When we speak about using more than one or two robots for an application, the application is usually termed a swarm robotics application. Swarm robotics is the study of how a collection of robots are used to perform a complex task. They are inspired by biological species that work in groups, such as a collection of bees, a flock of birds, or a group of ants.

All of these creatures work collectively and carry out tasks such as building the beehive, collecting food, or building ant nests, respectively. If you consider ants, they have a load-carrying capacity of 50-100 times their own weight. Now, imagine a group of such ants lifting even more than what they could lift individually. This is how swarm robotics works too. Imagine that our robot arm only has a designed payload of 5 kg and needs lift a 15-20 kg object. We could achieve the same using five such robot arms. Swarm robots are those that have the following characteristics:

• They work together as a group and have a leader or a master who is responsible for leading the robots to perform the tasks.

• They handle applications effectively so that, in case  of one of the robots in the group, the remaining robots ensure that the application is still up and running smoothly.
• They are simple robots with simple characteristics and only limited sensors and actuators.

With this simple understanding, let's look into the advantages and limitations of swarm robotics.

The advantages of swarm robotics are as follows:

• They can work in parallel to complete a complex task.
• They are scalable as they can handle and split the task accordingly in their group fails, as in the case of the removal or addition of robots.
• Since simpler robots are used to perform tasks instead of sophisticated robots, they are highly efficient.

The limitations of swarm robotics are as follows:

• The communication architecture between the robots is complex.
• Sometimes, it is difficult for the robot to detect other robots and this could cause interference.
• Robots are already costly, so imagine the application cost when using more than one such robot.

Now that we have a basic idea of swarm robotics, let's look at the classification of swarm robots.