Robot Combat - Unusual Propulsion

Unusual Propulsion

The great majority of combat robots roll on wheels, which are very effective on the smooth surfaces used for typical robot combat competition. Other propulsion strategies do pop-up with some frequency.

• Tank Treads – Numerous combat robots have used treads or belts in place of wheels in an attempt to gain additional traction. Treads are generally heavier and more vulnerable to damage than a wheeled system and offer no particular traction advantage on the types of surfaces common in robot combat. Most uses of treads are for their striking appearance. The RobotWars competitors 101 and Mortis along with the BattleBots super heavyweight Ronin used treads.
• Walking – The spectacle of a multi-legged robot walking across the arena into combat is a big audience favorite. Robot combat rules typically have given walking robots an additional weight allowance to offset their slower speed, the complexity of the mechanism, and to encourage their construction. What the event organizers had in mind was something like the spider-legged robot Mechadon, but what most often was produced were simple rule-shaving propulsion systems that attempted to save as much of the extra weight allowance as possible for additional weaponry. Attempts at more restrictive definitions of “Walking” have effectively eliminated walking robots from competition. BattleBots heavyweight champion Son of Whyachi used a controversial cam-driven “Shufflebot” propulsion system, which was promptly declared ineligible for additional weight allowance at subsequent competitions.
• Gyroscopic Precession – Used in the Antweight robot Gyrobot, this system uses a gyroscope and stationary feet that lift as the entire robot rotates due to gyroscopic precession when the gyroscope is tilted by a servo motor. This design can use the gyroscope as a spinning weapon (horizontal or vertical) which allows for efficient double-usage of the gyroscope mass. Although Gyrobot appears to be walking as it translates across the arena, it is not classified as a walking robot under current rules. This unusual drive train produces strange and often unpredictable movements, though has shown to be successful in combat.
• Suction Fan – Several competitors experimented with the use of fans to evacuate air from a low-clearance shell to suck the robot down onto the arena surface and add traction. Robotica competitor Armorgeddon used a suction fan to increase traction and pushing power, and Robot Wars UK robot TerrorHurtz used a suction fan to counter the forces from its hammer/axe weapon. Similar designs have appeared in robot-sumo competitions where traction is a key factor.
• Magnet Wheels – Another approach to gaining traction and stability involves the use of ring-shaped rare-earth magnets as wheels. This is, naturally, only effective in arenas which have magnetic metal surfaces. Due to the expense of large ring magnets, this trick has been used almost exclusively in three-pound and under “insect class” robots, although a lightweight battlebot General Gau tried implementing them. Heavyweight Robotica competitor Hot Wheels attempted to use a large chassis-mounted magnet to gain traction and apparent weight, and Beta Hurtz unsuccessfully attempted to use an electromagnet to counter the reaction forces of its massive hammer weapon at the BattleBots competition. The result ended in the robot being completely stuck to the floor.
• Mecanum Wheels – The previously mentioned RFL super-heavyweight competitor Alcoholic Stepfather uses Mecanum wheels and specialized motor control systems that allow it controlled motion in any direction without turning. This is eerie to watch, and disruptive of attack and defense maneuvers by opponents. Root Canal implemented a similar design at BattleBots using Omni wheels angled at 45 degrees.
• Translational Drift - Also known as Melty Brain or Tornado Drive, this sophisticated system supplements the thwackbot drivetrain with electronic rotation sensors and rapid speed controller switching that allows a rotating thwackbot to move in a controlled manner while spinning. Several robots have implemented this complex design, but none with particular success. Herr Gepoünden, a lightweight robot, has shown successful use of the Tornado Drive and has used it successfully in smaller competitions. The drive is implemented with an LED light system that tells the driver its current position, indicating where the robot should be driven to.
• Flying – The 1995 US Robot Wars event had a flying competitor: S.P.S. #2 was a lighter-than-air craft buoyed by three weather balloons and propelled by small electric fans. It attempted to drop a net on the opponent. Nearly invulnerable to attack, it won the first match against Orb of Doom (see reference below), but ventured too close to the arena floor in the second match and was dragged down and "popped".
• Rolling Sphere – The afore-mentioned Orb of Doom was a featherweight competitor at the 1995 US Robot Wars. It consisted of a remote-controlled toy car inside a hollow papier-mâché sphere. It was able to roll around the arena in a controlled manner, but was incapable of effective offense. A similar robot named Psychosprout appeared in the UK Robot Wars.
• Rolling Tube -Snake competed at Battlebots and the US Robot Wars using a series of actuators to bend its triangular cross-section tubular body to roll, writhe, and slither across the arena.
• Shuffling - refers to the movement of robots that are propelled by a cam-driven system. See Walking