A New Type Nonlinear Observer Design for AUV in Shallow Water

The proposed observer could estimate AUV´s low frequency motion and environmental disturbance force from the synthetical signals which include the low frequency motion signals, high frequency motion signals and measure noise from the sensors. The nonlinear observer is proved global exponential stability and passive. Passivity theory is used in designing the tuning parameters of the observer. The observer overcomes the essential shortcomings of the tradition Kalman filter which applies the linear theory and gain scheduling techniques. A set of computer simulations which is carried out to test the performance of the proposed observer proves the excellent capability.