How Robots Work
A robot is a machine that can act like a human. From common people to those working in technology, everyone has an interest in robots. Many types of robots require wires or cables to operate. Many robots look completely human again. However, all types of robots work in the same way. And these robots are mainly built on the same technique.
How Robots Work
A robot can generally be called an electro-mechanical device. Robots are made to work by sending instructions from outside with the help of devices like sensors or transducers. And these tasks of the robot are controlled through computer circuits. It may be difficult to define a robot, but it is not very difficult to understand how this widely used device works.
We humans receive information from the external environment through our 5 senses. And that information is processed in our brain to turn it into action. Robots work in phases just like us. In the case of robots, this instruction or input is given through sensors. And those instructions are processed by the CPU unit, and then only the expected result is obtained.
Before knowing about the different types of robots work, let’s know about how robots basically work.
Working Method Of The Robot
Any robot has three parts:
• ‘Sensor’ for input
• ‘CPU’ for processing
• The ‘mechanical work’ to display as a result, i.e. what the robot will do
Sensors can pick up the robot’s instructions when there is a difference in smell, touch or sight. And the ‘central processing unit’ (CPU) is also called microprocessor or microcontroller, whose job is to process information or instructions received from outside.
At the same time, pre-programmed instructions are given for what to do according to the information received. The job of the CPU is to send signals to the output section to convert the information received as input according to the instructions.
After receiving the signal, the robot completes the task. Let’s see how a robot that stops when it encounters an obstacle works.
Robot: Has the ability to jump or avoid obstacles
Input: Touch
Result: Inner pea stops
Purpose: The robot in the example moves freely in any direction and stops when it encounters an obstacle.
When the robot comes in contact with an object, its input (touch) sensor is activated. The sensor sends a signal to the processing unit as soon as it is activated. After receiving a signal, the CPU looks for instructions programmed into itself to turn that signal into action.
These instructions are actually some programs placed inside the robot. And since this interrupt instruction means to stop the robot, the CPU then sends a ‘stop’ signal to the output device (motor circuit). And thus the movement of the robot stops.
Parts That Are Usually Found In A Robot
What parts a robot will have depends on what it will be used for. However, the parts that a robot can usually have are:
1. Input Unit
Sensors and transducers are the devices that are used to instruct the robot. Some of the sensors used in robotics technology include:
• Contact / touch sensor to sense the sense of touch
• Temperature sensor to sense the temperature
• Light sensor for light sensing
• Sound sensor to understand sound
• Proximity sensor to sense the difference between far or near objects
• Distance sensor to sense the distance
• Pressure sensor to sense pressure
2. Processing Unit
The components used in the processing unit are microcontrollers or microprocessors. Which of these two parts to choose while building a robot depends on the robot’s capabilities. Microcontrollers are cheaper and easier to program than microprocessors. But because of the low working capacity of the microcontroller, it cannot take much workload.
Microprocessors on the other hand can do much more. How complex a robot’s task will be depends on its processing unit.
3. Output Unit
Each robot has different output units based on the workload. Output units commonly found in robots are:
• Actuators
• Relay
• Speaker
• CD screen
How to instruct the robot is determined based on the type of work it is doing. Wired robots use cables or wires. And in the case of wireless robots, wireless technologies like radio waves, RFID, Wi-Fi and DTSF are used.
Working Method Of Wired Robot
Now let’s discuss these two basic types of robots, wired and wireless. As the name suggests, these robots are controlled by wired devices. Such robots are controlled using keyboards, joysticks or switches.
When a particular button is pressed, it sends a signal of a certain electrical volt to its next circuit. If the input device for giving instructions is made in ‘analog’ technology, its output will be through ‘voltage signal’. And if this signal is digital, then its output will be in binary format like 1 and 0.
The ‘encoder circuit’ in the robot receives this signal and converts it into a format. The format is then converted so that it can be sent over a cable or wire. In this way, the signal format is continuously sent as output from the encoder circuit using a medium such as wire or cable.
Then the encoded signal goes to a special ‘decoder circuit’ for decoding. The decoder circuit then decodes this encoded signal and processes it, and then outputs it to the output device.
Let us try to understand the working of a wired robot with the following example:
Robot: Robot car
Input: Switch
Output: Change direction of motor clockwise
Objective: To move the car forward
Let’s say a robotic vehicle that can rotate in different directions has a keyboard-shaped input device. Such an input device has 4 switches. Each of these switches works to rotate in a different direction. If you want to move the robot forward, you have to press the button.
When the button is pressed, it sends a signal from the output voltage to the encoder circuit. And other buttons will send a signal of ‘0 voltage’ to the output device. That is, if the instructions to go forward are given through the keyboard, the 1 0 0 0 signal will go from the front, back, right and left buttons respectively. This parallel output will be sent as an instruction to an encoder. Let’s say this encoder is called ‘HT12E’.
This encoder IC (integrated circuit) named ‘HT12E’ is a widely used circuit in robotics. The encoder converts the parallel instruction to a serial output, and then sends it to the connecting wire. The wire or cable then sends these signals to the decoder circuit.
Now let’s say the name of the decoder is ‘HT12D’. The decoder converts this serial output signal to parallel output. The device, which then sends this output to the DC motor, is called a ‘motor driver’.
This motor driver might be named something like ‘IC L293D’. Finally 0 1 logic will actually rotate the motor clockwise ‘IC L293D’. And this will keep the robot car moving forward.
How Wireless Robots Work
Wireless technology is used in all types of robots, from autonomous robots to human-like robots. Except for the change in the ‘carrier circuit’, the operation of the wireless robot is almost identical to that of the wired robot. Basically, the operation of the wireless robot depends on the transmitter and the receiver.
A suitable frequency is chosen to transmit the output signal over the wireless medium. Then the transmitter and receiver antennas are determined based on the frequency on which the broadcast is to be made. The better the antenna, the better the broadcast signal will perform. Now let’s learn about the working method of wireless robot with the help of a robot car example.
Robot: Radio frequency controlled robot car
Input: Switch
Output: Clockwise motor drive and LED on
Objective: Move the robot car forward
Similar to the way wired robots work, wireless robots also have input modules. This input module gives the same output signal when the assigned button is pressed. The ‘encoder circuit’ converts this analog output into a continuous signal.
This serial information is sent to the radio frequency transmitter circuit. Basically the transmitter circuit adjusts by modulating the input wave over a wide range. This change in wave propagation is known as ‘Amplitude Shift Keying’ (ASK). The ‘Radio Frequency Transmitter’ sends this ‘ASK’ signal through the antenna.
This data is usually sent at 433 MHz at a speed of 1 kilobyte to 10 kilobytes per second. The antenna then receives this information and sends it to the radio frequency receiver circuit. The receiver circuit converts this data into a serial output and sends it to the CPU unit. This CPU unit can be a microcontroller or a microprocessor.
The processing unit decodes the successive input signals and sends that information to specific ‘pins’. This ‘pin’ again sends a similar output signal to the ‘motor driver circuit’.
This motor driver rotates the motor in the correct direction to rotate the wheels of the robot car. In this case multiple output devices can be run with one CPU. In addition to motor control, the CPU can be used to perform functions such as turning the LED on and off or sounding the horn.
The material to be used in the robot is selected by considering various damages and obstacles. Radio frequency is the best wireless medium because it allows signals to be sent over long distances. Even if there is an obstacle in between, the signal can be sent in this technology. Complex technology robots are also based on the same general rules for building wired and wireless robots.
