Practical Exercise No. 1
The purpose of this exercise is to use the a DP system in Auto Position mode, and to get familiarised with some of the different features available.
USE SET UP SHEET TO SET UP DP FIRST
• Use the simulator set-up values.
N : 60 00N
E : 002 00E
Wind: 10 m/s 340 0
Current : 0.5 m/s 310°
Draught : 7.0m
• Deploy acoustic beacon A (Simulation data tab) first
• Deploy 2 DGPS note that DGPS becomes RO (The position will change)
POSITION: ALARM 4m WARNING 2m HEADING: ALARM 3 °
Heading: 043 0
There are 4 alternative methods, which? ... Bring the vessel 10 m to starboard.
Bring the vessel 18 m in direction 113. Bring the vessel 18 m west.
How many methods are there of changing position? ……… Re-centre the display to put vessel back in the middle of the screen.
On Simulation page (mimic index) simulation data PME Toggle the acoustic beacon noise to High
Check PME weightings and repeatability
Weight increases or decreases ……… Repeatability increases or decreases ……….. Toggle beacon noise to low
Change ROTATION CENTRE (COR) to the bow.
What is your Position? N ……….. E ……….
Change the REFERENCE ORIGIN (RO) to Acoustic beacon on the coordinate setup page.
What is your Position? N ……….. E ……….
Has the vessel moved? Heading : 348˚ Speed : 0.6 m/s
Take the vessel to a position where the bow is 70 m south of your acoustic beacon. Real time trends view :
Trends from the "Mimic Index" - "Standard Mimics" or bottom tool bar Configure three TrendPlot windows :
Fig. 1. Thrust demand X Fig. 2. Thrust demand N Fig. 3. Position error X
What have maximum values been so far in this exercise ? Thruster demand X ...
Thruster demand N ... Position error X ……….. Change to MINIMUM POWER heading.
What is the system selected heading ? ………. When the heading has settled
what is the load on the thrusters ?
Resulting force ………. Tons Direction ……….
Rotate your vessel to the worst thinkable heading in current weather situation. Can you change the heading?
When the heading has settled what is the load on the thrusters ?
Resulting force ………. Tons
Direction ……….
Rotation moment ………….. T*m Change your rotation point back to CG Take the vessel 100m to north with a speed of 1,5 m/s and with a heading of 015˚ Use Low Gain, and observe the overshoot Take the vessel 100m straight fwd from present position. While you are moving toggle the radial error display How many meters overshoot? Use Medium Gain, and observe the overshoot Take the vessel 100m straight fwd from present position. How many meters overshoot? Reference Origin to DGPS Use DGPS as position reference system. Turn HPR off Display units/units Speed to knots (Mimic index -Options) When the vessel is in position with a steady heading, set the vessel speed to 1.5 m/s Heading: 0060 Position limit to: 002m WARNING. 004 m ALARM Which 2 pages show pitch and roll ……….
Which page shows the generators running ………
Which page shows thrusters set point feed-back ………
Move to a new position :
SURGE -16 m.
SWAY 25 m.
What is your Position? N ……….. E ……….
SURGE -16 m.
SWAY 25 m.
What is your Position? N ……….. E ……….
Under Mimic index-Options toggle Position notation between Grid and Geographic presentation, end up in Geographic
What is your Position? N ……….. E ……….
Bring the vessel to a new location, N 60° 00" 7"' E002° 00" 21"' After arrival on location, activate the HPR reference system.
After calibration OK, deselect the DGPS position reference system. Why does the position co-ordinates still show LAT-LON ? ………
Practical Exercise No. 2 Cable ship 2
The purpose of this exercise is to simulate the way a vessel would approach and execute an Auto-track. The exercise is divided into three parts: Planning, Set-up and Execution.
USE SET UP SHEET TO SET UP THE DP Planning:
Set Trainer position prior to going into simulator mode Select trainer. Position Lat 58 28 43.08N long 003 00 06.17E Wind 10 knots 015, wave 0.5m 025, current 1 knot 070 Set the position presentation to UTM co-ordinates. Make sure to be in Zone 31.
Define the following track on the TRACK FOLLOW page : Ensure entry option = E,N absolute
Add 8 waypoints using waypoint control menu Wpt1 E 500200
N 6482250
Wp2 E 500400 Line, Heading ABS 020˚ Speed 1.0 m/s N 6482400
W3 E 500600 Line, Heading ABS 090˚ Speed 1.5 m/s N 6482400
Wp4 E500700 ArcC, Heading INC+0°Spe ed 1.7 m/s, radius 150 m N 6482200
Wp5 E500600 Line, Heading ABS 000° Speed 1,0 m/s N6481990
Wp6 E500400 Arc A, Heading Inc +10° Speed 1.3 m/s , radius 500 m N6481990
Wp7 E500200 Line Heading AB S 315° Speed 1.1 m/s
N6482150
Wp8 E500200 N 6482250
Set-Up
Use DGPS as Reference Origin. Bring the vessel into DP mode.
Turn ON Vessel trail, and display track under screen options Check that the track looks correct.
Activate Limits warning and alarm to suitable values. Go through all the settings on the track follow page
Use these settings, all other settings you have to decide yourself:
Next waypoint = 2
Slider velocity /WP preset = WP presets Forward / Backwards = Forward Continuous / increment = Continuous
Heading = Follow WP presets Intro shift / to WP = To WP
Execution : Go to first WP
Modes select Follow track
When between Wpt 2 and Wpt 3 use the TRACKING button to stop the vessel. How much force is used during stopping? ……….
Start the vessel by pressing the stopped button
When you restart the vesselchange heading preset to follow course
When passed Wpt 4, input a Track offset of 15 metres. Vessel to move on the outer side of the track.
Should the input be left or right? ………..
After passing WP 5 change heading presets to WP presets After you pass WP 6 change heading to 300
Practical Exercise No. 3 Follow Target
Set up DP as per Start up sheet
In Modes menu/ Options set values to knots In SIMULATION set:
Latitude to 60 degrees north
Longitude to 02 degrees east
Wind to 17 knots from 055°
Sea Current to 0.5 knots from 075° Enable 2 DGPS.
In screen options ensure ROV trail is on.
PME display ensure 13 is showing position fixes.
On simulation set ROV "free" to "attached" Set offsets to stb 50m Fwd 0m Set recovered to deployed
Enter ROV speed and direction
Under modes menu select Follow ROV
Under alarm settings set the Reaction Radius to 12m. Set "stopped" to "moving"
Drive the ROV slowly Observe the reaction of the vessel to the transponder movements.
If the vessel is not keeping up (Observe "to destination" distance) what can you do? 1.
2. 3. 4.
While the ROV is moving, select successively High, Medium and Low Gain, and note the different thruster power used in each. Also, try changing the Reaction Radius to 5m., then to 25 m. (Alarm settings - Top menu).
Reverting back to Low Gain and 12m Reaction Radius, try increasing the speed of the Mobile transponder, noting the effects.
Slow the ROV down and then move the vessel 10m to starboard Change the vessels heading 90 degrees to port
Practical Exercise No. 4
The purpose of this exercise is to use the a DP system in Autotrack using a plough to lay cable.
USE SET UP SHEET TO SET UP DP
• Use the simulator set-up values.
N: 60 00N E: 002 00E Wind: 3 m/s 340 ° Current: 0.5 m/s 310° Draught: 5.5 • Use 2 DGPS Set heading 000
Set up follow track using the pointer option, the track does not have to be precise reasonably close will do
WP 1 present position WP2 500m 000 then WP3 500m 030 then WP4 500m 060 then WP5 500m 090 then WP6 500m 120
Use line for ali waypoints; Slider or track speed to 2 m/s, next waypoint 2
Under screen option ensure ROV trail is on PME display display beacon 12 fixes
On Simulation page select simulation tab, select plough tab Set "brake off' to "brake on"
Set "free" to "attached"
Set "recovered" to "deployed" Change to follo\v track
Then try and use track shift (under change position menu) to keep PLOUGH on track If heading does not match track heading use change heading function, or use follow course option