Software plays a crucial role in almost every aspect of running the robot. When we first started building robots, everything was hard-wired. If you wanted to make a configuration change to the transmitter then you flicked a DIP switch. If you wanted to reconfigure something in the robot, it probably required a jumper. When you have components buried deep inside the robot, that doesn’t allow for a lot of flexibility or configuration. Today, we use software extensively, allowing us to define performance characteristics.
There are three key locations where software plays a part:
- Team Storm exclusively use programmable HiTec Aurora 9 transmitters coupled with Optima 7 or Optima 9 receivers. The software in the controller allows us to configure the settings depending on which robot is being drive. For example, with software we can change the maximum voltage that the motors receive by limiting the travel of the throttle control from 0 – 100% where 100% delivers the full 42v to the drive motors. Depending on how we expect the fight to go (from either a slow, close up brawl, to a more energetic whole-arena tussle) we can choose how much power goes to the motors. The control software also allows us to define throttle response curves, and if the robot is inverted we can mix the left and the right signals so that the robot still drives in the same way. In addition, the software on the transmitter also provides the ‘Cockpit View’ where key performance data from the real-time telemetry is shown.
- The second place that software is deployed is in the two on-board computers that run the robot. Storm 2 uses two sets of speed controllers, each of which has a logic board and a power board where the Mosfets (or FETs) are located that control the motors. Each controller can switch up to 720 amps of current! We have adapted the software that runs the two brains of the robot to allow the same basic controller to be used – but with different performance characteristics in Storm 2 and Photon Storm. This enables us to have one pool of spares across both the robots.
- The third place that we use software is in the telemetry system. We use the 2.4Ghz radio system from HiTech which can also encapsulate and send telemetry data frames both back to the driver’s transmitter, and also back to a laptop in the pits where all the data is recorded. While this doesn’t help you if your robot is a pile of parts after a fight (telemetry isn’t needed to tell you that!), it has been amazingly useful in helping us refine the robot – and for the investment has saved the team a fortune thanks to being able to spot over-heating motors for example, or a misconnected battery, resulting in the robot not running on enough packs and the voltage decrease being a tell-tale. In Photon Storm we use current monitoring to tell us if the hydraulic system is working at full pressure, and on the spinning weapon for Storm 2, the person running the spinning weapon has a full second telemetry system telling them RPM, current draw, motor temperature and battery temperature. In the case of the spinning weapon this data allows us to make informed choices about how much voltage to put into it. The motor is rated for 24v, but if we’re not having the impact we want, and we aren’t overheating anything – we could take a chance at putting the full 42v into the weapon… And we have the data to tell us when we’d need to back off. Most people would be looking for the smoke to know when to stop!
In IT today, more and more we see software on generic hardware being the way forward. VMware’s Software-Defined Datacenter, which in turn is increasingly underpinning Software-Defined business, allows this freedom.
Watch out for our next blog in which we’ll explain some of the design choices that have gone into Storm 2 and Photon Storm, and why their construction is so different. Looking for more information on the process of building a robot ready for battle, then check out last week’s blog here.