A robust impact angle constraint guidance law with seeker’s field-of-view limit

Abstract

In this paper, a new robust guidance law is designed to satisfy both impact angle constraint and the seeker's field-of-view limit for missiles with strapdown seekers. Since the impact angle guidance law needs a highly curved trajectory and most strapdown seekers have a very narrow field-of-view, maintaining the seeker's lock-on is the key issue for these missiles. To address this problem, a switching logic is adopted, which adds an additional term in the original guidance law when the look angle exceeds the pre-designed boundary value to maintain the seeker's lock-on. An impact angle guidance law is designed based on terminal sliding mode control theory and the finite time convergence characteristic of the line-of-sight angle, as well as its derivative is proved through the Lyapunov method. Numerical simulations are performed to validate the effectiveness of the proposed guidance law. Some intuitive tunings of the design parameters are also offered in the simulation results to achieve large impact angles.

Impact time control guidance with field-of-view constraint accounting for uncertain system lag

“…Consider the state-constrained system (7) controlled by the proposed actual controller (38). Then, without violating the state constraint given by equation (9), all the signals in the closed-loop system are ultimately bounded and the tracking error s 1 can be driven into a small neighborhood of zero, whose size can be reduced to be arbitrarily small by adjusting the design parameters appropriately, if the following conditions are satisfied:…”

“…One of the methods to address this problem is the switching logic technique. [7][8][9][10][11] Its basic idea is that, when the lead angle achieves the critical value, switch the guidance law to another mode to prevent further increasing of the lead angle. However, with this approach, the guidance command suffers the undesirable abrupt jumping at the instant of guidance mode switching.…”

Two-Phase Optimal Guidance Law considering Impact Angle Constraint with Bearings-Only Measurements

“…However, it is always assumed in APN approaches that the target is stationary or the target's maneuvering path is known. Advanced guidance laws are designed based on modern control theories such as optimal control [4,5], sliding-mode control (SMC) [6,7], and robust control [8]. Compared with APN guidance laws, advanced guidance laws are more flexible to satisfy various requirements.…”

Optimal integral sliding mode guidance law based on generalized model predictive control

“…The motivation of imposing terminal angle constraint is to improve the overall interception performance, for instance, increasing kill probability, improving penetration capabilities, and reducing the warhead size. [1][2][3][4] Based on linearized kinematics via small angle assumption, some effective terminal impact angle constraint guidance laws were derived using linear optimal control theory. In this area, Kim and Grider 5 first proposed a suboptimal guidance law to impose desired terminal angle for reentry vehicles to intercept stationary or slowly moving ground targets.…”