Catch the Robot on YouTube

 Robot on YouTube

Snake Robot(All Motion)

Campus innovation awards 2012

We had participated in campus innovation award. Though name of one member is written but there are other team member,whom have equally contributed to the project.

Won 2nd Prize in AITS

SLYTHERIN rocks again by bagging 2nd rank in Project Presentation in Stealth 2012, a technical symposium held in our own college, Atmiya Institute of Technology and Science.

Won 1st Prize in GEC, Rajkot

A state level technical event 'Brizingr' was held at Government Engineering College, Rajkot on 27th Feb.  Our project, SNAKE ROBOT, won 1st prize in the Project Presentation Competition.  Had faced few hurdles there, but finally we came through. Each one of received a certificate and 'Headphones' as prize.  Now we are trying various other kind of motions like reverse motion, ability to overcome obstacles etc.  I recently read a book and remember few lines by Dr. A P J Abdul Kalam, which are apt for our project.
It is not a disgrace to not reach the stars,
But it is a disgrace to have no stars to reach for.......

Striving to achieve the stars... :)

Temperature displayed in LCD

Previously we had interfaced temperature sensor (LM 35) and displayed the result on Seven Segment. Now we moved one step ahead and tried to display it on LCD.    

Interfacing PIR sensor

PIR sensor stands Passive Infrared Sensor. It uses Pyroelectric material. This sensor is used to detect moving objects. The sensor compares the body heat of the object with the surrounding temperature. It can be very useful for detecting obstacles at night. The detailed information of this sensor can be obtained at http://www.ladyada.net/learn/sensors/pir.html.

OPHION

Ophion... This is name that we gave to our snake. The name OPHION is of Greek origin and means a 'mythical serpent' .  The Concertina motion of snake is achieved and now we are trying for Sinusoidal motion.   Also planning for interfacing few more sensors. Lets see..

Finally.. Hard Work pays..

We have now loaded the program of forward motion, turning left and right. The turnings are good but the forward motion is not yet up to the mark.  Previously the torque was not enough to drive the motor.  Now to increase the torque, we increased the motor voltage to 12volts and it worked.  Yet we need to work on our forward motion.  

Our First Move

Now the whole wiring is done and all the motors and batteries are attached.  Today we loaded our first program of operating six servos.  The snake did perform some movement but not as we desired.  It just moved to default position.  Don't know whether there is problem of Loading Effect or the servos are not able to carry the weight of Robot.  Lets see. Tomorrow we will try again.  Fingers Crossed !! 

The Chassis

The chassis of the motor is ready with the motors fitted in it. 

Testing the Servo motor

As in my previous post i wrote about PWM signal generation to test the motor. We generated pulses of various duty cycles and accordingly the motor rotated in various angles. The above video makes it more clear. 

PWM signal Generation

We generated PWM signals to test the servo motor using ATmega32. The motor that we are using is VS-2. The angle of rotation of the motor is dependent on the duty cycle of the pulse. The greater is the ON period, the greater is the angle of rotation. For any information on VS-2, refer to the following figure..

For further information, follow the link http://www.strikemodels.com/wp-content/uploads/VS-2-Servo.pdf

The picture of PWM signals generated by us is given below.

                          

Servo Tester Circuit

Today we tried to test our Servo Motor using LM555 circuit. There are two ICs. The first one working in Astable mode and the second one working in Bistable mode.   We generated a pulse with ON period 1.5 msec and off period 18.5 msec. But we got continuous rotation of motor i.e from 0 degree to 180 degree. Thus, the motor did not rotate as we desired.  The below shown is our 555 Servo Motor Tester Circuit.

Temperature Sensor Module

We are interfacing temperature sensor module to measure the temperature of the surrounding. The sensor used here is LM35. It can be used to measure temperature with accuracy of 0.5 degree centigrade. The resolution of AVRs ADC is 10bit and for reference voltage we are using 5V so the resolution in terms of voltage is

5/1024 = 5mV approx

The temperature measured is displayed on Seven Segment Display

Note: 

• Take care whether your Seven Segment Display is Common Anode or Common Cathode and so accordingly make the connections.
• Check, if you are using NPN or PNP transistor
• Don't forget to provide a common ground wherever ground is required

The above were some of the things which were neglected by us, that posed temporary challenge for our sensor to run.

                          

History

 Beginning with the work of Shiego Hirose and his Active Cord Mechanisms (ACM) in the 1970's, the modeling and biological mimicry advanced with the development of systems like ACM shown in Figure. Hirose developed his description of an effective, later undulation gait, with his formulation of the "serpenoid curve." The below figure shows the Hirose's Curve.

                                                               

Abstract

Unlike other motions, Snake-like locomotion is a less common method of locomotion but is superior when operating in variable terrains. The snake robot presented here observes a concertina motion.  It is controlled by six servo motors operating on dc voltage.  The brain of the robot is the AVR microcontroller, which has many features embedded in it unlike other microcontrollers.  There is temperature sensor for monitoring the surrounding temperature.   There is also a USB camera mounted on the head section of the robot to survey the situation.  The snake robot has the advantage if penetrating even in a small area in any condition.  This kind of device may prove to be very useful in disaster hit areas. The non-planar mobility allows it to negotiate both around and over obstacles.

Block Diagram

Brief Introduction

In an effort to relieve the burden of time consuming activities, a versatile robot is required to follow in man's footsteps. Commonly, robotic vehicles use a wheel and axle propulsion system, but this is often debilitating when traveling on variable terrain. For instance, wheel-based propulsion system must be specifically designed to ascend steps. It is virtually impossible for them to climb ladders. Successful propulsion systems are often similar to motion methods of animals. Legs are the most common method but are difficult and inefficient to reproduce mechanically. The more simple and often overlooked sinusoidal motion of a snake is a less obvious solution, but has tremendous advantages when navigating variable terrain. Snakes can use their entire body for propulsion, creating a larger surface area and providing greater traction. Their low center of gravity creates stability, lacking in legged and wheeled systems. The body structure can also be modeled as a series of independently controlled joints, each having many degrees of freedom. These freedoms allow the snake to raise body sections over obstacles and to create leverage for itself. Using leverage, the snake could elevate above or onto a step or obstruction, a feat that would be difficult if not impossible using wheeled propulsion. In order to acquire these advantages, a snake-like robot that resembles and behaves like a real snake will be presented. This robot will be the first step towards creating a versatile platform that will be capable of traversing variable terrain like humans.