Impact Angle Control Guidance Law With Seeker’s Field-of-View Constraint Based on Logarithm Barrier Lyapunov Function

Abstract

In recent years, the strapdown system has become the significant trend of the development of precision guided weapons. In order to effectively hit the lightly armored targets, researchers have done a series of studies on the impact angle control. However, most of them ignored the field-of-view constraint of the strapdown seeker. The existing impact angle control guidance laws with the field-of-view constraint have obvious drawbacks to some extent. For example, most of them are only applicable against nonmaneuvering targets and some of them suffer sudden hopping of guidance command due to the use of switching logic. Taking the strapdown seeker missile as the research object, this paper studies the field-of-view constrained impact angle control guidance problem against stationary targets, constant speed targets and maneuvering targets. According to the sliding mode control theory, two kinds of sliding surfaces are designed to make the missile achieve high precision attack under a desired impact angle within the field-of-view constraint. A quadratic barrier Lyapunov function and a logarithm barrier Lyapunov function are used to guarantee that the sliding surfaces designed for the impact angle constraint and the field-of-view constraint can converge to zero in finite time respectively. Then, a nonlinear extended state observer is proposed to estimate the unmeasurable disturbance of the system and alleviate the undesirable chattering by compensating it with the estimation of the disturbance. Finally, the feasibility of the proposed law is verified by numerical simulations.INDEX TERMS Field-of-view constraint, impact angle control, logarithm barrier Lyapunov function, nonlinear extended state observer, sliding mode control.

Impact Angle Control Guidance Law Considering the Seeker’s Field-of-View Constraint Applied to Variable Speed Missiles

“…Assumption 3: The AOA of the missile is small enough to be neglected. Hence, we can use the leading angle of the missile to replace the seeker's look angle and the FOV constraint can be given as (19) where ϕ max is the upper limit of the seeker's look angle, which usually satisfies ϕ max ∈ 0, π 2 . We can further assume that the initial leading angle of the missile also satisfies |ϕ M (t o )| < ϕ max .According to Assumption 1-3, we can make the following assumption without any loss of generality:…”

“…Liu et al [18] proposed a novel back-stepping FOV constrained IACG scheme by introducing a hyperbolic tangent function and its modification to make the missile fully utilize the maximum achievable range of the seeker's look angle. In [19], a logarithm barrier Lyapunov function based IACG law with the seeker's FOV constraint was proposed to improve the convergence rate of the system. Although the SMC based guidance laws proposed in [17]- [19] are verified to have perfect performance in achieving the impact angle control and addressing the FOV constraint, they are only designed for constant speed missiles.…”

“…In [19], a logarithm barrier Lyapunov function based IACG law with the seeker's FOV constraint was proposed to improve the convergence rate of the system. Although the SMC based guidance laws proposed in [17]- [19] are verified to have perfect performance in achieving the impact angle control and addressing the FOV constraint, they are only designed for constant speed missiles.…”

Capture Region of Tactical Missile Equipped With Semi-Active Laser Seeker Using Tobit Kalman Filter

“…A strapdown seeker may be used as part of the guidance system in low-cost missiles because the strapdown seeker can detect the target accurately although it has a relatively simple mechanical structure [13], [14]. However, one of the significant drawbacks of a strapdown seeker is that the seeker's field of view (FOV) is narrower than a gimbaled seeker [15]. In general, a highly curved trajectory is generated for the missile in engagements with the terminal impact angle constraint, and the target can easily move out of the seeker's FOV [6].…”

A fast L1 adaptive constrained back-stepping controller using barrier Lyapunov function for anuncertain submersible vehicle

“…This controller is applied to the real AC-ROV to compensate the effect of external disturbances and changes in the system parameters. A study, carried out in 31 , compares the performance of a common adaptive control method with an L 1 adaptive control by applying both controllers to a Rohrs and two carts as the benchmark problems.…”