In the 21st century where the world is driven by technologies, new hobbies are emerging out where people don’t need to go to the playground or to trek the dangerous hills, river beds, waterfalls, or even sports like racing, stunts, skydiving, etc. which pumps the adrenaline and keeps the mind off from the regular chores. Here I’m going to speak about a sport which pumps the adrenaline and keeps mind and body exercised as a non-conventional hobby.
Combat Robotics is a sport where two or more mobile robots built with lethal weapons and defense systems fight to knock the opponent off. It all started with the growing advances in the electrical and mechanical field and some geeks who found joy in building mobile metal structures and competing themselves. This sport is no different from the formula races or the WFC leagues, here instead of cars or humans, robots fight. Greater push to the field was started when the toymakers and electronic and mechanical component builders found an opportunity in growing their business by directly sponsoring or building pieces of equipment for the bots. Then with the growing interests among the Tech students and Universities, some open competitions are hosted. With the success of that, many TV shows started mainly ‘Battlebots’ in the USA and’ Robot combat’ in the UK.
As there are categories in formula races based on engine power and in wrestling based on weight, Combat robots too have classifications. It might be based on Weight or even based on the type of power and voltages used. Again, in the weight category metric system plays its role, in Europe and Asia ‘KG’ is used for determining the categories, in the USA ‘pound’ is used. Famous and quite standard weight categories are 1kg 5kg 8kg 15kg 30kg 60kg 120kg, but the difference in metric used causes problem when inter-continent teams participate in the events because the pound is slightly less than half of KG, and if there is a match in the USA under 30lbs category then 15KG bot must shed its weight to under 13.6KG to participate and vice versa. This is also a problem for the organizers when they invite foreign teams and set the weight metric.
Robots can be built by any materials which are chemically not harmful to the people or environment, Teams usually prefer strong and lightweight materials for the body so that it can withstand heavy forces. It all starts with the design, fabrication then testing, and finally competing. Design is usually done using CAD software; a lot of research has to be done at this point. Robots can also be attack or defensive ones and also weapons and armor must be the strongest yet not brittle and must be able to transfer or take huge impacts on contacts. A famous weapon system is a rotary system where a powerful motor rotates the weapon to its max speed and the kinetic energy of the rotating mass of the weapon is used to shear the opponent; this is not as simple as it said. For the weapon to run at its maximum efficiency and to deliver the maximum force it must be well balanced i.e., its Center of gravity must lie on the rotating axis. And the shaft must rotate the weapon freely without adding much resistance. Then the weapon motor is the next main element. Usually, the weapon system will be at least 20% in weight, and to rotate this, huge power is required. So the perfect choice of Weapon motor is very important. To attain this high power, the power system must deliver the required amount of current under specified voltage. Hence the power system is the next important thing. Power system consists of Batteries, Kill switch, Electronic speed controllers (ESC), Radio receivers. ESC also called the motor driver is the device that controls the speed of the motors and radio receivers is the device that helps in communicating the control signals from the person who controls through the transmitter remote. These transmitters and receivers run on Radio frequencies which are allotted under Hobby and restriction-free radio bands decided by the local authorities; the famous one is a 2.4GHz band. Then the most important part of the robot is its drive system which also consists of the ESCs, Motors, and wheels in general, but many other types of designs use limbs, chains, and also magnetic strips. Apart from the rotary weapon system, there are flamethrowers, pneumatic lifters, etc.
The Drive system is the thing that keeps the Bot alive. Immobility criteria depend on the drive system. So perfect type of motor and drive selection is most important. Now coming to the heart of the Bot i.e., Batteries, long back LI-Ion battery packs are used but the power delivery and charging time was not good, then came LI-Poly batteries which have very good power density and can charge quickly, but the downside is LI-Poly is dangerous when physical damage of Electrical damage occurs and it tends to catch fire so quest is still going on for the more reliable one. Hence perfect Battery selection and its safe handling is also an important part.
Next comes the body of the bot. The most famous material for the body is aluminum because it’s easy to machine, cheap, and damps impact well. But the heavy and long duty bot builders prefer stronger bodies made out of Titanium alloy or hardened steel. This is the sole choice of the builder. Apart from this backup and spares is the next important thing, components tend to break down, and replacing them must be easy and quick.
Then comes the safety. The safety of the people participating and watching the match is the most important aspect. For this 1st and foremost is having a failsafe in the Transmitter. Nowadays most of the Hobby level transmitters come with the failsafe option. Apart from this, a Kill switch can be used or some strong restraint that blocks the weapon from rotating when it’s not supposed to rotate. This sport can be played individually and also as a team. In majority of the competitions, there will be prize money too.
Combat Robotics is exciting and adventurous when played responsibly, and it’s just a growing field that still has the potential to attract many adults and children into the hobby which will develop the problem-solving ability, reasoning, tactics, sportsmanship, and other social skills along with the technical skills of Soldering, Welding, Using power tools and design software.
Automation Engineer - BOSCH Rexroth