Inertial navigation system

inertial guidanceINSinertial navigationinertial guidance systeminertialinertial reference systemInertial Navigation UnitstrapdownFog Pilot Assistance Systeminertial guidance systems
An inertial navigation system (INS) is a navigation device that uses a computer, motion sensors (accelerometers) and rotation sensors (gyroscopes) to continuously calculate by dead reckoning the position, the orientation, and the velocity (direction and speed of movement) of a moving object without the need for external references.wikipedia
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Accelerometer

accelerometersG-sensoracceleration sensor
An inertial navigation system (INS) is a navigation device that uses a computer, motion sensors (accelerometers) and rotation sensors (gyroscopes) to continuously calculate by dead reckoning the position, the orientation, and the velocity (direction and speed of movement) of a moving object without the need for external references.
Highly sensitive accelerometers are components of inertial navigation systems for aircraft and missiles.

Gyroscope

gyroscopicgyroscopesgyro
An inertial navigation system (INS) is a navigation device that uses a computer, motion sensors (accelerometers) and rotation sensors (gyroscopes) to continuously calculate by dead reckoning the position, the orientation, and the velocity (direction and speed of movement) of a moving object without the need for external references.
Applications of gyroscopes include inertial navigation systems, such as in the Hubble Telescope, or inside the steel hull of a submerged submarine.

Dead reckoning

Dead-reckonedPedestrian Dead Reckoningdead-reckoning
An inertial navigation system (INS) is a navigation device that uses a computer, motion sensors (accelerometers) and rotation sensors (gyroscopes) to continuously calculate by dead reckoning the position, the orientation, and the velocity (direction and speed of movement) of a moving object without the need for external references.
However, inertial navigation systems, which provide very accurate directional information, use dead reckoning and are very widely applied.

Pressure reference system

Because the navigation error is mainly influenced by the numerical integration of angular rates and accelerations, the Pressure Reference System was developed to use one numerical integration of the angular rate measurements.
Pressure reference system (PRS) is an enhancement of the inertial reference system and attitude and heading reference system designed to provide position angles measurements which are stable in time and do not suffer from long term drift caused by the sensor imperfections.

Navigation

nauticalnavigatemarine navigation
An inertial navigation system (INS) is a navigation device that uses a computer, motion sensors (accelerometers) and rotation sensors (gyroscopes) to continuously calculate by dead reckoning the position, the orientation, and the velocity (direction and speed of movement) of a moving object without the need for external references.
Inertial navigation system (INS) is a dead reckoning type of navigation system that computes its position based on motion sensors.

Submarine

submarinesdiesel-electric submarinediesel-electric
INSs are used on vehicles such as ships, aircraft, submarines, guided missiles, and spacecraft.
3 August 1958 – Nautilus used an inertial navigation system to reach the North Pole.

GPS/INS

By properly combining the information from an INS and other systems (GPS/INS), the errors in position and velocity are stable.
GPS/INS is the use of GPS satellite signals to correct or calibrate a solution from an inertial navigation system (INS).

Global Positioning System

GPSGlobal Positioning System (GPS)global positioning systems
In aerospace particularly, other measurement systems are used to determine INS inaccuracies, e.g. the Honeywell LaseRefV inertial navigation systems uses GPS and air data computer outputs to maintain required navigation performance.
More advanced navigation systems use additional sensors like a compass or an inertial navigation system to complement GPS.

Schuler tuning

Schuler tunedtuning
of the earth must incorporate Schuler tuning so that its
Schuler tuning is a design principle for inertial navigation systems that accounts for the curvature of the Earth.

Flight management system

FMSflight management computerControl Display Unit
One example of a popular INS for commercial aircraft was the Delco Carousel, which provided partial automation of navigation in the days before complete flight management systems became commonplace.
Using various sensors (such as GPS and INS often backed up by radio navigation) to determine the aircraft's position, the FMS can guide the aircraft along the flight plan.

Apollo PGNCS

Primary Guidance, Navigation and Control SystemApollo Primary Guidance, Navigation and Control System (PGNCS)GN&C
The primary guidance system of the Apollo spacecraft used a three-axis gyrostabilized platform, feeding data to the Apollo Guidance Computer.
The Apollo primary guidance, navigation, and control system (PGNCS) (pronounced pings) was a self-contained inertial guidance system that allowed Apollo spacecraft to carry out their missions when communications with Earth were interrupted, either as expected, when the spacecraft were behind the Moon, or in case of a communications failure.

Microelectromechanical systems

MEMSmicroelectromechanical systemmicrosystems
Recent advances in the construction of microelectromechanical systems (MEMS) have made it possible to manufacture small and light inertial navigation systems.
Inertial Measurement Units (IMUs): MEMS Accelerometers and MEMS gyroscopes in remote controlled, or autonomous, helicopters, planes and multirotors (also known as drones), used for automatically sensing and balancing flying characteristics of roll, pitch and yaw. MEMS magnetic field sensor (magnetometer) may also be incorporated in such devices to provide directional heading. MEMS are also used in Inertial navigation systems (INSs) of modern cars, airplanes, submarines and other vehicles to detect yaw, pitch, and roll; for example, the autopilot of an airplane.

Inertial frame of reference

inertial frameinertialinertial reference frame
Gyroscopes measure the angular velocity of the sensor frame with respect to the inertial reference frame.
Inertial navigation systems used a cluster of gyroscopes and accelerometers to determine accelerations relative to inertial space.

Delco Carousel

One example of a popular INS for commercial aircraft was the Delco Carousel, which provided partial automation of navigation in the days before complete flight management systems became commonplace.
The Delco Carousel was a popular INS-based navigation automation system for aircraft developed by Delco Electronics.

Rocket

rocketsrocketryrocket scientist
Inertial navigation systems were originally developed for rockets.
Vehicles frequently possess navigation systems and guidance systems that typically use satellite navigation and inertial navigation systems.

Attitude and heading reference system

AHRSattitude and heading reference systemsAttitude and Heading Reference Systems (AHRS)
Currently, devices combining different sensors are being developed, e.g. attitude and heading reference system.
In addition to attitude determination an AHRS may also form part of an inertial navigation system.

Advanced Inertial Reference Sphere

AIRS
These systems can have very high precisions (e.g., Advanced Inertial Reference Sphere).
The Advanced Inertial Reference Sphere (AIRS) is a highly accurate inertial guidance system designed for use in the LGM-118A Peacekeeper ICBM which was intended for precision nuclear strikes against Soviet missile silos.

LGM-30 Minuteman

MinutemanMinuteman IIIMinuteman missile
The desire to use inertial guidance in the Minuteman missile and Project Apollo drove early attempts to miniaturize computers.
Although lengthy, this was not considered to be a problem at the time, because it took about the same amount of time to spin up the inertial guidance system, set the initial position, and program in the target coordinates.

Motion capture

performance capturemotion-capturemotion tracking
These advances have widened the range of possible applications to include areas such as human and animal motion capture.
The motion data of the inertial sensors (inertial guidance system) is often transmitted wirelessly to a computer, where the motion is recorded or viewed.

Inertial measurement unit

IMUinertial sensorinertial sensors
Other terms used to refer to inertial navigation systems or closely related devices include inertial guidance system, inertial instrument, inertial measurement unit (IMU) and many other variations. Delco produced the IMUs (Inertial Measurement Units) for these systems, Kollsman Instrument Corp. produced the Optical Systems, and the Apollo Guidance Computer was built by Raytheon under subcontract (see Apollo on-board guidance, navigation and control system, Dave Hoag, International Space Hall of Fame Dedication Conference in Alamogordo, N.M., October 1976 ).
IMUs are often incorporated into Inertial Navigation Systems which utilize the raw IMU measurements to calculate attitude, angular rates, linear velocity and position relative to a global reference frame.

Draper Laboratory

Instrumentation LaboratoryDRAPERDraper Labs
The MIT Instrumentation Laboratory (later to become the Charles Stark Draper Laboratory, Inc.) was chosen by the Air Force Western Development Division to provide a self-contained guidance system backup to Convair in San Diego for the new Atlas intercontinental ballistic missile (Construction and testing were completed by Arma Division of AmBosch Arma).
Project areas that have surfaced in the news referred to Draper Laboratory's core expertise in inertial navigation, as recently as 2003.

Inertial platform

gyro stabilization platformgyroscopic stabilizerstabilized platform
Older INS systems generally used an inertial platform as their mounting point to the vehicle and the terms are sometimes considered synonymous.
An inertial platform, also known as a gyroscopic platform or stabilized platform, is a system using gyroscopes to maintain a platform in a fixed orientation in space despite the movement of the vehicle that it is attached to. These can then be used to stabilize gunsights in tanks, anti-aircraft artillery on ships, and as the basis for older mechanically-based inertial navigation systems.

Apollo Guidance Computer

guidance computerLM guidance computerApollo 11's lunar descent
The primary guidance system of the Apollo spacecraft used a three-axis gyrostabilized platform, feeding data to the Apollo Guidance Computer. Delco produced the IMUs (Inertial Measurement Units) for these systems, Kollsman Instrument Corp. produced the Optical Systems, and the Apollo Guidance Computer was built by Raytheon under subcontract (see Apollo on-board guidance, navigation and control system, Dave Hoag, International Space Hall of Fame Dedication Conference in Alamogordo, N.M., October 1976 ).
The command module had two DSKYs connected to its AGC: one located on the main instrument panel and a second located in the lower equipment bay near a sextant used for aligning the inertial guidance platform.

Kalman filter

unscented Kalman filterKalmanInformation filter
Estimation theory in general and Kalman filtering in particular, provide a theoretical framework for combining information from various sensors.
Inertial guidance system

Ring laser gyroscope

ring laser gyrolaser gyroscopering laser gyros
State-of-the-art strapdown systems are based upon Ring Laser Gyroscopes, Fibre Optic Gyrocopes or Hemispherical Resonator Gyroscopes.
Many tens of thousands of RLGs are operating in inertial navigation systems and have established high accuracy, with better than 0.01°/hour bias uncertainty, and mean time between failures in excess of 60,000 hours.