Study branch "Aircraft and Space Systems" of the master degree program "Cybernetics and Robotics"
 
Department of Measurement, Technicka 2, 166 27 Prague, Czech Republic


R&D activities of the Navigation group - NavLIS

Navigation group of the Laboratory of Aircraft Instrumentation Systems is a part of Department of Measurement, Faculty of Electrical Engineering, Czech Technical University in Prague (CTU in Prague).

NavLIS group activities
 
  • Calibration of inertial sensors and measuring units (multi-axial accelerometers and angular rate sensors), calibration of tilt sensors and magnetometers. Design and development of calibration devices.
  • Calibration of temperature dependencies of inertial sensors, tilt sensors, and magnetometer. Testing of vibration impacts on sensors' performance.
  • Estimation techniques of attitude and 3D position based on fusing data from measuring systems such as inertial sensors, magnetometers, tilt sensors, odometers, ultrasound distance sensors, and GNSS. The applicability is oriented at unmanned aerial and terrestrial vehicles, robots, hand-held devices, smart metal detectors etc.
  • Research and development of algorithms applied in navigation solutions enabling vibration impact reduction and correct dynamics recognition.
  • Research and development of data validation techniques.
  • Design and development of navigation systems with wide applicability in fields of unmanned aerial and terrestrial vehicles as well as on board the light aircrafts.
  • Research and development of human body motion capture system


Modular system for attitude and position estimation


Modular navigation system for attitude and position estimation
the project carried on from 2010 to 2012 and financed by Czech Technical University in Prague. The aim of the project was to design new approaches to complex data acquisition and an innovative structure of heterogeneous multi-sensor system (see Fig. 1) to satisfy criterions of precise positioning with low-cost and readily available sensors and measuring subsystems. For the purpose of the complex system experimental evaluation there was a need to develop an integrated system with a modular structure of used sensors and subsystems. The complex and integrated system in its final form included IMU (Inertial Measurement Unit) as a primary subsystem aided by GPS, ADC (Air Data Computer), magnetometer, electrolytic tilt sensors, optical and ultrasound distance sensors. The whole modular system in full configuration was experimentally verified when placed on board the UAV Bellanca Super Dectahlon XXL manufactured by Hacker Model Production Ltd.

 

Research and development of technologies for radiolocation mapping and navigation systems

the project is financed by Technology Agency of the Czech Republic under No. TA02011092. The project deals with the R&D of a radiolocation mapping and navigation system and with the extension of knowing-how in this field in the Czech Republic. The system consists of a radiolocation unit based on SAR (Synthetic Aperture Radar) technology, an inertial navigation unit, and of a control module. The integration of mentioned units brings a unique system fulfilling functions of a continual navigation and the evaluation of landscape image even under adverse weather conditions. In this project our group is responsible for a navigation unit research, design, and development, as well as the whole system integration and user interface. The system should be capable of real time navigation providing position, velocity, and orientation in space, and of monitoring terrestrial objects and terrain in a real time which covers image processing, evaluation of prominences, comparison of the image with its model.


Navigation system allowing connection of magnetometer and GPS receiver

     
Real scenery (left) and SAR scenery image (right)
 

The survey points range-finding system utilization for perimeter security (screen)


Principle scheme of the structure of the range-finding system used for perimeter security

is solved as a part of project VG20122015076 financed by Ministry of the Interior. The project deals with two survey points range-finding system (TRS) with horizontal or vertical base for protection of strategic infrastructure. A demonstration model of TRS will be designed and verified and it will enable an implementation of the TRS principle on the condition that the target will be observable by at least two cameras at the same time. It will enable measurement of the target axis, its velocity vector and trajectory extrapolation of the target incl. the data transfer to users.

 

Modern methods in development of inertial navigation systems

a project financed by Czech Technical University in Prague under grant No. SGS13/144/OHK3/2T/13. The project has two main objectives. First one is to develop a precise INS using only accurate inertial sensors, such as fiber optic gyroscopes DSP-3100 (KVH manufacturer) and quartz accelerometers INN-204 (Innalabs manufacturer), see Fig. 5. The challenge lies not only in the system development and realization including design and implementation of algorithms needed for attitude and position determination that is not relying on other sensor aiding, but also in the system testing, calibration, and experimental verification. Since high accuracy is required and precise inertial sensors are planned to use, it is necessary to implement a complex navigation equation calculation without any simplifications, which allows getting close to the accuracy of precise and expensive industrial navigation solutions. The second objective of the proposal lies in a miniature and very low-cost INS design, which could be further used for various purposes. Advantages of such a system will originate from unique integration of up-to-date sensors combined with algorithms improving the precision of the position and attitude estimates. The applicability of both units will be very broad, starting with small and medium sized aircrafts, intelligent mine detector, unmanned aerial vehicles or mobile robots, hand-held devices for pedestrian navigation.



"Tactical grade" inertial sensors, a fiber optic gyro DSP-3100 (left), a quartz accelerometer INN-204 (right)

 

Techniques and devices to calibrate and test measuring systems used for navigation purposes


Platform for the calibration of low-cost tilt measurement systems (left), a principle image of the All-In-One calibration platform (right)
research, design, and development of All-In-One calibration platform, shown in Fig. 6, supplemented by research and calibration algorithms and techniques to provide time and cost-effective approach. The platform can be used for multi-axial accelerometers, angular rate sensors, magnetometers, and tilt sensors calibration. The platform does not affect a magnetic field because it is made from non-magnetic materials. It utilizes reference measuring system formed by a fiber optic gyro DSP-3100 (see Fig. 5) and a precise inclinometer HCA528T, see Fig. 7. We also study the behavior of mentioned measurement systems under different environmental conditions, such as temperature and vibration, and consequently we include these behaviors into our navigation algorithms for their compensation.

     
System for precise tilt measurements - an inclinometer HCA528T (left), a PCB for its signal processing (right)

 

Human body motion capture system


the project aims at research and development of a biomechanical measurement system focused on medicine and human movement monitoring. The system will become useful in monitoring and rehabilitation of patients with movement disorders or in assessment of movement skills of sportsmen. Using obtained data, it will be possible to analyze the current state of subject's movement system and to observe the changes compared to former measurements. The system is primarily based on movement sensors with wireless data transmission to the PC. A software application will be created, including user interface for saving, displaying and analyzing biomechanical characteristics of movement, with various secondary functions specified by physicians.


How it may look like
ref. https://www.xsens.com/products/xsens-mvn/



Financial support of our research
 
  • SGS10/288/OHK3/3T/13 - Modular system for attitude and position estimation, internal CTU grant (2010-2012)
  • TA02011092 - Research and development of technologies for radiolocation mapping and navigation systems, the grant of the Technology Agency of the Czech Republic (2012-2014)
  • VG20122015076 - The survey points range-finding system utilization for perimeter security (screen), the grant of the Ministry of the Interior of the Czech Republic (2012-2015)
  • SGS13/144/OHK3/2T/13 - Modern methods in development of inertial navigation systems, internal CTU grant (2013-2014)
  • SGS15/163/OHK3/2T/13 - Systems for localization and navigation in ground and aeronautical applications under non-standard conditions, internal CTU grant (2015-2016)
  • SGS15/162/OHK3/2T/13 - Development of a water rocket and its control systems, internal CTU grant (2015-2016)

 

Industry collaboration in research
 

 

Selected publications
 
  • Alam, M. - Roháč, J.: Adaptive Data Filtering of Inertial Sensors with Variable Bandwidth. Sensors - Open Access Journal [online]. 2015, vol. 15, no. 2, p. 3282-3298. ISSN 1424-8220.
  • Ďaďo, S. - Roubíček, T. - Roháč, J.: Methods of Evaluation of Output Signals from Resonance Accelerometers. Sensors and Transducers [online]. 2014, vol. 177, no. 8, p. 286-293. http://www.sensorsportal.com/HTML/DIGEST/P_RP_0182.htm. ISSN 1726-5479.
  • Nováček, P. - Roháč, J. - Šimánek, J. - Ripka, P.: Metal Detector Signal Imprints of Detected Objects. IEEE Transactions on Magnetics. 2013, vol. 49, no. 1, p. 69-72. ISSN 0018-9464.
  • Nováček, P. - Svatoš, J.: Intelligent Metal Detector. Key Engineering Materials. 2013, vol. 543-543, no. 15, p. 133-136. ISSN 1013-9826.
  • Šipoš, M. - Pačes, P. - Roháč, J. - Nováček, P.: Analyses of Triaxial Accelerometer Calibration Algorithms In: IEEE Sensors Journal. 2012, vol. 12, no. 5, p. 1157-1165. ISSN 1530-437X.
  • Šipoš, M. - Roháč, J. - Nováček, P.: Analyses of Electronic Inclinometer Data for Tri-axial Accelerometer's Initial Alignment In: Przeglad Elektrotechniczny. 2012, vol. 88, no. 01a, p. 286-290. ISSN 0033-2097.
  • Šipoš, M. - Roháč, J. - Nováček, P.: Improvement of Electronic Compass Accuracy Based on Magnetometer and Accelerometer Calibration In: Acta Physica Polonica A. 2012, vol. 121, no. 4, p. 945-949. ISSN 0587-4246.
  • Nováček, P. - Roháč, J. - Ripka, P.: Complex Markers for a Mine Detector. IEEE Transactions on Magnetics. 2012, vol. 48, no. 4, p. 1489-1492. ISSN 0018-9464.
  • Svatoš, J. - Nováček, P. - Vedral, J.: sin(x)/x SIGNAL UTILIZATION IN METAL DETECTION AND DISCRIMINATION. Journal of Electrical Engineering. 2012, vol. 7, no. 63, p. 110-113. ISSN 1335-3632.
  • Roháč, J. - Šipoš, M. - Šimánek, J. - Tereň, O.: Inertial Reference Unit in a Directional Gyro Mode of Operation In: IEEE SENSORS 2012 - Proceedings. Piscataway: IEEE Service Center , 2012, p. 1356-1359. ISBN 978-1-4577-1765-9.
  • Roháč, J. - Reinštein, M. - Draxler, K.: Data Processing of Inertial Sensors in Strong-Vibration Environment In: Intelligent Data Acquisition and Advanced Computing Systems (IDAACS). Piscataway: IEEE, 2011, vol. 1, p. 71-75. ISBN 978-1-4577-1426-9.
  • Nováček, P. - Ripka, P. - Pribula, O. - Fischer, J.: Mine Detector with Discrimination Ability. Journal of Electrical Engineering. 2010, vol. 61, no. 7/s, p. 141-143. ISSN 1335-3632.
  • Reinštein, M. - Roháč, J. - Šipoš, M.: Algorithms for Heading Determination using Inertial Sensors In: Przeglad Elektrotechniczny. 2010, vol. 86, no. 9, p. 243-246. ISSN 0033-2097.
  • Ripka, P. - Nováček, P. - Reinštein, M. - Roháč, J.: Position Sensing System for Eddy-current Mine Imager In: EUROSENSORS XXIV - Proceedings [CD-ROM]. Linz: Elsevier BV, 2010, p. 276-279. ISSN 1877-7058.
  • Reinštein, M. - Šipoš, M. - Roháč, J.: Error Analyses of Attitude and Heading Reference Systems In: Przeglad Elektrotechniczny. 2009, vol. 85, no. 8, p. 114-118. ISSN 0033-2097.

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