Figure 1: Over view of AUV
Figure 2: Under view of AUV
Hello everyone. I am new to your community, but I have been visiting this great site for quite some time now to work on the AUV that I have posted above. If you get bored of all this, just skip to the video at the end! I am an Electrical Engineer now working towards my PhD at UCR. I built this AUV as a senior design project. A lot of the parts and methods are from various version of the ROVs posted on this site. This AUV in untethered. It is completely autonomous in its control as far as keeping it stabilized. Before the AUV is launched, the user writes a script that tells it what orientation to maintain and for how long. The user also is able to give the AUV depth commands and surge commands.
As you can see, I am driving 5 motors and 5 ESC's using 6 Trustfire 26650 batteries. The batteries are housed in some battery tubes from an older version of your ROV. The motors are the same 800kv motors that are in your bill of materials, the ESCs are the closest that I could find to what you were using. They have the same ratings except these are made by Trackstar. To keep cost low I have custom fabricated the chassis and motor mounts mostly from PVC, acrylic, and stainless steel hardware. The AUV is equipped with two ultrasonic sensors for depth control and object avoidance. We also use a IR sensor for close range objects or when close to the bottom. As input to the controller we use an IMU to calculate roll pitch and yaw angles using Kalman filtering. The brain of the entire system is an Mbed LPC1768 microcontroller.
PID controllers maintain roll, pitch, yaw, and depth set points. The AUV is tested to handle disturbances and to respond accordingly. An initialization file is used to calibrate different parameters of the controller, as well as constants for gains to each motor to handle any wear and tear. A mission file is also loaded which is what actually sequentially sets waypoints and orientation commands to the AUV. See below for system block diagram:
Figure 3: System Block Diagram
It would take forever to talk about this thing, but I think a video would help a lot. Also feel free to ask my any questions. I will post more about this in the future: