**MSS-Marine GNC Toolbox V3.0
Updates 2005-03-14**

This version incorporates a few extra m-files related to waves and a major re-structuring of the Simulink library marine.mdl, which has been replaced by marine_gnc.mdl

**New M-files:**

*wavespec.m*--evaluate 8 different wave spectra.*ww2we.m*--conversion from wave to encounter frequency (vector input-output. Negative encounter frequencies are allowed.)*hs2vw.m*--conversion from signif. wave height to average wind speed.*vw2hs.m*--conversion from average wind speed to signif. wave height.*rand_phases*--generates a vector of random phases with uniform distribution in [-pi,pi].

*Obsolete commands:* The function *wavespec * replaces
*pierson.m*, *mpierson.m*,* jonswap.m* and *torset.m * These
functions are still available in this version but may not be supported in future
versions of the toolbox.

The new library marine_gnc.mdl is organised in the following modules:

- Control -- control blocks for different operations
- Environment -- blocks for modelling wind wave and current (no current implemented in this version)
- Examples -- examples ready to simulate
- Guidance -- blocks for generating trajectory references for ship motion control
- Marine System (Basic) -- elementary blocks to construct models of marine vehicles
- Navigation -- blocks related to filtering and measurements
- Support -- math operations, unit conversions, etc.

**New Simulink blocks in the
library marine_gnc.mdl:**

**Environment / Waves:**

- Gaussian random process --this is to simulate random processes as a sum or sinusoids.
- Encounter Frequency Correction -- correction for the Waves block to work in the encounter freq. domain.
- W_wave2W_enc --conversion from wave to encounter frequency.

**Guidance:**

- Zig-Zag rudder command --reference for performing ziz-zag tests in surface ships.

**Models/ Control
surfaces:**

- Rudder/Fin Machinery
- Rudder
- Rudder Forces 4-DOF
- Fin Stabiliser Forces 4-DOF
- Steady State Hydrofoil.