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.

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 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.

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.

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.

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.

scholarly journals Impact-Time-Control Guidance Law for Missile with Time-Varying Velocity

2016 ◽  
Vol 2016 ◽  
pp. 1-14 ◽  
Author(s):  
Jun Zhou ◽  
Yang Wang ◽  
Bin Zhao
Keyword(s):  
Numerical Simulation ◽  
Sliding Mode Control ◽  
Constant Velocity ◽  
Sliding Mode ◽  
Time Varying ◽  
Attractive Feature ◽  
Impact Time ◽  
Time Control ◽  
Guidance Law ◽  
Variation Range

The problem of impact-time-control guidance (ITCG) for the homing missile with time-varying velocity is addressed. First, a novel ITCG law is proposed based on the integral sliding mode control (ISMC) method. Then, a salvo attack algorithm is designed based on the proposed guidance law. The performances of the conventional ITCG laws strongly depend on the accuracy of the estimated time-to-go (TTG). However, the accurate estimated TTG can be obtained only if the missile velocity is constant. The conventional ITCG laws were designed under the assumption that the missile velocity is constant. The most attractive feature of this work is that the newly proposed ITCG law relaxes the constant velocity assumption, which only needs the variation range of the missile velocity. Finally, the numerical simulation demonstrates the effectiveness of the proposed method.

scholarly journals Field-of-View Constrained Impact Time Control Guidance via Time-Varying Sliding Mode Control

Aerospace ◽  
2021 ◽  
Vol 8 (9) ◽  
pp. 251
Author(s):  
Shuai Ma ◽  
Xugang Wang ◽  
Zhongyuan Wang
Keyword(s):  
Sliding Mode Control ◽  
Sliding Mode ◽  
Field Of View ◽  
Time Varying ◽  
Sliding Surface ◽  
Impact Time ◽  
Mode Control ◽  
Time Control ◽  
Guidance Law ◽  
The Impact

The problem of impact time control guidance with field-of-view constraint is addressed based on time-varying sliding mode control. The kinematic conditions that satisfy the impact time control with field-of-view constraint are defined, and then a novel time-varying sliding surface is constructed to achieve the defined conditions. The sliding surface contains two unknown coefficients: one is tuned to achieve the global sliding surface to satisfy the impact time constraint and zero miss distance, and the other is tuned to guarantee the field-of-view constraint. The guidance law is designed to ensure the realization of the global sliding mode. On this basis, the guidance law is modified to a closed-loop structure, and the maximum detection capability of the seeker is utilized to a greater extent. Under the proposed guidance law, neither the small angle assumption nor time-to-go estimation is needed. The guidance command is continuous and converges to 0 at the desired impact time. Simulation results demonstrate the effectiveness and superiority of the proposed guidance law.

Guidance law to control impact angle and time based on optimality of error dynamics

2018 ◽  
Vol 233 (10) ◽  
pp. 3577-3588 ◽  
Author(s):  
Bin Li ◽  
Defu Lin ◽  
Jiang Wang ◽  
Song Tian
Keyword(s):  
Impact Angle ◽  
Error Feedback ◽  
Time Error ◽  
Optimal Error ◽  
Impact Time ◽  
Guidance Law ◽  
The Difference ◽  
Error Dynamics ◽  
Miss Distance ◽  
Impact Angle Constraint

In this work, a new guidance law with a meaningful performance index is designed to satisfy terminal impact angle and impact time constraints based on optimal error dynamics, which can be used for salvo attacks or cooperative missions of multi-missile. The analytical solution of the proposed guidance law is a combination of trajectory shaping guidance law and an additional impact time error feedback term that is proportional to the difference between the desired and the true impact times. Trajectory shaping guidance law aims to achieve the desired terminal impact angle and zero miss distance, whereas the extra term aims to meet the desired impact time. The minimum and maximum feasible impact times that consider the seeker's field-of-view limit, terminal impact angle constraint, and missile's maneuvering acceleration limit are calculated to provide the feasible boundary range of the desired impact time. Numerical simulations of several engagement situations demonstrate the effectiveness of the proposed guidance law in the accuracy of terminal impact angle and impact time.

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