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The Solar Boat: Electronics preserving the environment, Part 2

The autonomous solar powered boat is a great solution which utilizes electronics technology to realize a zero-impact for connected navigation on the water such as the case of the interesting SeaCharger experiment (see Figure 1):

“SeaCharger uses off-the-shelf electronics as much as possible. The brains of the boat are an Arduino Mega, an Adafruit GPS, a satellite modem from Rock Seven, a compass from Devantech, and a battery protection/charging circuit from AA Portable Power Corp. A typical brushless motor spins the propeller and an R/C servo turns the rudder. I don’t worry too much about the reliability of the electronics, but I do worry about the motor and servo. Water isn’t the problem: the motor transfers torque to the propeller through a magnetic coupling, so it stays perfectly dry. And the servo has its own custom enclosure with rubber shaft seals to keep water out. But the bigger issue is the time required to get from California to Hawaii: the motor will have to run almost nonstop for over a month, while the rudder servo will have to complete 2 to 3 million cycles….. This time SeaCharger really is dead, but not before it traveled an impressive 6,480 nautical miles.” (Source: makezine.com)

Figure 1

The SeaCharger, an autonomous boat solar powered which has travelled autonomously for 6,480 nautical miles (Source: makezine.com)

The SeaCharger, an autonomous boat solar powered which has travelled autonomously for 6,480 nautical miles (Source: makezine.com)

Electronics technology can be utilized to integrate solar power conversion to feed an autonomous solar powered boat, driven by an “ArduCopter” board, as described in Part 1 of this blog series, with a remote connectivity board:

“ Since the intended use of the ArduCopter board is as an autopilot for a limited-range autonomous vehicle, it comes with an (external) serial radio (using a 433MHz radio to transmit a full-duplex serial stream at 57,600 baud) to communicate with the ground controller. While this radio is perfectly useful for short range operation, to be able to be tracked and controlled no matter where it is the craft needs to be able to use a long-range radio of some form. The original plan was to use a satellite modem (using the Idridium network) to send infrequent (hourly) position reports, and check for mission updates. However, this idea was exchanged for a 3G modem designed for remote access to RS232-based equipment. This modem removed the need for writing and debugging both a communications protocol, and communicating with the satellite modem, and the cost of reducing craft's control range. With the new modem available, the existing telemetry code (which uses a protocol called “MAVLink”) could be leveraged, and combined with the modem's in-built TCP/IP stack sending the transmitted messages to a remote server, a basic tracking server can be written. The ArduPilot source however still needed to be modified, as the update message rate is only configurable in 1Hz increments (which leads to several hundred megabytes per month of data). To reduce this rate to something more reasonable (e.g. an update every 10s) some custom code was used that disabled the built-in periodic updates and replaced with a long-period burst of messages….” (Source: Project Report: Autonomous Solar Powered Boat by John Hodge)

Figure 2

The electronic racks inserted in an autonomous solar powered boat can be utilized to integrate the electronics components into the smart boat: 'Tying all of the parts together is two planks of pine with the various controllers screwed and zip-tied down, and holes cut out for the batteries. This allows the electronics to be easily inserted and removed for maintenance and testing, as well as keeping wiring (and circuit boards) away from the bottom of the hull (preventing failure in the unlikely case of a leak). Connecting the various components (autopilot, modem, radio, ESCs, solar controller ...) is a collection of lightweight signal wire and relatively heavy-gauge power wire. All cables entering the hulls are fully insulated and sealed with a combination of epoxy and silicone. To allow complete removal of the racks without needing to remove this sealing, all of the external cables have distinct and keyed connectors to both allow removal, and to ensure that the cables are always connected correctly'
(Source: Project Report: Autonomous Solar Powered Boat by John Hodge)

The electronic racks inserted in an autonomous solar powered boat can be utilized to integrate the electronics components into the smart boat: “Tying all of the parts together is two planks of pine with the various controllers screwed and zip-tied down, and holes cut out for the batteries. This allows the electronics to be easily inserted and removed for maintenance and testing, as well as keeping wiring (and circuit boards) away from the bottom of the hull (preventing failure in the unlikely case of a leak). Connecting the various components (autopilot, modem, radio, ESCs, solar controller …) is a collection of lightweight signal wire and relatively heavy-gauge power wire. All cables entering the hulls are fully insulated and sealed with a combination of epoxy and silicone. To allow complete removal of the racks without needing to remove this sealing, all of the external cables have distinct and keyed connectors to both allow removal, and to ensure that the cables are always connected correctly” (Source: Project Report: Autonomous Solar Powered Boat by John Hodge)

Do you think the autonomous solar powered boat will be successful?

4 comments on “The Solar Boat: Electronics preserving the environment, Part 2

  1. David Ashton
    March 27, 2019

    Nice project.  But if it was using a 3G modem, how did it communicate in the middle of the Pacific ocean?  Not too many cell towers out there…..

    Was the boat retrieved, and if so what had been the points of failure?  Mechanical, or water getting into the electronics?

  2. Steam Kid
    April 2, 2019

    Just read the article and it says satellite modem, not 3G modem.

  3. David Ashton
    April 2, 2019

    Quote… “The original plan was to use a satellite modem (using the (sic) Idridium network) to send infrequent (hourly) position reports, and check for mission updates. However, this idea was exchanged for a 3G modem designed for remote access to RS232-based equipment.” ….??

  4. CameronRobertson
    April 8, 2019

    Apart from just perserving the environment while out at sea, a similar concept can be applied to a land vehicle. This way, we will get to be as environmentally-friendly as we can be regardless of our location. The main aim is to stay as green as we can be especially when a large volume of work needs to be performed.

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