Realisierung und Bewertung von Navigationsmethoden zur fahrzeugautonomen Positionsbestimmung mit low-cost Sensorik

This research paper describes the implementation and validation of navigation algorithms for vehicle-autonomous positioning with low cost sensors for safety-critical navigation systems. The investigation of the navigation methods allows showing the potential of modern sensor systems in car navigation. First the requirements are presented for a navigation solution for the use in a safety-critical application, for example a modern surface movement, guidance and control system (A-SMGCS) on Frankfurt airport. Most important are here: accuracy, integrity and reliability of the navigation solution. Other research papers were evaluated and a differentiation to map matching algorithms is shown. After an analysis of existing car navigation systems the description of the applicable sensor system is presented. For the realization of the onboard-autonomous navigation algorithms, existing systems were analyzed and implemented after a selection of sensors for three different methods. These methods are based on vehicle-autonomous dead reckoning methods with a micromechanical gyroscope, odometer and/or differential-odometer. In this work a procedure with redundant calculation of turn rate with the differential-odometer and the micromechanical gyroscope is developed, which allows improved error detection. The maximum position errors could be reduced by a factor of 3 compared to a gyroscope/odometer solution as well as the position error CEP95 from 8m to 5m. The sensor data fusion is realized in an extended Kalman filter with error detection algorithm. A system model is built and a detailed investigation of the measuring errors of the sensors to adopt the systematic error behavior as well as external influences to fulfill the high requirements concerning accuracy. The developed algorithms are validated on the basis of a precise reference trajectory in numerous test runs, which were partly accomplished on the airport Frankfurt/Main, and then analyzed and rated. For the execution of the test runs for data capturing a navigation test vehicle with selected, adequate sensor system is developed. In the evaluation the position and course error of the implemented navigation algorithms are compared with the reference trajectory and the achieved position accuracy over all test runs is represented