Robotics

Robotics is an interdisciplinary field focused on the design, construction, operation, and use of robots.

A specialist in this field is known as a roboticist. The primary goal of robotics is to create machines that assist humans across many different sectors. These include industries like medicine, agriculture, manufacturing, and space exploration. However, the rise of robotics also has social impacts. Some experts believe robots may displace human workers in various jobs. This has led to discussions about economic solutions like basic income. Despite these challenges, robotics remains a lucrative and growing professional field.

To function, a robot requires four essential design components working together. The first is a power source to provide energy. This can be wired electricity, petrol, or a battery.

Designers must balance factors like weight, safety, and cycle lifetime when choosing batteries. Lead-acid batteries are common because they are safe and long-lasting. However, they are heavier than silver-cadmium batteries, which are smaller but more expensive. The second component is mechanical construction. This is the physical form, such as wheels, caterpillar tracks, or hydraulic limbs.

The third component is the control system, which uses electrical circuits to govern movement. These circuits utilize components like diodes and transistors to read sensors and manage motors.

The fourth component is software, the program that dictates how a robot acts. Software can be controlled via remote command or through artificial intelligence (AI). AI is particularly vital for helping robots navigate environments and interact with humans.

Movement in robots is driven by actuators, which act as artificial muscles by converting energy into motion. Most portable robots use electric motors, specifically brushed or brushless DC motors. Industrial robots often use AC motors for heavier rotational tasks. In contrast, linear actuators move in a straight line and are common in factory settings. These are often powered by electricity via a leadscrew or by compressed air.

Some advanced systems use piezoelectric motors. These use tiny piezoceramic elements that vibrate thousands of times per second to create motion. They offer incredible precision, sometimes reaching nanometer resolution.

Researchers are also developing biomimetic materials to mimic biological muscles. Pneumatic artificial muscles, or air muscles, are tubes that expand up to 42% when filled with air. Shape memory alloys, called muscle wire, contract by less than 5% when electricity is applied. Even more advanced are electroactive polymers. These plastics can contract by as much as 380% and help humanoid robots move their faces or arms.

Experimental technology like elastic carbon nanotubes may one day allow robots to outperform human muscle strength. These filaments can deform elastically without defects, storing significant energy.

Locomotion, or how a robot moves, varies greatly based on its environment. Some robots use a single wheel to balance, like the Ballbot from Carnegie Mellon University. Others use two wheels and a gyroscope to maintain balance through inverted pendulum dynamics.

Many mobile robots use four or six wheels, or even continuous tracks for better grip on off-road terrain. Walking robots present a greater challenge. Some, like Honda's ASIMO, use the Zero Moment Point (ZMP) algorithm. This algorithm balances gravity and acceleration forces to prevent the robot from rotating or falling.

History shows that walking robots have become increasingly dynamic over time. In the 1980s, Marc Raibert at the MIT Leg Laboratory demonstrated robots that could stay upright by hopping. This movement was similar to a person using a pogo stick. Later, researchers developed robots that could trot, run, or even perform somersaults. Modern approaches, such as passive dynamics, use the momentum of swinging limbs to walk. This method might be ten times more efficient than older algorithms.

Robotics also extends into the air and onto vertical surfaces. Biomimetic flying robots (BFRs) take inspiration from birds, bats, or insects. Some use flapping wings to generate lift, which can be more efficient than propellers.

On the ground, some robots are designed to climb walls. Some mimic human climbers, while others use the toe-pad method used by geckoes.

By combining these diverse mechanical and software systems, robotics continues to expand the limits of what machines can achieve.