In 1920, Czech writer Karel Capek came up with a name for a machine invented to do work instead of a person: “robot.” The definition took root over time and from the end of the 20th century began to mean a system of components, sensors and mechanisms designed to perform a set of operations in accordance with the laid down program.
The progress of science and technology has allowed design engineers to create more and more advanced machines that can replace humans in extreme conditions: in space, under water, on the battlefield. The robot does not know fatigue and is capable of performing precise movements without errors - this is why robotic mechanisms are gradually replacing human labor in production.
(Types of robots)
There are dozens of basic types of robots, which differ in several ways - from purpose to appearance. In order to understand how a robot works, let’s consider its form, which is closest to the appearance of a person - an android robot.
Android design
A humanoid robot consists of several main parts:
- The head is the upper part of the structure;
- The torso is the main frame of the robot;
- Manipulator arms with power mechanisms;
- The legs are a walker consisting of two lower limbs, if the chassis, then the caterpillar drive.
(Visual design of the robot)
Contrary to popular belief, in the head of an android, like a living person, there is a “brain”, i.e. a computer or central processor, most often at the top of the mechanism there are other elements of the system: video cameras, sensors, a gyroscope. This is due to the relatively small size of the “head”, the internal space of which is not capable of accommodating a large volume of electronics.
The torso is the most protected part of the robot. Electronics that control the system and an autonomous power source (battery) are placed in the internal space of the frame.
(Classic manipulative arm)
Capturing/moving loads, performing other operations, including actions with tools - tasks for the upper limbs - manipulators. The carpal endings can have the shape and function of human hands.
Android robots move in steps on two “legs.” The chassis copies the anthropological features of the structure of the human body: the legs consist of several components connected by hinge joints. Some robot models are capable of running, i.e. move in such a way that both legs do not touch the surface at the moment of movement.
Roboy (University of Zurich)
To begin with, we note that what sets this robot apart from others is its joints, which are driven by tendons, which allow it to move almost like a human.
It is soft to the touch and very reactive, compensating for shocks and regaining its position by mimicking muscles. His face can express emotions, and he also blushes. This is also the first of two robots on this list that looks like a child. Unveiled in Zurich last year, Roboy will be about a meter tall. It is small, but designed to one day become a good helper for the elderly, as well as a great companion. The project is open, all you need is a 3D printer and 200,000 euros to print it.
By the way, it took about nine months to develop it, which is symbolic.
Head
To recognize the surrounding environment - objects, landscape features - robotic systems are equipped with high-resolution video cameras (Figure 1). They are usually placed in the android's head. Thanks to a camera (or several cameras), the machine can identify (recognize) surrounding objects, estimate their size and distance to objects.
Depending on the landscape or architectural features of the building, the robot is able to decide on the method of movement and shifting the center of gravity, for example, when climbing/descending steps or inclined surfaces, overcoming a ditch or obstacle.
(Figure 1. Eye-video camera tracking robot)
Video cameras are equipped with several modules to obtain additional information:
- In the infrared range;
- In thermal imager mode.
In addition to cameras, the design of robots involves the use of a system of sensors that determine the spatial position of the android on the ground or indoors, the compression force of the manipulators, the speed of movement, etc. The most important sensor for an android is the gyroscope; it is the one that maintains a stable vertical position of the car while driving. This is the device equipped with the Atlas android robot, the brainchild of the American company Boston Dynamics. From sensors and cameras, information goes to the “brain” of the car - a computer or system of computers.
2.1. Basic Set Components
The set includes [https://education.lego.com/ru-ru/lego-education-product-database/mindstorms-ev3]:
- Microcomputer EV3.
EV3 microcomputer specifications:
- ARM 9 type processor with Linux-based operating system
- 4 information input ports with operating frequency up to 1 kHz
- 4 output ports for command execution
- Built-in memory including 16 MB flash memory and 64 MB RAM
- slot for reading Mini SDHC memory cards with support for reading cards up to 32 GB
- six-button control interface with the function of changing the backlight (3 colors) to indicate the operating mode of the microcomputer
- monochrome display with a resolution of 178 x 128 pixels allows for detailed viewing of graphs and reading data from sensors
- high quality built-in speaker
- Possibility of programming and data logging using a microcomputer, created programs and acquired data can be exported to EV3 software
- Supports communication with computers via built-in USB port or plug-in WiFi or Bluetooth receivers
- USB 2.0 hosting mode, allowing microcomputers to be connected in a daisy chain
- WiFi support and support for connecting USB flash cards
- Powered by 6 AA batteries or 2050 mAh EV3 DC battery
- EV3 battery.
The EV3 DC Lithium-Ion Battery has a capacity of 2050 mAh and is specifically designed to work with the new EV3 Bricks
- Two large servo motors.
- built-in rotation sensor with measurement accuracy up to 1 degree
- maximum speed up to 160-170 rpm
- maximum torque of 40 Ncm
- automatic identification by EV3 software
- Medium servo motor.
- built-in rotation sensor with measurement accuracy up to 1 degree
- maximum speed up to 240-250 rpm
- maximum torque of 12 Ncm
- automatic identification by EV3 software
- Ultrasonic sensor.
- measures distances from 1 to 250 cm
- measurement accuracy is +/- 1 cm
- in listening mode the external LED flashes constantly, in emission mode the LED lights constantly
- if the ultrasonic signal is recognized, the sensor returns the Boolean value "True"
- automatic identification by EV3 software
- Color sensor.
- measures reflected red light and ambient ambient light, from complete darkness to bright sunlight
- captures and identifies 8 colors
- polling rate up to 1 kHz
- automatic identification by EV3 software
- Gyroscopic sensor.
- angle measurement mode with an accuracy of +/- 3 degrees
- built-in gyroscope detects rotations with a torque of up to 440 degrees/s
- polling rate up to 1 kHz
- automatic identification by EV3 software
- Two touch sensors.
- built-in front button
- automatic identification by EV3 software
- LEGO Technic assembly elements (541 pieces) and two plastic organizer trays for storing and sorting parts.
Torso
In the most protected and spacious part of the robot, electronic control boards and autonomous power supplies are installed.
During the mission, the robot is controlled by a computer - a set of chips designed to receive, accumulate information, process it and send signals to actuators operating using motors (Figure 2). The progress of computer technology makes it possible to install more and more advanced analysis systems in androids, capable of using several of the most advanced technologies:
- Object recognition;
- Speech recognition;
- Recognition of movements, gestures;
- Self-learning based on the information received;
- Memorizing the appearance of objects and people's faces.
You can set a task for the android programmatically, i.e. by entering a list of commands into the CPU, or verbally, by pronouncing a set of words to begin performing the task. Some models of androids are able to respond to hand gestures and changes in a person’s location.
The robot control system is very similar to the construction of the human nervous system depending on its development:
- Direct execution of specific operator commands;
- The need to constantly adjust the actions of the android when performing a common task;
- Entering the final goal (indicating the direction of action).
In the first case, the machine's memory stores commands that the CPU (central processing unit) sends to the actuators to perform certain operations. For example, moving the robot, changing the position of the manipulator, etc. at the operator's command. One of the cheapest and easiest to manufacture models.
When moving an android from point A to point B, operator intervention is necessary in cases where the set of algorithms (pre-recorded actions in memory) does not provide for overcoming complex obstacles (for example).
More advanced intelligence, having received information from a system of sensors and video cameras, independently assesses the situation and chooses the most optimal solution on its own.
(Figure 2. DC motor)
The main source of energy for modern android robots is electricity. The power source can be:
- Autonomous - batteries, solar panels;
- External - electricity is supplied via cable.
In the first case, the car is not tied to an energy resource and is capable of performing tasks at any distance from the charging station. The disadvantages are the increased weight of the robot and short operating time. Cable power supply has its advantages: less weight of the android, the ability to use a larger number of nodes, sensors, mechanisms, unlimited operating time.
iCub (Italian Institute of Technology)
This is iCub, the most impressive humanoid robot on the list.
iCub is so similar to a person that you can address him by his first name and patronymic. Developed by several universities and created by the Italian Institute of Technology, the iCub is the size of a two-year-old child and even learns the same way. iCub is able to identify people and objects, find differences between them and interact accordingly. He is also capable of finding his way out of complex 3D mazes on his own. He can touch, grab and lift objects on demand and even shoot a bow, trying to get better and better at hitting the bull's-eye.
It is likely that iCub will become an ideal companion and assistant for a person in the not too distant future.
Manipulating hands
The manipulators copy the structure of human hands (Figure 3) and consist of several parts connected by hinges:
- Carpal;
- Forearms;
- Shoulder.
(Figure 3. Manipulating arm)
Manipulators have several degrees of freedom, i.e. the robot can raise its arms, spread them to the sides, rotate its hands, and grab objects with its “fingers.” The manipulators are driven by power mechanisms—servos. Often, for accurate and precise work, fingers are equipped with special sensors that regulate the compression force. Instead of load-handling devices, other devices and mechanisms are installed in the hand sections of the manipulators: welding machines, etc.
Bebionics3 (RSLSteeper)
Bebionic3 is today's most advanced prosthetic arm, capable of lifting up to 45 kilograms, but still sensitive enough to write with a pen or hold a paper cup.
Using sensors that come into contact with the user's skin, it is easily controlled by the fingers, and the speed and strength can be adjusted at any given moment. The prosthesis can be purchased along with a glove, which will give the hand a human appearance. Remember the famous scene from the second Terminator when Arnie cuts the skin off his arm, revealing the robotic skeleton underneath? Who would have thought that we were on the verge of similar technology just 20 years ago?
The prosthesis will cost 25-35 thousand dollars. It's not cheap, but it's invaluable for amputees who want to regain their independence.
Walker legs
By analogy with the structure of the human body, android robots move in steps. The design of the legs provides the ability to run and overcome various obstacles (stairs, holes, inclined surfaces). The legs, like the manipulator arms, are driven by motors (Figure 4).
(Figure 4. Stepper motor)
For all types of robots, several types of actuators are used:
- Mechanical;
- Electrical;
- Hydraulic;
- Pneumatic;
- Hybrids (electromechanical, hydromechanical, etc.).
Due to the design features of android robots (small dimensions, the chassis system is a walker), servo drives or servomotors (Figure 5), which are based on an electric motor, are most often used to mechanize units.
(Figure 5. Servomotor)
Unlike a conventional electric motor, a complete servo drive is capable of:
- Determine and change the angle of the shaft position with high accuracy;
- Consume exactly as much electricity as necessary to perform a specific action;
- Reduce the load on robot parts, increasing their service life.
Creating a wireframe
There is no "ideal" way to create a frame. A compromise is almost always required. Perhaps you need a lightweight frame. But it may require the use of expensive materials or materials that are too fragile.
You may want to make a robust or large chassis. Although you understand that it will be expensive, difficult or difficult to produce. Your "ideal" frame or frame may be very complex. Making a robot frame may require too much time to design and build.
At the same time, a simple frame can be no less good. The perfect shape is rare, but some designs can look more elegant due to their simplicity. Perhaps other projects may attract attention due to their complexity.
Robot work-action
An example of how all systems of an android robot work together
- Robot type: android
- Control method: autonomous
- Objective: climb a flight of stairs
- After turning on the power, the CPU is loaded, which checks all systems.
- After receiving confirmation that the machine is operational, the computer stabilizes the vertical position of the android using a gyroscope and evaluates the obstacle with cameras.
- Having established the range to the first stage and its height, the distance to other nearby objects, the robot begins to move.
- Servo drives drive the lower limbs, which raise the supporting platforms (feet) to the desired height.
- The balance of the machine is maintained by a gyroscope.
- After overcoming the last step, the robot stops or continues moving forward, depending on the program or the command received.
Kuratas (Suidobashi Heavy Industry)
Kuratas is the world's first giant robot.
Its height is 4 meters, it weighs about 4.5 tons. You can climb into it. The driver interface works using Kinect, but if you prefer to control your robots from a safe distance, you can use your phone's touchscreen as a remote control. The artist Kogoro Kurata decided to develop this robot, inspired by anime. He was assisted by Wataru Yoshizaki, a roboticist.
Kuratas moves with four wheels, can accelerate to 10 km/h and carry weapons. Kogoro Kurata calls Kuratas a “work of art,” which is not surprising considering the modest $1.3 million price tag.
In any case, this is not the most outstanding piece of engineering art.
Required Skills
To make robots, beginners will need the following skills:
- ability to design and create mechanisms;
- knowledge of how little helpers interact with the external environment;
- studying the topic, since making a walking robot with your own hands is not an easy task;
- an initial understanding of programming - variables, algorithms, modern languages.
Having become familiar with the basics of programming, you can move on to creating homemade robotic vacuum cleaners, pool cleaners and window cleaners in the house. Robots can be used in other areas of life.
