Thesis - Leigh Moody.pdf - Bad Request - Cranfield University

Chapter 1 / Introduction
_ _
concludes with a description of the tracking simulator, its control and
interaction with the target and sensor simulators, and the simulation
infrastructure.
1.3.4 Chapter 6 : Conventional Missile Guidance
§2 to §5 provide the target and missile data required for missile guidance.
§6 closes the loop on this process through the autopilot, starting with a
description of the missile simulator, its interaction with preceding
simulators, and the simulation infrastructure. It ends with the conversion of
the guidance demands into STT and BTT missile motion first constrained by
the launcher, then by speed dependent g-limiting up to Mach 1, before freeflight.
The order of presentation is dictated by the simulator, starting with
missile mass, thrust and drag characteristics, and their Jacobians for
trajectory optimisation. The focus of §6 thereafter is on conventional
guidance laws, as distinct from on-line trajectory optimisation dealt with in
§7.
Fossier [F.2] reviews the course of sensor development and its links with
conventional missile command (3 point), homing (2 point), and inertial
guidance since World War 2. Inertial guidance to a geodetic reference point
is the province of long range ballistic and cruise missiles, although it can be
employed for mid-course guidance of medium-range missiles. Command
guidance uses ground-based target tracking data and up-linked CLOS
guidance commands. Homing guidance is autonomous using seeker data
and PN guidance commands.
By the mid-60s the improvement in radar tracking and ground processing
capacity proved irresistible and expensive seekers/PN were replaced by
radar/CLOS in many air-defence systems. These systems rely on up-linked
steering commands to eliminate the differential angle between the missile
and target after “gathering” into the radar beam. Phased array radar
technology introduced in the 80s uses separate beams to reduce the initial
gathering acceleration demands. These systems have proven remarkably
adaptable considering the advances in target manoeuvrability and defensive
countermeasures. However, both command and homing guidance systems
can be compromised by reliance on a single sensor exhibiting sub-optimal
characteristics during some part of the engagement. By the late-80s it was
recognised that their performance could not be improved indefinitely and so
research began into multi-spectral seekers, data fusion and the combination
of PN and CLOS. Systems are emerging in which approach angle
controlled PN guidance is generated from inertial information combined
with up-linked radar data before switching to homing using the reestablished
seeker.
A review of PN guidance laws in two and three dimensions (2D and 3D)
derived by conventional solution of the underlying differential equations
defining the relative motion between the missile and target. The removal of
steady-state constraints is charted over 50 years and the emergence of
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