Time to read: 4 min
Perhaps you watched BattleBots in the early 2000’s, or maybe you recently got into combat robotics and thought to yourself “what goes into building one of these gladiator bots?” Well, we’re team RoboGym, and we’re here to answer your question. We’ve been building and refining our BattleBot, Deadlift for years, and we’ll be guiding you through what it takes to create a competitive combat robot for the world stage!
In this article, we’re going to discuss combat robotics and competitions, and in Part Two we share how we built Deadlift, and give you tips for designing and building a combat robot of your own.
Rules of Engagement
Before delving into weapons and armor designs, you first need to understand how the game is played. BattleBot matches are all 1v1: your robot pitted against theirs in an enclosed, bulletproof arena. How do you claim victory? There are two paths to winning: by technical knock-out (TKO) or via a judge’s decision.
Winning By Knockout
The more straightforward, and arguably more exciting path to victory is a TKO. However, a robot can be missing a wheel, be on fire, or suffer other extreme damage and still be considered “in the fight.” A BattleBot is only truly knocked-out if it can’t demonstrate controlled movement. That means it must be able to intentionally move towards its opponent — spinning around in circles with one wheel doesn’t cut it.
Winning By Decision
Just like in other combat sports, such as boxing or MMA, a match may go the distance without either competitor achieving a knockout, which is when the judges step in. In BattleBots, each match can last up to three minutes before going to a judge’s decision. A panel of three judges will allot points in the following manner: up to 5 points for damage, 3 points for aggression, and 3 points for control.
Damage is fairly intuitive. Your robot hits the opponent so hard that a wheel flies off? That’s damage. Leave a large gash in the side of your opponent’s robot? More damage. Torching them with your flamethrower and setting them on fire? Super fun, and also, damage! You get the idea.
Aggression and control are a little more difficult to parse, and scoring well in these categories requires a responsive, quick robot and a well-practiced driver. Where aggression is sheer ferocity, control is finesse. If aggression is staying on top of your opponent and affording them no respite from your armaments, control is attacking the opponent’s weak spot while avoiding their main weapon.
Another important aspect of combat robotics tournaments is robot weight. No matter your skill as a driver, size matters. Just as a lightweight boxer would have little hope withstanding punches from heavyweight, a lighter robot will struggle against a much larger one. And there is almost always a strategic benefit to adding weight to the armor, weapon, or other systems of a robot. So, combat robotics competitions enforce weight limits — in BattleBots, the weight limit is 250lbs.
Finally, most combat robotics competitions have an exhaustive list of banned weapons. No electrical, chemical, or other non-mechanical types of weapons are allowed. The occasional exception to this is a gas-based flamethrower, which is permitted in BattleBots, but you’ll never be allowed to pour water on opponents, set off explosives, or jam their control signals.
Forming Your Grand Strategy
Now that you’ve got a solid grasp on the rules, it’s time to talk strategy! Team RoboGym members have been competing at combat robotics tournaments for over a decade, so we’ve seen just about every type of combat robot out there. Generally speaking, there are three types of combat robots: offensive, defensive, and innovative.
Offensive robots put a greater emphasis on dealing damage and value aggression over control. Common designs are centered around a large, spinning weapon that cuts through armor or a device that can launch opposing robots 20+ feet into the air. We refer to these robot types as “spinner” and “flipper” robots, respectively.
On the flip side, defensive robots focus on aggression and control points over damage points. These robots are designed to outlast opponents through using faster, stronger drivetrains and thicker armor. Most combat robotics competitions require the use of an “active” weapon, so many defensive robots fulfill the requirement with a grappling or lifting device designed to pin down and control opponents. Plus, in BattleBots, the arena has many hazards that can be utilized to further damage opposing robots when you’re in full control.
Aside from the standard offensive and defensive designs, there are many robots that break the mold of what one normally sees at competitions, too. For example, we’ve seen a design with an arm-mounted spinning weapon that targets the thin top armor on many robots with attacks from above. Other robots are uniquely large or oddly shaped, which makes them much harder to hit — most designers don’t account for those unusual designs when designing their own robot’s weapon.
When choosing which type of robot you want to build, it‘s critical to understand and consider the specifics of the competition you plan on entering. Some competitions may not have arena hazards, while others may disallow certain types of weapons, or even have restrictions on how fast you can spin a weapon.
Now that you know the basics of combat robots and competitions, check out Part 2 to learn how we built our BattleBot, Deadlift!