Partial Integrated Guidance and Control with Impact Angle Constraints

Abstract

Novel sliding-mode control laws are proposed in this paper to stabilize a class of uncertain nonlinear systems. Considering that the sign function, which is often used in the sliding-mode control can cause chattering of control input, the saturation function is used to take its place in proposed controllers. What is more, not only the proposed controllers are continuous but also convergence to the origin asymptotically and in finite time can both be guaranteed in theory. For asymptotic convergence, it is only required that uncertainties and disturbances are bounded and the bounds may be unknown by virtue of adaptive laws. The obtained results are then applied to partial integrated guidance and control design for a missile, completing desired terminal impact angle and hit-to-kill interception. Finally, simulations are conducted on the nonlinear longitudinal missile model and results demonstrate the effectiveness of the proposed method. Nomenclature A Tr , A Tλ= projections of target acceleration along and orthogonal to the line of sight, m∕s 2 c x , c z , c m = aerodynamic coefficients F x , F z = aerodynamic forces, N g = gravity acceleration, m∕s 2 I yy = moment of inertia around the pitch axis, kg∕m 2 k F , k M = constants determined by the missile geometry, m 2 and m 3 , respectively M = pitching moment, N · m M m = Mach number m = missile mass, kg n L = missile normal acceleration, m∕s 2 q = pitch rate, rad∕s r = the range along the line of sight, m V M = missile velocity, m∕s V r , V λ = components of relative velocity along and orthogonal to the line of sight, m∕s α = angle of attack, rad γ M = missile flight-path angle, rad δ e = elevator deflection, rad θ = pitch angle, rad λ = line-of-sight angle, rad ρ = atmospheric density, kg∕m 3

Guidance Laws With Input Constraints and Actuator Failures

“…4e illustrates. Finally, it is observed that the proposed fault-tolerant guidance laws (15) can result in actuator effectiveness, even if actuators are fully failed in a specific time interval, and high performance can be obtained.…”

“…The numerical simulation of the closed-loop nonlinear system equations of pursuit-evasion motion (7) in conjunction with the proposed fault-tolerant control guidance laws (15) is carried out to examine the performance of the proposed governing nonlinear control system. The abbreviations of units used in simulation are m for meter, rad for radian, and s and sec for second.…”

“…For an ISS system, bounded disturbances can be suppressed to get bounded states. Additionally, to improve the control precision, impact time and impact angle constraints have been taken into account in the design process of a three-dimensional guidance law [14,15].…”

New Integrated Guidance and Control of Homing Missiles with an Impact Angle against a Ground Target

“…The first is the classical guidance and control (CGC) law [1], which treats the guidance and control system as two separate processes, and the second is the partial integrated guidance and control (PIGC) law [11], which combines the backstepping technique and sliding mode control method.…”

“…The first category method mainly focuses on the twoloop control structure in an IGC framework, and the outer loop and inner loop are separated in the guidance and control system [9][10][11][12] due to inherent time scale separation between the faster and slower dynamics. Although the outer loop takes the body rates as the virtual control input to directly yield the body rate command and the inner loop tracks the body rate commands with fin deflections as the control inputs, the settling time of response of different loops affects the performance of the whole system due to the delay problem.…”