Peter the hexapod - Tesina per tecnico industriale

“G. Marconi”

IIS

Candidates: Rosa Davide

Tadini Matteo

Bresciani Jacopo

Class 5°AET

“Peter the hexapod” is a robot that uses three servos to move. It is able to move backward and forward and can also turn right and left. Two forward-looking distance sensors provide obstacle avoidance. The brain of the hexapod is the Pololu Micro Maestro, a 6-servo controller that can read input and play motion sequences in a stored script.

Complete robot

Materials

• Pololu Micro Maestro
• Sub-micro servos 3.7 g generic
• Pololu carrier with Sharp GP2Y0D810Z0F digital distance sensor 10 cm
• Battery pack: 4.8 V, 200 mAh
• Paper clips

First step

1. Assemble the body of the robot;
2. Solder the wires to the microcontroller;
3. Attach the sensors, the battery and the microcontroller to the body of the robot.

Second step

1. Programming the microcontroller;
2. Testing the functioning of the robot. 1/3

How does a robot work?

Human beings are made up of five major components: a body structure, a muscle system, a sensory system, a power source and a brain system.

A robot is made up of the same components:

1. A movable physical structure;
2. A motor;
3. A sensory system;
4. A power supply;
5. A computer that controls all of these elements. 2/3

How does a robot work?

Robots need an actuator to operate. For example, in our project the three servos are our actuators that allow the robot to move.

These actuators need a power source to operate and they are also wired to an electrical circuit. Robots can be reprogrammed by rewriting the program for the controller 3/3

How does a robot work?

Not all robots have a sensory system, and few have the ability to see, hear, smell or taste.

The most common robotic sense is the sense of movement.

In our project the robot is able to see the obstacles and avoid them.

Computer languages and programs

Preparing a program is structured following six different steps:

1. Interview the professional responsible for the job to be done;
2. Write a complete detailed description of the job;
3. Analyse the job in order to break it down into steps;
4. Construct a diagram showing the sequence of the most important steps in the job;
5. Write the program;
6. Test the program on the computer to detect mistakes, known as “bugs”. The testing of programs is called “debugging”.

Artificial intelligence

Artificial intelligence is a controversial field.

Computers can already solve problems but they can only solve problems for which they are programmed because they don’t have any generalized analytical abilities.

Some robots are able to learn but the problem is that robots can only do this in very limited situations.

Some robots can interact socially because they recognize human body languages and voice inflection and respond correctly.

The real challenge of A.I. is to understand how natural intelligence works.

Isaac Asimov

Born in 1920 in Russia

He became famous as science-fiction writer

According to Asimov

Robots are mere machines and they cannot feel emotions

Isaac Asimov

The three laws of robotics

1. A robot may not injure a human being, or allow a human being to come to harm.
2. A robot must obey the orders given it by human beings except when such orders would conflict with the first law.
3. A robot must protect its own existence as long as such protection does not conflict with the first and second law.

Robots: past and present 1/2

Some years ago the Philadelphia Museum in the United States acquired what seemed to be a mechanical doll.

This robot and others made by Henri Maillardet in the early 19th century were by no means the first mechanical devices designed to imitate the actions of living creatures.

Robots: past and present 2/2

In fact we remember Leonardo da Vinci’s inventions.

“Robot”

The word first appeared in 1921 in a Czech play about rebellious humanoid machines.

It derives from the Czech word for “forced labour”.

After some initial problems they are now widely used for jobs such as welding, machining and assembling electronic parts. Gallery

Thanks to all teachers that have contributed to the success of this project

Itis G. Marconi

Dalmine (-BG-)

Study course: Electrical engineering and automation

Project work

“Peter the hexapod”

Candidates: Bresciani Jacopo

Rosa Davide

Tadini Matteo

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Index

1. Project charter....................................................pag 3
2. WBS (Work breakdown Structure)........................pag 6
3. Gantt Diagram......................................................pag 6
4. Introduction to the project....................................pag 7
5. Materials and Tools...............................................pag 8
6. Construction..........................................................pag 15
7. Sequencing the Hexapod Gait.................................pag 23
8. Using a Script for Obstacle Avoidance....................pag 29
9. Conclusion.............................................................pag 31
10. Sources and credits................................................pag 31

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1. Project charter

Purpose of the document

The purpose of this document is to clear the basis the project is based on, to make known the resources that involved Necessary information for analysis and sharing of project objectives.

Project name

Peter the hexapod

Motivations behind the project

Develop a project to be presented to the examination commission in order to demonstrate the concepts we learned in the school career

Expected benefits

1. Try to independently develop a design that is able to function properly;
2. Submit a complete project that meets the goals set at the start of work;
3. Present a project work that is able to exemplify in the best way the skills learned during the study course;
4. Develop a project that allows us to get a high score on examination.

Purposes of the project

Develop a robot with microcontroller-based technology that is able to walk through the use of three servos and to avoid the objects thanks to two proximity sensors. The whole is powered by a battery of 4.8 V and 200 mAh which will be charged by a charger suitably constructed by us. The movement of the robot will be controlled by a program that we have written on a PC using a special software and then have inserted into our microcontroller connected via a USB port. The development of the project must be able to satisfy correctly the objectives set at the beginning of the work and expected benefits.

Macro activities and organization

The macro activities into which our project can be divided are the following:

1. Design;
2. Assembly;
3. Programming;
4. Test;
5. Project definition.

The choice of developing this project was made taking into account our technical skills. The probabilities of success of this project are therefore very high and on a careful pre-analysis we have reached the conclusion to conduct all activities independently, without delegating anything outside.

Main actors and their roles

Time and costs

Project duration

Project start 02/04/2012 Project end date 06/06/2012 date

Cost

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Risk analysis

In project management methodologies, an important space is devoted to the techniques of risk analysis (risk analysis).

The risk associated with an event (or threat) is the product of the probability of occurrence for the scale of the impact caused.

RISK = Probability * Damage

The damage caused by a threat can be economic, temporal, social, or all possible combinations between the three.

Regarding the damage, it has the impact that the damage can lead to the project (sometimes the risk analysis is evaluated directly by calculating the economic impact).

The head of Project management must carefully include the issues associated with evaluating risk in context.

In our project we may run into some risks related to:

• Timing;
• Delivery units ordered;
• Damage to mechanical parts;
• Malfunctioning of the project

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2. WBS (Work breakdown structure)

The first essential step of a project is to divide the project into tasks to be assigned to specific