liang ◽  
Jianan Wang
Keyword(s):  
Three Dimensional ◽  
Fixed Time ◽  
Impact Angle ◽  
Impact Time ◽  
Guidance Law ◽  
Cooperative Guidance ◽  
Impact Angle Constraint

Guidance law to control impact time constraining the seeker’s field of view?

2018 ◽  
Vol 91 (1) ◽  
pp. 20-29 ◽  
Author(s):  
Jian Hu ◽  
Naigang Cui ◽  
Yuliang Bai ◽  
Yunhai Geng
Keyword(s):  
Stability Theory ◽  
Lyapunov Stability Theory ◽  
Field Of View ◽  
Convergence Time ◽  
Stationary Target ◽  
Content Type ◽  
Impact Time ◽  
Finite Time Stability ◽  
Guidance Law ◽  
The Impact

Purpose The purpose of this paper is to present a novel guidance law that is able to control the impact time while the seeker’s field of view (FOV) is constrained. Design/methodology/approach The new guidance law is derived from the framework of Lyapunov stability theory to ensure interception at the desired impact time. A time-varying guidance gain scheme is proposed based on the analysis of the convergence time of impact time error, where finite-time stability theory is used. The circular trajectory assumption is adopted for the derivation of accurate analytical estimation of time-to-go. The seeker’s FOV constraint, along with missile acceleration constraint, is considered during guidance law design, and a switching strategy to satisfy it is designed. Findings The proposed guidance law can drive missile to intercept stationary target at the desired impact time, as well as satisfies seeker’s FOV and missile acceleration constraints during engagement. Simulation results show that the proposed guidance law could provide robustness against different engagement scenarios and autopilot lag. Practical implications The presented guidance law lays a foundation for using cooperative strategies, such as simultaneous attack. Originality/value This paper presents further study on the impact time control problem considering the seeker’s FOV constraint, which conforms better to reality.

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.

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