Hey all,
My name is Bret and I work as a research assistant for the University of Vermont. Our department has been approved to build a SeaFox for use in studying and analyzing lake trout spawning habitat. Having very little experience building an ROV for use other than in a pool, I'm very thankful for this site! I plan to build something that resembles the SeaFox retrofit. We have no need for an arm but eventually want to add a shocking electrode and suction sampler...But I'm getting ahead of myself...
I have the basic frame built and I am about to begin purchasing electronics. This is were my expertise is lacking. I'm a fisheries guy and will need all the help I can get! The first thing I'm wondering is if anyone out there has devised a way to control the ROV directly from tether to a computer with a joystick. I'm also wondering if it may be worth it to spend extra money on mini trolling motors rather than use the altered bilge pumps. Did you find trust to be sufficient? The test videos show plenty of movement and I'm not sure it would be work the $300 a pop. I'm sure more questions will persist and I will post pics as I progress. Thanks again for maintaining this site. You made my job a hell of a lot more pleasurable!
Bret
Sea Fox for research
Re: Sea Fox for research
Hello Bret,
For the control, if you can connect the ROV up to the computer then anything is possible. With USB ports they supply power, if you can find a way to supply enough power out then you could power something like a motor (but probably shall require heavy modification of a computer considering USB ports supply from 6V to 24V at 6A). Once you have worked on this you then would need to work on a computer programme which can control power flow to the ROV. This computer programme would then need yet another one to allow it to operate with a joystick. As you can see from this, your best chance would be to ask a computer wizard who is willing to help modify a computer (to get enough power out) and create a computer programme for you.
I hope this helped and good luck!
For the control, if you can connect the ROV up to the computer then anything is possible. With USB ports they supply power, if you can find a way to supply enough power out then you could power something like a motor (but probably shall require heavy modification of a computer considering USB ports supply from 6V to 24V at 6A). Once you have worked on this you then would need to work on a computer programme which can control power flow to the ROV. This computer programme would then need yet another one to allow it to operate with a joystick. As you can see from this, your best chance would be to ask a computer wizard who is willing to help modify a computer (to get enough power out) and create a computer programme for you.
I hope this helped and good luck!
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SoakedinVancouver
- Posts: 117
- Joined: Dec 31st, 2010, 9:38 pm
Re: Sea Fox for research
hi Bret,
I think AHarris meant that the USB ports cannot supply more than 5Vdc @ a maximum of 500mA, but that your thrusters will most likely require between 6 and 24Vdc. No laptop is built to do that, so you will have to lug a battery around no matter what. You could install the battery inside the ROV, or have it in the boat, beside the laptop. You will require an interface between the laptop and the motors. Look up H bridge motor drivers, another choice is relay interfacing. Both setups will let you go in both forward and reverse.
Considering you will be sneaking on nervous nellies, ahem, trouts, you might want to consider controlling the speed of your ROV, which will ideally involve PWM (Pulse Width Modulation) control of your thrusters, as opposed to jogging the thruster ON and OFF... PWM modules are available in kit form, as are the H bridges, "out there"...
I suggest first that you go over all the conversations on this site and hit as many links as you can find. There is a lot of technical info, with plenty of nitty gritty details out there.
I'd be curious to see what you will think of as for a "suction device". I have been playing with the idea of a single shot water displacement/feathery closing fingers arrangement myself, to somewhat gently catch small underwater insects and crustaceans.
Keep us posted, sneaking up, err, I mean, studying trouts in their habitats is one of the reason I am building an ROV, ( don't worry, I would never go and "annoy" them during reproduction time, I am no biologist!)
Mind you, your post reminded me of a long time ago, in Quebec, my father had me and my brother out fall hunting for grouse by a lake where we had a cabin. The neighbors had a "left over of a dock" (hard winters) and our dad had us crawl on our bellies and peek over the end of the dock. To our amazement, there was half a dozen massive brookies just slowly swirling in the shallow water. Dad told us there was a spring under the dock and it kept the gravel nice and clean, and maintened the water at an even temperature, thereby attracting the "monsters" (I mean, we never caught such big trouts in that lake!) in the Fall. For a few years after, I would try to go at least once during the Fall, if only to cut off and trash the fixed lines rigged up by the local poachers...
I think AHarris meant that the USB ports cannot supply more than 5Vdc @ a maximum of 500mA, but that your thrusters will most likely require between 6 and 24Vdc. No laptop is built to do that, so you will have to lug a battery around no matter what. You could install the battery inside the ROV, or have it in the boat, beside the laptop. You will require an interface between the laptop and the motors. Look up H bridge motor drivers, another choice is relay interfacing. Both setups will let you go in both forward and reverse.
Considering you will be sneaking on nervous nellies, ahem, trouts, you might want to consider controlling the speed of your ROV, which will ideally involve PWM (Pulse Width Modulation) control of your thrusters, as opposed to jogging the thruster ON and OFF... PWM modules are available in kit form, as are the H bridges, "out there"...
I suggest first that you go over all the conversations on this site and hit as many links as you can find. There is a lot of technical info, with plenty of nitty gritty details out there.
I'd be curious to see what you will think of as for a "suction device". I have been playing with the idea of a single shot water displacement/feathery closing fingers arrangement myself, to somewhat gently catch small underwater insects and crustaceans.
Keep us posted, sneaking up, err, I mean, studying trouts in their habitats is one of the reason I am building an ROV, ( don't worry, I would never go and "annoy" them during reproduction time, I am no biologist!)
Mind you, your post reminded me of a long time ago, in Quebec, my father had me and my brother out fall hunting for grouse by a lake where we had a cabin. The neighbors had a "left over of a dock" (hard winters) and our dad had us crawl on our bellies and peek over the end of the dock. To our amazement, there was half a dozen massive brookies just slowly swirling in the shallow water. Dad told us there was a spring under the dock and it kept the gravel nice and clean, and maintened the water at an even temperature, thereby attracting the "monsters" (I mean, we never caught such big trouts in that lake!) in the Fall. For a few years after, I would try to go at least once during the Fall, if only to cut off and trash the fixed lines rigged up by the local poachers...
Re: Sea Fox for research
Thanks for the input! It now appears that our budget will not allow us to use a computer interface so that solves the first issue. I will most likely use a 12Vdc battery kept on the boat.
I'm intrigued by the PWM control. Does this also allow for reverse? I was thinking I would use the Johnson 750gph bilge pump for thrusters but if I can modulate the speed maybe I should go with the 1250gph? I am guessing that the higher circulation rate requires more power. Is the PWM control difficult to integrate into the electronics?
Great story by the way, apart from the poaching. Brook trout are one of my favorite species! Speaking of clean spawning gravel, another task of our ROV is to look at the condition and characteristics of the sediment being used by lake trout to lay eggs and how different reef characteristics effect their survival
I'm intrigued by the PWM control. Does this also allow for reverse? I was thinking I would use the Johnson 750gph bilge pump for thrusters but if I can modulate the speed maybe I should go with the 1250gph? I am guessing that the higher circulation rate requires more power. Is the PWM control difficult to integrate into the electronics?
Great story by the way, apart from the poaching. Brook trout are one of my favorite species! Speaking of clean spawning gravel, another task of our ROV is to look at the condition and characteristics of the sediment being used by lake trout to lay eggs and how different reef characteristics effect their survival