2. INERTIAL NAVIGATION SYSTEM
In this chapter we will discuss about the principles of inertial navigation system. At first we describe about the basics of modelling motion in land vehicle. Second an introduction to inertial sensors is given and then discuss about some useful information like position, velocity, what we get from inertial navigation system as output. Finally we will discuss the drawbacks of inertial navigation systems and try to understand why inertial navigation system is better to use with other navigation system than using it alone.
2.1 Motion in of a land vehicle
In most of the cases, navigation system is used to detect the position of an object. The general motion of a land vehicle is typically calculated by the values that are given by accelerometer and gyroscope.
2.2 Principle of inertial navigation sensors
The principle of inertial navigation system is mainly related to Newton’s 1st and 2nd law of motion. The 1st law of motion is described that “changes in motion are caused by outside forces” and 2nd law is described that “acceleration is proportional and in the same direction as the resultant forces” (EI-Sheimy, 2006). The 1st law tells that keep an eye on all outside forces on the object, knowledge of whether the object is moving or not and whether it is continuous its uniform motion or changes its course are known. The 2nd law tells that measuring the resultant forces that affect the object knowledge of the objects acceleration is known. If we know the acceleration of a particular vehicle, we can easily calculate the displacement by integrating it twice and velocity by integrating it once. Just like through integration we can calculate angular velocity from angular rotation. (EI- Sheimy, 2006)....
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...ity or rotation of a vehicle. It was first invented in 1852 by the French physicist Leon Foucault (1819-1868) and it works on the principle of conservation of angular momentum. Now in market you have lots of but the first gyroscopes were purely mechanical and worked with a rotor (spinning mass) which is used for the spin of one axis. Here is the diagram of gyroscope is given, in the diagram we see that that there is a rotor mounted in two gimbals that were again mounted to the base. For these two gimbals it gave the gyroscope a 3 degrees of freedom to the rotor and made it possible to keep its orientation while the base was rotated in any direction. An error will always occur because of the friction between the moving parts.
There are so many types of gyroscopes are there
1) MEMS gyroscope
2) FOG gyroscope
3) Laser gyroscope
MEMS gyroscope:-
The aircraft needs to use two beams to ensure that the pulses return to the aircraft. In certain situations the pulse may not return to the aircraft due to flat glassy water surface (because of the law of reflection) . The Lads software automatically compiles arrival times and fixes errors in the data like tidal variations. Maps can be made after data is compiled from the aircraft by using Global Positioning Satellites, which constructs coordinates and data collected.
My earliest contribution was gathering a portion of the background information about accelerometers and Gravitational forces. Furthermore I found the first commercially available accelerometer of the group. Unfortunately we were unable to obtain all of the in depth information that we were searching for about it.
Christopher Columbus was known as a “dead reckoning navigator”[2]. Dead Reckoning Navigation, or also known as Deduced Navigation, was used by an umpteen of sailors. In Dead Reckoning Navigation the helmsman can find his locus by measuring the distance he has sailed to a known point. Each day, the ending position was the starting point for the next day. However, this method is not as elementary as it sounds. In order for this tactic to work, the helmsman needs to measure his course and distance sailed. Therefore, a course is measured by a magnetic compass, and distance with a time and speed calculation. One can conclude then that this was a nettlesome process. Of course, since then humans have immensely improved in this area. Today, there is a way to know where one is at while at sea that is much less problematic.
The question you might ask next is; well, how does this global positioning technology work today? There are three main key words which are essential in the understanding of how GPS technologies work in our world today. These are Trilateration, Synchronization, and Time Travel…yes time travel.
The guidance, navigation, and control system is all about the destination, current location, and path of the CEV. These devices detect the vehicle’s motion and informs the GNC what is happening. Inertial measurement units (IMUs) contain gyros to measure and provide inertial attitude and velocity data to the G...
A prime example of this is satellite navigation; which is what people often think of when they hear “GPS,” acronym for Global Positioning System. Satellite navigation, sometimes shortened to Sat Nav, allows for users to pinpoint their location with about 7.8 meter accuracy 95% of the time, according to the Federal Aviation Administration. It is used by people all over the world for countless purposes such as; navigating roads, helping search and rescue efforts, piloting planes, environmental protection, and military operations (“GPS
The invention of the GPS started with Dr. Ivan Getting leaving his position at Raytheon Company, and armed with the knowledge of what was at the time the most advanced navigational technology in the world, they began developing the Global Positioning System. He, Roger L. Easton, and Bradford Parkison began in the 60’s with a constellation of 24 satellites (placed in six orbital planes) orbiting the earth at a very high altitude (about
Galileo used this great invention to report astronomical facts such as the moon is cover with craters instead of being smooth, the Milky Way is composed of millions of stars, and Jupiter have four moons. Perhaps the most famous discovery is the Earth revolves around the Sun and the Earth is not the center of the universe (even though he was discredited at the time).
Signals Intelligence (SIGINT) has access to many traditional and non-traditional dynamic elements that provide superior capabilities to collect and monitor visual, seismic, and acoustic signatures of motorized vehicles. SIGINT is the only system that can be operational and maintainable in any type of climate and terrain, which provides an advantage over the United States’ (U.S.) adversaries. The process of obtaining the intelligence starts with the collection of any type of signal, whether it be infrared, electro-optical, or electronic. After the signals are collected, analysts encounter the tasks of cryptanalysis, transcription, traffic analysis, and translations of the enemy information systems; analyst then determine size, location, distance, and terrain features. The data is usually processed in overlays and graphic displays within the United States. End products are then populated into National databases for the use of the Intelligence Community. The increasing utilization of computers, the internet, satellites, sophisticated encryption, and cellular telephones have streamlined effective and accurate Human Intelligence (HUMINT); implementation of Signals Intelligence has became an important role to maintain superiority over adversaries.
The GPS is sensing knowledge to help with navigation with the car and destinations. Autonomous cars are not yet available on a large scale of the world such as out of the United States of America, but have been programmed and developed to travel along the roads of America. Most autonomous cars are programmed only for American roads, we have made a big step towards the future with autonomous cars, with them being only available mainly in America, they are a luxury. They are making their way to larger scale autopilot features, and will eventually be available on a larger scale.(Ali
There was a time a person would use a roadmap to get from one location to another. Some also would stop and ask for directions. Today, you seldom see paper maps and people stopping at a local gas station for directions. Many vehicles come with a navigation system that provides a real-time map of the vehicle’s current location as well as systematic directions to requested destination.
GPS is a system of satellites radio-transmitters that orbit the planet in great numbers; their purpose is to be able to pinpoint the exact location of an individual or any type of vessel that is equipped with a receiver transmitter within a very small radius. GPS navigation has had a great impact upon society in general as well and its commercial and military applications. Global Positioning is made available at no cost to anyone who has a GPS receiver unit anywhere on the planet. A GPS unit is able to give the user longitude/latitude information as well as, altitude, traveling speed, distance traveled, distance remaining and time in any type of weather conditions imaginable.
Land transportation is the dominant form of transportation in the world. People can move about land under their own power, either by walking or by other forms of human-powered transportation such as the bicycle. People also use domestic animals as a means of transportation, both for riding and for pulling wheeled wagons or carts.
This allows for the vehicle to get an estimate on where you are at all times. It will basically get the vehicle ready for any type of sharp turns or construction. Another component to perception would be cameras put on all sides of the vehicle. This helps the car to detect the actual lane that the car is in, so this prevents swerving from lane to lane or bumping into other cars as your driving. And one last component would have to be lasers on the front and back of the vehicle. This is going to help you detect the random objects in the road that could possibly mess up your car frame. This will also protect the driver from anyone crossing the street or even any major potholes in the roadway.