By: Jack Murray, Jr., CLI
It used to be that any animation we did had to be done by an outside
studio and usually the cost made it prohibitive for all but the biggest
cases. Now, there are several packages available that give you the capability
of doing your own animated reconstruction presentations.
Vehicle Dynamics International, 2600 Forum Blvd., Suite C, Columbia, Missouri,
65203-5431 has a software package (LVDS), developed to investigate the complex
dynamic responses of light vehicles in a variety of maneuvers including
skidding, spinning, and rollover. LVDS utilizes state of the art techniques
inmodeling tire behavior, tire roadways interaction, suspension effects,
steering control systems and vehicle dynamics. A3-D non-linear vehicle model
of intermediate detail is generated according to used specifications, and
properly accounts for vehicle forward, lateral, vertical, roll and directional
dynamics. The program is menu driven and fully interactive and allows the
user to reconstruct and investigate any vehicle motion.
The LVAS Software package , is a package of micro computer programs developed
to provide state of the art accident animations utilizing data obtained
from LVDS or other simulation programs. Any three dimensional vehicle motion
can be animated and played back in real time, in slow motion, or frame by
frame, on color and monochrome monitors. LVAS software programs enable the
user to quickly assess and analyze the overall response of all types of
light vehicles in critical accident situations. This is particularly useful
in visualizing the time history of response variable for a given vehicle,
quickly and reliably.
Engineering Dynamics Corporation, 8625 SW Cascade Boulevard, Suite 200,
Beaverton, OR 97005, has a package of five vehicle dynamics programs, called
EDVAP.
While each program is suited to a particular need, all the programs have
the same menu structure. The user responds to a series of questions regarding
the vehicles and accident site. The results are then displayed in a format
requested by the user. Some of the capabilities include high resolution,
color accident site drawings and vehicle/occupant motion. Intercommunication
of data between programs allows merging of results from input, output, and
graphics, automatic loading of typical vehicle and occupancy information
and on-line help prompts.
Scale Drawings
Many of us have been doing scale drawings for years without any kind of
computer aide, but like everything else, this area is now so much easier
and more efficient with the use of computers you are almost forced into
their use.
I was never very good at college drafting courses, but with a set of K &
E pens, scribes, lettering templates, etc., I survived. Depending on the
amount of detail that was necessary, a considerable amount of time would
be spent laying out streets, noting final resting place of vehicles, making
sure you got the correct scale and everything "fit." The original
would be in pencil and then you had to go back over it in ink. One little
slip, and you had a real time problem on your hands. Clients don't pay for
your carelessness.
With any number of CAD programs on the market, you can take your same measurements,
do a rough field sketch, take a good set of photos and then go back and
put together a professional quality diagram in about a third of the time
it used to take and it's generally a lot more accurate. Here, more than
anywhere else, the finished product is a reflection of your accuracy in
developing the input. Never has the "garbage in, garbage out,"
theory been more prevalent.
At present we do our measurements, shoot the film, and take our field work
to a professional engineering firm that produces court size scales, as well
as extra 8 x 10s for depositions, interviews with witnesses, etc. This is
cheaper for us and saves a lot of time. Ultimately, we will probably be
doing our own CAD work, but for the moment, we farm it out. A good suggestion
for those of you who do not do a high volume of this kind of work.
The actual measurements at a site are now a lot simpler with the use of
laser guns and laptop computers. Laser Technology, Inc., 7399 South Tucson
Way, Englewood, CO 80112 has a package called LTI20-20 which is basically
a laser gun that you use with your own laptop or home-based computer. The
gun is guaranteed to be accurate plus or minus six inches, working on non
cooperative targets for easy triangulation. It has a non detectable lazer
beam, is lane selective and has computer interface technology available.
I have worked with an engineer here in the Dallas area who uses on of these
units and they are really neat for very complex intersections, and/or cloverleafs.
They can save you an unbelievable amount of time and their accuracy is superb.
The only problem is the cost: about $8,000 plus the laptop. Here again,
budget is a serious consideration. We just don't do enough drawings requiring
this kind of usage to justify owning one. It is much simpler and economically
more feasible to subcontract the work.
Everything we have discussed here is geared to IBM compatibles as that is
the format with which I am most familiar. I know there are programs out
there for MacIntosh, like Collision Calculator produced by Joe Coyle &
Associates, 5694 Mission Center Road, Suite 328, San Diego, CA 92168. This
package advertises as being able to calculate 65 separate equations that
instantly calculate all of the things that STARS does and is priced considerably
less, under $100.00.
Unfortunately, space limitations prevent my going into more detail about
the listed products and we have left out a lot of other really good products
in the market place. Plans for our new book call for reviewing more equipment,
and in greater detail.
Jack W. Murray, CLI, has been a member of NALI since 1984. He is the author
of several books on investigative subjects. Murray may be contacted at:
3942 Rochelle, Dallas, TX 75220. Phone: (214)902-9156.
JACK MURRAY WILL BE SPEAKING AT THE 96 NAIS PI CONVENTION
REVIEW JACK MURRAY BOOK ON ACCIDENT
INVESTIGATION
REVIEW JACK MURRAY BOOK ON INVESTIGATIVE PHOTOGRAPHY
REVIEW JACK MURRAY BOOK ON SEX CRIMES INVESTIGATION
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