- R O V - P I L O T - T R A I N E R -


1 Introduction

The ROV simulation software has been developed to meet request of Polish Navy to develop a realistic training facility for MCM system operators. It was created with a few limitations assumed:

- The software will be run on IBM compatible, off the shelf, industrial grade hardware
- Computer simulator will use data from real ROV control system and simulation results will be presented using equipment that is utilised in real ROV pilot console.
- Modular software structure is to allow easy implementation commissioning and modifications.
- Lecture interface will allow easy modifications of environmental conditions, space
geometry and structures both on the bottom as well as in water space.

Currently the software is used for simulation of cable supplied and controlled medium size ROV equipped with specific manipulation devices. It can be run in dedicated training console but is also run on computers integrated into real ROV control console permanently installed in ships cabin. It allows the ROV pilots to switch the system to simulator mode and practice simulated missions.


2 General software characteristics

A kernel of the software is a ROV physics simulator that calculates vehicle position and orientation changes as results of control commands and external influences and limitations. The ROV movement is further limited by space geometry and umbilical presence.
Specific feature is change of a vehicle geometry due to action of several components such as pan and tilt units and manipulators. Space geometry and environmental characteristics are defined around a vehicle. This includes water surface, bottom and structures. Optical and acoustical characteristics are defined for every geometrical element too. Definition of environmental conditions regards range of features such as turbidity, current, day time. Local sediment disturbances and plankton presence are also introduced.
Data regarding current position and orientation in space together with data regarding space geometry and surface characteristics are used by specialised software modules to create images and information presented to a Pilot using dedicated displays, widows and other adequate means.
For effectiveness and simplicity only one graphical presentation software module is active in single piece of hardware (computer). A simulator is built using software/hardware modules in number required by an application and customer preferences. In fact, all the modules run the same software using different device simulation element. Modules are synchronized by one of them, indicated as master module.
The modules are integrated using local Ethernet network. The same network is utilized to integrate simulator with external elements such as vehicle control computers, navigation computers and other devices required to make virtual reality close to real as much as possible. 8 modules are currently run including one dedicated to lecturer or training supervisor.
Principal feature of the software used for simulation is ability to generate required results in real time. Simulation step lasts 1/30s that assures good perception of presented images by human operator.

3 Device simulation modules
Several device simulation modules were developed to meet ROV simulator needs.
Principal are TV and sonar space image simulators. These are supplemented by 2 navigation modules, supervisor and space editors.
  3.1 TV camera imager

The module uses data regarding camera position and orientation. Orientation depends on vehicle orientation as well as current pan and tilt axes position. Externally mounted camera view can be also selected to facilitate training of a vehicle dynamics and space awareness.
A pilot view presented on display is deteriorated by environmental conditions defined generally for a mission to be performed by a trainee. Application of several software/hardware camera modules can simulate all the vehicle cameras simultaneously.


3.2 Sonar imager

Sonar imager is self efficient module that uses data similar to that used by TV camera imager. To build the image module uses ray tracing metords developed. Several acoustic characteristics can be adjusted to achieve simulation quality according to local requirements.
It is wise however to simulate behaviour of specific sonar. It means use of standard (for the make) sonar controls and screen appearance. To achieve this requirement sonar imager generates sonar head data that are fed to other computer running sonar image presentation software.
In current application Tritech Seaprince head is simulated. Sonar data are than supplied to computer containing AIF 3 card running SONV3 software. Tritech SCU RAT is used to control head activity. Standard Seaprince communication protocol implemented on RS232 is used for this purpose.


The solution allows easy modifications to follow sonar changes and changes to other sonar systems.


3.3 Navigation

Two types of navigation modules are run in trainer and can be selected for other applications.
One is typical module, running simulation software and displaying data projected on bathymetric map with indication position of selected features (transponders, targets etc). ROV symbol with an umbilical length and shape are overlayed on bathymetric map to help pilot to act against currents.

Bathymetric map of the area can be loaded in electronic form of agreed format.

Other module is navigation data integration computer that gathers data from ROV control system, hydroacoustic navigation system, and ship's navigation system. Current tactical situation in geographic coordinates is displayed to a ROV pilot botch in graphical as well as in alphanumerical for. The computer is external to the simulator itself but uses data generated when simulator is running.

  4 Lessons and high level modifications
4.1 Lessons

To allow a pilot to develop mental and manual skills several lessons are prepared. One can start from experimental tank navigation with defined coordination training. This allows to get familiar with vehicle dynamics and principles of interactions with manipulated objects. More task oriented lessons can follow with difficulty increase. The lessons can be utilised both in training end skills evaluation (exams). Further lessons can be created using dedicated script language according to expected mission tasks and conditions.

4.2 Space editor

Current space definition is limited to 400m x 400m area. Using space editor a training supervisor is able to customise ROV operational space. Basic operation is to build bottom geometry. This is accomplished by simple self graphical tools similar to that used in drawing programmes. This is followed by location of objects and structures. Located objects can be oriented and partly buried in sediments.
Extensive base of objects (mines, stones, coke cans) has been built for current application. This can be extended by introduction of any objects that can be defined by geometry, optical and acoustical characteristics and dynamic behaviour if object is suspended or can be moved on the bottom.


4.3 Mission planer

Using means available in simulation software can be used to prepare current mission environmental and geometrical data and experiment with several ways solutions of objectives Best way to accomplish the mission task can be found this way prior to planned dive.

4.4 3D navigation tool

Application of the simulator graphical and interfacing capabilities can be used to present current tactical situation in 3Ds. It is valuable toll for Pilot operating in difficult spaces such as rig structures, wrecks, caves etc. Data for this application are to be collected from real ROV system and presented overlayed on data (in graphical form) regarding space geometry.


5 Range of an offer

Several options of software/hardware configurations can be offered to a customer. Basic feedback information from customer regards:

- Simulation system purpose (training, examination, planning, real time 3D navigation)
- Vehicle dynamics, visualisation means and manipulation devices
- Environment data and space geometry
- Installation data (free standing, built in, delivered as complete trainer)
- Hardware preferences.

Using these information a range of feasible solutions will be built and offered ranging from single device simulator running on office PC to the set of modules operating in or beside copy of customers ROV console. ROV console built in systems can also be offered in cooperation with vehicle manufacturer.

80-233 Gdańsk, ul.Narutowicza 11/12, Poland
ph. (48 58) 347 19 91, fax: (+48 58) 347 26 99, e-mali: sek8oce@pg.gda.pl