Once it is determined that the data is representative of the physical evidence of the crash, the evaluation of other factors such as timing and position of a vehicle prior to impact or whether a vehicle stopped at a signal light may be made.
We utilize the Crash Data Retrieval (CDR) and the Engine Control Module (ECM) tool kits to forensically image module information and analyze its data.ĭata collected from passenger vehicles and heavy trucks is utilized to corroborate with the results of the accident reconstruction. Gathering evidence has evolved with increasingly more information than just roadway marks and vehicle damage. Vehicle speed, engine speed, throttle percentage, cruise control, braking and other variables are typical parameters reported during a crash involving a heavy truck. The ECM is also capable of recording data during a crash event. Heavy trucks are equipped with Engine Control Modules (ECM) that monitor and report conditions of the truck such as fuel consumption, miles driven and oil pressure. Other vehicles may record crash related data by other means such as the Powertrain Control Module (PCM) in some Ford vehicles. The data may include crash severity (Delta-V) as well as pre-crash data such as vehicle speed, engine speed, throttle position and brake application. This means that the airbags do not have to be deployed during a crash for there to have been data recorded. The EDR may record deployment or non-deployment events. The data may be retrieved after a crash using a commercially available tool. The EDR is capable of recording data during a crash event. Most passenger vehicles are equipped with airbag systems that are controlled by modules that contain an Event Data Recorder (EDR).
These travel directions and distances are determined from evidence collected during the site inspection and from the digital mapping. The calculation for momentum is based on the before and after travel directions of the vehicles and the distances traveled after impact. However, the after impact momentum remains equivalent to the before impact momentum. In a collision, the colliding vehicles exchange momentum. Momentum is defined as the vehicle’s mass multiplied by its velocity. MomentumĪ momentum analysis is typically performed to compute the impact velocities of the vehicles. The stiffness factors are derived from crash tests. The stiffness factors vary from vehicle to vehicle as well as the involved part of a vehicle such as the rear, front or side. The amount of crush and direction of material deflection is determined from the vehicle inspection. The energy methods employ an algorithm that utilizes the amount of crush to the vehicle, the direction of material deflection and the stiffness factors associated with the vehicle’s damaged structure. Delta-V is computed utilizing energy methods. The severity of a collision is defined in terms of Delta-V, or change in velocity.
0 kommentar(er)
