13 research outputs found
Contributions to Positioning Methods on Low-Cost Devices
Global Navigation Satellite System (GNSS) receivers are common in modern consumer devices that make use of position information, e.g., smartphones and personal navigation assistants. With a GNSS receiver, a position solution with an accuracy in the order of five meters is usually available if the reception conditions are benign, but the performance degrades rapidly in less favorable environments and, on the other hand, a better accuracy would be beneficial in some applications.
This thesis studies advanced methods for processing the measurements of low-cost devices that can be used for improving the positioning performance. The focus is on GNSS receivers and microelectromechanical (MEMS) inertial sensors which have become common in mobile devices such as smartphones. First, methods to compensate for the additive bias of a MEMS gyroscope are investigated. Both physical slewing of the sensor and mathematical modeling of the bias instability process are considered. The use of MEMS inertial sensors for pedestrian navigation indoors is studied in the context of map matching using a particle filter. A high-sensitivity GNSS receiver is used to produce coarse initialization information for the filter to decrease the computational burden without the need to exploit local building infrastructure. Finally, a cycle slip detection scheme for stand-alone single-frequency GNSS receivers is proposed.
Experimental results show that even a MEMS gyroscope can reach an accuracy suitable for North seeking if the measurement errors are carefully modeled and eliminated. Furthermore, it is seen that even a relatively coarse initialization can be adequate for long-term indoor navigation without an excessive computational burden if a detailed map is available. The cycle slip detection results suggest that even small cycle slips can be detected with mass-market GNSS receivers, but the detection rate needs to be improved
Mapping rollercoaster forces using acceleration and GNSS data
Acceleration testing has been an integral part of amusement device safety for years. It is often included during the commissioning and design verification of new rides and as a preventative maintenance tool throughout their operating life cycle. However, there are limitations to current testing methods as the acceleration forces are measured and displayed as a function of time and have no direct connection with the fixed track upon which they are enacting.
This study has endeavored to correlate three-dimensional displacement with tri-axial acceleration data. The desired outcome was to produce a βforce mapβ of the amusement device that mirrors the fixed track in its dimensions. The method of achieving this was to couple precise MEMS accelerometer signals that are prone to drift with less precise but highly accurate GNSS receiver signals by aligning these datasets with wheel rotation counts as the train moves around the track.
Established and respected standards were used to determine feasibility requirements and the testing methods needed for acceleration sensors to produce accurate and repeatable data sets. The high vibration and acceleration forces of roller coasters proved to make this a challenging endeavor but a proof of concept was established. The learnings from this project can be used to build on the application of correlating acceleration data with GPS track location using revolution of wheel counts
Practical investigations in robot localization using ultra-wideband sensors
Robot navigation is rudimentary compared to the capabilities of humans and animals to move about their environments. One of the core processes of navigation is localization, the problem of answering where one is at the present time. Robot localization is the science of using various sensors to inform a robot of where it is within its environment. Ultra-wideband (UWB) radio is one such sensor technology that can return absolute position information. The algorithm to accomplish this is known as multilateration, which uses a collection of distance measurements between multiple robot tag and environment anchor pairs to calculate the tagβs position. UWB is especially suited to the task of returning precise distance measurements due to its capabilities of short duration, high amplitude pulse generation and detection. Decawave Ltd. has created an UWB integrated circuit to perform ranging and a suite of products to support this technology. Claimed and verified accuracies using this implementation are on the order of 10cm. This thesis describes various experiments carried out using Decawave technology for robot localization. The progression of the chapters starts with commercial product verification before moving into development and testing in various environments of an open-source driver package for the Robot Operating System (ROS), then the development of a novel phase difference of arrival (PDoA) sensor for three-dimensional robot localization without an UWB anchor mesh, before concluding with future research directions and commercialization potential of UWB. This thesis is designed as a compilation of all that the author has learned through primary and secondary research over the past three years of investigation. The primary contributions are:
1. A modular ROS UWB driver framework and series of ROS bags for offline experimentation with multilateration algorithms.
2. A robust ROS framework for comparing motion capture system (MoCap) ground truth vs sensor data for rigorous statistical analysis and characterization of multiple sensors.
3. Development of a novel UWB PDoA sensor array and data model to allow 3D localization of a target from a single point without the deployment of an antenna mesh
DRONE DELIVERY OF CBNRECy β DEW WEAPONS Emerging Threats of Mini-Weapons of Mass Destruction and Disruption (WMDD)
Drone Delivery of CBNRECy β DEW Weapons: Emerging Threats of Mini-Weapons of Mass Destruction and Disruption (WMDD) is our sixth textbook in a series covering the world of UASs and UUVs. Our textbook takes on a whole new purview for UAS / CUAS/ UUV (drones) β how they can be used to deploy Weapons of Mass Destruction and Deception against CBRNE and civilian targets of opportunity. We are concerned with the future use of these inexpensive devices and their availability to maleficent actors. Our work suggests that UASs in air and underwater UUVs will be the future of military and civilian terrorist operations. UAS / UUVs can deliver a huge punch for a low investment and minimize human casualties.https://newprairiepress.org/ebooks/1046/thumbnail.jp
Aeronautical engineering: A continuing bibliography with indexes (supplement 301)
This bibliography lists 1291 reports, articles, and other documents introduced into the NASA scientific and technical information system in Feb. 1994. Subject coverage includes: design, construction and testing of aircraft and aircraft engines; aircraft components, equipment, and systems; ground support systems; and theoretical and applied aspects of aerodynamics and general fluid dynamics
GNSS Signal Tracking Performance Improvement for Highly Dynamic Receivers by Gyroscopic Mounting Crystal Oscillator
In this paper, the efficiency of the gyroscopic mounting method is studied for a highly dynamic GNSS receiverβs reference oscillator for reducing signal loss. Analyses are performed separately in two phases, atmospheric and upper atmospheric flights. Results show that the proposed mounting reduces signal loss, especially in parts of the trajectory where its probability is the highest. This reduction effect appears especially for crystal oscillators with a low elevation angle g-sensitivity vector. The gyroscopic mounting influences frequency deviation or jitter caused by dynamic loads on replica carrier and affects the frequency locked loop (FLL) as the dominant tracking loop in highly dynamic GNSS receivers. In terms of steady-state load, the proposed mounting mostly reduces the frequency deviation below the one-sigma threshold of FLL (1ΟFLL). The mounting method can also reduce the frequency jitter caused by sinusoidal vibrations and reduces the probability of signal loss in parts of the trajectory where the other error sources accompany this vibration load. In the case of random vibration, which is the main disturbance source of FLL, gyroscopic mounting is even able to suppress the disturbances greater than the three-sigma threshold of FLL (3ΟFLL). In this way, signal tracking performance can be improved by the gyroscopic mounting method for highly dynamic GNSS receivers
Aerial Vehicles
This book contains 35 chapters written by experts in developing techniques for making aerial vehicles more intelligent, more reliable, more flexible in use, and safer in operation.It will also serve as an inspiration for further improvement of the design and application of aeral vehicles. The advanced techniques and research described here may also be applicable to other high-tech areas such as robotics, avionics, vetronics, and space
Social work with airports passengers
Social work at the airport is in to offer to passengers social services. The main
methodological position is that people are under stress, which characterized by a
particular set of characteristics in appearance and behavior. In such circumstances
passenger attracts in his actions some attention. Only person whom he trusts can help him
with the documents or psychologically
ΠΠΎΡΠΌΠΈΡΠ΅ΡΠΊΠΎΠ΅ ΠΏΡΠΈΠ±ΠΎΡΠΎΡΡΡΠΎΠ΅Π½ΠΈΠ΅ : ΡΠ±ΠΎΡΠ½ΠΈΠΊ Π½Π°ΡΡΠ½ΡΡ ΡΡΡΠ΄ΠΎΠ² III ΠΡΠ΅ΡΠΎΡΡΠΈΠΉΡΠΊΠΎΠ³ΠΎ ΡΠΎΡΡΠΌΠ° ΡΠΊΠΎΠ»ΡΠ½ΠΈΠΊΠΎΠ², ΡΡΡΠ΄Π΅Π½ΡΠΎΠ², Π°ΡΠΏΠΈΡΠ°Π½ΡΠΎΠ² ΠΈ ΠΌΠΎΠ»ΠΎΠ΄ΡΡ ΡΡΠ΅Π½ΡΡ Ρ ΠΌΠ΅ΠΆΠ΄ΡΠ½Π°ΡΠΎΠ΄Π½ΡΠΌ ΡΡΠ°ΡΡΠΈΠ΅ΠΌ, Π³. Π’ΠΎΠΌΡΠΊ, 8-10 Π°ΠΏΡΠ΅Π»Ρ 2015 Π³.
Π‘Π±ΠΎΡΠ½ΠΈΠΊ ΠΏΠΎΡΠ²ΡΡΡΠ½ ΡΠ΅ΠΎΡΠ΅ΡΠΈΡΠ΅ΡΠΊΠΈΠΌ ΠΈ ΠΏΡΠ°ΠΊΡΠΈΡΠ΅ΡΠΊΠΈΠΌ Π°ΡΠΏΠ΅ΠΊΡΠ°ΠΌ ΠΊΠΎΡΠΌΠΈΡΠ΅ΡΠΊΠΎΠ³ΠΎ ΠΏΡΠΈΠ±ΠΎΡΠΎΡΡΡΠΎΠ΅Π½ΠΈΡ. ΠΡΠ΅Π΄ΡΡΠ°Π²Π»Π΅Π½ ΡΠΈΡΠΎΠΊΠΈΠΉ ΠΊΡΡΠ³ ΠΈΡΡΠ»Π΅Π΄ΠΎΠ²Π°Π½ΠΈΠΉ Π°ΡΠΏΠΈΡΠ°Π½ΡΠΎΠ², ΡΡΡΠ΄Π΅Π½ΡΠΎΠ², ΠΌΠΎΠ»ΠΎΠ΄ΡΡ
ΡΡΡΠ½ΡΡ
ΠΈ ΡΠΊΠΎΠ»ΡΠ½ΠΈΠΊΠΎ
Dynamical systems : mechatronics and life sciences
Proceedings of the 13th Conference βDynamical Systems - Theory and Applications"
summarize 164 and the Springer Proceedings summarize 60 best papers of university
teachers and students, researchers and engineers from whole the world. The papers were
chosen by the International Scientific Committee from 315 papers submitted to the
conference. The reader thus obtains an overview of the recent developments of dynamical
systems and can study the most progressive tendencies in this field of science