Page 1 of 1

msmac3D Reconstruction of 17th Street Dental Office Crash

Posted: Sat Jan 20, 2018 3:08 pm
by MSI
Another update of our recontruction
This is in addition to our preliminary msmac3D We've added another preliminary based on cloud scan of median and using billboard option to allow pictures to be inserted into the video (the cloud scan was only B&W)
so we got a picture of the front of the dental office The entire street could not be captured because the median had trees. We will soon post up a HOWTO demo as this recon and video to demonstrate it only take 10 minutes or so to create from scratch.

Re: msmac3D Reconstruction of 17th Street Dental Office Crash

Posted: Mon Jan 22, 2018 6:37 am
by MSI
The following are questions and answers posted up to our McHenry Software Linkedin on this msmac3D simulation:
Q: Nice work! How much time is required to calculate this sequence?
  • A: if you review our videos on HOW TO it's a very quick process:
    • 1) grab vehicle specs from our database,
    • 2) add in weight for occupants,
    • 3) grab 3D model from our library,
    • 4) bring in the cloud scan or DXF or manual terrain information,
    • 5) bring in a google overhead map to drape on 3D data,
    • 6) then for this case simply select approximate speed and location for start of simulation and simulate.
    • 7) the simulation time can be near real time so for 5 second simulation takes 5 seconds or so, at most 30 to 60 seconds
    The whole initial process takes 5 to 10 minutes
    • Then varying the speed and starting location for the vehicle till you get an approximate match of the impact location on the front of the building and you're done!
      In most cases you'd also have tire marks, impact/rest locations, damage extent and locations to try to match
    Total time spent approx an hour.
Q: The simulation does a great job illustrating the dynamics of the crash. I have been wondering about it when I saw it on the news. What is the minimum telemetry data that you have to enter for into your SW for the vehicle simulation to run effectively? I ask in light of you comment about the speed potentially being higher. What kind of data do enter for the vehicle damage and the associated energy absorption? It is impressive what can be revered engineered out of the forensic data.
  • A: This is a preliminary reconstruction with the msmac3D simulation program. msmac3D is like running a mathematical full scale test.
    • In this msmac3D simulation we set up the vehicle (based on specs and occupant weight approx) and imported the scan of the median measurements and building locations relative to the median (A colleague quickly scanned)
      We didn't (yet) include modeling the dirt plowing as the vehicle went through the median (a LOT of dirt is flying in the security and Bus videos) The plowing of dirt by the vehicle might vary the forces and moments and change the speed slightly.
      We also haven't examined the vehicle to determine the extent of damage due to the interaction with the median and front of building (not our case, we're just having fun demonstrating capabilities). Please see Introduction: Crash Reconstruction Techniques and Accuracy
Q: What a spectacular crash. Must have been fun setting up the simulation. What type of data can the software output? Can it export positional data for XYZ and Roll, Pitch and Yaw?

  • A: The msmac3D program is a 3D multi-vehicle simulation program which calculates and outputs all information on position(x,y,z), orientation(roll,pitch,yaw), forces, moments, suspension forces, tire positions and orientations, etc for every millisecond it calculates (normal output interval is 0.033 which is for real time display 30 frames per second) The 3D graphics merely an illustration of the vehicle. You can also look at charts too of the time history data. We've also used the program to design a vehicle stunt(as a validation of the model), the spiral jump used in the James Bond movie and more recently the Jaguar e-pace rollout stunt

Re: msmac3D Reconstruction of 17th Street Dental Office Crash

Posted: Wed Jan 24, 2018 4:28 pm
by MSI
Another minor tweak...folks asked: can you add trees and buildings? yes. Folks wanted to see different speeds and multiple exposure...yes and yes.

Re: msmac3D Reconstruction of 17th Street Dental Office Crash

Posted: Thu Jan 25, 2018 8:56 am
by MSI
msmac3D is SIMULATION! See beow for charts of the time history of accelerations, elevation, & roll & pitch angles which are calculated for every millisecond and are a standard output of our msmac3D program in CSV format (we have a charting function too!)
xyz accel.jpg
xyz accel.jpg (24.15 KiB) Viewed 2976 times
CG Z location.jpg
CG Z location.jpg (12.74 KiB) Viewed 2976 times
roll pitch.jpg
roll pitch.jpg (16.87 KiB) Viewed 2976 times