SMACITERTM  Automatic Iteration of M-SMAC  last update 06/28/2013

As part of our research related to the Automatic Iteration of SMAC:

What is SMACITER?

In prior studies researchers were interested in automating the process by which SMAC is used to reconstruct an accident. As any user of SMAC is aware, SMAC requires an initial approximation of the impact speeds and positions of impact. And with SMAC you can sometimes get close by 'engineering standards' but then sometimes spend hours or days on iterative runs try to match 'as best as possible' the physical evidence.

The prior research was constrained by computer time and resources. The prior research projects were performed on mainframe computers where all use of computers included payment for CPU time and memory resources. SMAC computer runs on mainframe computers normally took 5-10 minutes or so and required 600K or so of memory (an expensive and computational intensive demand for computers at that time!). Therefore the research was extremely constrained in number of runs performed to iterate to a solution due to budget concerns.

Today with gigahertz Pentium computers and unlimited memory, aside from the initial cost of the computer, the cost per SMAC run is virtually free and the time for a run is measured in seconds rather than minutes. The expense for a SMAC run is the time and effort required to iterate SMAC to an acceptable solution. Therefore with the creation of an intelligent iterative procedure which can quickly and efficiently iterate to the 'best match' of the physical evidence, we are entering a new phase of accident reconstruction.

How will SMACITER help?

Quickly and efficiently you can use the iterative procedure to determine the best match for a given set of inputs and then test your reconstruction with various constraints (e.g., limit certain vehicle speeds, make certain assumptions for inputs, etc.).

Currently with this program we automatically iterate the speeds and impact positions of a SMAC run to try to match as best as possible the target damage measurements and Positions of Rest.

What is needed to run SMACITER?

• Trajectory measurements
• The approximate positions and orientations of the vehicles at impact
• The measured positions and orientations of the vehicles at rest
• Damage measurements:
• Damage width
• Damage depth
• Damage area
• Vehicle Information
• Information on driveline drag, damage effects and steering effects
• Vehicle types, makes, model, approximations of vehicle loading

This is all the information normally created to setup a m-smac  input file. Additional inputs have been added  which includes the damage measurements, the positions of impact and rest (see m-smac input cards 80, 85 and 87  ). The program can then be used to quickly and efficiently test the sensitivity of various variables on the match of the physical evidence.

Please let us know if you would be interested in this technology. We are interested in feedback you have on the topic. Please email us with your questions and/or comments.

We published and presented our research results at the 2003 SAE International Congress in a paper entitled SMAC2003- The Automatic Iteration of SMAC

Thank you for your interest in McHenry Software, Inc.