This line follower uses:

• 8 proximity sensor array using phototransistor,
• Microcontroller ATMega16.
• L298 motor driver
• C programming language

Download the document of line follower robot tutorial with ATMega16 HERE

This is an useful report and you could be need this report for your robotics reference. This report contains 3 main parts. Part I deals with the sensors used in mobile robot positioning, while Part II discusses the methods and techniques that use these sensors. The report is organized in 9 chapters.

Part I: Sensors for Mobile Robot Positioning
1. Sensors for Dead-reckoning
2. Heading Sensors
3. Active Beacons
4. Sensors for Map-based Positioning
Part II: Systems and Methods for Mobile Robot Positioning
5. Reduction of Dead-reckoning Errors
6. Active Beacon Navigation Systems
7. Landmark Navigation
8. Map-based positioning
9. Other Types of Positioning
Part III: References and Systems-at-a-Glance Tables

Download the report: Sensors and Methods for Autonomous Mobile Robot Positioning
Download Link I (myfilehost.us)
Download Link II (4shared.com)

This is a very interesting robotic tutorial. You will learn how to build a spy robot (spybot) featured with WiFi connection. This robot needs a network camera and a WiFi router to work as a spy. You need little knowledge of computer networking, especially about Router and IP address configuration.

Visit this page for the tutorial of how to build WiFi SpyBot

This line follower robot is very small and simple. This robot is running fast and follow the line very smoothly. You may see the video here.

Mechanics

All mechanical and electrical parts are mounted on a proto board, and it also constitutes the chasis.

The line following robot is upheld in three points of two driving wheels and a free wheel. The driving wheels are made with a 7 mm dia ball bearing and a rubber tire. The free wheel is a 5 mm dia ball bearing attached loosely. To drive driving wheels, two tiny vibration motors that used for cellular phone, pager or any mobile equipment are used. Its shaft is pressed onto the tire with a spring plate, the output torque is transferred to the wheels.

The steearing mechanism is realized in differential drive that steear the robot by difference in rotation speed between the left wheel and the right wheel. It does not require any additional actuator, only controling the wheel speed will do.

Line detector and Photo reflector

To detect a line to be followed, most contestants are using two or more number of poto-reflectors. Its output current that proportional to reflection rate of the floor is converted to voltage with a resister and tested it if the line is detected or not. However the threshold voltage cannot be fixed to any level because optical current by ambent light is added to the output current like the image shown right.

Most photo-detecting modules for industrial use are using modurated light to avoid interference by the ambient light. The detected signal is filtered with a band pass filter and disused signals are filtered out. Therefore only the modurated signal from the light emitter can be detected. Of course the detector must not be saturated by ambient light, this is effective when the detector is working in linear region.

In this project, pulsed light is used to cancel ambient light. This is suitable for arraied sensors that scanned in sequence to avoid interference from next sensor. The microcontroller starts to scan the sensor status, sample an output voltage, turn on LED and sample again the output voltage. The difference between the two samples is the optical current by LED, output voltage by the ambient light is canceled. The other sensors are also scanned the same avobe in sequence.

Line Detection Signal Processing

Right image shows the actual line posisiton vs detected line position in center value of 640. The microcontroller scans six sensors and calcurates the line position by output ratio of two sensors near the line. Thus the line position can be detected lineary with only six sensors. All the sensor outputs are captured as analog value that proportioning to reflection ratio, and the sensitivity have variety between each one of them. In this system, to remove the variations from the outputs, calibration parameters for each sensor can be held into non-volatile memory. This can be done with online mode. The microcontroler enters the online mode when an ISP cable is attached, and it can be controlled with a terminal program in serial format of N81 38.4kbps. S1 command monitors sensor values, and S2 command calibrates variation of sensor gain on the reference surface (white paper). The ATmega8 must be set to 8MHz internal osc.

Tracking Control

The line position is compeared to the center value to be tracked, the position error is processed with Proportional/Integral/Diffence filters to generate steering command. The line folloing robot tracks the line in PID control that the most popular argolithm for servo control.

The proportional term is the commom process in the servo system. It is only a gain amplifire without time dependent process. The differencial term is applied in order to improve the responce to disturbance, and it also compensate phase lag at the controled object. The D term will be required in most case to stabilize tracking motion. The I term is not used in this project from following resons. The I term that boosts DC gain is applied in order to remove left offset error, however, it often decrease servo stability due to its phase lag. The line following operation can ignore such tracking offset so that the I term is not required.

When any line sensing error has occured for a time due to getting out of line or end of line, the motors are stopped and the microcontroller enters sleep state of zero power consumption.
Notes:

• Development diary [Ja]
• Circuit diagram
• Firmware May 23, 2004
• Following motion with only P control
  This is a video file of line following motion with only P control. The servo system oscllated.
• Following motion with P and D controls
  Adding D control could improve the servo stability. The robot follows the line correctly. Therefore the servo parameter must be optimized for mechanical characterristics to improve the tracking stability.

Source: elm-chan.org

Built based on PIC microcontroller, this robot has multi functions, you might use this robot for several objectives.

The robot’s objectives are the following:

1. Follow a line with sharp turns
2. Maneuver through breaks in the line
3. Detect obstacles and manuever around them
4. Identify colors to be able to locate green and aluminum victims.

You can find the complete tutorial here

By the time you complete the text and projects you will:

PDA Robotics – Using Your Personal Digital Assistant to Control Your Robot will give you the expertise to create anything. One of many areas that I will touch on is the smart distributed network, where each robot can pass the information that it gains onto the

I’ve collected some schematic diagrams of sound activation as follow:

Sound Activation schematic 1

Sound Activation schematic 2

Sound Activation schematic 3

Sound Activation 4 schematic

Sound Activation schematic 5

Preface:
In recent years robots have captured the interest of more and more people. Thanks to movies and TV, the notion of the robot as a mechanical companion and servant has become a common concept. As interest in robots grew, a number of books showing how to build robots at home began to appear. These books, however, were very technical, showing how to build computer-controlled mobile platforms that are considered by most to be true robots.

Download Robotics Ebook: Build a Remote-Controlled Robot
Download link 1
Download link 2
Download link 3

Note: this is old book created in year 2002.

The Bluetooth Boe-Bot Robot Kit for Microsoft Robotics Studio (MSRS) is a Parallax Boe-Bot Robot and an A7 Engineering eb500-SER Bluetooth module. The eb500 module makes it possible for the Boe-Bot robot

Vex Robotics Design System is a robotic kit intended to introduce students as well as adults to the world of robotics. The Vex Robotics Design System is centered around the Vex Starter Kit (which retails for about USD $500). This kit comes with the Vex “brain” (a microcontroller), a hobby-grade remote control, various sensors (2 bumper sensor and 2 limiter switches), three electric motors and a servo, wheels (4 small, 2 medium all purpose, and 2 large high traction tires), gears, and structural parts. Additional sensors (ultrasonic, line tracking, optical shaft encoder, bumper switches, limit switches, and light sensors), wheels ( small and large omni-directional wheels, small, medium, and large regulars), tank treads, motors, servos, gears (regular and advanced), chain and sprocket sets, extra transmitter and receivers, programming kit (easy C) extra metal and rechargeable battery power packs,can all be purchased separately.

This tutorial will show you how to maximize your Vex Robotics Design System. Here are some previews of Vex Robotics Tutorial which will guide you how to get the maximum performance.

You can download the tutorial here;

For the Vex Robotics Kits, you can buy it from Amazon.com:

Overal Design:

Fig. 1.A

Figure 1A shows a 3D graphical representation of the robot, where different parts can be clearly identified according to the following table:

For the detail explanation, please visit this page

I have built 2 line follower robot and 1 firefighting robot just using modified motor servo… and great, the robot is very easy to be controled…

Here the my first line follower robot using modified motor servo (old picture):

The robot’s movement is very slow, added more voltage and increase the wheel’s size is very important to increase the robot speed.

Step by step of modifiying motor servo from societyofrobotics.com:

What is a servo? A servo, unmodified, typically has a rotation of some set amount. In other words, they cannot rotate continuously. This is because of the built in angle feedback control system. There is an internal potentiometer which is used to determine the angle which the servo is at. Pots, or variable resistors, cannot rotate continuously.

There is however a way to modify a servo so that they can rotate continuously. Why do this? Because although you lose position control, you gain speed control. Neat, huh? To do this, obviously the pot needs to be altered in someway. There is also a mechanical stop within the gears which needs to be removed as well.

A note to what will be tricky about this servo tutorial. There are many types of servos, and they all have variations in how the mechanics work. It will be too much work for a tutorial to cover all types, so I will cover the basic concepts instead. Fortunately, most servos made today are designed to be easily modified.

So the first step would be to open up the servo.
1) First make sure the servohorn is removed from the output shaft. The servohorn attaches to the main output gear (the biggest gear), so removing it helps keep the gears from all falling out when you open the servo up. Also, use a microcontroller to command the servo to rotate to 0 degrees, the point between the maximum and minimum angle the servo can rotate to. You may also do this step by hand, although it might not be as exact.

Note, if you are making The $50 Robot (or at least using the ATmega8 microcontroller), download this .hex file and upload it to your ATmega8. You dont need to compile anything, as I already did that for you. This program will tell the microcontroller to send a signal at 1.5ms, the signal your servos need to hold at the zero position.

2) Next unscrew the four really long screws in the corners. Be careful not to strip the screw heads.

3) Now open up the top half of the servo. There are two parts that will open. The bottom half has the circuitry and wiring – make sure that remains closed. The top half contains the gearing. When opening, be careful not to have all the gears fall out. Memorize the gear locations just incase they do, so that you can reassemble everything. Make sure all the gears remain with the main part of the servo, with the exception of the large gear connected to the output shaft. Be careful not to contaminate the servo grease, as that would lead to an increase in gear wear.

4) Now you need to find the pot. It is connected to and under the largest gear. You must pull off the main gear to find it.

5) Next we need to center the servo. Do this by plugging it in to your controller and send the signal required for it to go to 0 degrees. You should probably see the gears rotating without stopping. Now rotate the pot head (no, not that type of pot head) so that the gears stop rotating. It will probably be very sensitive so take your time. It is very important for this to be perfect. Get some superglue and glue the pot head to make sure it remains in place.

6) Now while the glue is drying, try to find the mechanical stop on the main gear. It will be something protruding that prevents the gear from rotating continuously when the gearing is assembled. Metal gears usually have a protruding metal pin, pull it out. Plastic gears have a protruding plastic peice that you need to cut off. Get a pair of snips and carefully cut it off. You might also have to file it down if your trim was not perfect. Rarely will it be. Don’t damage the gear teeth during this process.

7) Attached to the gear that was connected to the pot is a little slot for the pot to fit in. Remove the slot from the gear. Chances are you can just pull it right out with a flathead screwdriver. This slot is so when the gear rotates, the pot will rotate with it. Keeping the pot in a fixed location tricks the servo to think it is at the same location.

Reassemble everything. Make sure the output shaft rotates continuously. Then send PWM to the servo. You will notice that by telling the servo to go to a particular angle, instead it will rotate at a particular speed. Neat, huh?

Not Working?
I just finished this tutorial but I’m having problems! Help!

Well you aren’t alone. Try these forum posts:

http://www.societyofrobots.com/robotforum/index.php?topic=4400.0
http://www.societyofrobots.com/robotforum/index.php?topic=507.0
http://www.societyofrobots.com/robotforum/index.php?topic=1732.0
http://www.societyofrobots.com/robotforum/index.php?topic=1350.0

h bridge schematics

DC Motors which need high current and high voltage usually give high velocity and high torque. For small robots like line follower robot or fire fighting robot, I think IC motor driver L298 (up to 2A total current) is better choice. While for large and heavy robot, you need high current DC motors also H-Bridge suit to your DC motor.

This article sould be useful for you to build high

The motors as actuator device is very and very important to understand. There are many things need to be calculated… velocity, torque, motor voltage and motor current. There is nice post from societyofrobotics about DC Motors. The most important one is about torque… I’ve so confused about choosing DC motors for my robot and now I am figuring that DC motors must have enough torque for running smoothly…

Here the nice article about DC motors:

=============================

From the start, DC motors seem quite simple. Apply a voltage to both terminals, and weeeeeeee it spins. But what if you want to control which direction the motor spins? Correct, you reverse the wires. Now what if you want the motor to spin at half that speed? You would use less voltage. But how would you get a robot to do those things autonomously? How would you know what voltage a motor should get? Why not 50V instead of 12V? What about motor overheating? Operating motors can be much more complicated than you think.

Voltage
You probably know that DC motors are non-polarized – meaning that you can reverse voltage without any bad things happening. Typical DC motors are rated from about 6V-12V. The larger ones are often 24V or more. But for the purposes of a robot, you probably will stay in the 6V-12V range. So why do motors operate at different voltages? As we all know (or should), voltage is directly related to motor torque. More voltage, higher the torque. But don

Ant robots are simple and cheap robots with limited sensing and computational capabilities. This makes it feasible to deploy teams of ant robots and take advantage of the resulting fault tolerance and parallelism. Ant robots cannot use conventional planning methods due to their limited sensing and computational capabilities. Rather, their behavior is driven by local interactions. For example, ant robots can communicate via markings that they leave in the terrain, similar to ants that lay and follow pheromone trails.

In the past couple of years, researchers have developed ant robot hardware and software and demonstrated, both in imulation and on physical robots, that single ant robots or teams of ant robots solve robot-navigation tasks (such as path following and terrain coverage) robustly. Thus, ant robots might provide a promising alternative to the currently very popular robabilistic robot navigation approaches. Researchers have also developed a theoretical foundation for ant robotics, based on ideas from real-time heuristic search, stochastic analysis, and graph theory. This half day tutorial on the current state of the art n ant robotics is given by experts who will give an overview of this exciting area of mobile robotics without assuming any prior knowledge on the topic. It will cover all important aspects of ant robotics, from theoretical foundations to videos of implemented systems. To this end, it will bring together the various research directions for the first time, including theoretical foundations, ant robot hardware, and ant robot software.

Its primary objective is to give non-specialists a comprehensive overview of the state of the art of the field, for example, to allow researchers and students to do research in the area and to allow practitioners to evaluate the current state of the art in ant robotics. Consequently, it is of interest to anyone who is interested in mobile robotics and artificial intelligence.

Download the tutorial here

It uses the tri-state switch to control speed, direction, and braking.

Schottky output diodes are used that match the current and voltage for your motors.

The only ‘real’ difference compared with the 1 amp circuit is that we using an L298 rather than one of the L293 series. The L298 lends itself to mounting a heatsink, due to the higher current, but is a bit of a swine to solder onto strip board or matrix board and is more designed for PCBs. It uses a ‘Mulitwatt 15′ package – and comes with two strips of pins each using a standard 0.1″ pin separation. But the problem is that the second bank of pins is offset by 0.05″. So if you are using strip/matrix board then you will need to be very carefull when bending one set of pins to fit.

Cost
This requires one tri-state switch per motor;
one L298N for every two motors. The L298N costs about $3.57
four diodes per motor at about 50 cents per diode.
So about $11 in total – for driving two motors

Download the schematics here

Here the robot preview:

Microcontroller ATMega8
Sensor: 5 pieces phototransistor
Motor: Lynxmotion motor
Programming language:

Download tutorial (mechanics, schematics, source code)

The L297 integrates all the control circuitry required to control bipolar and unipolar stepper motors. Used with a dual bridge driver such as the L298N forms a complete microprocessor-to-bipolar stepper motor interface. Unipolar stepper motor can be driven with an L297 plus a quad darlington array. This note describes the operation of the circuit and shows how it is used.

Download motor stepper controller using motor driver L297 and L298N

Microcontroller : Atmel ATMega8535
Sensor: 6 photodioda sensor
Motor driver : L298 dual driver (up to 1A of electric current)

Download the full tutorial include schematic diagram and program code ( C language ):
Download link