Flight Control of a Small-Diameter Spin-Stabilized Projectile Using Imager Feedback

Abstract

Small-diameter gun-launched projectiles pose a challenging platform on which to implement closed-loop guidance and control. This paper presents a novel imager-based guidance and control algorithm for small-diameter spinstabilized projectiles. The control law is specifically formulated to rely on feedback only from a strapdown detector and roll angle sensors. Following introduction of the projectile nonlinear dynamic model, an integrated guidance and control algorithm is presented in which control commands are computed directly from detector feedback using a gainscheduled proportional control. Time-varying controller gains are derived through a surrogate modeling approach, and controller performance is further enhanced through use of an observer that filters unwanted angular motion components from detector feedback. Example closed-loop flight simulations demonstrate performance of the proposed control system, and Monte Carlo analysis shows a factor of 2 accuracy improvement for the closed-loop system over ballistic flight. Results indicate that delivery system improvements are achievable in small, gyroscopically stabilized projectiles containing low-cost guidance elements using the proposed integrated guidance and control approach.

Dynamic Response Analysis for a Terminal Guided Projectile With a Trajectory Correction Fuze

“…For terminal guided projectile, the time-to-go is limited, so the coefficient C N δ can be regarded as a constant within this duration. For the same reason, we take the same approach of Frank Fresconi [11] and regard parameter V as a constant, which equals the initial velocity during the correction. So for a short time-to-go, the control force and control moment for correction are assumed as invariable for convenience.…”

“…Consequently, in pursuit of further developments in trajectory correction fuzes, correction schemes based on target imager feedback have begun to be considered. Some recent efforts regarding trajectory correction with imager feedback can be found in references [11] and [12].…”

A novel quasi-dynamic guidance law for a dynamic dual-spin projectile with non-conventional, asymmetric roll constraints

“…If volumetric restrictions permit, on-board image sensing hardware could be used. 37 Linear ballistic theory could also be used to estimate the change in roll rate of the projectile along the trajectory beyond what is known from the projectile launch to supplement information from the sensors.…”

Research on Instability Boundaries of Control Force for Trajectory Correction Projectiles

“…Numerous correction models such as impact point prediction [4][5][6][7] and model trajectory prediction [8][9][10] can be found in the literature. For the pursuit of further improvements in accuracy, the guidance law based on target imager feedback is proposed and becomes a tendency in the future [11,12]. Unlike the scheme mentioned above, this correction strategy can be used only during the terminal phase with a limited time-to-go.…”