Tag Archives: Robotics

Tracked Wheel Robotics Platform

Tracked Robot, Chain Links   Tracked Robot, Chain Links   Chain Links Connected   Metal Connecters   How to connect chain links.   Complete Tracks with 18 links These tracks then can be fitted on the wheels. The track wheel set comes with the chain links, metal connecter and four plastic wheels. For more details check out Track Wheel Set for hobby robotics. Tracked Wheels   A complete mobile platform. The above platform is a four wheel drive, using 200 RPM Gear DC Motors on all four wheels. Bottom View   Gear motor for robots Other wise if you want to control the cost you may use dummy motor in place of two front motors. Dummy Motor Shaft The platform was built over the High Quality Metal Chassis. The Chassis

Servo Motor Control by Using AVR ATmega32 Microcontroller

Servo motors are a type of electromechanical actuators that do not rotate continuously like DC/AC or stepper motors, rather they used to position and hold some object. They are used where continuous rotation is not required so they are not used to drive wheels (unless a servo is modified). In contrast they are used where something is needed to move to particular position and then stopped and hold there. Most common use is to position the rudder of aircrafts and boats etc. Servos can be used effectively here because the rudder do not need to move full 360 degrees nor they require continuous rotation like a wheel. The servo can be commanded to rotate to a particular angle (say 30) and then hold the rudder there. Servos also employs a feedback mechanism, so it can sense an error in its positioning and correct it. This is called servomechanism. So if the air flow exerts pressure on rudder and deflects it the servo will apply force in opposite direction and try to correct the error. Say if you ask servo to go and lock itself to 30 degrees and then try to rotate it with your hand, the servo will try hard and its best to overcome the force and keep servo locked in its specified angle. Servos are also used […]

Obstacle Avoiding Robot using AVR ATmega32 – Part III

Hello All, Welcome to the third part of the Obstacle Avoiding Robot Tutorial. Till now we have completed the mechanical construction and made the sensor for our robot. I have shown you how to control the motors and read values from sensor in last two parts of the tutorial. In this tutorial we create the master program for our robot. The job of the program is simple, to read values from the sensors, make a decision and command two motors. In this way our robot will roam about the room avoiding obstacles in its path. In our program we define three constants, namely RTHRES,CTHRES and LTHRES in the following way :- //Threshold Values For Sensor Triggering #define RTHRES 195 #define CTHRES 275 #define LTHRES 195 The constant value next to them is the triggering values. You can get this values as described in previous tutorial. Simply run the IR Sensor Test program and bring any obstacle near the sensor at about 15cm (6 inches) and note down these values against respective sensor threshold values. Do same for all three sensor. Now the program knows when the value comes near this threshold value, the sensor has a obstacle in front of it. Note that the value shown above is may not match with the values you obtained, that OK. In our […]

Obstacle Avoiding Robot using AVR ATmega32 – Part II

Hello and Welcome back to the second part of Obstacle Avoiding Robot Tutorial. In the last part we studied the drive system and the mechanical construction of our robot. In this part we will make the sensor part. The sensors will help our robot detect obstacle in its path. The sensor system is of very basic type of infrared(IR) reflectance sensor. It is made up of an IR Transmitter and an IR receiver. The IR transmitter is an IR LED which emits light in IR spectrum that is invisible to human eye. The IR receiver can detect those rays. A Matching Pair of IR Rx and Tx, The Blue One is Tx (LED). The IR Sensor Element The IR Sensor element is made up of an IR Tx,IR Rx and few resistors. The schematic is given below. We need three such elements mounted in front of the robot to sense obstacles in front of it. IR Reflectance sensor schematic. As you can see the sensor element has two pins for power supply and an Output pin. The output is a variable voltage between 0 and 5v depending on the type and distance of the obstacle. It tends to 5v as some obstacle comes near it. IR Sensor Construction Guidelines. The value of R1 is 150 ohms and R2 is 22K. […]

Obstacle Avoiding Robot using AVR ATmega32 – Part I

Hi and Welcome All, In this tutorial series I will show you how to make a simple obstacle avoiding robot using the xBoard v2.0 microcontroller board. xBoard v2.0 is well suited for developing small intelligent robots as it is compact in size, has four DC motor controller, can be programmed using USB Port and many other features. It is also very easy to learn and use. The xAPI, which is a set of C functions which makes complex programming tasks such as PWM ,LCD, Remote Control etc very easy for beginners. You can buy it from here http://shop.extremeelectronics.co.in/product_info.php?cPath=23&products_id=111 Its design is open so if you don’t want to buy the board you can make it yourself at home by the help of its schematic. The Robo’s Task The task of our robo is simple. To move randomly in an area avoiding obstacles, that’s it ! Though the task is simple, its a complete autonomous robot in itself. It has a brain which reads sensors and makes decisions and command the motors. In the course of making the robot you will learn various basic techniques which will be of great use for your further projects. Our Final Robot will look like this. AVR ATmega32 Based Obstacle Avoiding Robot The following Video Demo Shows the Robo in Action The following Video was […]