When many people hear the word “robot“, they might think of terms like “cool design”, “powerful functions”, and “high-end”, imagining robots as something high-tech and flashy like the “Terminator” in science fiction movies. However, this is not the case. In this article, we will explore the basic concepts of robotics and understand how robots accomplish their tasks.
1 Components of a Robot
At the most basic level, the human body consists of five main components:
· Body structure
· Muscular system, used to move the body structure
· Sensory system, used to receive information about the body and the surrounding environment
· Energy source, used to provide energy to the muscles and senses
· Brain system, used to process sensory information and command muscle movements
Of course, humans also possess some intangible traits, such as intelligence and morality, but on a purely physical level, this list is quite complete.
The components of a robot are very similar to those of humans. A typical robot has a movable body structure, a motor-like device, a set of sensory systems, a power source, and a computer “brain” that controls all these elements. Essentially, robots are “animals” created by humans, machines that mimic human and animal behaviors.
Bionic Kangaroo Robot
The definition of a robot is broad, ranging from industrial robots serving factories to home cleaning robots. By the broadest definition currently available, if something is widely considered a robot, then it is a robot. Many robotics experts (those who manufacture robots) use a more precise definition. They stipulate that a robot must have a reprogrammable brain (a computer) used to move its body.
According to this definition, the difference between robots and other movable machines (like cars) lies in their computer components. Many new cars have an onboard computer, but it is only used for minor adjustments. The driver directly controls most of the vehicle’s components through various mechanical devices. In terms of physical characteristics, robots differ from ordinary computers in that they are connected to a body, while ordinary computers are not.
Most robots indeed share some common characteristics.
First, almost all robots have a movable body. Some have only motorized wheels, while others have many movable parts, typically made of metal or plastic. Similar to human skeletal structures, these independent parts are connected by joints.
The wheels and axles of robots are connected by some type of drive mechanism. Some robots use motors and solenoids as drive mechanisms; others use hydraulic systems; and some use pneumatic systems (driven by compressed gases). Robots can utilize any of these types of drive mechanisms. Metal processing is quite impressive.
Second, robots require an energy source to drive these mechanisms. Most robots use batteries or wall outlets for power. Additionally, hydraulic robots require a pump to pressurize the liquid, while pneumatic robots need a gas compressor or a compressed gas tank.
All drive mechanisms are connected by wires to a circuit board. This circuit directly powers the electric motors and solenoids, and manipulates electronic valves to activate the hydraulic systems. Valves can control the path of pressurized fluids flowing within the machine. For example, if a robot needs to move a hydraulically driven leg, its controller will open a valve that leads from the hydraulic pump to a piston in the leg. The pressurized fluid will push the piston, causing the leg to rotate forward. Typically, robots use pistons that can provide bidirectional thrust, allowing parts to move in both directions.
The robot’s computer can control all the components connected to the circuit. To make the robot move, the computer will activate all the necessary motors and valves. Most robots are reprogrammable. If you want to change the behavior of a robot, you simply write a new program into its computer.
Not all robots have sensory systems. Very few robots possess vision, hearing, smell, or taste. The most common sense that robots have is motion sense, which is their ability to monitor their own movement. In standard designs, wheels with grooves are installed at the joints of the robot.
On one side of the wheel is a light-emitting diode that emits a beam of light that passes through the groove and shines on a light sensor located on the other side of the wheel. When the robot moves a specific joint, the grooved wheel rotates. During this process, the groove will block the light beam. The optical sensor reads the pattern of the light beam flashing and sends the data to the computer. The computer can accurately calculate the distance the joint has rotated based on this pattern. The basic system used in a computer mouse is similar to this.
The above are the basic components of a robot. Robotics experts have countless ways to combine these elements to create infinitely complex robots. Robotic arms are one of the most common designs.
2 How Robots Work
The term “robot” in English comes from the Czech word robota, which is usually translated as “forced laborer”. This is quite fitting to describe most robots. Most robots in the world are used for heavy repetitive manufacturing tasks. They are responsible for tasks that are very difficult, dangerous, or tedious for humans.
The most common type of manufacturing robot is the robotic arm. A typical robotic arm consists of seven metal parts connected by six joints. The computer controls stepper motors connected to each joint to manipulate the robot (some large robotic arms use hydraulic or pneumatic systems). Unlike ordinary motors, stepper motors move precisely in increments. This allows the computer to move the robotic arm accurately, enabling it to repeat the exact same action over and over. Robots utilize motion sensors to ensure they move the correct amounts.
This six-jointed industrial robot is very similar to a human arm, having parts equivalent to the shoulder, elbow, and wrist. Its “shoulder” is typically mounted on a fixed base structure (rather than a movable body). This type of robot has six degrees of freedom, meaning it can rotate in six different directions. In comparison, a human arm has seven degrees of freedom.
A joint of a six-axis industrial robot
The role of the human arm is to move the hand to different positions. Similarly, the role of the robotic arm is to move the end effector. Various end effectors suitable for specific applications can be installed on the robotic arm. One common end effector can grasp and move different objects; it is a simplified version of a human hand. Robotic hands often have built-in pressure sensors to inform the computer of the force applied when the robot grips a specific object. This prevents items from falling or being crushed in the robot’s grip. Other end effectors include spray torches, drills, and paint sprayers.
Industrial robots are specifically designed to repeatedly perform the same task in a controlled environment. For example, a robot may be responsible for screwing the lids on jars of peanut butter being transported on an assembly line. To teach the robot how to perform this task, a programmer uses a handheld controller to guide the robotic arm through the entire sequence of actions. The robot accurately stores the sequence of actions in its memory, and whenever a new jar comes down the assembly line, it will repeat this sequence of actions.
The robotic arm is one of the fundamental components used in automobile manufacturing
Most industrial robots work on automotive assembly lines, responsible for assembling cars. When performing large volumes of such tasks, robots are significantly more efficient than humans due to their precision. No matter how many hours they have worked, they can still drill holes in the same spot and tighten screws with the same force. Manufacturing robots also play a crucial role in the computer industry, where their incredible precision can assemble extremely small microchips.
The manufacture and programming of robotic arms are relatively straightforward since they operate within a limited area. However, if you need to send a robot into the vast external world, things become more complicated.
The primary challenge is providing the robot with a feasible motion system. If a robot only needs to move on flat ground, wheels or tracks are often the best choice. If the wheels and tracks are wide enough, they can also be suitable for rough terrain. However, robot designers often wish to use leg-like structures because of their greater adaptability. Creating legged robots also helps researchers understand natural kinematics, which is beneficial in biological research.
The legs of robots are typically driven by hydraulic or pneumatic pistons that move back and forth. Various pistons are connected to different leg parts, much like muscles attached to different bones. Ensuring that all these pistons work together correctly is undoubtedly a challenge. In the early stages, a human brain must figure out which muscles need to contract simultaneously to avoid falling while walking upright.
Similarly, robot designers must determine the correct combinations of piston movements related to walking and program this information into the robot’s computer. Many mobile robots have a built-in balance system (such as a set of gyroscopes) that informs the computer when it needs to correct the robot’s movements.
The latest upgraded version of Boston Dynamics’ Atlas humanoid robot
The bipedal walking motion itself is inherently unstable, making it extremely challenging to achieve in robot manufacturing. To design a more stable walking robot, designers often look to the animal kingdom, particularly insects. Insects have six legs and often possess extraordinary balance, adapting easily to various terrains.
Some mobile robots are remotely controlled, allowing humans to command them to perform specific tasks at specific times. Remote control devices can communicate with robots using wired connections, radio, or infrared signals. Metal processing is quite impressive. Remote-controlled robots are often referred to as puppet robots, which are very useful for exploring dangerous environments or areas inaccessible to humans (such as deep-sea or inside volcanoes). Some robots are only partially remote-controlled. For example, an operator might instruct the robot to reach a specific location but not guide it along the route, allowing it to find its own way.
The NASA-developed remote-controlled space robot R2
Autonomous robots can act independently without relying on any operators. The basic principle is to program the robot to react to external stimuli in a certain way. Extremely simple collision-response robots can illustrate this principle well.
This type of robot has a collision sensor to check for obstacles. When you start the robot, it generally moves in a zigzag path. When it encounters an obstacle, the impact is registered by its collision sensor. Each time a collision occurs, the robot’s program instructs it to back up, turn right, and then continue moving forward. In this way, the robot will change its direction whenever it encounters an obstacle.
Advanced robots apply this principle in more sophisticated ways. Robotics experts develop new programs and sensory systems to create smarter, more perceptive robots. Today’s robots can perform well in various environments.
Relatively simple mobile robots use infrared or ultrasonic sensors to detect obstacles. These sensors operate similarly to the echolocation system in animals: the robot emits a sound signal (or a beam of infrared light) and detects the reflection of the signal. The robot calculates the distance to the obstacle based on the time taken for the signal reflection.
More advanced robots utilize stereo vision to observe the surrounding world. Two cameras provide depth perception, while image recognition software enables the robot to determine the location of objects and recognize various items. Robots can also use microphones and odor sensors to analyze their environment.
Some autonomous robots can only operate in familiar, limited environments. For example, lawn-mowing robots rely on buried markers to determine the boundaries of the lawn. Robots used for cleaning offices require a map of the building to move between different locations.
More advanced robots can analyze and adapt to unfamiliar environments, even adapting to rugged terrains. These robots can associate specific terrain patterns with specific actions. For instance, a rover robot generates a map of the ground ahead using its visual sensors. If the map shows a rugged terrain pattern, the robot will know to take another route. This system is extremely useful for exploratory robots working on other planets.
A set of alternative robot designs employs a looser structure that incorporates randomization factors. When such a robot gets stuck, it moves its limbs in various directions until its actions yield results. It accomplishes tasks through close cooperation between force sensors and drive mechanisms, rather than being entirely guided by a computer program. This is similar to how ants attempt to navigate around obstacles: ants seem to try various methods until they find a way around the obstruction.
3 Homemade Robots
In the final sections of this article, we will look at one of the most intriguing areas of the robotics world: artificial intelligence and research robots. For years, experts in these fields have made significant advances in robotics, but they are not the only creators of robots. Over the decades, although few in number, passionate hobbyists have been building robots in garages and basements all around the world.
Homemade robots are a rapidly growing subculture, wielding considerable influence on the internet. Amateur robotics enthusiasts assemble their own creations using various commercial robotic tools, mail-order parts, toys, and even old video recorders.
Like professional robots, the types of homemade robots are diverse. Some weekend hobbyists have created very sophisticated walking machines, while others have designed household robots for themselves, and some enthusiasts are keen on building competitive robots. Among competitive robots, the most familiar are remote-controlled robot warriors, like those seen on the show “BattleBots”. These machines are not considered “real robots” because they do not have a reprogrammable computer brain. They are merely enhanced remote-controlled cars.
More advanced competitive robots are controlled by computers. For example, soccer robots can play small soccer matches entirely without human input. A standard robot soccer team consists of several individual robots that communicate with a central computer. This computer “watches” the entire field through a camera and distinguishes between the ball, goals, and players on both teams by color. The computer constantly processes this information and decides how to direct its team.
Adaptability and Versatility
The personal computer revolution is marked by its exceptional adaptability. Standardized hardware and programming languages allow computer engineers and amateur programmers to create computers for their specific purposes. Computer parts are somewhat similar to craft supplies, with countless applications.
So far, most robots resemble kitchen appliances. Robotics experts have manufactured them for specific uses. However, their adaptability to completely different applications is not very good.
This situation is changing. A company called Evolution Robotics has pioneered the field of adaptive robotic hardware and software. The company aims to carve out its niche market with an easy-to-use “robot developer toolkit”.
This toolkit features an open-source software platform that provides various common robotic functions. For instance, roboticists can easily equip their creations with capabilities such as target tracking, responding to voice commands, and avoiding obstacles. From a technical perspective, these functions are not revolutionary, but what is unusual is that they are integrated into a simple software package.
The toolkit also comes with some common robotic hardware that can be easily combined with the software. The standard toolkit includes infrared sensors, motors, a microphone, and a camera. Robotics experts can assemble all these components using a set of reinforced mounting components, which include some aluminum body parts and sturdy wheels.
Of course, this toolkit is not for creating mediocre works. It costs over $700, which is by no means a cheap toy. However, it represents a significant step toward new robotics science. In the near future, if you want to create a new robot that can clean rooms or care for pets while you are away, you might only need to write a BASIC program to do so, saving you a significant amount of money.
4 Artificial Intelligence
Artificial intelligence (AI) is undoubtedly the most exciting and controversial field in robotics: everyone agrees that robots can work on assembly lines, but there is disagreement about whether they can possess intelligence.
Just like the term “robot”, it is also challenging to define “artificial intelligence”. The ultimate artificial intelligence is the reproduction of human thought processes, that is, a man-made machine with human-like intelligence. Artificial intelligence includes the ability to learn any knowledge, reasoning ability, language ability, and the ability to form its own opinions. Currently, robotics experts are far from achieving this level of artificial intelligence, but they have made significant progress in limited areas of AI.
Computers now have the ability to solve problems within limited domains. The execution process of solving problems with artificial intelligence is complex, but the basic principles are quite simple. First, an artificial intelligent robot or computer collects facts about a situation through sensors (or human input). The computer compares this information with stored information to determine its meaning. The computer calculates various possible actions based on the collected information and predicts which action will yield the best results. Of course, the computer can only solve problems that its program allows it to solve; it does not possess general analytical capabilities. Chess computers are an example of such machines.
Some modern robots also have limited learning capabilities. Learning robots can recognize whether a certain action (such as moving a leg in a particular way) achieved the desired result (such as avoiding an obstacle). The robot stores this information and attempts to perform the successful action the next time it encounters the same situation. Similarly, modern computers can only do this in very limited scenarios. They cannot collect all types of information like humans. Some robots can learn by mimicking human actions. In Japan, robotics experts demonstrated dance moves to a robot, allowing it to learn how to dance.
Some robots possess interpersonal communication abilities. Kismet, a robot created by the MIT Artificial Intelligence Lab, can recognize human body language and tone of voice, responding accordingly. The creators of Kismet were interested in the interactions between adults and infants, which can be completed based solely on tone and visual information. This low-level interaction can serve as the basis for humanoid learning systems.
Kismet Robot
Kismet and other robots created by the MIT AI Lab employ an unconventional control structure. These robots are not controlled by a central computer governing all actions; instead, their low-level actions are controlled by lower-level computers. Project leader Rodney Brooks believes this is a more accurate model of human intelligence. Most human actions are made automatically, rather than being decided by higher-level consciousness.
The true challenge of artificial intelligence lies in understanding how natural intelligence works. Developing artificial intelligence is different from creating an artificial heart; scientists do not have a simple and concrete model to reference. We know that the brain contains billions of neurons, and our thinking and learning are accomplished by establishing electronic connections between different neurons. However, we do not know how these connections achieve advanced reasoning capabilities or even the principles behind low-level operations. The neural networks in the brain appear to be complex beyond comprehension.
Thus, artificial intelligence largely remains theoretical. Scientists propose hypotheses about the principles of human learning and thinking and then use robots to experiment with their ideas.
Just as the physical design of robots is a convenient tool for understanding the anatomy of animals and humans, research into artificial intelligence also aids in understanding how natural intelligence works. For some robotics experts, this insight is the ultimate goal of designing robots. Others fantasize about a world where humans live alongside intelligent machines, using various small robots to perform manual labor, healthcare, and communication. Many robotics experts predict that the evolution of robots will ultimately lead us to become cyborgs, humans fused with machines. There is reason to believe that future humans will implant their thoughts into robust robotic bodies, allowing them to live for thousands of years!
Regardless, robots will play an important role in our daily lives in the future. In the coming decades, robots will gradually expand beyond industrial and scientific fields into everyday life, similar to how computers began to permeate households in the 1980s.