Navigation System

Navigational Sensors

Sparton AHRS-8 IMU: The Sparton AHRS-8IMU (Inertia Measurement Unit) provides critical BumbleBee Autonomous Underwater Vehicle 4 inertial data at a rapid rate of 100 Hz. The IMU’s proprietary algorithms ensure the output of correct data despite the presence of electromagnetic interference generated by the BumbleBee’s suite of electronics and thrusters.

Teledyne RDI Explorer DVL: The DVL (Doppler Velocity Log) is an active sonar system that tracks the velocity of the instrument via a four-beam solution directed at 30 degrees nominal from the sensor’s ceramic head. The velocity readings obtained are combined with tilt and altitude measurements, then resolved into the three orthogonal x, y and z axes via a least squares fit solution. These resolved readings are further filtered through a direct three-degree of freedom Kalman filter, which serves to attenuate noise. The calculations outputs a more accurate positional coordinate of the vehicle.

Navigation

The data provided by the navigational sensors are fused together via simple trigonometric equations to generate a global position vector. The odometric data obtained from this vector allows the vehicle to navigate precisely to any given spatial co-ordinate.