The original research hardware for ROS is the Willows Garage PR2, a very expensive robot. To make ROS accessible to people with thinner wallets, the TurtleBot line was created. The original TurtleBot was based on the iRobot Create, a hacking-friendly variant of their Roomba home robot vacuum. Even then, the “low-cost” robot was still several thousand dollars.
The market has advanced in that time. TurtleBot 3 has evolved beyond a robot vacuum base, and the iRobot Create 2 itself is available for $200. Not exactly pocket change but far more accessible. The market pioneered by Roomba is also no longer dominated by iRobot, with lots of competitors, which brings us to cheap Chinese clones. Some of which are sold by Monoprice, and right now, it seems like Monoprice is either abandoning the market or preparing for new products – their robot vacuums are on clearance sale presenting tempting targets for robotic hacking.
The low-end option is the “Cadet“, and looking at the manual we see its basic two-wheel differential drive mechanism is augmented by three cliff sensors in addition to the bump sensors. The hardware within only has to support the basic random walk pattern, so the expectation is not high. But that might be fine at its clearance sale price of $55.
The higher-end option is the “Intelligent Vacuum“. It has a lot more features, some of which are relevant for the purposes of robot hacking. It still has all the cliff sensors, but it also has a few of those proximity sensors pointing outwards to augment the bump sensors. But most interesting to robot hacking – it is advertised to vacuum in one of several patterns and not just random walk. This implies wheel encoders or something to track robot movement. There’s also a charging base docking station that the robot can return to charge, backing up the speculation there exists mechanisms on board the robot for odometry. Its clearance sale price of $115 is not significantly higher than the cost of building a two-wheeled robot with encoder, plus its own battery, charger, and all the sensors.
As tempting as they are, though, I think I’ll go down a different path…