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research tech.txt
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<div class="col-sm-6 col-md-3 isotope-item web-design">
<div class="image-box">
<div class="overlay-container">
<img src="images/Research/Sensors/sensors.jpg" alt="">
<a class="overlay" data-toggle="modal" data-target="#project-6">
<i class="fa fa-search-plus"></i>
</a>
</div>
<a class="btn btn-default btn-block" data-toggle="modal" data-target="#project-6">SENSORS AND ACTUATORS</a>
</div>
<!-- Modal -->
<div class="modal fade" id="project-6" tabindex="-1" role="dialog" aria-labelledby="project-6-label" aria-hidden="true">
<div class="modal-dialog modal-lg">
<div class="modal-content">
<div class="modal-header">
<button type="button" class="close" data-dismiss="modal"><span aria-hidden="true">×</span><span class="sr-only">Close</span></button>
<h2 class="modal-title" id="project-6-label">SENSORS AND ACTUATORS</h2>
</div>
<div class="modal-body">
<div class="row">
<div class="col-md-12">
<h3> SENSORS </h3>
<ol>
<li>INS ( Inertial Navigation System)</li>
<ul>
<li>
An inertial navigation system (INS) is a navigation aid that uses a computer, motion sensors (accelerometers)
and rotation sensors (gyroscopes) to continuously calculate via dead reckoning the position, orientation,
and velocity (direction and speed of movement) of a moving object without the need for external references.
It comprises an IMU and sometimes a GPS unit too. Further, the IMU has angular and linear
accelerometers (for changes in position);
some IMUs include a gyroscopic element (for maintaining an absolute angular reference) .An inertial measurement
unit works by detecting the current rate of acceleration using one or more accelerometers, and detects changes in
rotational attributes like pitch, roll and yaw using one or more gyroscopes. And some also include a magnetometer,
mostly to assist calibrate against orientation drift.
We use Vectornav's VN-200 rugged which incorporates a wide assortment of inertial sensors including a 3-axis
accelerometer, 3-axis gyroscope, 3-axis magnetometer, a barometric pressure sensor and a GPS module.
<br/><br>
<img src="images/Research/Sensors/pic1.png"/>
<br><br>
<img src="images/Research/Sensors/pic2.png"/>
<br><br>
A laser rangefinder (or light radar) is a sensor that uses a laser beam to determine the distance to obstacles in front
of it. The most common form of laser rangefinder operates on the time of flight principle by sending a laser pulse in a
narrow beam towards the object and measuring the time taken by the pulse to be reflected off the target and returned to
the sender, by looking at the phase of the returned beam.
LIDAR is becoming more and more popular as a guidance system for autonomous vehicles. The speed and accuracy of a scanner
means that data can be passed to a system to process the return in more or less real-time. This allows the device controlling
the vehicle to detect obstacles and to update its route in a very small amount of time.
Since the LIDAR involves the use of low power laser, the device temperature rises and this may spoil the performance
of the device. Also, indoor LIDARs are not designed to work in daylight and the presence of any highly illuminated object
gives absurd results.
</li>
</ul>
<li class="topics">OMNIDIRECTIONAL CAMERA</li>
<ul>
<li>It is a special type of camera that can capture, at any instant a full 360 degree view of a scene from a single point.
In robotics, it is of importance as it does away with the need of multiple cameras to capture the whole surroundings of
the robot, concurrently stitching the whole view to present a single image. An omnidirectional camera can be used to
create panoramic images in real time, without the need for post processing, and will typically give much better quality output.
This can be basically used to alarm the vehicle of approaching dangers from all directions.
</li>
<br>
<img src="images/Research/Sensors/pic3.png"/>
<br>
</ul>
<li class="topics">STEREO CAMERA</li>
<ul>
<li>A Stereo camera is a camera that has two lenses about the same distance apart as your eyes and takes two pictures at the
same time. This simulates the way we actually see and therefore creates the 3D effect when viewed. A stereo vision system is
designed to extract 3D information from digital images and use these for examining the position of objects in two images, to
build an advanced object recognition system that recognizes objects in different arrangements. Among the advantages of a stereo
vision system can be included its reliability and effectiveness in extracting various
information (like color, or dimension), it can be used for different vision routines like tracking or
detecting objects, and it’s a passive sensor which cannot be influenced by environment. The stereo camera basically works upon
the difference or shift in the images of the same object from the two lenses. This allows the depth calculation and hence the 3D effect.
</li>
</ul>
<br/>
<img src="images/Research/Sensors/pic4.png"/>
</ol>
<h3>ACTUATORS</h3>
<p>
An actuator is a type of motor that is responsible for moving or controlling a mechanism or system. An actuator is the mechanism by which a control
system acts upon an environment.
</p>
<ol>
<li>Hydraulic</li>
<ul>
<li>A hydraulic actuator consists of a cylinder or fluid motor that uses hydraulic power to facilitate mechanical operation. The mechanical
motion gives an output in terms of linear, rotary or oscillatory motion. Because liquid is nearly incompressible, a hydraulic actuator
can exert considerable force, but is limited in acceleration and speed.
</li>
</ul>
<li>Pneumatic</li>
<ul>
<img src="images/Research/Sensors/pic5.png"/>
<li>A pneumatic actuator converts energy formed by vacuum or compressed air at high pressure into either linear or rotary motion. Pneumatic energy
is desirable for main engine controls because it can quickly respond in starting and stopping as the power source does not need to be stored in
reserve for operation.
Pneumatic actuators enables large forces to be produced from relatively small pressure changes. These forces a re often used with valves to move
diaphragms and so affect the flow of liquid through the valve.
</li>
</ul>
<li>Electric</li>
<p>
An electric actuator is powered by a motor that converts electrical energy to mechanical torque. The electrical energy is used to actuate equipment
such as multi-turn valves. It is one of the cleanest and most readily available forms of actuator because it does not involve oil.
</p>
<li>Mechanical</li>
<li>
A mechanical actuator functions by converting rotary motion into linear motion to execute movement. It involves gears, rails, pulleys, chains
and other devices to operate.
<dl><i>
<dt>Screw:</dt>
<dd> lead-screw, screw jack, ball screw and roller screw actuators all operate on the principle of the simple machine known as the screw.
By rotating the actuator's nut, the screw shaft moves in a line.
</dd>
<br>
<img src="images/Research/Sensors/pic6.png">
<br>
<dt>Wheel and axle:</dt>
<dd> Hoist, winch, rack and pinion, chain drive, belt drive, rigid chain and rigid belt actuators operate on the principle of the wheel
and axle. A rotating wheel moves a cable, rack, chain or belt to produce linear motion.
</dd>
<br>
<dt>Cam:</dt>
<dd> Cam actuators function on a principle similar to that of the wedge, but provide relatively limited travel. As a wheel-like cam
rotates, its eccentric shape provides thrust at the base of a shaft.
</dd>
</dl>
<br/>
<img src="images/Research/Sensors/pic7.png"/>
<br><br>
<h2><b>Types of motors</b></h2>
<h3><b>Stepper motor</b></h3>
<p>
A stepper motor is an electromechanical device which converts electrical pulses into discrete mechanical movements. The shaft or spindle of a
stepper motor rotates in discrete step increments when electrical command pulses are applied to it in the proper sequence. The motors rotation
has several direct relationships to these applied input pulses. The sequence of the applied pulses is directly related to the direction of motor
shafts rotation. The speed of the motor shafts rotation is directly related to the frequency of the input pulses and the length of rotation is
directly related to the number of input pulses applied
</p>
<br/>
<img src="images/Research/Sensors/pic8.png">
<br>
<h3><b>Servo motor</b></h3>
<p>
There are some special types of application of electrical motor where rotation of the motor is required for just a certain angle not continuously
for long period of time. For these applications some special types of motor are required with some special arrangement which makes the motor to
rotate a certain angle for a given electrical input (signal). For this purpose servo motor comes into picture. This is normally a simple DC motor
which is controlled for specific angular rotation with help of additional servomechanism (a typical closed loop feedback control system).
</p>
<br><br>
<h3><b>Mechanism</b></h3>
<br><br>
A servo system mainly consists of three basic components - a controlled device, a output sensor, a feedback system.
This is an automatic closed loop control system. Here instead of controlling a device by applying variable input signal, the device is controlled
by a feedback signal generated by comparing output signal and reference input signal.
When reference input signal or command signal is applied to the system, it is compared with output reference signal of the system produced by output
sensor, and a third signal produced by feedback system. This third signal acts as input signal of controlled device. This input signal to the device
presents as long as there is a logical difference between reference input signal and output signal of the system. After the device achieves its
desired output, there will be no longer logical difference between reference input signal and reference output signal of the system. Then, third signal
produced by comparing theses above said signals will not remain enough to operate the device further and to produce further output of the system until
the next reference input signal or command signal is applied to the system. Hence the primary task of a servomechanism is to maintain the output of a
system at the desired value in the presence of disturbances.
<br/><br/>
<img src="images/Research/Sensors/pic9.png">
<br/><br/>
</i>
<br><br>
<hr />
<b><h3>KEY FACTS</h3></b>
<ol>
<li>Extraction of accessible path from image</li><br/>
<li>Object extraction and tracking</li><br/>
<li>Controls optimisation</li><br/>
<li>Environment modelling for SLAM</li><br/>
<li>Advancement in planning with experience</li><br>
<li>Improvement in decision making</li><br>
</ol>
<br/><br/>
</div>
</div>
</div>
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</div>
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<div class="col-sm-6 col-md-3 isotope-item web-design">
<div class="image-box">
<div class="overlay-container">
<img src="images/Research/Researched.jpg" alt="">
<a class="overlay" data-toggle="modal" data-target="#project-500">
<i class="fa fa-search-plus"></i>
</a>
</div>
<a class="btn btn-default btn-block" data-toggle="modal" data-target="#project-500">Researched Technologies</a>
</div>
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<h2 class="modal-title" id="project-500-label">Researched Technologies</h2>
</div>
<div class="modal-body">
<div class="row">
<div class="col-md-12">
<p><b>
The following are some of the research projects which were successfully undertaken by the members of Team AGV:
</b></p>
<br><br>
<ul>
<li>
A distance transformed based path planning for autonomous ground vehicle.
</li>
<b><i>Key Innovation:</i></b> Corner detection based light weight optimization for the planner.
<li>
A <b>6D SLAM</b> for autonomous ground vehicle.
</li>
<b><i>Key Innovation:</i></b> Real time 3D map construction of the environment using
the extraction feature
<li>
<b>Simultaneous Localization and Mapping.</b>
</li>
<b><i>Key Innovation:</i></b> Implementing SLAM (Simultaneous Localization and Mapping) on a robot by eliminating associated noises.
<li>
<b>A framework for driver assistance system.</b></li>
<li>
<b> Vision Based Sensing and Path Planning of Autonomous Ground Vehicle.</b>
</li>
<b><i>Key Innovation:</i></b> A robust and real time Lane Detection algorithm,
detection of drivable regions using a Stereo Camera and a novel path
planning algorithm for a differential drive were developed in this process.
<li>Adaptive Planning and Control of Micro Aerial Vehicle using RGB-D sensor.</li>
` <li>
<b> SLAM based Digital Mapping using Autonomous Ground Vehicle.</b>
</li>
<li>Underground mine mapping using 6D SLAM based autonomous mobile robot.</li>
<li> Development of a stereo vision based "foot" placement algorithm and algorithm output visualization tool.</b></li>
<li> Development of a high level interface for one open architecture robot arm.</li>
<li>Design and construction of a low cost 3D Lidar using a 2D Lidar.</li>
<li> 6D SLAM based Digital Mapping using Autonomous Ground Vehicle</li>
<b><i>Key Innovation:</i></b> A Novel method for 3D map generation of the environment
using an autonomous vehicle by solving the problem of Simultaneous Localization
and Mapping in 6D.
<li>Position estimation and 2D mapping using an extended Kalman filter.</li>
<li>
We have been successful in making the steering of cars autonomous and
have also achieved static and dynamic obstacle avoidance capabilities.
</li>
</ul>
</div>
<div style="position:relative;
float:right;width:400px;background-color:rgba(199,199,199,0.44);box-shadow:3px 3px 15px rgb(15,15,15);border-radius:5px;margin:30px 20px 10px ;padding:20px;" >
<h1 class="heading">At a Glance</h1><br/>
<ul class="keyfac" >
<li>Static Obstacle Avoidance</li><hr/>
<li>Pedestrian Avoidance</li><hr/>
<li>Development of low cost 3D lidar</li><hr/>
<li>Driver Assitance System</li><hr/>
<li>Real time 3D environment mapping</li><hr/>
<li>Underground mine mapping</li><hr/>
<li>Automatic steering system</li><hr/>
</ul>
</div>
</div>
</div>
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