AT CAD Team/AT ship control stand
The AT ship control stand is a control stand that can be used on both watervehicles and LTA aerial vehicles. It also includes a self-steering system, allowing the vessel to operate autonomously (after input of the GPS-coordinates).
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[edit] Setup
[edit] Automated steering
As can be read at the image, the control stand has footpedals that are used to steer the vessel. The footpedals are linked together meaning that by pressing one of the pedals, the other pedal will automatically raise. The footpedals are pressed using the servo which is controlled solely by the servo control (SC). The UMPC is used to only display the map and the current GPS position thereon, GPS compass and the suggested coarse corrections. The UMPC itself does thus not provide any steering. It does export the GPS-data though, and as too can be read on the image, can export the plotted coarse as follows:
- using a single GPS-coordinate: this allows great coarse deviation using ie the sensors (wind/current meters)
- using several GPS-coordinates (= a "GPS-coodinate cue"); points are close together and thus do not allow great coarse deviation. This method is necessairy for following a narrow path ie a river, ...
The first method can be made manually and exported to the SC, the second will need to be downloaded using the internet.
[edit] Detecting of vehicles and people
The system uses RFID to detect vehicles and people. Each vehicle has an RFID code and will transmit these at a certain interval. In addition, each ship also transmits a horn sound at a certain interval (both at the same moment). The horn sound simply mentions the position of the vehicle in respect to the lane (ie right or left, see http://en.wikiversity.org/wiki/Improved_boating_regulations ) Once 2 vehicles get near each other (ie 50m apart or so), the vehicles will detect each other due to the combined sound/RFID signal (each vehicles both has a microphone and a RFID receiver) and will, upon receiving of these signals, then communicate their their exact GPS position and heading (heading can be given since each vessel can determine his own heading based on the previous GPS-navigation point). If the system sees that a collision would result if both vehicles continue their path, the system shuts off by engaging KS1. Both vehicles then stop, and the driver himself is then expected to take over the steering.
People on the other hand can also be detected. Each person can be equipped with a RFID code (passive transmitter, implant). The vehicle then sees any people in the vicinity; for usage in MOB (man over board) operations, the system will signal with the horn when a person is in the close vicinity of the vessel (ie at 25m from the vessel, hence in the water). This is especially useful when a person has fallen overboard and can not be easily found due to high waves or bad visibility.
[edit] The meters
What is immediatelly obvious with the system is that, although there are meters for wind speed, current speed, current direction, ... these are not shown on the control stand. This is because the meters are electronical, and the data is immediatelly inputted to the UMPC to allow the UMPC itself to calculate the best coarse.
For safety reasons, a backup system is present though, in the form of manual calculation of a (near optimal) coarse. This is done using the magnetic compass and the scratchpad. Using dead reckoning, we can keep track of our position. Given that a magnetic compass doesn't point to the true north, the compass tables need to be used. In addition, we can (roughly) take into account the deviation by the wind (but not the current) by taking a look at the global wind currents (from the blank world map; BWM btw also doubles to put down your location) and/or by looking at the wind vane. The wind vane is thus visible from the steering booth, but the wind speed meter offcourse isn't, so we will need to use a rough general measure (ie 10% drift) for the deviation.
[edit] The kill switches
- KS1: you want to power off the automatic pilot (to pilot the ship manually), yet still be able to view the meters
- KS2: you want to disconnect the providing of meter information to the UMPC; this is useful if a meter malfunctions and provides wrong information, causing the airship to do unexpected manouvres. Note that both the meters on the control panel, and the electric meters will be switched off (the latter by means of a wireless transmitter)
- KS3: you want to power off everything, including meters. This KS can be engaged/disengaged wirelessly, so that the owner, while on the ground can halt the airship from where he is.
[edit] Automated sailing ?
Automated sailing (rotating the sail itself towards the wind) isn't present in the system, the system only changes the course of the boat itself (=steers using the helm). This is because although most sails can not rotate 360°, some can (ie wind energy harvester) and these are better used. For special vessels like the AT catamaran, a special system is used since this design is quite specific.
