Virtual road generation from governmental geo data

Transcription

1 Virtual road generation from governmental geo data Mattias Hjort Senior Research Leader Ph.D Computational Physics Laban Källgren, Research Engineer M.Sc. Applied Physics and Electrical Engineering Jonas Andersson Hultgren Research Engineer M.Sc. Computer Science and Engineering Erik Olsson Research Engineer M.Sc. Applied Physics and Electrical Engineering

2 VTI Swedish National Road and Transport Research Institute VTI is an authority under the ministry of enterprise with ~200 employees.

3 Vehicle technology and simulation Tire Properties Vehicle dynamics Active Safety Train simulations Driving simulation Embedded systems Research: Vehicle properties Mathematical modeling, driving simulation, tire testing, field testing. Customers: EU, National authorities and private companies (i.e. OEM) etc.

4 VTI s simulators Sim IV Sim II Sim III VTI Foerst simulator Train simulator Sim I ( )

5 Virtual Prototyping and Assessment by Simulation

6 ViP Known Roads KnownRoads real roads in simulated environments for the virtual testing of new vehicle systems

7 ViP Known Roads So why put so much effort in accurate road modelling? Testing of vehicle dynamics (cars, trucks, long vehicle combinations) Energi saving transportation systems (electrified roads, hybrid engines) Driver comfort (wheel suspension, cabin damping for trucks) Traffic system planning, visualization and prestudies

8 Virtual roads Road data is stored in OpenDRIVE format: A number of roads are connected through simple or advanced connections A road consists of : Road alignment a sequence of geometric primitives which constitute the road chord line A primitive may be a stratight line, a constant radii curve or a clothoid (spiral) Elevation cubic splines H(s) [m] Crossfall cubic splines A(s) [rad] High frequency road information as cracks, potholes is described in opencrg data which is connected to road model Road data is used in the simulator: simulator kernel CORE (dynamics, autonomous traffic) graphics engine VISIR (visual modelling) Sound engine SIREN (noise)

9 Datafusion: VTI Road Surface Tester Road alignment (planview)? Swedish National Road Database Road elevation Height map (Lantmäteriet) Road crossfall and damages (lateral profile and opencrg)

10 RST Output data: GPS points (20m) Curvature = 1 / R (0.1m) Longitudinal slope (0.1m) Average slope (20m) Surface laser (17 tracks, 0.1m) Advantages: The only data set that gives us information under two meter wave length

11 Objectives & Challenges Objective: Reduce large amounts of measured data into an analytic parametric format - Use different data sets (data fusion) - Real time systems (motion simulators) - Approach: Find a golden medium Objective: Recreate the measured road as realistic as possible - A person who is well familiar with the way must recognize it in the simulator! - Reproduce data ranging från microscopic to macroscopic levels - Driver's impression of alignment, unevenness and surrounding terrain is important - Vehicle model should respond appropriately Objcetive: Develop and document a methodology - Stable generalized method with little need for hand finishing - In a short time (<1 day) to model roads of interest Challenge: Conflicting requirements - Demands for reduced data sets deteriorates the road realism - Demands for reduced data sets is contrary to the requirement of correct geographical position - Motion system is sensitive to non continous curve radius Challenge: Validation - What is the correct position, height,...? - Which accuracy should we expect - What can we expect? Challenge: Algorithms - Generated road alignment must be geographically synched with elevation data

12 Modelling of Töllsjö vägen Used in Wicta lab for Curve Advisor software evaulation Curvy, hilly, crappy road

13 Plan view road alignment in XY plan use NVDB GPS points non uniformly distributed

14 Plan view Crucial question: How to create spline of geometric primitives from GPS points without loosing accuracy? Our answer: Sketching Clothoid Splines Using Shortest Paths Baran I, Lethinen J. and Popovic J. (2010) Sketching Clothoid Splines Using Shortest Paths Computer Graphics Forum Volume 29, Issue 2, pages

15 Plan view

16 Plan view Result: Splines of lines, curves and clothoids 6 Error less than 1 m! 4 x x 10 4 Yellow is spline, red dots are NVDB gps points

17 BAO Bisection Adaptive Optimization developed at VTI or Benny Andersson Orchestra (former ABBA member) Elevation - Use generated plan view chord line - Make bilinear interpolation in heightmap each 0.1 m - Generate cubic spline from sampled points A n = interp(s n ) with BAO algorithm

18 Crossfall - Use RST s 17 laser tracks and lateral inclinometer - Lateral sampling of road surface and slope each 0.1 m - Make linear interpolation of cross-section to get lateral slope (lateral profile) - Generate cubic spline from sampled points A n = interp(s n ) with BAO algorithm BAO Bisection Adaptive Optimization developed at VTI or Benny Andersson Ocrhestra (former ABBA member)

19 Road surface unevenness - Residual of laser tracks (difference between measurments and modelled crossfall) - Middle to high frequency noise to patch onto road surface - Export as opencrg and connect to OpenDRIVE database

20 Resulting opendrive database Modelled road Photo of real road Graphics generated by Dynagraph

21 Thank you for your attention! Questions and discussion? Mattias Hjort Senior Research Leader Ph.D Comutational Physics Laban Källgren Research Engineer M.Sc. Applied Physics and Electrical Engineering Jonas Andersson Hultgren Research Engineer M.Sc. Computer Science and Engineering Erik Olsson Research Engineer M.Sc. Applied Physics and Electrical Engineering