In the context of autonomy for underwater vehicles, we assume that a usual suite of feedback controllers are present in the form of autopilot functions that provide for the regulation of vehicle speed, heading and depth or altitude. In this chapter. we consider the topic of guidance laws, obstacle avoidance and the use of artificial potential functions (APFs). This topic deals with the computations required to plan and develop paths and commands, which are used by these autopilots. Simple guidance laws such as 'proportional guidance' have been used for many years in missiles to provide interception with targets. Lateral accelerations are commanded proportional to the rate of change of line of sight. So long as the chaser vehicle has a speed advantage over the non-manoeuvring target, simply reducing the angle of line of sight (LOS) to zero will result in an interception. For applications with unmanned underwater vehicles, guidance laws allow vehicles to follow paths constructed in conjunction with mission objectives.

Inspec keywords: underwater vehicles; marine control; remotely operated vehicles; collision avoidance; feedback

Other keywords: guidance law; line-of-sight; obstacle avoidance; lateral acceleration; autopilot function; proportional guidance; APF; LOS; unmanned underwater vehicle; artificial potential function; underwater vehicle; vehicle speed; feedback controller

Subjects: Marine system control