Two Birds, One Stone

Establishing the locomotion method and footprint was the fist step in my chassis design.  Every mobile robot requires a few essential systems; they are, power, computing, sensing and locomotion.  The robot will need at lease one circuit board for voltage regulation, computing, connectors and sensors.  In past designs I used aluminum and plastic sheets to build decks of the chassis.    The propulsion motors attached to the base deck and additional decks stacked up to mount circuit cards, sensors and actuators.  For the most part, the decks did nothing more than to serve as a place to attach these devices.

            The printed circuit boards (PCB) that I use are made from FR-4.  FR-4 is fiberglass sheets glued together with a epoxy resin.  Circuit boards made from FR-4 are rigid and very strong.  The rigidity and strength of the PCB make it suitable to replace the aluminum and acrylic decking in my previous mobile robots.  Since FR-4 has suitable strength and rigidity for the chassis, and I can use it for PCBs, it makes sense to combine the needed electronics onto the chassis.  The energy source, voltage regulation, connectors, computing, and sensing will be built on the base deck.  The base deck will also support the propulsion motors, the rear castor, and will include mounting holes for additional decks. 

            Making the robot’s decking out of the PCB will combine the electronics and the chassis structure, and also reduce the overall cost.  One draw back to this concept is that there will be exposed circuitry that can be susceptible to damaging Electro-Static Discharge (ESD).  I have a preliminary solution to this problem that I'll work out and write about in a later blog.  Until then...

- keep rockin