Dollbot #2: Initial design

We have decided to start working on Dollbot first as it works in a more controlled environment than Pescabot.

After a few weeks of tinkering, we have agreed on the following design criteria:

Propulsion

We will use holonomic propulsion, based on the UPenn Moblab prototype (We can't stop watching this video!). This means that the boat can move in any direction and not just the typical forward with steering of more traditional boats.

The holonomic propulsion system uses four small DC motors that need to operate in either direction, so that the water flows through the vectored thrust channels. We will use the Adafruit Motor Shield  (19.95 USD) to control the motors, as developing the H-Bridges ourselves for a robot that will be in the water does not seem like the best idea - this will reduce the size of the control components.

RC Control

Erin wants to be able to control the boat with RC as well as to program it automatically to pick-up and deliver dolls, so we will need to connect a R/C receiver to the system, which will take preference from autonomous control and work as a fail-safe mode.

Autonomous operation

The boat is designed to operate in closed bodies of fresh water (e.g. a swimming pool), we want the autonomous operation to discover the geometry of the pool and detect dolls waiting to be picked up / points where to drop the dolls as well as to do some obstacle / swimmer avoidance. We want to try to use an Arduino Uno as the microcontroller, as it provides an easier IDE than the Tiva, and we all want to participate in the autonomous algorithm design.

Water proofing

We need to operate the robot in the water, no two ways about that :-) We need to think of some water-proofing for the boat, so that even if it tips over the electrical components are protected.