BRUCE THE AUTONOMOUS ROBOT AUTOPILOT

In the crewed vessels of old a boat was steered using a compass heading plotted on charts. A crew member would adjust the course of the boat using a tiller connected to a rudder, or with the ships wheel connected via cables or hydraulics to the rudder(s). This was a demanding job for experienced crew members who must read the compass needles and make course corrections to keep the boat on course. The course was plotted on the chart to begin with before the voyage and the heading (the angle in degrees of the compass) to the next destination (waypoint) was the instruction to the helmsman to steer toward.

Today, this task can be handed to an autopilot, which steers the boat automatically to the next waypoint.

Add a Chart Plotter and paper charts and the traditional magnetic compass become redundant. Add an autopilot and the skipper becomes redundant, save for inputting the waypoints (a waypoint is a compass bearing, or rather a point of longitude and latitude) from one destination to another. Note here that an autopilot does not control the boat speed, it just steers the boat to keep it on course.

A skipper comes into his own when something out of the ordinary happens, such as something breaks on the boat; another ship veers into your course, pirates attack the ship, or there is a Mayday call to be answered - even a man overboard distress signal - but we'll come to that when we introduce Captain Nemo.

An autonomous autopilot, is one where the skipper is replaced for all of the usual navigation events with an onboard computer based skipper. In this Project we refer to our autonomous skipper as Bruce. The picture below is of a model aircraft autonomous autopilot, where if the model goes out of radio range, so that the human pilot has lost control, this tiny box of tricks will take control and automatically return the aircraft to the point of origin.

This tiny microcomputer, linked to a GPS antenna, a radio receiver and a camera, can pilot a model aircraft back to base all by itself for just $299. $299 purchase includes: (1) RVOSD (1) GPS (1) 70A current sensor (1) IR Remote (4) 150mm male to male wires. Integrated sensors include: - 2x Gyro 1x accelerometer - Barometric pressure sensor - Magnetometer. Flying by video is much the same as flying a drone aircraft, only a hobby version of the military systems for the Predator by General Atomics

Development of the basic digital steering controls depends on a proportional rudder servo and motor speed controller. This system would provide control in a similar manner to a remote (radio) control system, through general throttle and rudder commands.

An Autopilot, though, goes one stage further being driven by a digital signal via a program, to instruct a mechanical tiller or hydraulic actuator servos, to steer a course from one point on the planet (bearing A) to another point on the planet (bearing B) using the GSP to establish the boat's position. These bearings are called waypoints and the waypoints are all strung together via a computer program, linked to a visual display generated from digital maps, rather than paper charts.

With an origin and destination provided, and constant waypoint comparison with the boat's actual position, the distance and direction between them can be easily calculated and corrections made - a hundred times a second if necessary.

If SolarNavigator is to achieve a world circumnavigation unaided, Bruce the computer skipper must go one step further. An Autopilot and Chart Plotter cannot anchor a boat, nor dock a boat. For that we need something special. For that we need Onboard Robotics, to carry out all the functions that a human crew might perform - automatically.

Electronic self-steering is controlled by electronics operating according to one or more input sensors, invariably at least a magnetic compass and sometimes wind direction or GPS position versus a chosen waypoint. The electronics module calculates the required steering movement and a drive mechanism (usually electrical, though possibly hydraulic in larger systems) causes the rudder to move accordingly.

There are several possibilities for the interface between the drive mechanism and the conventional steering system. On yachts, the three most common systems are:

Depending on the sophistication of the control unit (e.g. tiller pilot, steering wheel attached Chartplotter, ...), electronic self-steering gear can be programmed to hold a certain compass course, to maintain a certain angle to the wind (so that sailing boats need not change their sail trim), to steer towards a certain position, or any other function which can reasonably be defined. However, the amount of power required by electrical actuators, especially if constantly in action because of sea and weather conditions, is a serious consideration. Long-distance cruisers, which have no external source of electricity and often do not run their engines for propulsion, typically have relatively strict power budgets and do not use electrical steering for any length of time. As the electronic autopilot systems require electricity to operate, many vessels also make use of PV solar panels or small wind turbines on the boat. This eliminates extra pollution and cuts costs.

C-Map owns this ‘historic’ machine, which is thought to be the first chart plotter sold in the U.S in 1985. Navionics founders Giuseppe Carnevali and Fosco Bianchetti developed the first crude vector charts and this Datamarine-labeled plotter to show them. (Bianchetti later founded C-Map). About 5 years later the first PC based charting programs came out.

CHART PLOTTING MACHINES - THE NEXT LEVEL

It was only a short time ago that the only alternative for computer navigation systems were devices called chart plotters. Almost all use proprietary formats for their data and maps which they sell on data cards. Each of these covers a geographic region and the user purchases one for each area they boat. These are rugged hardware systems that can support external sensors to record and display water depth, water temperature, wind direction and much more. Some can communicate with other systems on a boat such as radar and autopilots. They are still evolving and are still expensive to buy and maintain when compared to Global Positioning Systems (GPS) which use a worldwide network of satellites to determine a very accurate location and may now be had for under $100.00 today with free charts. That apart, we are developing a robot boat that has a hugh degree of failsafes built in.

Modern chartplotters may integrate GPS data with an electronic navigational chart (ENC). The chartplotter displays the ENC along with the position, heading and speed of the ship, and may display additional information from radar, automatic information systems (AIS) or other sensors. As appropriate to particular marine applications, chartplotters may also display data from other sensors, such as echolocators/sonar.

Electronic chartplotters are by nature processor intensive. They need to retrieve the GPS signal and overlay that on a map updating every few milliseconds. Some GPS software can run on standard computers, but most of the higher end is dedicated equipment. Especially when the chartplotter generates three-dimensional displays, as used for fishing, considerable processing power and video memory can be needed.

As with all marine systems, chart-plotters generally are not used alone. In commercial ships, they are integrated into a full system of marine instruments that can guide the ship under any conditions. These other instruments include Sonar transducers, integration with 2 Way Radio communication devices and emergency locators (EPRIB).

The integration of these devices is very important as it becomes quite distracting to look at several different screens. Therefore, displays can often overlay charting, radar, sonar into a single system. This gives the captain unprecedented instrumentation to maneuver the ship. With digital backbones, these devices have advanced greatly in the last years. For example, the newer ones have 3D displays that allow you to see above, below and all around the ship, including overlays of satellite imaging

Electronic Charts

An individual electronic chart, or, more commonly, a database of charts, is the heart of a chartplotter. The chartplotter system can be no more accurate than its charts. While there are different formats for electronic charts, there are even more important quality and legal aspects.

Without charts that are accredited by appropriate governmental organizations, a chartplotter is an example of an Electronic Charting System (ECS). When the charts meet the technical requirements of the International Maritime Organization (IMO) and national hydrographic bodies, the chartplotter can qualify as an Electronic Chart Display and Information System (ECDIS). ECDIS legally can be substituted for paper charts while navigating in active waterways, but vessels are required to maintain paper charts if their chartplotter does not use ECDIS.

ECDIS will use IMO-standardized formats, but some chartplotters require specific data formats. A charter may use one or both types of ENC:

Capsize drill is something most serious catamaran and trimaran sailors familiarize themselves with. No matter how well a boat is designed it is always a compromise. In the normal course of events it is unlikely that SolarNavigator could overturn. Captain Nemo would have folded the solar wings and lowered the hull into the sea to act as a sea anchor, at the first hint of a serious storm, which should cope with the forces that might roll the boat over, such as a freak wave in the Perfect Storm.

But what if Captain Nemo is taking a nap? Let us say that a serious wave has managed to roll the Navigator over. The danger is that if there are passengers, they may be injured. Bruce will attempt to right the boat the moment storm conditions subside. The SolarNavigator has a bubble hull. What that means is that if inverted, the watertight hatches close and seal. A typical boat hull is not watertight and cannot form a safety bubble. There are some exceptions, such as lifeboats, many of which are self-righting. Remember Tony Bullimore? He was lucky to be rescued - his racing yacht could not self-right, but at least it did not sink when inverted.

Well, so far so good, with this off-the-shelf equipment, the SolarNavigator can be set to steer itself around the world.

The next part of the puzzle is to make sure that the vessel can cope with storms. A Cartrplotter cannot do that.

Alloys -	Paints - Coatings
Autonomy - Computers - Software	Project Estimates
Batteries -	Project Objectives
Composites -	PR Events -
Construction - Modular	Propeller -
Diving - Hull survey & repair	Record Attempt
Electronics - Collision Avoidance COLREGS	Screens -
Galley -	Solar Arrays - tracking theory PIC PCB MPPT PV trackers Actuators & circuits
Hydraulics - Active hull -	Stealth - Scorpion laser - Mine hunter
Hull Design - Capsize - SWASSH - Lubrication - Mass	Timber -
Life Support -	Tank Testing - Open water collision avoidance
Model Construction - Hulls - Wings - W'gens - ROV - AI	Tooling -
Motors - DC v AC synchronous	Transmission - gearing & prop shaft/seals
Navigation - Oceanographic Hydrographic Surveying	Treasure hunting - marine archaeology
Paints - Antifouling	Wind Turbines -