Determining Impact of Navigation Errors on Mission Capabilities

Author(s):  
Kathleen A. Kramer ◽  
Stephen C. Stubberud
Keyword(s):  
Author(s):  
Giulio Avanzini ◽  
David S Martínez

A procedure for evaluating the risk related to the use of unmanned aerial systems over populated areas is proposed. A nominal trajectory, planned for performing a given mission, is represented by means of motion primitives, that is segments and arcs flown in a steady-state condition. The risk of hitting a person on the ground after catastrophic failure is evaluated as a function of vehicle reliability and population density (assumed known), and position of the impact point (which depends on initial conditions at the time of failure and trajectory flown afterwards). In the deterministic case, a lethal area is introduced and the risk at each point on the ground is proportional to the amount of time spent by the point inside the lethal area. Under the assumptions of a ballistic fall, the position of the lethal area with respect to the nominal trajectory depends only on altitude and velocity at the time of failure. When the effect of navigation errors is introduced, impact points are described by a statistical impact footprint, assuming that position and velocity errors at time of failure are normally distributed with known standard deviations. The two approaches are compared for a fictitious, yet realistic, mission scenario.


2017 ◽  
Vol 2017 (3) ◽  
pp. 84-106
Author(s):  
Stanisław Popowski ◽  
Witold Dąbrowski

Abstract The article presents the Individual Autonomous System Navigation (IANS) supporting–rescuer or firemen in terms of navigation. Basic assumptions, which such a system has to fulfill in terms of functionality and accuracy, are presented. The concept of the ISAN system is based on the implementation of inertial navigation system which the only one to permit fully autonomous functioning. Measurement sensors of the navigation system with microprocessor board are placed in the rescuer’s shoe. To limit the escalation of the navigation errors value, which in the case of inertial navigation rises exponentially, a procedure of navigation parameters upgrading at every step of the rescuer is introduced to the proposed system. This procedure guarantees the required accuracy of navigation achievement. The article describes a developed and manufactured demonstrator of the technology and presents main results of its research. The research conducted in a building consisted in walking on the same level several hundred meters in less than 10 minutes. A walking test with a change of walking height was also performed in order to estimate the accuracy of the vertical channel. Results of the demonstrator’s tests let us conclude that the error of navigation is below 1% of the travelled distance and the accuracy is linear in respect to time. The achieved accuracy is fully sufficient for a practical IANS application.


2000 ◽  
Author(s):  
S. Morice ◽  
S. Ronen ◽  
K. Welker ◽  
P. Canter

Author(s):  
Mehdi Dehghani ◽  
Hamed Kharrati ◽  
Hadi Seyedarabi ◽  
Mahdi Baradarannia

The accumulated error and noise sensitivity are the two common problems of ordinary inertial sensors. An accurate gyroscope is too expensive, which is not normally applicable in low-cost missions of mobile robots. Since the accelerometers are rather cheaper than similar types of gyroscopes, using redundant accelerometers could be considered as an alternative. This mechanism is called gyroscope-free navigation. The article deals with autonomous mobile robot (AMR) navigation based on gyroscope-free method. In this research, the navigation errors of the gyroscope-free method in long-time missions are demonstrated. To compensate the position error, the aid information of low-cost stereo cameras and a topological map of the workspace are employed in the navigation system. After precise sensor calibration, an amendment algorithm is presented to fuse the measurement of gyroscope-free inertial measurement unit (GFIMU) and stereo camera observations. The advantages and comparisons of vision aid navigation and gyroscope-free navigation of mobile robots will be also discussed. The experimental results show the increasing accuracy in vision-aid navigation of mobile robot.


2019 ◽  
Vol 125 ◽  
pp. 14-19 ◽  
Author(s):  
Xiaoyan Zhang ◽  
Xingda Qu ◽  
Hongjun Xue ◽  
Da Tao ◽  
Tao Li

2020 ◽  
Vol 8 (10) ◽  
pp. 775
Author(s):  
Dejan Žagar ◽  
Matija Svetina ◽  
Andrej Košir ◽  
Franc Dimc

This paper is intended to give an overview of the experiments to evaluate the cognitive load of the officer on watch (OOW) during a collision avoidance maneuver in a full-mission simulator. The main goal is to investigate the possibilities of recording the biometric parameters of an OOW during a simulated collision avoidance maneuver. Potentially dangerous navigation errors known as human erroneous action (HEA) are induced by excessive cognitive load. Despite modern navigational aids on the ship’s bridge, investigators of maritime incidents typically link the reason for incidents at sea with human factors, including high cognitive load. During the experimental tasks on the bridge, the biometric parameters of the OOW are recorded. Statistical tools are used to visualize the data and evaluate the cognitive load of the OOW. Biometric peaks of the OOW typically occur either during the collision avoidance maneuver or when the OOW has been exposed to disturbing factors that increase reaction time and cause potentially dangerous navigation. Assessing the cognitive load of OOWs in the simulator is challenging for several reasons: e.g., the environmental conditions of the simulator, the type of task to be simulated, and even the type of sensor used. After careful study of the available literature, an original experimental design using non-invasive biometric sensors is proposed.


2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Junjun Tang ◽  
Peijuan Li

Considering the drawbacks that GPS signal is susceptible to obstacles and TAN becomes useless in some area when without any terrain data or with a featureless terrain field, to realize long-distance and high-precision navigation, a navigation system based on SINS/GPS/TAN/EOAN is presented. When GPS signal is available, GPS is used to correct errors of SINS; when GPS is unavailable, a terrain selection method based on the entropy weighted gray relational decision-making method is use to distinguish terrain into matchable areas and unmatchable areas; then, for the matchable areas, TAN is used to correct errors of SINS, for the unmatchable areas, EOAN is used to correct errors of SINS. The principles of SINS, GPS, TAN, and EOAN are analyzed, the mathematic models of SINS/GPS, SINS/TAN, and SINS/EOAN are constructed, and finally the federated Kalman filter is used to fuse navigation information. Simulation results show that the trajectory of SINS/GPS/TAN/EOAN is close to the ideal one in both matchable area or unmatchable area and whose navigation errors are obviously reduced, which is important for the realization of long-time and high-precision positioning.


Sensors ◽  
2018 ◽  
Vol 18 (9) ◽  
pp. 2921 ◽  
Author(s):  
Jie Sui ◽  
Lei Wang ◽  
Tao Huang ◽  
Qi Zhou

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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