integration of a space-segment model with gps satellites ...€¦ · taking you to the next level...

Taking you to the next level

Integration of a space-segment model with GPSlli i h hi l d i i l isatellites in the vehicle dynamics simulation

Dipl.-Ing. Tobias Butz, Dipl. Ing. (FH) Bernhard Schick IPG Automotive GmbHProf Dr Ing Gert F Trommer Dipl Ing Matthias Wankerl Institute of System Optimization

IPG Automotive GmbH | Tobias Butz | “apply & innovate 2012“ – IPG Technology Conference 20.09.2012 1

Prof. Dr.-Ing. Gert F. Trommer, Dipl.-Ing. Matthias Wankerl Institute of System Optimization

Motivation

Motivation

Use of navigation solutions for advanced driver assistance systems (ADAS)

U f i i l i i f i i l d i i i i

Motivation

Use of navigation solutions in safety-critical driving situations

To simulate the significantly enhanced for the informationenhanced for the information content, quality and redudancy by means of suitable fusion algorithms


Motivation

Motivation

To develop and evaluate GPS/INS-based integration and fusion algorithms in the seamless process with IPG CarMaker

Motivation

Makes artificial, but realistic, pseudo and delta range measurements available. In addition to these, error models and error functions in the receiver, the GPS observation parameters as well as in the vehicle’s inertial sensors have been integrated into the vehicle dynamics simulation


The IPG CarMaker

IPG CarMaker

“Virtual Test Driving” to evaluate concepts, models, controllers and systems

The IPG CarMaker


The Global Positioning System (GPS)

Global Positioning System (GPS)

GPS consists of three segments:

The Global Positioning System (GPS)

Space Segmentneeds to be integrated

The Control-Segment is

User Segment issimulated by the car


pay further by the use ofcurrent ephemeris-data

How does GPS?

Global Positioning System (GPS)

How does GPS?Transmisson to Receiver

Generates a Pseudo Random Code Also generates a Pseudo RandomAlso generates a Pseudo Random Code and compares the two codes4x

Zeit t

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Distance of least foursatellites known

Self-localization by By means of the time difference


triangulation possible is determined the distance

Difference between GPS and the Implementation

Implementation

Normally, based on the reception time of the satellite signal and the pseudo-ranges of at least

Difference between GPS and the Implementation

four satellites, one‘s own position and that of the clock fields of the satellite receiver are calculated

As the positional data of the virtual vehicle are known in the CarMaker simulation environment the calculation is modified accordingly in this case: The positions of satellites are calculated by means of these positional data, using the reception time of the satellite signals and the

h i id l d tepherimidal data.


Implementation

Calculation of the SatelliteCalculation of the SatelliteSpace-Segment

Calculation of satellite position in ECEF (Earth centered Earth fixed) at time of transmission using

Calculation of transmission time of the satellite

centered, Earth fixed) at time of transmission usingephemeridal data

signal

Recalculation of signal runtime

Repetition of steps 2 – 5 until desired accuracy has been achieved


accuracy has been achieved

Implementation of the Space-Segment Model

Implementation

Implementation of the Space Segment Model

Parameterized and controlled by means of a

clearly structured, user-friendly graphical user

interface (GUI)

Prior to starting the virtual road test the desired

values an parameters are entered here


Errors and Faults

Errors and Faults

Errors and Faults

In order to allow a realistic simulation of the errors and faults in the signals and

sensors are modeled

Th di t b f th GPS b h d ll t d ff i th GUI The disturbance of the GPS can be changed as well as turned off via the GUI

In addition the IMU error can be simulated and the quality of the inertial sensorsIn addition, the IMU error can be simulated and the quality of the inertial sensors

determined with the help of the GUI


Overview of Integrated GPS Errors

Errors and Faults

Overview of Integrated GPS Errors

Receiver Clock Error

Ephemris-Error

Ionospheric Error Ionospheric-Error

Troposheric-Error

Receiver Noise

• Pseudorange Noise

• Delta-Range-Noise

• Range-Rate-Noise


The Goodness of the IMU

Errors and Faults

The Goodness of the IMU

The IMU (Inertial Measurement Unit)

i l d thincludes three

accelerometers and

gyros

The goodness is described by three fault sizes:

• Bias

• Scale Factor Error

• Angle/Velocity Random Walk


New Applications through the Integration

Benefit

New and updated driver assistance systems / map-based driver assistance systems


Predictive driving / lower emissions through reduced fuel consumption / optimized energy management strategies for hybrid electric and battery electric vehicles



Benefit

Newly developed functional algorithms can be examined in virtual road tests involving a wide range of traffic and traffic situations (corresponding to real-world


customer use cases)

Simulation of complex traffic scenarios using a highly capable traffic model

Interlinking of vehicles: Car-to-Car (C2C) or Car-to-Infrastructure (C2I)


Conclusion

Conclusion

The integration of the space-segment-model into the vehicle dynamics simulation CarMaker makes a highly capable tool available that allows newly developes

Conclusion

functions and functional algorithms to be tested and evaluated in virtual road tests at a very early stage

Ability to even repeat complex traffic scenarios which is very important for theAbility to even repeat complex traffic scenarios, which is very important for the development and to evaluate Car-to-X-Communication

Consequently, this new method offers major optimization potential for both existing and new driver assistance systems as well as for innovative energy management systems and operating strategies

Thi t l ll i ifi t t ib ti t f t d f l ffi i This new tool allows an significant contribution to safety and fuel efficiency


integration of a space-segment model with gps satellites ...€¦ · taking you to the next level...

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