Humanoid robots are robots that are at least loosely based on the appearance of the human body. Most humanoid robots have a humanoid torso, two legs, two arms, and some form of a head. Some humanoid robots also include a face on the head, which can come in different degrees of expressiveness. Although the ideas behind this type of robot have existed for some time now, it is only within the last decade that large enough strides have been made to actually present relatively humanoid robots to the world.
The term android is often used as a simple synonym for humanoid robots, but it may also be used to describe something a bit more specific. Some people hold that, strictly speaking, an android is only a robot meant to resemble a male human, while a gynoid would technically be the proper term for a female-appearing robot. Others use the term android to describe a more sophisticated form of humanoid robot, not yet possible. In this sense, an android not only has the physical appearance of a human, but has a fairly advanced artificial intelligence, allowing it to reasonably approximate human behavior and interactions. This type of android is seen only in science fiction and in the theoretical field, although it is the ultimate goal of many at work in the field of robotics.
For something to truly be a human robot, it must have a few limited autonomous capabilities, not simply appear in the shape of a human. A simple calculator moved into a container that looked humanoid, for example, would not be a humanoid robot. Humanoid robots are able to adapt to their environments to some extent, and are usually built with some form of learning system so that they can continue to progress and become better at the tasks they’re built for.
Locomotion is one of the more challenging aspects of building good humanoid robots, as the human body is actually quite complex in its locomotive capabilities. Building a robot that is able to jump, for example, proves to be incredibly difficult, because the amount of power needed to move a heavy robot is substantial, and the computations and fine motor adjustments needed to retain balance on impact are extremely complex. While the humanoid robot Dexter is capable of jumping, for example, it has been engineered almost exclusively for that purpose, and its ability to jump is still very limited and awkward when compared to a human.
Even with their currently limited capabilities, humanoid robots still have a number of uses, and in the future they may be capable of doing many important tasks. Humanoid robots can be used to do dangerous work that requires a human-like form, especially to operate equipment that has already been designed to fit and be operated by a human body. They can also be used to care for the elderly, and to look after and entertain young children. In fact, one of the growing uses of humanoid robots is as a teacher for very young children, who can become engaged and bonded to them without suffering many of the negative responses that adults have. As humanoid robots continue to develop, they may take many human roles for work, especially for situations like space missions, undersea missions, or exploratory missions to dangerous locales on earth.