Adaptive Vision-Based Guidance Law with Guaranteed Performance Bounds for Tracking a Ground Target with Time-Varying Velocity

Author(s):  
Lili Ma ◽  
Chengyu Cao ◽  
Naira Hovakimyan ◽  
Vladimir Dobrokhodov ◽  
Isaac Kaminer
2019 ◽  
Vol 123 (1262) ◽  
pp. 464-483
Author(s):  
X.L. Ai ◽  
L.L. Wang ◽  
Y.C. Shen

ABSTRACTThis study focuses on the co-operative salvo attack problem of multiple missiles against a stationary target under jointly connected switching topologies subject to time-varying communication delays. By carefully exploring certain features of the typical pure proportional navigation guidance law, a two-stage distributed guidance scheme is proposed without any information on time-to-go in this study to realise the simultaneous attack of multiple missiles. In the first guidance stage, a co-operative guidance law is proposed using local neighbouring communications only to achieve consensus on range-to-go and heading error to provide favourable initial conditions for the latter phase, in which switching topologies and time-varying communication delays are taken into account when obtaining sufficient conditions of consensus in terms of linear matrix inequalities. Then, missiles disconnect from each other and are guided individually by the typical pure proportional navigation guidance law with the same navigation gain to realise salvo attack in the second guidance phase. Finally, numerical simulations are carried out to clearly validate the theoretical results.


Author(s):  
Jie Luo ◽  
Chengyu Cao

This paper presents an extension of the L1 adaptive controller to a class of nonlinear systems where the control effectiveness is time-varying and unknown, but with a known sign. Moreover, this class of nonlinear systems contains time-varying and unknown state-dependent nonlinearities. The proposed L1 adaptive controller consists of three components, a state predictor used to estimate real states, an adaptive law used to update the adaptive parameters in the state predictor, and a low-pass filtered control law. First, the stable closed-loop reference system is constructed. Then, the estimation errors between estimated states and real states are proved to be arbitrarily small by increasing the adaptation rate. After that, we further prove that the adaptive controller ensures uniformly bounded transient and asymptotical tracking of the reference system. The performance bounds can be systematically improved by increasing the adaptation rate. Simulation results on a single-link nonlinear robot arm verify the theoretical findings.


Aerospace ◽  
2021 ◽  
Vol 8 (8) ◽  
pp. 231
Author(s):  
Zhanyuan Jiang ◽  
Jianquan Ge ◽  
Qiangqiang Xu ◽  
Tao Yang

The paper proposes a two-dimensional impact time control cooperative guidance law under constant velocity and a three-dimensional impact time control cooperative guidance law under time-varying velocity, which can both improve the penetration ability and combat effectiveness of multi-missile systems and adapt to the complex and variable future warfare. First, a more accurate time-to-go estimation method is proposed, and based on which a modified proportional navigational guidance (MPNG) law with impact time constraint is designed in this paper, which is also effective when the initial leading angle is zero. Second, adopting cooperative guidance architecture with centralized coordination, using the MPNG law as the local guidance, and the desired impact time as the coordination variables, a two-dimensional impact time control cooperative guidance law under constant velocity is designed. Finally, a method of solving the expression of velocity is derived, and the analytic function of velocity with respect to time is given, a three-dimensional impact time control cooperative guidance law under time-varying velocity based on desired impact time is designed. Numerical simulation results verify the feasibility and applicability of the methods.


Author(s):  
Haitong Xu ◽  
M. A. Hinostroza ◽  
C. Guedes Soares

Abstract This paper presents a time-varying vector field guidance law for path-following control of underactuated autonomous vehicles. The proposed guidance law employs a time-varying equation to calculate the desired heading angle. A sliding mode controller is designed to track the desired heading angle, and it is proved to be globally exponentially stable (GES). With this controller, the stability proof for guidance system is presented and the equilibrium point of the guidance system is Uniform Global Asymptotic Stable (UGAS). In order to avoid the obstacle when ship approaching the predefined path, a combined Path-following and repelling field based obstacle avoidance system is proposed in this paper. Simulations are carried out to validate the performance of the combined path-following and collision avoidance system.


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