Alignment Method for FOG Single-Axis Rotation-Modulation SINS

2012 ◽  
Vol 229-231 ◽  
pp. 1127-1131 ◽  
Author(s):  
Fang Liu ◽  
Wei Wang ◽  
Kui Li ◽  
Lei Wang
Keyword(s):  
Navigation System ◽  
Inertial Navigation System ◽  
Low Cost ◽  
Inertial Navigation ◽  
Open Loop ◽  
Modulation Method ◽  
Alignment Method ◽  
Fiber Optic Gyroscope ◽  
Actual System ◽  
Axis Rotation

Aircrafts with common attitude maneuverability (e.g. helicopter) are in more and more urgent need of low cost and high precision inertial navigation system (INS). To meet this demand, a scheme of fiber-optic gyroscope (FOG) strapdown inertial navigation system (SINS) with single-axis to and fro rotation-modulation method is adopted. A short-time alignment method bases on open-loop mathematic platform misalignment model is studied. The test results from the actual system show that this method has characteristic of high accuracy and simple, reliable operation. The estimate accuracy of azimuth error and is less than 2’. And the estimate error of north drift achieves 0.001º/h. Simultaneously, the input-axis accelerometer bias and gyroscope drift are estimated exactly.

scholarly journals A Fast and High-Accuracy Compass Alignment Method to SINS with Azimuth Axis Rotation

2013 ◽  
Vol 2013 ◽  
pp. 1-12 ◽  
Author(s):  
Xixiang Liu ◽  
Xiaosu Xu ◽  
Yiting Liu ◽  
Lihui Wang
Keyword(s):  
Navigation System ◽  
Calculation Method ◽  
Inertial Navigation System ◽  
Inertial Navigation ◽  
Low Frequency ◽  
High Accuracy ◽  
Alignment Accuracy ◽  
Alignment Method ◽  
Axis Rotation ◽  
Sensor Errors

Azimuth axis rotating modulation was introduced to improve the alignment accuracy of strapdown inertial navigation system (SINS) through compass algorithm, in which the limit accuracy was determined by equivalent sensor errors in the eastern and northern direction. In this modulation, horizontal sensor errors were modulated into zero mean periodic variables. Furthermore, two methods were introduced to ensure alignment accuracy and speed: (1) shortened rotating cycle and redesigned compass parameters were selected to eliminate or ease the amplification to low-frequency senor error inputs in compass loop caused by rotation and (2) a data repeated calculation method was designed to shorten prolonged alignment time caused by the above redesigned parameters. Based on a certain SINS, turntable test proves that alignment accuracy and time were significantly improved and slightly shortened in comparison with the classical compass alignment.

MODELING AND NUMERICAL SIMULATION OF AN ALGORITHM FOR THE INERTIAL SENSORS ERRORS REDUCTION AND FOR THE INCREASE OF THE STRAP-DOWN NAVIGATOR REDUNDANCY DEGREE IN A LOW COST ARCHITECTURE

2010 ◽  
Vol 34 (1) ◽  
pp. 1-16 ◽  
Author(s):  
Lucian T. Grigorie ◽  
Ruxandra M. Botez
Keyword(s):  
Navigation System ◽  
Inertial Navigation System ◽  
Lower Cost ◽  
Inertial Sensors ◽  
Low Cost ◽  
Inertial Navigation ◽  
Noise Power ◽  
Integration Algorithm ◽  
The Cost ◽  
Miniaturized Sensors

In this paper, an algorithm for the inertial sensors errors reduction in a strap-down inertial navigation system, using several miniaturized inertial sensors for each axis of the vehicle frame, is conceived. The algorithm is based on the idea of the maximum ratio-combined telecommunications method. We consider that it would be much more advantageous to set a high number of miniaturized sensors on each input axis of the strap-down inertial system instead of a single one, more accurate but expensive and with larger dimensions. Moreover, a redundant system, which would isolate any of the sensors in case of its malfunctioning, is obtained. In order to test the algorithm, Simulink code is used for algorithm and for the acceleration inertial sensors modeling. The Simulink resulted sensors models include their real errors, based on the data sheets parameters, and were conceived based on the IEEE analytical standardized accelerometers model. An integration algorithm is obtained, in which the signal noise power delivered to the navigation processor, is reduced, proportionally with the number of the integrated sensors. At the same time, the bias of the resulted signal is reduced, and provides a high redundancy degree for the strap-down inertial navigation system at a lower cost than at the cost of more accurate and expensive sensors.

scholarly journals Analysis and Self-Calibration Method for Asynchrony between Sensors in Rotation INS

Sensors ◽  
2018 ◽  
Vol 18 (9) ◽  
pp. 2921 ◽  
Author(s):  
Jie Sui ◽  
Lei Wang ◽  
Tao Huang ◽  
Qi Zhou
Keyword(s):  
Navigation System ◽  
Inertial Navigation System ◽  
Inertial Navigation ◽  
Calibration Method ◽  
Velocity Error ◽  
Self Calibration ◽  
Axis Rotation ◽  
The Impact ◽  
Navigation Errors

The gyroscope, accelerometer and angular encoder are the most important components in a dual-axis rotation inertial navigation system (RINS). However, there are asynchronies among the sensors, which will thus lead to navigation errors. The impact of asynchrony between the gyroscope and angular encoder on the azimuth error and the impact of asynchrony between the gyroscope and accelerometer on the velocity error are analyzed in this paper. A self-calibration method based on navigation errors is proposed based on the analysis above. Experiments show that azimuth and velocity accuracy can be improved by compensating the asynchronies.

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