Society of Robots - Robot Forum

Electronics => Electronics => Topic started by: ron.striker on December 14, 2008, 05:23:04 AM

Title: Help Required ..
Post by: ron.striker on December 14, 2008, 05:23:04 AM
hi,

I'm a beginner to robotics have only designed one bot before,

I wish to actuate a wireless remote controlled underwater robot, which operates on battery (rechargeable), 2 differential motors, 1 motors to control the depth along with floaters to maintain balance underwater, solar panel to recharge the battery, robotic arm and also wish to include camera vision to maneuver the bot .

 i have a few questions about all of this before i start:
1.will i be able to set an automated battery level monitor to alarm when battery level to low?
2.how many channels of transmissions will i require to control the bot, the robotic arm and receive video output from the camera?
3.will i be able to cut off power to the entire bot will surfaced to recharge?
4.how many battery's and solar panel will i require to work the bot?
5.which microcontroller must i use?

any help will be appreciated .. thanks
Title: Re: Help Required ..
Post by: Farmerboy08 on December 14, 2008, 08:01:26 PM
I not the best with servos or micro controllers but your best bet is to put a separate panel and battery for the motors the arm and the camera also i would put a emergency battery that can be tuned on to run the motors
Title: Re: Help Required ..
Post by: ron.striker on December 15, 2008, 04:57:19 AM
so its better if i put seperate panels for each set of batterries ?? .. then wouldnt it be hard to detect battery level and stuff ?? ..
Title: Re: Help Required ..
Post by: ozbot on December 15, 2008, 05:22:45 AM
you said you had only designed one robot.  Does this mean you actually built it?  I have designed about 5 different robots (by design here, I mean have completed the conceptual and basic mechanical side, sans electronics) but am still only building my first basic bot. 

My advice would be to separate functions of this bot, build each part (arm, solar experiments ect.) as independant projects (unless you already have, & understand each part) and then it starts to make sense how all will go together.
Especially regarding protecting your electrics from water.  I know it's hard to hear sometimes, but we all start at the bottom of the stairwell.

there is no microprocessor you MUST use.  The web is a wonderful resource.  research...... :)
Title: Re: Help Required ..
Post by: ron.striker on December 15, 2008, 06:26:41 AM
when i said design .. i meant built .. I've built a working underwater ROV only with motors to maneuver in water .. just basic model with floaters to maintain the depth .. what I'm planning to do now is attach a robotic arm .. a camera and a solar panel to recharge .. but that gets all the more complicated .. for the first bot i didn't use a microcontroller .. cause i sill don't understand the use of one .. i used motor drivers and logical gates to work my previous circuits .. i had a receiver and transmitter with four channels .. but for this I'd surely require more rite ? ..
Title: Re: Help Required ..
Post by: cyclopediatechtilon on December 15, 2008, 09:31:51 AM
Use avr microcontrollers.
easiest to program
vey  convenient if you have AVR studio
http://www.atmel.com/dyn/products/tools_card.asp?tool_id=2725
Title: Re: Help Required ..
Post by: Farmerboy08 on December 16, 2008, 03:10:31 PM
so its better if i put seperate panels for each set of batterries ?? .. then wouldnt it be hard to detect battery level and stuff ?? ..
 
It would be harder but if only one fails you can put your backup on the device that lost power. with only one panel you would have to use that 1 backup for everything
Title: Re: Help Required ..
Post by: Razor Concepts on December 16, 2008, 06:23:35 PM
Video should be transmitted separately using a separate transmitter/receiver (900mhz, 1.3ghz, or 2.4ghz).
Title: Re: Help Required ..
Post by: HDL_CinC_Dragon on December 16, 2008, 08:26:26 PM
so its better if i put seperate panels for each set of batterries ?? .. then wouldnt it be hard to detect battery level and stuff ?? ..
 
It would be harder but if only one fails you can put your backup on the device that lost power. with only one panel you would have to use that 1 backup for everything
Why does it have to be harder? Theres a few options you can use so that its really not that difficult. Heres one:
Have a battery monitor (http://www.societyofrobots.com/schematics_batterymonitor.shtml) for each battery connect to a separate A2D pin, lets say Pin A being the main battery and Pin B being the backup battery. Have the robot monitor them both separately. If the robot determines that the main battery is getting low on juice have it flip a relay or something that switches over to the backup battery. Nothing too fancy
Title: Re: Help Required ..
Post by: jamort on December 18, 2008, 06:37:41 PM
theres a problem with computer vision under water What if it gets dark?
you might be better off with sonar on it one pointin down to measure depth and one facing forward to see were its going... im no expert but im pretty sure the dark would throw the camera off... or you could have a light sensor on it to since when light level equals so much switch from camera to the sonar mode
Title: Re: Help Required ..
Post by: SeagullOne on December 19, 2008, 12:06:56 AM
Or give it a flashlight too ;D
Title: Re: Help Required ..
Post by: ron.striker on December 22, 2008, 02:23:07 PM
this is actually my first robot I'm gonna involve a microcontroller .. What all can a micro controller do ?? .. does it come with any inbuilt logic gates ?? .. thanks for the sonar idea .. but i think I'm gonna stick with camera vision with a flash light !! .. and Wat did u mean when u said "flip a relay" .. didn't get you ..

when I'm using solar panels .. do i really need a backup battery pack .. cant i just surface to recharge ?? ..
Title: Re: Help Required ..
Post by: Farmerboy08 on December 23, 2008, 01:13:08 PM
this is actually my first robot I'm gonna involve a microcontroller .. What all can a micro controller do ?? .. does it come with any inbuilt logic gates ?? .. thanks for the sonar idea .. but i think I'm gonna stick with camera vision with a flash light !! .. and Wat did u mean when u said "flip a relay" .. didn't get you ..

when I'm using solar panels .. do i really need a backup battery pack .. cant i just surface to recharge ?? ..

What if your main battery fails and you cannot surface due to the failure??
Title: Re: Help Required ..
Post by: ron.striker on December 23, 2008, 01:16:23 PM
true ... but if it does fail how do i actuate the swtich from main to backup battery ?
Title: Re: Help Required ..
Post by: Razor Concepts on December 23, 2008, 04:00:52 PM
Maybe only use one battery and surface when the battery is almost discharged?
Title: Re: Help Required ..
Post by: HDL_CinC_Dragon on December 23, 2008, 04:18:03 PM
The point of a backup battery is to kick in when the main battery is almost dead. Not completely dead. If it was completely dead the MCU wouldnt be able to switch the circuit power over to the backup.
Title: Re: Help Required ..
Post by: cooldog on December 23, 2008, 07:30:48 PM
this is actually my first robot I'm gonna involve a microcontroller .. What all can a micro controller do ?? .. does it come with any inbuilt logic gates ?? .. thanks for the sonar idea .. but i think I'm gonna stick with camera vision with a flash light !! .. and Wat did u mean when u said "flip a relay" .. didn't get you ..

when I'm using solar panels .. do i really need a backup battery pack .. cant i just surface to recharge ?? ..

What if your main battery fails and you cannot surface due to the failure??


just give it a positive buoyancy