olegodo
Hi. I am curious if the EZ-Robot hardware and software might be a good solution as a control system for my underwater ROV that I am building.
Although I have tried to create something using arduino myself, the programming is really a steep learning curve for me.
I will be running a wired Ethernet connection from the surface and have a wifi hot spot in the rov to allow connection to the bv4. It must control 9 brushless esc's. 6 for movement (thrusters) and 3 for a robotic arm. Also one servo for moving the camera vertically. The esc's use the same signal as servo's do, so I don't think this will be a problem.
I will also need to control 3 relays.
I have this unit for sensing battery voltage and current draw: https://www.coolcomponents.co.uk/attopilot-voltage-and-current-sense-breakout-180a.html This can be connected to the ADC pins correct? This is made for 3.3volts, but can it still be used maybe?
I have this IMU from OpenROV that I want to use:
http://store.openrov.com/collections/frontpage/products/openrov-imu-depth-module
I see there already is support for the MPU-9150 chip. But is it possible to also get the depth and temperature rating from the MS5803-14BA chip?
I want all to be controlled with a gamepad/joystick. This means that multiple motors must react differently to stick movements. For instance, if I want the ROV to turn in place. 2 motors must turn clockwise and two counterclockwise.
Would all this be possible to do?
Br Ole
Hi again.
Thanks for all the replies! This seems promising! The recent price drop is also welcome
I have been working on this ROV for quite some time now and most of the hardware parts I already have.
I have also designed a 3D printable thruster that I will use. Tests of it can be seen here:
And using the same motors, I have made a 3D printable linear actuator design I hope to be able to use in the manipulator arm.
In order to give you a better overview of what will go in to this project, I made a diagram showing all the electrical components I plan on connecting. Note that all the components marked with "*" is stuff I already have.
If you have questions or comments, please let me hear them. Does this still look like a good job for the EZ-B4?
Regards Ole
I think EZ-B will be a perfect solution for this. Is your tether going to be strong enough that you ca use it for fail-safe recovery or are you going to have a way to drip ballast or inflate bladders or something in the case if a connection loss? Although highly reliable, I like to think about what could go wrong. When working underwater, recovery becomes a significant concern.
Alan
Can you post more information about your 3d printed linear actuator and the clutch system? I love the design and am looking for linear actuator ideas on my astromech
Thanks Aaron
@thetechguru
The tether will be strong enough to pull the Rov and lift it out of the water. Also, the Rov will be slightly positively buoyant. So that if all fails it will slowly float to the surface. This also means that the vertical thrusters must spin constantly in order to keep it from floating up. This way of doing it is quite standard on the smaller rov's and the extreme depth type. Some sort of "hold depth" would be nice to have if possible to implement in the software.
@robot56 At the moment I have only made a proof of concept prototype. It's made to fit the magnets and threaded rod I already had. But I have no problem sharing what I already have and the finished design later on.
About the control of the ESC's. They operate on a PWM signal between 1000 and 2000 pulses pr second I believe. 1000 is full reverse, 1500 is natural and 2000 is full forward. This is the same signal type that the EZ-B4 sends to the servos right?
I see in the BV4 datasheet that you can supply it with a maximum of 16 vollts. (I know the D0-D23 pins are unregulated) Does this mean the board will blow up if I supply it with 16.8 volts max? The reason is that I am using a 4s lipo battery pack witch at a 100% charge has 16.8 volts. If I could use this directly I could use the built in voltage sensor to see my battery voltage instead of finding some other way of doing it.
Ole.
Sorry to bump this thread. But can anyone comment on my last post about the battery voltage?
No, the board will not blow up, but it may run a little hotter than usual. That being said, I haven't done any prolonged testing at that voltage (I've only tested for an hour or 2) so there's no guarantees for prolonged usage above 16V.
I see. Thank you for the reply! My v4 is on its way now and I am looking forward to playing with it