Hi All,
Some background: I'm a Senior at Penn State working on my Senior Capstone Project which happens to be an autonomous boat. We were interested in the project mainly because it was attempted a few years ago and failed epically and we wanted to make it, make it work, and make it better. Some criterial we have is that it need to switch in and out of RC mode to fully autonomous WHILE being able to detect and avoid all collisions. While being in autopilot is also needs to be able to come back to the launch location. We are planning to use a Jetdrive to make the boat move so any information on that would also be helpful.
So some of my main questions are: which of the ardupilot boards would "you" recommend, will a jetdrive communicate with the ardupilot, what would "you" use as a collision detection and avoidance device.
I have done some research on proximity sensors and know that most use radar but I am unaware if this is the most recent technology being used.
Any and all help would be greatly appreciated!
Thanks,
Randi B.
Replies
Hi Randi,
Great sounding project.
I have a very similar project, Jet Driven Mono Hull.
For my set up I am using the AMP 2.5 & 2.6 (I bought the 2.5 but could get out put channels 2, 4, 5, 6, 7, & 8 to work so I purchased a 2.6 to test if I had damaged the APM.
I have since found out that the Rover firmware make the APM's output channels 2, 4, 5, 6, 7, & 8 redundant.
I am currently looking for solutions.
I am handicapped by my lack of electronics knowledge (I am a design engineer specializing in composite structures). So I am currently looking at using the analogue board or using the Arduplane firmware. I will test the plane firmware in a test boat this week.
For collision prevention I am looking at using a small boat radar and overlaying the data onto the mission planner or QGround Control via a drone cell module and long term RockBLOCK sat coms.
Other critical data is Marine Traffic AIS data http://www.marinetraffic.com/.
For your project and choosing the drive system I would look at the maneuvering requirements of the vessel, the speeds the vessel will be traveling at and the load to displacement ratio.
As you may already know, jet drive only has directional control while under thrust, therefore not the most maneuverable under low speeds. The other point to consider is efficiency, until the hull breaks on to plane jet drive is less efficient than shaft drive or pod drive. But once on plan jet drive can achieve high speeds due to less drag.
As far as I understand there are no small jet drive units available, I am using an old Jet Ski pump (jet drive unit). But for a boat of your size all you would need is a 3D printer and SolidWorks and you will be set.
An option you may want to look at is Pod Thrusters http://www.bluerobotics.com/If you still want to go for a jet drive system and need help let me know?
Keep us posted on your progress?
Regards,
Richard
http://www.kenzenrc.com
http://www.kehrer-modellbau.de/kmb-jet28/
http://www.westbourne-model.co.uk/acatalog/Water_Jet_Drives.html
I was going to use these on my project but after contacting the manufacturers, they didn't endorse their products for extended run times. I was looking at 6hrs a day, several days a week. On the plus side, they are relatively cheap. I ended up using commercial thrusters from ROV's as I need the reliability and these have good torque without the top end speed. My boat needs to carry 20kg of Sounder, Dual Beam Transducer cm RTK GNSS unit and 2 x 19Ah Batteries.
In my new found journey I found this obstacle avoidance video
@Randi,
Try this: Link
Regards,
TCIII AVD
Hi Randi,
As far as navigation processors go, I would go with a Pixhawk as you can enable the Extended Kalman Filter function for highly accurate navigation and be able to use two GPSs.
I am presently using an APM2.6 on my Pontoon RSV project but can easily switch to the Pixhawk as I made the mount for the navigation processors interchangeable on each one of my navigation platforms (I also do ArduRovers:-))
If you plan to use a jetdrive (water type I assume) I assume that its output will be steerable with a servo for direction control and you can use a standard ESC to control the jetdrive pump rpms for speed control. I have not seen any model jetdrives, but that does not mean they do not exist or can be hand built from parts. Unless you really need a jetdrive, I would go for a brushless motor driven prop with a standard rudder with cooling water pickup as they are readily available from HK and other manufacturers.
Regards,
TCIII AVD