This master thesis is a study on how a rategyro triad, an accelerometer triad, and a magnetometer triad can be integrated into a navigation system, estimating a vehicle’s attitude, i.e. its roll, tipp, and heading angles. When only a rategyro triad is used to estimate a vehicle’s attitude, a drift in the attitude occurs due to sensor errors.

When an accelerometer triad and a magnetometer triad are used, an error in the vehicle’s heading, appearing as a sine curve, depending on the heading, occurs. By integrating these sensor triads, the sensor errors have been estimated with a filter to improve the estimated attitude’s accuracy.

To investigate and evaluate the navigation system, a simulation model has been developed in Simulink/Matlab. The implementation has been made using a Kalman filter where the sensor fusion takes place. Simulations for different scenarios have been made and the results from these simulations show that the drift in the vehicle’s attitude is avoided.