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The working principle of the robot
Release Time:2018-04-17 11:17:00    Page views:2546
Many people think that robots are as high-end and cool as Terminators in science fiction movies when they hear the words "robots". Otherwise, in this article, we will discuss the basic concepts of robotics and how robots accomplish their tasks.

1 Component of Robot

At the most basic level, the human body consists of five main components:

Body structure

Muscle system, used to move body structure

Sensory system, which receives information about the body and its surroundings

Energy source, used to provide energy for muscles and senses

The brain system, which processes sensory information and directs muscle movements

Of course, human beings have some intangible characteristics, such as intelligence and morality, but at the purely physical level, this list is quite complete.

The components of robots are very similar to those of humans. A typical robot has a mobile body structure, a motor-like device, a sensor system, a power supply and a computer "brain" that controls all these elements. In essence, robots are "animals" made by human beings. They are machines that imitate human and animal behavior.

Bionic Kangaroo Robot

Robots are widely defined, ranging from industrial robots serving in factories to home cleaning robots. According to the current broadest definition, if something is considered by many people as a robot, then it is a robot. Many roboticists (roboticists) use a more precise definition. They stipulate that robots should have a reprogrammable brain (a computer) to move the body.

According to this definition, robots differ from other mobile machines, such as cars, in their computer elements. Many new cars have an on-board computer, but it's only used for minor adjustments. The driver controls most parts of the vehicle directly through various mechanical devices. Robots are different from ordinary computers in physical characteristics. They each connect a body, but ordinary computers are not.

Most robots do have some common characteristics.

First, almost all robots have a mobile body. Some have only motorized wheels, while others have a large number of movable parts, which are usually made of metal or plastic. Similar to human bones, these independent components are joined together by joints.

The wheels and shafts of the robot are connected by some kind of transmission device. Some robots use motors and solenoids as transmission devices; others use hydraulic systems; and others use pneumatic systems (systems driven by compressed gases). Robots can use any of the above types of transmission. Metal processing is really good.

Secondly, the robot needs an energy source to drive these transmission devices. Most robots use batteries or wall sockets to power them. In addition, the hydraulic robot needs a pump to pressurize the liquid, while the pneumatic robot needs a gas compressor or a compressed gas tank.

All transmission devices are connected to a circuit through wires. The circuit directly powers the electric motor and the screw coil, and operates the electronic valve to start the hydraulic system. The valve can control the flow path of the pressurized fluid in the machine. For example, if a robot moves a hydraulic leg, its controller opens a valve that is directed by a hydraulic pump to the piston cylinder on the leg. The pressurized fluid will propel the piston and rotate the leg forward. Normally, robots use pistons that provide bi-directional thrust to enable components to move in both directions.

The computer of the robot can control all the components connected to the circuit. In order for the robot to move, the computer will open all the motors and valves needed. Most robots are reprogrammable. If you want to change the behavior of a robot, you just need to write a new program to its computer.

Not all robots have sensing systems. Few robots have vision, hearing, smell or taste. One of the most common sensations a robot has is the sense of motion, which is its ability to monitor its own motion. In standard design, grooved wheels are installed at the joints of the robot.

On one side of the wheel is a light-emitting diode, which emits a beam through the groove and shines on the light sensor on the other side of the wheel. When a robot moves a particular joint, grooved wheels rotate. In this process, the groove will block the beam. The optical sensor reads the mode of the beam flickering and transmits the data to the computer. The computer can accurately calculate the rotation distance of the joint based on this model. The basic system used in computer mouse is the same.

These are the basic components of robots. Robot experts have countless ways to combine these elements to create infinitely complex robots. Robot arm is one of the most common designs.

2 How do robots work

The term "Robot" in English comes from the Czech word robota, which is often translated as "forced labor". It is very appropriate to use it to describe most robots. Robots in the world are mostly used for heavy repetitive manufacturing. They are responsible for tasks that are very difficult, dangerous or boring for humans.

The most common manufacturing robot is the robot arm. A typical robot arm consists of seven metal parts, which are joined by six joints. The computer rotates a stepping motor connected to each joint separately to control the robot (some large robotic arms use hydraulic or pneumatic systems). Unlike ordinary motors, stepping motors move accurately in an incremental manner. This allows the computer to move the arm precisely, so that the arm repeats exactly the same actions continuously. Robots use motion sensors to ensure that they move in exactly the right amount.

This industrial robot with six joints is very similar to the human arm. It has parts similar to shoulders, elbows and wrists. Its "shoulders" are usually mounted on a fixed base structure rather than a moving body. This type of robot has six degrees of freedom, that is to say, it can rotate in six different directions. In contrast, the human arm has seven degrees of freedom.

Joints of a six-axis industrial robot

The function of the human arm is to move the hand to different positions. Similarly, the role of the robot arm is to move the end effector. You can install various end effectors on the arm for specific application scenarios. There is a common end-effector that can grasp and move different objects. It is a simplified version of the human hand. Robot hands often have built-in pressure sensors, which are used to tell the computer the strength of the robot when it grasps a particular object. This keeps the object in the robot's hand from falling or being crushed. Other end effectors include spray lamps, drills and lacquer sprayers.

Industrial robots are designed to perform exactly the same tasks repeatedly in controlled environments. For example, a robot might be responsible for screwing the lid on a peanut butter jar delivered on the assembly line. In order to teach the robot how to do this work, the programmer uses a hand-held controller to guide the robot arm to complete the whole set of actions. The robot accurately stores the action sequence in memory, and then repeats the action whenever new cans are delivered on the assembly line.

Robot arm is one of the basic components used in manufacturing automobiles.

Most industrial robots work on automotive assembly lines and are responsible for assembling automobiles. Robots are much more efficient than humans in doing a lot of such work because they are very precise. No matter how many hours they have worked, they can still drill holes in the same place and screw the screws with the same force. Manufacturing robots also play an important role in the computer industry. Their ingenious hand can assemble a tiny microchip.

Robot arms are relatively difficult to manufacture and program because they only work in a limited area. If you want to send robots to the vast outside world, things will get a little complicated.

The first problem is to provide a feasible motion system for robots. Wheels or orbits are often the best choice if the robot only needs to move on the flat ground. If the wheels and tracks are wide enough, they are also suitable for more rugged terrain. But robot designers often want to use legged structures because they are more adaptable. Manufacturing legged robots can also help researchers understand natural kinematics, which is a useful practice in the field of biology.

The legs of a robot usually move back and forth driven by a hydraulic or pneumatic piston. Pistons are connected to different leg parts, like muscles attached to different bones. It is undoubtedly a difficult problem to make all these pistons work together in the right way. In infancy, the human brain has to figure out which muscles need to contract at the same time to keep from falling while walking upright.

Similarly, the robot designer must understand the correct piston motion combination related to walking and incorporate this information into the robot's computer. Many mobile robots have a built-in balancing system (such as a set of gyroscopes), which tells the computer when it needs to correct the robot's movements.

Boston Power Upgraded Atlas Humanoid Robot

Biped walking is unstable in itself, so it is very difficult to realize in the manufacture of robots. In order to design more stable walking robots, designers often look to the animal world, especially insects. Insects have six legs. They often have extraordinary balance and are able to adapt to many different landforms.

Some mobile robots are remotely controlled, and humans can direct them to perform specific tasks at specific times. The remote control device can communicate with the robot using connection lines, radio or infrared signals. Metal processing is really good. Long-range robots, often referred to as puppet robots, are very useful in exploring environments that are dangerous or inaccessible to humans, such as deep oceans or volcanoes. Some robots are only partially remotely controlled. For example, the operator may instruct the robot to reach a specific location, but it will not direct the path for it, but let it find its own way.

NASA develops a remotely controlled space robot R2

Autonomous robots can act independently without relying on any controllers. Its basic principle is to program the robot so that it can respond to external stimuli in some way. Extremely simple collision reaction robots can well explain this principle.

The robot has a collision sensor for checking obstacles. When you start the robot, it generally zigzags along a straight line. When it encounters an obstacle, the impact force acts on its collision sensor. Every time a collision occurs, the robot's program instructs it to retreat, turn right, and move on. In this way, a robot will change its direction whenever it encounters obstacles.

Advanced robots will use this principle in a more sophisticated way. Robot experts will develop new programs and sensing systems to create robots with higher intelligence and perception. Robots today can play in a variety of environments.

Simpler mobile robots use infrared or ultrasonic sensors to sense obstacles. These sensors work in a similar way to animal echo positioning systems: the robot sends out a sound signal (or a beam of infrared light) and detects the reflection of the signal. The robot calculates the distance between the robot and the obstacle according to the time it takes to reflect the signal.

Higher-level robots use stereo vision to observe the world around them. Two cameras can provide depth perception for robots, while image recognition software enables robots to locate objects and identify various objects. Robots can also use microphones and odor sensors to analyze their surroundings.

Some automatic robots can only work in limited environments they are familiar with. For example, mower robots depend on buried landmarks to determine ranges of grasslands. Robots used to clean offices need maps of buildings to move between locations.

Higher-level robots can analyze and adapt to unfamiliar environments, and even to rough terrain. These robots can associate specific terrain patterns with specific actions. For example, a rover robot uses its visual sensors to generate maps of the ground ahead. If the map shows rugged terrain patterns, the robot will know that it should take another path. This system is very useful for exploratory robots working on other planets.

There is an alternative robot design scheme which adopts a looser structure and introduces randomization factors. When the robot is stuck, it will move its appendages in all directions until its action produces an effect. It accomplishes tasks through close collaboration of force sensors and transmission devices, rather than being guided by a computer through a program. This is similar to the way ants try to get around obstacles: when they need to get through obstacles, they don't seem to be quick-witted, but try all kinds of ways until they get around obstacles.

3 Home-made Robots

In the last few parts of this article, let's look at the most striking areas in the robotic world: artificial intelligence and research robots. Over the years, experts in these fields have made great progress in robotics science, but they are not the only makers of robots. For decades, few, but enthusiastic, people have been making robots in garages and basements around the world.

Home-made robots are a rapidly developing sub-culture with considerable influence on the Internet. Amateur robotics enthusiasts use a variety of commercial robotic tools, mail-order parts, toys and even Vintage video recorders to assemble their own works.

Like professional robots, there are many kinds of home-made robots. Some robot enthusiasts who can't work until the weekend have made very elaborate walking machines, while others have designed home robots for themselves, and others are keen on making competitive robots. Among competitive robots, the most familiar is the remote-controlled robot fighter, as you saw on Battle Bots. These machines are not "real robots" because they don't have a reprogrammable computer brain. They are just reinforced remote control cars.

The more advanced competitive robots are controlled by computers. For example, soccer robots do not need human input at all in small soccer matches. The standard robotic soccer team consists of several separate robots that communicate with a central computer. The computer "watches" the whole course through a camera, and distinguishes football, goal and players from each other according to color. The computer is always processing such information and deciding how to command its team.

Adaptability and versatility

The personal computer revolution is marked by its remarkable adaptability. Standardized hardware and programming languages allow computer engineers and amateur programmers to build computers for their specific purposes. Computer parts are somewhat similar to craft articles, and they can be used for countless purposes.

So far, most robots are more like kitchen utensils. Robot experts have built them for specific purposes. But their adaptability to completely different application scenarios is not very good.

This is changing. Evolution Robotics pioneered the field of software and hardware for adaptive robots. The company hopes to tap into its niche market with an easy-to-use Robot Developer Toolkit.

The toolkit has an open software platform that provides a variety of commonly used robotic functions. For example, roboticists can easily give their work the ability to track targets, listen to voice commands and bypass obstacles. From a technical point of view, these functions are not revolutionary, but unusually, they are integrated in a simple software package.

The toolkit also comes with some common robotic hardware that can easily be combined with software. The standard toolkit provides some infrared sensors, motors, a microphone and a camera. Robot experts can assemble all these components using a set of reinforced mounting components, including some aluminium body parts and durable wheels.

Of course, this toolkit does not allow you to create mediocre works. It sells for more than $700 and is by no means a cheap toy. However, it has taken a big step towards new robotics. In the near future, if you want to build a new robot that can clean your room or take care of your pets when you leave, you may only need to write a BASIC program to do so, which will save you a lot of money.

4 Artificial Intelligence

Artificial intelligence (AI) is undoubtedly the most exciting and controversial field in robotics: everyone believes that robots can work on assembly lines, but there are differences on whether they can have intelligence.

Just like the term "robot" itself, it's also difficult to define "artificial intelligence". The ultimate artificial intelligence is the reproduction of human thinking process, that is, an artificial machine with human intelligence. Artificial intelligence includes the ability to learn any knowledge, reasoning ability, language ability and the ability to form their own views. At present, robotics experts are far from achieving this level of AI, but they have made great progress in the limited field of AI. Nowadays, machines with artificial intelligence can imitate certain intelligence elements.

Computers have the ability to solve problems in limited areas. The implementation process of solving problems with artificial intelligence is very complicated, but the basic principles are very simple. First, AI robots or computers collect facts about a situation through sensors (or manual input). Computers compare this information with stored information to determine its meaning. The computer calculates all possible actions based on the information collected, and then predicts which one works best. Of course, a computer can only solve the problems that its program allows it to solve, and it does not have the analytical ability in the general sense. Chess computers are an example of such machines.

Some modern robots also have limited learning ability. Learning robots can recognize whether a certain action (such as moving legs in some way) achieves the desired results (such as bypassing obstacles). Robots store such information, and the next time they encounter the same situation, they try to make actions that can be successfully coped with. Similarly, modern computers can only do this in very limited situations. They can't collect all kinds of information like humans. Some robots can learn by imitating human actions. In Japan, robotics experts demonstrated dance movements to a robot and taught it to dance.

Some robots have interpersonal communication skills. Kismet is a robot made by MIT's Laboratory of Artificial Intelligence. It can recognize human body language and tone of speech and respond accordingly. Kismet's authors are interested in the way adults and babies interact, which can be accomplished only by intonation and visual information. This low-level interaction can be used as the basis of human-like learning system.

Kismet Robot

Kismet and other robots manufactured by MIT's Artificial Intelligence Laboratory use an unconventional control structure. These robots do not use a central computer to control all the actions. Their low-level actions are controlled by a low-level computer. Rodney Brooks, project manager, believes that this is a more accurate model of human intelligence. Most human actions are automatic, not determined by the highest level of consciousness.

The real problem of AI is to understand the working principle of natural intelligence. Developing artificial intelligence is different from manufacturing artificial hearts. Scientists do not have a simple and concrete model for reference. We know that the brain contains tens of billions of neurons, and our thinking and learning are accomplished by establishing electronic connections between different neurons. But we don't know how these connections achieve advanced reasoning capabilities, or even how low-level operations are implemented. Brain neural networks seem to be too complex to understand.

Therefore, AI is still a theory to a large extent. Scientists hypothesize 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, the study of artificial intelligence also helps to understand the working principle of natural intelligence. For some robotics experts, this view is the ultimate goal of designing robots. Others are imagining a world in which humans live with intelligent machines, in which humans use small robots for manual labor, health care and communication. Many robotics experts predict that the evolution of robots will ultimately make us semi-robots, that is, humans integrated with machines. There is reason to believe that future humans will implant their ideas into robust robotic bodies and live for thousands of years!

In any case, robots will play an important role in our future daily life. In the coming decades, robots will gradually expand beyond industry and science into daily life, similar to the process in which computers began to spread to families in the 1980s.