apps for iphone
AntiCollision for iPhone and iPad version 1.0.0 is now available
The first version of AntiCollision for iPhone and iPad was published yesterday. Version 1.0.0 is now available for download in the App Store. This is a totally free app, with no advertisements.
A user manual will soon be published, until such time the manual for AntiCollision on Android can be downloaded from this website, from the page ‘User manuals for Oil Calculators and other apps’. There are only minor differences between the two versions.
The updated manual for AntiCollision on iOS is now available from the following page in our blog: User manuals for Oil Calculators and other apps.
AntiCollision is a ship simulator with accurate real-time ship behaviour, coupled with a RADAR/ARPA simulator that lets you be in charge of your own ship and do what is necessary to prevent a collision with any ship.
This is a great tool for junior deck officers who are preparing for their exams and want to have some hands on experience in avoiding close quarter situations with other vessels. The app can run both in Portrait and Landscape mode, and can be rotated at any time without having to interrupt the session (contrary to the Android version, where you have to select either Portrait or Landscape before running a simulation).
You have control over the main engine, and you can use either auto pilot or manual steering on your own ship. The preferred mode is obviously auto pilot, this is also necessary (at least prior to running a simulation) in order to be able to set up an ARPA scenario correctly.
Main Screen
The ship model is a VLCC, which you can choose to be fully loaded or in ballast in the General Settings screen. The user can select either Nautical Miles or Metres as distance unit, and telegraph setting, speed and course can be setup here in preparation for a simulation run. When selecting a telegraph setting, the corresponding speed is set automatically but this can be overridden with a custom value. During simulation, the vessel will automatically work it’s way to the speed that corresponds to the telegraph setting.
There is a switch called ‘Swingtest Autofinish’, which will automatically complete a swing test when running the Auto Pilot Control Unit, if the app detects that the controller has reached steady state after carrying out the swing. Below that there is a switch which lets the user choose between 500 milliseconds and 1000 milliseconds, which is the interval at which the graph is recorded during monitoring or swing test / step response test. At the bottom of the General Settings screen, there is an ARPA Alarm level switch, which decides at which CPA target vectors will change color to red from white. In below image, the alarm is set to 1 NMile, so that any target with a CPA less than 1 Mile is shown in red color on the radar screen.
General Settings
Rudder Settings: you can choose if you wish to use one or two steering motors, and you can set the rudder limit and rate of turn limit (for when you are using auto pilot mode). Rate and rudder limit can be set between zero and 35 degrees. When using auto pilot, the rate and rudder limit are by default both set to 10 degrees.
Rudder Settings
The ARPA editor lets you activate a maximum of 6 targets for which you can choose individual range, bearing, course and speed.
You can also choose to let the app set these targets with random parameters. Any target data that you enter in the ARPA editor for the 6 ships is saved in the app and will be available the next time you open the app. The green switch on the right hand side activates and de-activates a selected target.
The selected target is shown in green color, our own vessel in yellow and the other available targets are shown in white. When you de-activate a target, it disappears off the screen, and will not be visible in the radar during a simulation.
The ARPA screen as shown below can be zoomed in and out between 24 NMiles and 0.5 NMiles. For running a simulation, entry of range, bearing, course and speed is important, length and width can be left empty as these parameters currently bear no significance in the simulation.
To select another target, press the button on the top (marked ‘1’), this will present a small window with a choice of the six available targets. Upon pressing the desired number, the data of the newly selected target will be shown. The clear button clears all data for the currently selected target. The ‘Random’ button assigns semi random values for course, speed, range and bearing to the selected target, based on our own ship course and speed.
ARPA editor
The app also contains an ARPA scenario chooser: there are 7 pre-defined scenarios to choose from. When you select one of these, either 2 or 3 target ships are automatically setup, in scenarios that put your own ship in a close quarter situation. You then have to decide what to do to put your vessel back in a safe condition. This is a bit quicker than entering ships in the ARPA editor.
Ships that are entered through the ARPA scenario chooser are automatically copied into the ARPA editor as well, but they both override each other. If for example you choose scenario 7 (which is shown in the ARPA editor in above screen shot)in the ARPA scenario screen, and you then go to the ARPA editor and change the range and bearing of a target, or de-activate it, what you will see in the Radar during the simulation is the targets confirming to the last edit you carried out in the ARPA editor.
Conversely if you set up targets in the ARPA editor and then go to the ARPA scenario screen and select an ARPA scenario, this scenario will override whatever was done in the ARPA editor. So if you activate all six targets in the ARPA editor, only three targets will be active if you afterwards select scenario number 7 in the ARPA scenario screen.
It is important to note that prior to setting up targets either in the ARPA scenario chooser or in the ARPA editor, the simulator must be set to Auto Pilot by pressing the ‘Set to Auto Pilot’ button.
Once own ship course, speed and telegraph setting have been set up, steering has been set to auto pilot, and targets have been selected and set up, the user can start the simulation by pressing the ‘Start’ button. At this time the clock will start running, speed and telegraph setting will show as selected in General Settings and our own ship’s position will update every 2 seconds. We can now press the ‘View Radar’ button to see what is going on in our radar screen:
Radar Screen
In the above screenshot we can see the three target vessels around us. By default the radar screen is set at a range of 12 NMiles, showing North up, with the ARPA off, so we would only see the blips of our three targets on the radar.
When we press ‘ARPA’, the vectors for the three targets will show (initially in true motion). By pressing the range selector we can set the range to for example 6 NMiles, and by pressing the plot interval selector we can set the plot interval to for example 12 minutes.
By default range rings are turned off, and by pressing ‘Rings’ we can turn them on. Trails are also by default set to off and we turn them on by pressing ‘Trails’, so you can see the past tracks of both your own ship and the targets.
The radar display can be set to either ‘Head Up’ or ‘North Up’ by pressing the appropriate labels in the bottom of the screen. The default presentation is North Up.
If we want to see TCPA, CPA, speed, course, range and bearing of a target, we just have to press anywhere near that target and the ARPA computer will pick up the necessary data and display them in the bottom right corner of the radar screen, as shown in the above image. Targets and target data can be shown in either true or relative motion by pressing the ‘True’ or ‘Rel’ label.
By pressing on the data display in the bottom right corner we can remove the selection and select another target. When a target is selected, it has a green square inside its target vector as can be seen in the above screenshot, where the target on our port side has been selected. By pressing on the ‘Sweep’ label, we can turn the sweep on or off.
In the top right corner of the screen alternately the time running and our own ship’s course and speed are displayed. In the top left corner the range and bearing of our cursor is shown.
If we want to change course or speed, we can do so within the radar screen by pressing the ‘Action’ label. A window will pop up with the choice of increasing or decreasing telegraph, and increasing or decreasing our set course, either by 1 degree or by 10 degrees.
The Auto Pilot Control unit is a great tool for the scientists among us, who wish to optimize the steering behavior of our own vessel. The app can carry out swing test and step response test automatically, at the push of a button.
The swing test can also be stopped automatically, on the controller reaching a settled state after completing the swing. At any time during a test, the user can stop the test and save the current graph data to a csv file, which can either be downloaded, or viewed in excel or a similar app.
The control parameters of the pilot control unit can be changed, so that the user can optimize the controller for their specific iphone / ipad.
The unit has five buttons: Start Monitor, Update, PV x 1, Swing Test and Step test. Start Monitor does just that, it monitors and records the auto pilot’s behavior during a simulation, and can be used for example to manually observe a course change that is being carried out by the auto pilot.
The Update button lets the user save the 4 parameters (PGain, DGain, Tpi and Td) upon changing them. Parameters can only be changed if no monitoring or swing test / step test is carried out.
Monitoring, Swing test and Step test can only be carried out if the simulation is running, and both Swing test and Step test can only be started if the auto pilot is in a steady state, while Monitoring can be done anytime, also if the vessel is in the process of carrying out a course alteration. Upon completion of a Swing or Step test, or when a Swing test is stopped automatically, the app will ask the user if they want to export the data to local storage.
Auto Pilot Control Unit
Pressing ‘Yes’ in this case will result in the visible graph data being exported to a csv file, which will be saved in the iphone’s / ipad’s documents folder. The exact file name and path will be shown on screen for 4 seconds so the user can take note of it:
Auto Pilot Control Unit saving data
This data can then be viewed in for example excel, or it can be saved to a desktop, for producing a detailed graph. It is important to note that the graph data as shown on screen during a simulation and the actually exported graph data are slightly different: the exported graph data are the actual data collected during the run, whereas the graph data as shown in the screen like above have been adjusted for convenient viewing: MV data on screen has been clipped between 0 and 100, and PV / SV data has been adjusted in order to be able to position the two graphs nicely on top of each other. The exported data contains all the actual, unadjusted values including the spikes in the MV data, shown below:
Exported raw data
Ship manoeuvring: the app contains a real time accurate manoeuvring model, that simulates accurately the behavior of a real VLCC.
Quick start guide:
- Go to General Settings, use the telegraph drop down to select the desired speed, and enter a heading of your choice. You can also choose between loaded and ballast condition. This changes the manoeuvring behavior of your ship. In General Settings you can also choose whether you want to run the app in landscape or portrait mode.
- Return to the main screen (by pressing ‘OK’) and press the ‘Auto Steering’ button to turn on the auto pilot.
- Press ARPA Scenario. Select one of the seven available scenarios.
- You are automatically returned to the main screen.
- Press ‘Start’ to start the simulation.
- Press ‘View Radar’ to go to the radar screen; targets that have a CPA equal to or less than the ARPA alarm limit (by default 1 NMile) show up in red color, if the CPA is more than the ARPA alarm limit the vector is shown in white. You can get information on a target by moving the cursor on top of a target. You will see the info appear on the lower right corner of the radar screen. If you want the info to disappear, you can move the cursor on top of the target info and it will be erased.
- If you have a target that you want to take action for, you can either select the ‘Actions’ checkbox, or return to the main screen to adjust either course or speed. If you use the ‘Actions’ checkbox, a menu will appear that gives you a choice of speed and course alterations. Then, if you select one of the options in that menu, such as ‘Course +10’, your ship will alter course 10 degrees to starboard (in real time).
- If you select ‘Trails’ when you start, you will see the effect that a course or speed alteration has on the CPA of your targets.
Mooring Marine Consultancy 