Altitude Estimation and Control of ROV by use of DVL

A new method for altitude estimation and control of a remotely operated vehicle (ROV) by use of a Doppler velocity log (DVL) is presented in this paper. Altitude measurements from the DVL are used to approximate the gradient of the sea floor. The altitude rate of change is found from the sea floor gradient and ROV motions. This is used in an observer for altitude estimation. A guidance law for altitude control is also proposed. The altitude observer and guidance law have been implemented in the control system of NTNU's ROV Minerva. Results from sea trials demonstrating the performance of the proposed altitude estimation and controller are presented in the paper.