The VC3000DAQ is a data acquisition system which incorporates a two-axis accelerometer. In October 2004, extensive testing at the Minnesota Highway Safety Center at St. Cloud State University demonstrated that the VC3000 with version 2.14 of the Vericom firmware was accurate to within one percent for acceleration, speed, time, and distance. The accelerometer reports the instantaneous acceleration at a rate of 100 Hz (i.e., 100 times each second). The onboard computer records the data at the sample rate while continuously displaying the instantaneous rate. With a detailed record of acceleration over time, integration (a mathematical process typically learned in Calculus) can provide data regarding speed and distance.
In earlier models of recording accelerometers by other manufacturers (and including some presently available devices), the integration of the recorded values over the elapsed time would not yield results consistent with known initial speed and/or known distance over which the deceleration occurred. Factors responsible for those discrepancies included overdamping of the accelerometer and the inability to segregate the vehicle's suspension effects from the gross deceleration of the vehicle. (In almost all circumstances, the VC3000 is mounted in the passenger compartment. The frame of the vehicle and certain other components are generally the only ones not affected by the suspension.) Repeated testing of the Vericom Computers VC3000 has demonstrated its accuracy and repeatability.
My charge for the VC3000 is $100 per use. If I use one of my personal vehicles for skid or sideslip testing, there will be a $25 per test additional charge for adverse wear and tear. Generally, three skid tests should be conducted at a given location with an exemplar or similar vehicle to provide a data set which will thoroughly substantiate the use of a drag factor value or drag factor range.
Due to my not previously having a device with this accuracy, I have been forced to use tabulated values for ranges in conducting my reconstructions. Now that I have this device, I will be able to narrowly define a range of drag factors for most collision reconstructions and will have the scientifically derived data set to prove the validity.
If you wish to return to the home page, you may use this link.