PROJECT 2021

 

5.- PROJECTS

 You must choose between 3 projects.

1.- The easiest is the light traffic

2.- Secondly the Batman's car


3.- Following the line




ACTIVITIES


Make your robot (one of these or whatever you want). Then prepare a presentation (less 15 minutes) explaining your project. You can use fotos,, videos or whatever you need.

4.- DC MOTOR & ARDUINO BOARD

DC motors are a classic of technological projects. If we consider the operating conditions of the ARDUINO card, it turns out that it is only possible to control it if we use a transistor. The transistor can operate in cut when its base circulates a low intensity, which makes the intensity of the collector is zero and the motor does not work. On the other hand, if the current flowing through the base is very high, the transistor is in saturation and the motor operates in these conditions. Between both situations, the transistor is active and the intensity that flows through the collector is B (approximately 100) times the intensity of the base. That's why you have to mount the next circuit.

Find a transistor that can work in the conditions of the ARDUINO card with adequate resistance. I have put a potentiometer of 10K, and a transistor BC 547.

Although you can programm the ARDUINO board using Bitbloq, if you use ARDUINO, the programm for this circuit is:

"int motorPin = 10;

void setup(){

pinMode(motorPin, OUTPUT);

}

void loop(){

digitalWrite(motorPin, HIGH);

delay(1000);

digitalWrite(motorPin, LOW);

delay(1000);

}"

              With this program, the engine speed is changed periodically.

            The result of it is:

3.- ARDUINO BOARD: BASIC USES

       Last year we already used the ARDUINO card. This year we are going to use it in a more complex way. First we will use a basic digital output: the LED diode. It is a diode that illuminates when connected in direct polarization. Therefore it is a digital output. It is necessary to connect to the digital pins and define it as an output (OUTPUT). In order for the operation to be optimal, a 220 Ohm resistor must be connected in series with it, except for the PIN 13 that already has it incorporated. The entries will be different In practice 1 the input is time. That although it is a physical input the card itself has, internally, the corresponding sensor. In practice 2 we will use as a digital input a button (INPOUT) that will be connected in PIN 2 and that requires a resistance of 10K. In practice 3 an LDR is used as input. The LDR is a variable resistance with light. More light less resistance. So it is an analog input that should be connected in the analog pins with a resistance of 10K. The last practice is a traffic light and the control is done through the time input that does not require external sensor.

PRACTISE	DESCRIPCITION	CIRCUIT	CONEXIONS	PROGRAMM	RESULT
LED flashing	LED flashing in PIN 13			Práctise 1	Video 1
Controlling a LED with a push button	When  the button is pushed, the LED lights			Práctise 2	Video 2
Controlling a LED with a LDR	If you have poor light the LED lights			Práctise 3	Video 3
Controlling light traffic	You have leds to control traffic			Práctise 4	Video 4

       

2.- ROBOTIC: INTRODUCTION

The economy of our society is based on the laws of supply and demand in the market and in the productive system. Lowering production costs means reducing prices and making products accessible to more people. The highest cost in production systems is always labor. For this reason, the third industrial revolution is transforming our factories and automating processes. This means reducing labor to a minimum. But it also has a social and human cost. The workers of the future will not develop manual jobs all routine tasks will be replaced by robots. New workers should be able to take care of them. But what is a robot? Outside of what science fiction movies tell us as SUPERHUMAN, robots are simple machines and like any other they present circuits and systems.

Like any other machine, robots have two fundamental systems 1.- STRUCTURAL: That gives them physical form 2.- FUNCTIONAL: That allows to perform the task for which they have been manufactured. A robot can be defined as:

"Multifunctional machine and reprogrammable"

The great advantage of robots is that they can be reused with the same structure and that the same structure can perform different functions depending on the program they incorporate.         But let's start with the most elementary, the structure. From the structural point of view there are two types of robots 1.- MOBILE ROBOTS: A mobile robot is everything that moves. To do this, use legs or wheels. Traditionally it is said that the basic structure has 3 wheels and not 4. Although that is not really important. What is important is that mobile robots must overcome obstacles. And in that task the legs are superior to the wheels. However, larger wheels improve stability and help overcome obstacles.

2.- INDUSTRIAL ROBOTS: Industrial robots are used in warehouses and have a basic structure of links that resembles the human arm. In fact the links are named in the same way. Depending on the type of movement they can be Cartesian, cylindrical and spherica

If we differentiate between robot (capable of anwering from its environment) and automatism (whose task can not be modified), it is clear that the functional system of the robot is very complex. In addition to mechanical systems with a multitude of belts and gears, robots must have a sensorial system. This sensorial system must consist of sensors (inputs) and actuators (outputs). The answer to the environment can be done through a program. Therefore, in all there must be a controller card that will serve as an interface between the physical system and the computer in which a certain program is compiled. In this controller card can not miss 2 important elements 1.- The microcontroller: Electronic circuit that gathers all the functionalities 2.- Memory: In which the orders must be stored. It will be ROM and RAM. Depending on these elements, the controller cards are more or less relevant. There are many in the market. However, let's focus on the ARDUINO ONE. Among other reasons because it has FREE SOFTWARE and a collaborative platform. In addition to being very versatile and economical.

1.- CONTROL SYSTEM

Control and automations have helped the development of automated industrial processes. However, control systems have a high conceptual component that will be the subject of this teaching unit.

Let's start by defining some of the main components of such systems

1.- FLOOR Set of components and parts that have a certain objective

2.- PROCESS Set of operations that will have a certain purpose.

3.- SYSTEM Combination of components that act together to perform the control

4.- INTERRUPTIONS All unwanted signals involved adversely.

5.- INPUT OF MANDO Excitator signal of the system

6.- REFERENCE SELECTOR Item that is placed to have a reference.

7.- REFERENCE INPUT. Signal produced by the reference selector

8.- CONTROL UNIT. A unit that reacts with an active signal to produce the desired output.

9.-OUT Amount to be maintained

10.- OPEN LOOP CONTROL SYSTEM. System in which the output has no influence on the input.

11.- FEEDBACK ELEMENT. A unit that provides means to increase or decrease the output signal.

12.- ACTIVE SIGNAL. Difference between input and reference.

13.- CLOSED LOOP CONTROL SYSTEM. System in the output affects the input.

The control system regulates and controls the operation of an automation or process so that it works as intended.

We can represent an open loop control system with the following scheme:

In contrast, a closed loop control system can be represented by the following scheme:

In both system we differentiate a number of characteristic elements:

1.- SENSOR OR TRANSDUCTOR: Transforms the physical signal into an electrical signal

2.- COMPARATOR Compares the input signal with the reference signal

3.- CONTROLLER Depending on the signal that arrives decides if the actuator should be activated

4.- ACTUATOR: Changes the output so that there is no error to the input.

Control is one of the foundations of modern engineering. Its theoretical foundations involve knowledge of electronics and mathematics at a high level, since to simplify such systems are used Laplace transforms.

ACTIVITIES

1.- Classify the following systems in open loop and closed loop


Washing machine, fridge and programmed air conditioning

2.- Describe the elements that appear in each of the previous systems

3.- SOLID STATE COMPONENTS

We are living in the digital era. Digital electronic is part of our daily life, however it is the evolution of analogue electronic. The basics of analogue electronic  are semiconductor materials. In this video I have explained the science of semiconductors and two components: Diode and Bipolar transistor. Indeed they haven`t many applications, but they was important in the past.




ACTIVITIES

1.- A npn transistor, has a value of B-100. Determine the operating region if

a) Vbe -0.2 V and Vce s 5 V.

We have Vbe< 0 and Vbc's Vbe - Vce's -0.2 -5 <0. In other words, the two transistor diodes are polarized in reverse and therefore the transistor must be cut.

b) ib x 50 uA (microampere) Ic x 2 mA.

The ratio Ic/Ib > 100 (B) what is only possible if the transistor is in saturation

c) Vce 5V & Ib 50 uA (microampere)

Because of the data given to us by the transistor, it must be active.

2.- A npn transistor has a value of B-100. Determine the operating region if

a) Ib 50 uA and Ic 3 mA

b) Ib 50 uA e Vce s 5V

c) Vbe-2V and Vce-1V

3.- Explain the operation of the next circuit in which there is an LDR resistor