Fundamentals of Robotics

ESCUELA SUPERIOR POLITECNICA DE CHIMBORAZO FACULTAD DE INFORMATICA Y ELECTRÓNICA

INGENIERIA ELECTRONICA EN CONTROL Y REDES INDUSTRIALESFUNDAMENTALS OF ROBOTICS

DESIGN AND BUILDING OF A MAZE ROBOT

Authors:Dayana Carrillo Calderón

[email protected] Gálvez

[email protected] Jara Moncayo

[email protected] Méndez

[email protected]

ABSTRACT. - In this paper all parameters for our maze robot which contains a free software that manages Arduino , sensors , cables , so that we can design our very similar to a shopping structure is exposed . The maze robot is built by Arduino which is responsible for control by the signals receptan of sound sensors possessing mobility and dexterity that it has to find a way to take you from start to finish according to the this priority is granted and so to fulfill its task of completing the track maze. presenting the main details of hardware and software of a robot that is capable of moving through a maze , following rectilinear trajectories with deviations at 90 or 180 with the detection of an edge or wall of the maze, when it gets in the right way .

KEYWORDS: actuators, sensors, maze, mobile robot, arduino, Ultrasonic.

I. INTRODUCTIONRobotics and Electronics areas are important because they allow us to create an unlimited number of practical applications. Today mobile robotics has become a topic of great interest, because development has major projects in the world with the help of mobile robots.

The aim was to develop and implement an autonomous robot capable of navigating a maze , with a distance between walls of the corridors of minimum20 inches and a maximum of 300 centimeters.

Based on "Arduino " open electronic platform ( hardware source and open ) allowing based prototyping hardware software and flexible [1] prototype was designed .

In particular, for the construction of the robot control system an Arduino Uno was used [2] , ultrasonic sensors to measure distances and servos modified to achieve the displacement of the robot in the maze (Fig 1).

Three ultrasonic sensors HC- SR04 of which two were arranged on the sides of the chassis of the robot to measure the distances to the corridor walls of the maze and a front sensor HC- SR04 to detect an obstacle ( example. end were used corridor).

Regarding the programming code that can command the various electronic components input and output interface Arduino was used.

II. CONTENT DEVELOPMENT

MAZE ROBOT STRUCTURE

Several features that affect the successful implementation thereof is taken into account.

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ESCUELA SUPERIOR POLITECNICA DE CHIMBORAZO FACULTAD DE INFORMATICA Y ELECTRÓNICA

INGENIERIA ELECTRONICA EN CONTROL Y REDES INDUSTRIALESChassis MonementsSensorsProcessor (Arduino)Actuators (Motors and wheels)

A.The Chassis

The chassis design is a very important factor in the success or failure of the implementation of the robot, since according to its shape allows us to perform movements with varying degrees of accuracy within the maze.

For this case, a square frame which will contain the Arduino sensors and other elements was designed.

" The circular form , together with other features of implementation, allow us to perform movementsmore accurate (this form is used to make the rotation center of the circle is exactly the center of the chassis ) . "The elements used for construction are acrylic and other materials.

B.Movements

The path that takes the robot in the path of the labyrinth is straight with turns 90 ° or 180 ° when it detects a new road or obstacle ( end of the road ) that allows you i prevents further his career.

The drive used is differential (fig. 2), which causes the spins are simpler and also allows movement without more space than is occupying (rotates on its axis).

Another aspect of the design was defined a priori was the location of the wheels, as this also impacts on the location of the center of rotation.

C.Sensors

The distance sensors used are ultrasonic HC- SR04 (fig. 3). These are able to detect and calculate the

next object distance that is in a range from 2 to 450 cm.

They work by sending and receiving ultrasonic pulses and contain all the electronics in charge of measurement. Its use is based on sending a start pulse and timing the return pulse after reflection on the object.

3 Similar sensors are used to detect obstacles in the robot, one located in the front and two on the sides (fig. 4).

D.Processor (Arduino)

The Arduino is already pre-built out of the box; that will be used later when we finally build the program and test out the robot. This is the brain of the robot; this will hold the code that will allow the robot to follow the line and this will have most of the signal connections plugged in from the motor control board and sensors.

Arduino is a family of single-board microcontrollers, intended to make it easier to build interactive objects or environments. The hardware consists of an open-source hardware board designed around an 8 bit Atmel AVR microcontroller or a 32-bit Atmel ARM. Current models feature a USB interface together with six analog input

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ESCUELA SUPERIOR POLITECNICA DE CHIMBORAZO FACULTAD DE INFORMATICA Y ELECTRÓNICA

INGENIERIA ELECTRONICA EN CONTROL Y REDES INDUSTRIALESpins and 14 digital I/O pins that can accommodate various extension boards (fig. 5).

Software:

The Arduino integrated development environment (IDE) is a cross-platform application written in Java, and derives from the IDE for the Processing programming language and the Wiring projects. It is designed to introduce programming to artists and other newcomers unfamiliar with software development. It includes a code editor with features such as syntax highlighting, brace matching, and automatic indentation, and is also capable of compiling and uploading programs to the board with a single click. A program or code written for Arduino is called a sketch.

E. The Actuators (Motors and wheels)

The movement system is an important part of a robot and its objective is how to move robot from one point to another point. This system has some details which show us how to use motors and wheels. There are many kinds of motors and wheels. Our choice is dependent on the robot function, power, speed, and precision.

We used two servo motors because, Servo motors (fig. 6) have been around for a long time and are used in many applications.

They are small in size but pack a big punch and are very energy efficient. Because of these features, they can be used to operate remote-controlled or radio-controlled toy cars, robots and airplanes. Servo motors are also used in industrial applications, robotics, in-line manufacturing, pharmaceutics and food services. But how do the little guys work?

The servo circuitry is built right inside the motor unit and has a positionable shaft, which usually is fitted with a gear (as shown below). The motor is controlled with an electric signal which determines the amount of movement of the shaft.

Usually there are two movement systems for robots:

1. Wheel2. Tank system

It is better to use wheels for line follower robots. We can use three wheels. Two of them are joined to the motors and installed rear the robot and the other wheel is free and installed front of the robot as a passive caster.

Ball Caster

This will be the front-turning wheel that will allow the robot to swivel one way or the other without scraping the chassis. The ball caster is easy to mount; add the spacer to give it enough height so that the platform stays level with the ground (or you can leave it out as long as the sensors that will be mounted are not too close to the ground)(fig. 7).

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ESCUELA SUPERIOR POLITECNICA DE CHIMBORAZO FACULTAD DE INFORMATICA Y ELECTRÓNICA

INGENIERIA ELECTRONICA EN CONTROL Y REDES INDUSTRIALES

FIG 7 Ball Caster

III. APPLICATION OF CONTROL OF MAZE ROBOT

Began a functional diagram of the whole system (Fig. 8). The algorithm used to control the actuators from the information obtained from the sensors S1 (left laterial sensor ) S2 (front sensor) and S3 ( right side sensor ) can be seen there. The following convention is used : If the sensor Si = 1 means that it is sensing a nearby wall , therefore no rotation to that side is enabled and if Si = 0, the corresponding rotation is enabled.

IV. CONCLUSIONS

The realization of this project enabled us to strengthen our knowledge of mobile robots to maneuver them power and control over it.

Line robots followers are mobile robots that follow a single path usually marked with a black line.

The locations of the sensors responsible for maintaining the follower on the line are essential, because otherwise the robot will not perform desired.

Servo motors and wheels must be in the correct axis for the robot to function properly in designated paths.

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ESCUELA SUPERIOR POLITECNICA DE CHIMBORAZO FACULTAD DE INFORMATICA Y ELECTRÓNICA

INGENIERIA ELECTRONICA EN CONTROL Y REDES INDUSTRIALES Servomotors show the speed with which the

follower moves.

Tires gives us support our tracker addition of balance.

The main objective, which the project was, in this case a line follower robot, thanks to the knowledge acquired in the subject and collaboration of family and friends we achieved.

The power stage and control stage are separate circuits that are intertwined by the Arduino Uno, which in turn serves as a source and driver inputs analog to digital converted by means of an operational in response to the movement of the robot.

V. RECOMENDACIONES

We must be careful when connecting our arduino because we could burn.

The actuators must be properly truncated at the required angle axis, otherwise the follower will not work correctly in the trajectories.

Correctly connect our sensors, since they depend on the movement of the actuators.

VI. REFERENC

[1] Arduino: www.arduino.cc

[2] Arduino Uno: www.arduino.cc/en/Main/arduinoBoardUno

[3] Mccomb G “The robot builder’s bonanza”,TAB Books, United States of America,1987

[4] Halliday, D. “Física Volumen 1”, Compañíaeditorial continental, México, Décimasegunda impresión.

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