Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Rate Thread Display Modes
Old 05-08-2015, 04:45   #1
Registered User

Join Date: Aug 2015
Posts: 3
¿Radar and autopilot together?

Hello, I am new here, I hope to enjoy and learn from all of you.

I have a question:

Now cars are starting to "self-drive". At least intuitively, it seems it would be easier to "self-drive" a boat rather than a car. In particular, I am thinking in an autopilot slightly changing the direction if and when a radar finds "something strange" a few miles ahead.

Does this interplay between radar and autopilot exist?

I am asking this because people on board could sleep on long trips at night (of course, with reasonable precautions).
__________________

__________________
farstar is offline   Reply With Quote
Old 05-08-2015, 05:58   #2
Senior Cruiser
 
Sailmonkey's Avatar

Cruisers Forum Supporter

Join Date: Sep 2009
Location: Houston
Boat: '76 Allied Seawind II, 32'
Posts: 5,766
Re: ¿Radar and autopilot together?

Have you never watched radar when the seas pick up or a squall line passes through?


Sent from my iPhone using Cruisers Sailing Forum
__________________

__________________
Sailmonkey is online now   Reply With Quote
Old 05-08-2015, 06:15   #3
Registered User

Join Date: Aug 2015
Posts: 3
Re: ¿Radar and autopilot together?

There will be "false negatives". But that is fine. Think about cars: the number of potential pitfalls/errors from radars and autopilots on the road is billions of times higher than the corresponding risks at sea. But it seems we are on the verge of having cars with autopilot.

So, if cars can do it (with dozens of other cars interacting, at high speeds, at very short distances, with lots of unknowns), boats can also do it (the only risk is ONE other boat, usually at low speeds, with identifiable trajectory, and probably a single, small movement of trajectory avoids any potential problem).
__________________
farstar is offline   Reply With Quote
Old 05-08-2015, 06:26   #4
Registered User
 
FamilyVan's Avatar

Join Date: Nov 2014
Posts: 1,779
Re: ¿Radar and autopilot together?

There are autpilots that can be programmed to follow routes on chart plotters. As far as RADARs go, the preferred method is to set "guard zones", with audible alarms. These alarms will wake up or get the attention of the crew so they can make an assessment of the situation and manually alter course or reprogram their autopilot.

One of the things I like least about sailing is steering, I always use my autopilot but the thought of using a computer for dynamic collision avoidance gives me the willies. I don't think machines are smart enough yet.

Sent from my XP7700 using Cruisers Sailing Forum mobile app
__________________
FamilyVan is offline   Reply With Quote
Old 05-08-2015, 06:46   #5
Registered User

Join Date: Aug 2015
Posts: 3
Re: ¿Radar and autopilot together?

You can consider the current status with guard zone is the interaction between the radar and the autopilot is "do nothing".

I believe there would be nothing to lose and a lot to win, if the interaction said "if we are at 1 mile from a big metal object, steer 5 degrees from the current direction".

If my trigonometrics does not fail me, 1 degree in a mile is about 30 meters. 5 degrees is about 150 meters. So, a small change in direction simply avoids a potential crash.

Why not have that?
__________________
farstar is offline   Reply With Quote
Old 05-08-2015, 06:49   #6
Registered User
 
FamilyVan's Avatar

Join Date: Nov 2014
Posts: 1,779
Re: ¿Radar and autopilot together?

That technology is called ARPA or MARPA on small vessels and has existed for many years. It will help you calculate your course to steer to avoid a collision, but human interference is still a part of the process.

Sent from my XP7700 using Cruisers Sailing Forum mobile app
__________________
FamilyVan is offline   Reply With Quote
Old 05-08-2015, 07:25   #7
Registered User

Join Date: Oct 2007
Location: Winters cruising; summers Chesapeake Bay
Boat: Catana 471
Posts: 1,239
Re: ¿Radar and autopilot together?

Quote:
Originally Posted by farstar View Post
I am asking this because people on board could sleep on long trips at night (of course, with reasonable precautions).
I recommend you Google and understand "Rule 5, Proper Lookout". A good place to start learning how to manage a vessel. Bottom line, somebody has to be awake being a lookout and gadgets can't take their place.

Dave
__________________
2Hulls is offline   Reply With Quote
Old 05-08-2015, 07:44   #8
Registered User

Join Date: Mar 2015
Location: NC, USA
Boat: IslandPacket Packet Cat 35
Posts: 23
Re: ¿Radar and autopilot together?

You may want to check out the Office of Naval Research self driving boat competition. MIT won this year with a self driving RIB, I think.

Sent from my LG-H443 using Cruisers Sailing Forum mobile app
__________________
ramalkin is offline   Reply With Quote
Old 05-08-2015, 07:57   #9
Eternal Member
 
monte's Avatar

Cruisers Forum Supporter

Join Date: Jul 2011
Location: Australia
Boat: Lagoon 400
Posts: 3,650
Images: 1
Re: ¿Radar and autopilot together?

As mentioned above, radar returns more false targets than real. Waves, birds, rain etc. radars need to be continuously tuned for the conditions to give the desired image. Many yachts and timber or glass fishing boats don't even show up at close range when an offshore standard setting is used. So in answer to your question about automatically changing course to avoid a target, it's just as likely you would run over another vessel unseen by the radar. Also detecting a target on radar requires thought about the crossing situation. Turn to port, turn to starboard, stand on, reduce speed, etc, not to mention trimming sails after a course change. Maybe a good idea for a video game but not practical in real life navigation.
__________________
monte is offline   Reply With Quote
Old 05-08-2015, 09:00   #10
Registered User

Join Date: Jun 2009
Location: Back in San Diego after 7 years in Mexico
Boat: Cal39 MrkIII, 1982
Posts: 133
Re: ¿Radar and autopilot together?

There are existing vessels that integrate data from chart plotters, radar, AIS and fathometers allowing for sleep during long passages. They are cruise ships. All the reputable ones also keep a 7/24 human watch system in place.

This is said in humor, with tongue firmly planted in cheek. A tragic example of what can happen in the absence of proper watch keeping was the drowning of an entire crew on a mid-30 foot sailboat in the Newport to Ensenada race several years ago. Around midnight of the first night out, they sailed into the rocky shore of the north Coronado Island. All hands lost. Nothing substitutes for an alert watch around the clock while underway.
__________________
neophytecruiser is offline   Reply With Quote
Old 05-08-2015, 10:14   #11
Senior Cruiser

Cruisers Forum Supporter

Join Date: Mar 2014
Location: Anacortes
Boat: previous - Whitby 42 new - Goldenwave 44
Posts: 1,735
Re: ¿Radar and autopilot together?

You obviously don't grasp that boats on the water don't follow the same rules that cars on a road do. A car avoidance system can reasonably expect that other cars will "tend" to stay in the right lane. Boats are under no restrictions and can cross in front of you with no restrictions. A guard zone on your radar can be useful if you can put up with all the false negatives (and false positives). Knowing the current state of common failures in electronics in everyday life, I am reluctant to give my life over to them. Airplanes should be even easier to fly on autopilot but you won't find anyone suggesting that the pilots all take naps at the same time.

I have actually been known to nap on watch when well off shore and not in shipping lanes but I am always in the cockpit ready to deal with all the issues that can come up on a boat in the dark on the water. But I have also had to change course a thousand miles from any land when four ships over a week period were on a collision course with us - in daylight. But there was also the time last year when I crewed on a boat and we could not pick up on the radar a very large USCG tender two miles away - in daylight - despite no problems with picking up any other boats/ships up until then. And then two days later, a brand new aluminum catamaran was passing through our "fleet" and asked us if we could pick him up on radar. It was poor visibility at dusk but not one of 6 boats could pick him up despite having his exact location known. We did finally pick up his nav lights going north but no one ever got a radar signature. Three of the boats had the latest and greatest digital radars.

Is it technically possible - or course it is. But I doubt very much that any radar manufacturers will build in this tech any time soon, for liability reasons. And, as noted, a watch is required by nav rules. But go for it. May be you can patent a new design and make your fortune.
__________________
exMaggieDrum is offline   Reply With Quote
Old 05-08-2015, 10:47   #12
Registered User

Join Date: Jul 2013
Posts: 52
Re: ¿Radar and autopilot together?

PI times the diameter of 2 miles is the circumference, equals 6.28318 miles times feet in a mile equals about 39,174 feet , divided by 360 degrees equals approximately 92 feet per mile per degree. So the approximation of 30 meters is close but slightly larger. To make it work, there would have to be something in the program to decide how much deviation from course would be enough to safely clear the obstruction, plus it would have to integrate with the GPS charts,etc. pretty complex, but eventually someone will have it in the price range of cruisers,
__________________
stevebein is offline   Reply With Quote
Old 05-08-2015, 21:24   #13
Registered User

Join Date: Mar 2015
Posts: 10
Re: ¿Radar and autopilot together?

If welike it ir not it is comming as sure as GPS, cell phones or the personal pc came
__________________
Bjooste is offline   Reply With Quote
Old 05-08-2015, 21:35   #14
Registered User
 
sy_gilana's Avatar

Join Date: Jan 2005
Location: On board
Boat: Van de Stadt 50'
Posts: 1,101
Send a message via Skype™ to sy_gilana
Re: ¿Radar and autopilot together?

Don't like the idea at all...

Imagine your autonomous vessel changing course to avoid a target picked up a mile ahead. Great, you say, success you say, and merrily carry on sailing right past a family in a liferaft that have been holding up a bucket on an oar to be spotted by a diligent watch-keeper like you should be.

Autonomous vessels are a danger to all those that put to sea.

There is NO substitute for a good look-out.
__________________
Tight sheets to ya.
http://gilana.org
sy_gilana is offline   Reply With Quote
Old 05-08-2015, 22:44   #15
Registered User
 
buzzstar's Avatar

Join Date: Apr 2012
Location: ashore in So Calif.
Boat: No more boat (my medical, not the boat's)
Posts: 1,267
Re: ¿Radar and autopilot together?

Not a good Idea to depend on a mechanical/electronic watch in place and stead of a proper lookout. It is done, perhaps most often by solo sailors in the open ocean away from shipping lanes, but it is still not within the rules, even if those rules are stretched for solos.

My own past solo sailing practice has been to sail at night, and heave to during the day with anchor light, and when it has been available, a radar watch. I figure I am easier to see in daylight, and even if I am not anchored, being hove to is close enough so the anchor light violation is minimal. My anchor chain, even mated with everything else on board I can tie to it, does not have any scope at say, 1,000 fathoms, particularly when the anchor is just hanging there.
__________________

__________________
buzzstar is offline   Reply With Quote
Reply

Tags
autopilot, radar

Thread Tools
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Can a ST 5000+ Raymarine Autopilot Control head work together with a Autohelm 2000 St Franziska Marine Electronics 12 08-08-2015 08:33
Beans and Rice Together in Pressure Cooker ? saltysiren Provisioning: Food & Drink 33 01-03-2011 18:20
Nav Systems, Charts and Weather Together JamesANGreen Marine Electronics 6 15-10-2010 20:38
Generator and Power Surge Protector Won’t Play Together Dream Maker Electrical: Batteries, Generators & Solar 3 10-07-2008 11:46
AGM and Wet Cell Together MV Electrical: Batteries, Generators & Solar 21 29-04-2008 13:30



Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 05:31.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.