Observer-Based Guidance Law With Impact Angle Constraint

Author(s):  
Pingping Qu ◽  
Di Zhou ◽  
Sheng Sun

Accounting for the autopilot as second-order dynamics, an observer-based guidance law with terminal impact angle constraint is designed using the dynamic surface control method. Some first-order low-pass filters are introduced into the designing process to avoid the occurrence of high-order derivatives of the line of sight (LOS) angle in the expression of the guidance law such that the guidance law can be implemented in practical applications. The proposed guidance law is effective in compensating for the second-order autopilot lag. In simulation of intercepting targets with sinusoidal acceleration, the guidance law is compared with the biased proportional navigation guidance (BPNG) law in the presence of missile autopilot lag. Simulation results show that the proposed observer-based guidance law with terminal impact angle constraint is able to guide a missile with large autopilot lag to impact a target with a desired angle and achieve a small miss distance, even if the target escapes in a great and fast maneuver.

Author(s):  
Di Zhou ◽  
Pingping Qu ◽  
Sheng Sun

A sliding-mode guidance (SMG) law is designed to intercept maneuvering targets with impact angle constrained flight trajectories under the assumption of ideal missile autopilot. Furthermore, accounting for the autopilot as second-order dynamics, a new guidance law with terminal impact angle constraint is designed using the dynamic surface control method. Some first-order low-pass filters are introduced into the designing process to avoid the occurrence of high-order derivatives of the line of sight (LOS) angle in the expression of the guidance law such that the guidance law can be implemented in practical applications. The proposed guidance law is effective in compensating for the second-order autopilot lag. Simulation results show that it is able to guide a missile to impact a maneuvering target with a desired angle and a small miss distance.


Author(s):  
Xiang Liu ◽  
Xiaogeng Liang

To solve the multi-interceptor coordination problem and to intercept the target with impact angle constraint, a novel distributed cooperative control algorithm with impact angle constraint based on integrated guidance and control is proposed. First, the mathematic model of integrated guidance and control is established by combining the interceptor-target relative motion model with the dynamic equation of the interceptor on pitch plane. The time varying gain extended state observer is developed to estimate and compensate the unknown disturbance. Based on the estimated value and fast nonsingular dynamic surface sliding control method, the IGC algorithm of leader is given; Then, based on distributed cooperative "leader-follower" model, the cooperative control strategy of multi-interceptor is designed, and gives out speeds in two directions on pitch plane, which are transformed to the command of total velocity and trajectory angle based on kinematic relations. Finally, to control the follower, the time varying gain extended state observer and the dynamic surface sliding control method are adopted. The simulation results demonstrate the effectiveness of the distributed cooperative control algorithm.


Author(s):  
Hui Wang ◽  
Jiang Wang ◽  
Defu Lin

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.


2019 ◽  
Vol 2019 ◽  
pp. 1-11
Author(s):  
Kuanqiao Zhang ◽  
Suochang Yang

Aiming at the requirement that some missiles need to meet certain impact angles when attacking targets, we consider the second-order dynamic characteristics of autopilot, thereby proposing a second-order sliding mode guidance law with impact angle constraint. Firstly, based on the terminal sliding mode control, we design a fast nonsingular terminal sliding mode guidance law with impact angle constraint. Based on the second-order sliding mode control, a second-order sliding mode guidance law with impact angle constraint is proposed. We have proved its finite time convergence characteristics and presented the specific convergence time expression. Subsequently, the dynamic characteristics of the autopilot are approximated to the second-order link. Combined with the dynamic surface control theory, we proposed a second-order sliding mode guidance law considering the second-order dynamic characteristics of the autopilot and proved its finite-time convergence characteristics. Finally, the effectiveness and superiority of the proposed guidance law are verified by comparative simulation experiments.


Author(s):  
Chunwang Jiang ◽  
Guofeng Zhou ◽  
Rui Lv ◽  
Haifeng Tu ◽  
Fengjun Yang ◽  
...  

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.


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.


IEEE Access ◽  
2021 ◽  
Vol 9 ◽  
pp. 29755-29763
Author(s):  
Mu Lin ◽  
Xiangjun Ding ◽  
Chunyan Wang ◽  
Li Liang ◽  
Jianan Wang

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