TABLE OF CONTENTS This section examines some current applications in which inertial sensors and systems are used to maintain control of land, sea and airborne vehicles during normal operations and throughout manoeuvres. These range from autopilots to safety system, as well as fault diagnostic approaches.
Autopilots have a number of functions, as discussed below, but the fundamental objective of an autopilot is to modify the intrinsic natural behaviour of a vehicle to produce the desired response characteristic. This involves making the behaviour of the vehicle more predictable and less influenced by external disturbances and variations in component characteristics. Moreover, the ideal design aim is to make the response of the vehicle constant over its entire operating envelope. This section will consider two common applications; autopilots in guided weapons and in aircraft.
An autopilot is a closed loop system used to stabilise the chosen or demanded flight path of a vehicle. In the case of an aircraft or missile it maintains a response and track that is reasonably resistant to external disturbances, but is still responsive to control demands.
The fundamental requirement for a guided weapon is for the projectile to hit its target. This is achieved by generating guidance commands, derived from the perceived engagement conditions, usually in the form of lateral acceleration (latax) commands.
At a given speed, a latax command may be thought of as a rate of turn, or curvature of the trajectory. The purpose of the autopilot is...
