scholarly journals Dynamic Lever Arm Error Compensation of POS Used for Airborne Earth Observation

2018 ◽  
Vol 2018 ◽  
pp. 1-13
Author(s):  
Lu Zhaoxing ◽  
Fang Jiancheng ◽  
Gong Xiaolin ◽  
Li Jianli ◽  
Wang Shicheng ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Global Positioning System ◽  
Error Compensation ◽  
Inertial Measurement Unit ◽  
Measurement Accuracy ◽  
Earth Observation ◽  
Measurement Unit ◽  
Lever Arm ◽  
Global Positioning ◽  
High Measurement

The position and orientation system (POS) is widely applied in airborne Earth observation, which integrates the strapdown inertial navigation system (SINS) and global positioning system (GPS) to provide high-accuracy position, velocity, and attitude information for remote sensing motion compensation. However, for keeping the appointed direction of remote sensing load, the inertial measurement unit (IMU) and remote sensing load will be driven to sweep by the servo machine. The lever arms among IMU, GPS, and remote sensing load will be time varying, and their influence on the measurement accuracy of POS is serious. To solve the problem, a dynamic lever arm error compensation method is proposed, which contains the first-level lever arm error compensations between IMU and GPS and the second-level lever arm error compensation between POS and remote sensing load. The flight experiment results show that the proposed method can effectively compensate the dynamic lever arm error and achieve high measurement accuracy for POS.

scholarly journals An Optimized Tightly-Coupled VIO Design on the Basis of the Fused Point and Line Features for Patrol Robot Navigation

Sensors ◽  
2019 ◽  
Vol 19 (9) ◽  
pp. 2004 ◽  
Author(s):  
Linlin Xia ◽  
Qingyu Meng ◽  
Deru Chi ◽  
Bo Meng ◽  
Hanrui Yang
Keyword(s):  
Global Positioning System ◽  
Inertial Measurement Unit ◽  
Feature Matching ◽  
Robot Navigation ◽  
Measurement Unit ◽  
State Estimator ◽  
Localization And Mapping ◽  
Global Positioning ◽  
Tightly Coupled ◽  
Association State

The development and maturation of simultaneous localization and mapping (SLAM) in robotics opens the door to the application of a visual inertial odometry (VIO) to the robot navigation system. For a patrol robot with no available Global Positioning System (GPS) support, the embedded VIO components, which are generally composed of an Inertial Measurement Unit (IMU) and a camera, fuse the inertial recursion with SLAM calculation tasks, and enable the robot to estimate its location within a map. The highlights of the optimized VIO design lie in the simplified VIO initialization strategy as well as the fused point and line feature-matching based method for efficient pose estimates in the front-end. With a tightly-coupled VIO anatomy, the system state is explicitly expressed in a vector and further estimated by the state estimator. The consequent problems associated with the data association, state optimization, sliding window and timestamp alignment in the back-end are discussed in detail. The dataset tests and real substation scene tests are conducted, and the experimental results indicate that the proposed VIO can realize the accurate pose estimation with a favorable initializing efficiency and eminent map representations as expected in concerned environments. The proposed VIO design can therefore be recognized as a preferred tool reference for a class of visual and inertial SLAM application domains preceded by no external location reference support hypothesis.

scholarly journals Soaring energetics and glide performance in a moving atmosphere

2016 ◽  
Vol 371 (1704) ◽  
pp. 20150398 ◽  
Author(s):  
Graham K. Taylor ◽  
Kate V. Reynolds ◽  
Adrian L. R. Thomas
Keyword(s):  
Global Positioning System ◽  
Inertial Measurement Unit ◽  
Mechanical Energy ◽  
Measurement Unit ◽  
Cost Of Transport ◽  
Inertial Measurement ◽  
Dynamic Soaring ◽  
Energy Flows ◽  
Weak Evidence ◽  
Global Positioning

Here, we analyse the energetics, performance and optimization of flight in a moving atmosphere. We begin by deriving a succinct expression describing all of the mechanical energy flows associated with gliding, dynamic soaring and thermal soaring, which we use to explore the optimization of gliding in an arbitrary wind. We use this optimization to revisit the classical theory of the glide polar, which we expand upon in two significant ways. First, we compare the predictions of the glide polar for different species under the various published models. Second, we derive a glide optimization chart that maps every combination of headwind and updraft speed to the unique combination of airspeed and inertial sink rate at which the aerodynamic cost of transport is expected to be minimized. With these theoretical tools in hand, we test their predictions using empirical data collected from a captive steppe eagle ( Aquila nipalensis ) carrying an inertial measurement unit, global positioning system, barometer and pitot tube. We show that the bird adjusts airspeed in relation to headwind speed as expected if it were seeking to minimize its aerodynamic cost of transport, but find only weak evidence to suggest that it adjusts airspeed similarly in response to updrafts during straight and interthermal glides. This article is part of the themed issue ‘Moving in a moving medium: new perspectives on flight’.

Cartesian Control for the Inertial Measurement Unit Calibration Platform

2000 ◽  
Author(s):  
John J. Hall ◽  
Robert L. Williams ◽  
Frank van Graas
Keyword(s):  
Global Positioning System ◽  
Inertial Measurement Unit ◽  
Vertical Motion ◽  
High Accuracy ◽  
Measurement Unit ◽  
Positioning System ◽  
Ohio University ◽  
Inertial Measurement ◽  
Gps Technology ◽  
Global Positioning

Abstract The Department of Mechanical Engineering and the Avionics Engineering Center at Ohio University are developing an electromechanical system for the calibration of an inertial measurement unit (IMU) using global positioning system (GPS) antennas. The GPS antennas and IMU are mounted to a common platform to be oriented in the angular roll, pitch, and yaw motions. Vertical motion is also included to test the systems in a vibrational manner. A four-dof system based on the parallel Carpal Wrist is under development for this task. High-accuracy positioning is not required from the platform since the GPS technology provides absolute positioning for the IMU calibration process.

An autonomous rice transplanter guided by global positioning system and inertial measurement unit

2009 ◽  
Vol 26 (6-7) ◽  
pp. 537-548 ◽  
Author(s):  
Yoshisada Nagasaka ◽  
Hidefumi Saito ◽  
Katsuhiko Tamaki ◽  
Masahiro Seki ◽  
Kyo Kobayashi ◽  
...  
Keyword(s):  
Global Positioning System ◽  
Inertial Measurement Unit ◽  
Measurement Unit ◽  
Positioning System ◽  
Inertial Measurement ◽  
Global Positioning

GPS Receiver Operations on the Disaster Monitoring Constellation Satellites

2005 ◽  
Vol 58 (2) ◽  
pp. 227-240 ◽  
Author(s):  
Takuji Ebinuma ◽  
Elizabeth Rooney ◽  
Scott Gleason ◽  
Martin Unwin
Keyword(s):  
Remote Sensing ◽  
Global Positioning System ◽  
Earth Observation ◽  
Lessons Learned ◽  
Positioning System ◽  
Gps Receiver ◽  
Gps Receivers ◽  
Global Positioning ◽  
Disaster Monitoring ◽  
Observation Programme

The Disaster Monitoring Constellation (DMC) is an international Earth observation programme to provide a rapid global remote sensing service for the monitoring and mitigation of natural and man-made disasters. Although the Global Positioning System (GPS) was originally designed for terrestrial and air applications, satellite operations have benefited greatly from the use of on-board GPS receivers. This paper describes the GPS receiver operations on the DMC satellites, performance analysis, lessons learned, and upgrades planned for the future.

scholarly journals Vehicle location measurement method for radio-shadow area through iBeacon message

2018 ◽  
Vol 14 (11) ◽  
pp. 155014771881257
Author(s):  
ChoonSung Nam ◽  
Dong-Ryeol Shin
Keyword(s):  
Global Positioning System ◽  
Inertial Measurement Unit ◽  
Measurement Unit ◽  
Positioning System ◽  
Inertial Measurement ◽  
Location Data ◽  
Shadow Area ◽  
Global Positioning ◽  
Vehicle Location ◽  
Roadside Unit

Information communication technology related vehicle services need to support location and the transmission of communication and traffic information between vehicles, or between vehicles and infrastructure. In particular, the technology for the measurement of the accurate location of a vehicle is dependent on location-determination technology like Global Positioning System, and this technology is very important for vehicle driving and location services. If, however, a vehicle is in a Global Positioning System radio-shadow area, neither a Global Positioning System nor a Differential Global Positioning System can accurately measure the corresponding location because of a high error rate caused by the shadowing intervention. Even an Inertial Measurement Unit could provide inaccurate location data due to sensor drift faults around corners and traffic-road speed dumps. Vehicles, therefore, need an absolute location to prevent the provision of inaccurate vehicle-location data that is due to radio-shadow areas and relational Inertial Measurement Unit positions. To achieve this, we assume that vehicle-to-infrastructure communication is possible between a vehicle and roadside unit in Vehicular Ad hoc Networks. We used iBeacon at the roadside unit and revised its Universally Unique Identifier so that it generates absolute Global Positioning System location data; that is, moving vehicles can receive absolute Global Positioning System data from the roadside unit-based iBeacon. We compared the proposed method with current Global Positioning System and Inertial Measurement Unit systems for the following two cases: one with a radio-shadow area and one without. We proved that the proposed method generates location data that are more accurate than those of the other methods.

Three-Axis Gimbal Surveillance Algorithms for Use in Small UAS

2008 ◽  
Author(s):  
Jaganathan Ranganathan ◽  
William H. Semke
Keyword(s):  
Coordinate System ◽  
Global Positioning System ◽  
Inertial Measurement Unit ◽  
Target Location ◽  
Measurement Unit ◽  
Positioning System ◽  
Inertial Measurement ◽  
University Of North Dakota ◽  
Global Positioning ◽  
Accurate Position

An active three-axis gimbal system is developed to allow small fixed wing Unmanned Aircraft Systems (UAS) platforms to estimate accurate position information by pointing at a target and also to track a known target location. Specific targets vary from a stationary point on the ground to aircraft in the national airspace. The payload developed to accomplish this at the University of North Dakota is the Surveillance by University of North Dakota Observational Gimbal (SUNDOG). This paper will focus on a novel, nonlinear closed form analytical algorithm developed to calculate the exact rotation angles for a three-axis gimbal system to point a digital imaging sensor at a target, as well as how to estimate accurate position of a target by using the pointing angles of a three-axis gimbal system. A kinematic analysis is done on a three-axis gimbal system to get the appropriate model of gimbal rotations in order to point at a certain location on the ground. The mathematical model includes an inertial coordinate system that has coordinates fixed to the Earth, a coordinate system that is body-fixed to the aircraft, and a third coordinate system that is fixed to the gimbal. Therefore, multiple three-dimensional transformations are required to accurately provide the necessary pointing angles to the gimbal system. The autonomous control system uses Global Positioning System (GPS), Inertial Measurement Unit (IMU), and other sensor data to estimate position and attitude during flight. Since the algorithm is entirely based on Inertial Measurement Unit (IMU) and Global Positioning System (GPS) device inputs, any error from these devices cause offset in the target location. Hence, an error analysis is carried out to find the offset distance and the operating range of the algorithm. The main advantage obtained in the three-axis gimbal system is that the orientation of the image will always be aligned in a specified direction for effective interpretation. The closed form expressions to the non-linear transformations provide simple solutions easily programmed without large computational expense. Experimental work will be carried out in a controlled environment and in flight testing to show the autonomous tracking ability of the gimbal system. Simulation and experimental data illustrating the effectiveness of the surveillance algorithms is presented.

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