Vehicular accidents are a common occurrence in many parts of the world and, unfortunately, vehicular accidents, even at low impact and separation velocities, are often accompanied by injury to vehicle occupants. It is often desirable to reconcile actual occupant injury reports to a potential for energy based on vehicular accident information. Trained engineers and accident reconstruction experts evaluate subject vehicles involved in a collision, and based on their training and experience, may be able to arrive at an estimated change in velocity for each the subject vehicles. The potential for injury can be derived from knowledge of the respective change in velocity for the subject vehicles.
However, involving trained engineers and accident reconstruction experts in all collisions, especially in the numerous low velocity collisions, is often not cost effective. Other techniques also have concerns. For example, energy-based methods commonly employed to assess collision severity require an estimate of the deformation to both vehicles involved in the collision. For some insurance carriers, it is not part of their standard claims process to collect post-accident photographs for a third party vehicle. For these carriers, the information about the physical damage to the third party vehicle may be limited to what can be inferred from a police report or a repair estimate, which can prevent use of certain techniques.
In one aspect, a method comprises: receiving, in an impact severity determination logic of a computer system, first information for a first vehicle involved in a collision and second information for a second vehicle involved in the collision, where crush depth information is not available for the second vehicle; initializing, in the impact severity determination logic, a Monte Carlo simulation; calculating, in the impact severity determination logic, for each of a plurality of iterations of the Monte Carlo simulation, a collision force on the first vehicle based at least in part on the first information; calculating, in the impact severity determination logic, for each of the plurality of iterations of the Monte Carlo simulation, a crush depth for the second vehicle based at least in part on the calculated collision force on the first vehicle and the second information; calculating, in the impact severity determination logic, for each of the plurality of iterations of the Monte Carlo simulation, first total energy absorbed by the first vehicle based on the first information including first crush depth information for the first vehicle, and calculating second total energy absorbed by the second vehicle based on the calculated crush depth and the second information; calculating, in the impact severity determination logic, for each of the plurality of iterations of the Monte Carlo simulation, a first impact severity for the first vehicle using the first total energy, and calculating a second impact severity for the second vehicle using the second total energy; and reporting a range of the first impact severity for the first vehicle and a range of the second impact severity for the second vehicle based on the Monte Carlo simulation, via an output device of the computer system.
In another aspect, a system comprises: an input processing logic to receive first information regarding a first vehicle involved in a collision and to receive second information regarding a second vehicle involved in the collision, the second information not including crush depth information for the second vehicle; a Monte Carlo simulation module, a report generation logic to generate a report including the first estimated impact severity for the first vehicle and the second estimated impact severity for the second vehicle, for each of a plurality of iterations of a Monte Carlo simulation; and a report output logic coupled to the report generation logic to output the report to an end user.
In an example, the Monte Carlo simulation module has one or more constituent logics, including a collision force determination logic to calculate a collision force on the first vehicle based at least in part on the first information; a crush depth calculation logic to calculate a crush depth for the second vehicle based at least in part on the calculated collision force on the first vehicle and the second information; an energy absorption calculation logic to calculate first total energy absorbed by the first vehicle based on the first information (including first crush depth information for the first vehicle), and to calculate second total energy absorbed by the second vehicle based on the calculated crush depth and the second information; and an impact severity calculation logic to calculate a first estimated impact severity for the first vehicle using the first total energy and a second estimated impact severity for the second vehicle using the second total energy.
In yet another aspect, a non-transitory computer readable medium comprises instructions that when executed enable a computer system to perform a method comprising: receiving first information for a first vehicle involved in a collision and second information for a second vehicle involved in the collision, where crush depth information is not available for the second vehicle; initializing a Monte Carlo simulation; calculating, for each of a plurality of iterations of the Monte Carlo simulation, a collision force on the first vehicle based at least in part on the first information; calculating, for each of the plurality of iterations of the Monte Carlo simulation, a crush depth for the second vehicle based at least in part on the calculated collision force on the first vehicle and the second information; calculating, for each of the plurality of iterations of the Monte Carlo simulation, first total energy absorbed by the first vehicle based on the first information including first crush information for the first vehicle, and calculating second total energy absorbed by the second vehicle based on the calculated crush depth and the second information; calculating, for each of the plurality of iterations of the Monte Carlo simulation, a first impact severity for the first vehicle using the first total energy, and calculating a second impact severity for the second vehicle using the second total energy; and reporting a range of the first impact severity for the first vehicle and a range of the second impact severity for the second vehicle based on the Monte Carlo simulation, via an output device of the computer system.
In various embodiments, a system is configured to perform a biomechanical analysis of a vehicle collision when physical damage to one of the vehicles cannot be objectively estimated from post-accident information, such as photographs, report information or so forth. As described herein, an Unknown Damage Analytics (UDA) technique may be used to accurately and readily determine various factors regarding an accident and vehicle for which information is not known (an unknown damage vehicle).
An UDA algorithm as described herein leverages Newton's third law of motion, which states that: for every action, there is an equal and opposite reaction. In a two-vehicle collision, this means that the collision force acting on the second vehicle is equal in magnitude and opposite in direction to the collision force acting on the first vehicle:
{right arrow over (F)}2=−{right arrow over (F)}1,|{right arrow over (F)}2|=|{right arrow over (F)}1|=F Equation 1
Embodiments may calculate a collision force on a first vehicle (for which at least certain information is known) using the vehicle's structural characteristics (stiffness), and a good estimate of deformation (referred to herein also as crush). In an embodiment, this deformation estimate may be obtained from post-accident photographs, and in a particular embodiment may leverage photogrammetric and other techniques such as disclosed in U.S. Pat. Nos. 6,381,561 and 8,239,220, the disclosures of which are hereby incorporated by reference.
The UDA algorithm uses a linear stiffness model in which force per unit width is proportional to crush depth:
In Equation 2, C is crush depth, A and B are vehicle stiffness coefficients derived from staged crash tests, and W is the width of the crush area. The total force magnitude is calculated by integrating this function over the crush area:
If the crush is constant over the crush area, it can be shown that:
F=W(A+BC) Equation 4
In an embodiment, the crush area can be approximated by dividing it into a series of equal-width crush zones, each having a uniform crush depth, as shown in
Using this approximation for crush profiles, the integration of Equation 3 becomes:
where Cavg is the average crush depth for a series of N crush zones.
In an embodiment, the energy required to produce a crush profile is calculated by doubly integrating the force over both the crush depth and crush width:
E=∫∫(A+BC)dCdW Equation 6
E=∫(AC+½BC2+G)dW Equation 7
Here, G, the threshold force, is the maximum amount of force that can be applied to the vehicle without causing any permanent deformation. G is given by:
For a uniform (constant) crush profile, it can be shown that:
Therefore, for a crush profile approximated by equal-width crush zones, each with a uniform crush depth, the total energy is the sum of the individual zone energies:
Equation 10 reduces to:
E=GW+(A+BCcg)Area Equation 11
where Area is the area of the crush profile given by:
and Ccg is the centroid of the crush profile, given by:
In an embodiment, it is assumed that both vehicles' crush profiles have the same width (W, as shown in
In one embodiment, the basic operation of the UDA algorithm is as follows:
In Equations 15 and 16, (M1, M2) are the masses of each vehicle and (E1, E2) are the damage energies of each vehicle. Note that in the above outline, subscript 1 represents the known damage vehicle and subscript 2 represents the vehicle with unknown damage.
Referring now to
As seen, method 100 begins by receiving first information from a known damage vehicle (block 110). Such information may include, in an embodiment, vehicle identification information, primary point of impact information, pre-impact motion and collision deformation information. In addition, second information may be received regarding the unknown damage vehicle (block 120). This information may include, at a minimum, vehicle identification information, primary point of impact, pre-impact motion, and approximate area of damage information.
From this information, control passes to block 130 where a collision force may be determined on the known damage vehicle. Details regarding this determination are described above. Next, control passes to block 140 where a crush depth may be determined for the unknown damage vehicle. More specifically, this crush depth determination may be based on the known damage vehicle collision force and unknown damage vehicle parameters. Thereafter, control passes to block 150 where a total energy absorbed in the collision on each of the vehicles may be determined. In an embodiment, this determination may be based on crush depth (for both vehicles) and the corresponding vehicle parameters. From this total energy absorbed information, control passes thereafter to block 160 where an impact severity for each of the vehicles may be determined based on the total force. Note that this collision severity may further be used for additional accident analysis determinations, such as performing a biomechanical analysis with regard to occupants of one or more of the vehicles. Understand while shown at this high level in the embodiment of
Thus using collision severity as determined as described herein, additional accident analysis determinations may be performed, such as performing an injury causation analysis with regard to occupants of one or more of the vehicles. Injury causation analysis is the application of medical and physical science in order to assess how injuries are caused in accidents. In some cases, the assessment may determine whether a given medical condition was or was not caused in an accident. In the context of vehicular accidents, the process typically involves a combination of evaluations performed in the scientific disciplines of vehicle dynamics, occupant kinematics, biomechanics and medical analysis. Injury causation analysis is possible because both the vehicle and the occupant respond predictably to forces and stresses in accordance with the basic physical principles contained in the laws of motion described by Newton. Once the occupant kinematics and the range of magnitude and direction of the biomechanical stresses in a specific accident are understood, injury potential can then be assessed using analytical and descriptive techniques of clinical medical science in conjunction with available information about the range of human tolerance to physical forces. The range of human tolerance to biomechanical stresses is informed by experimental impacts involving human volunteer subjects, field accident studies and published human impact tolerance criteria. Embodiments may thus use the vehicle collision information determined as described herein to determine likelihood and/or range of potential injuries, and so forth.
As described above, certain information is used to perform a UDA algorithm in accordance with an embodiment. Example information used is shown below in Table 1. As shown, year, make, and model are obtained for both vehicles, and certain parameters regarding the vehicles can be obtained using this information. For example, mass information may be obtained and used (as described above) because collision severity is directly proportional to the mass ratios of the vehicles involved. The primary point of impact (front, rear, side) also may be obtained for both vehicles. The vehicle stiffness characteristics are based on the vehicle model and the primary point of impact. To calculate the principal direction of force (PDOF), the pre-impact motion for both vehicles may be obtained (moving forward/backward or stopped). For the vehicle with known damage, a reasonable estimate of crush or contact damage is used (which may be obtained as described above). For the vehicle with unknown damage, simply an approximate area of damage is obtained. This approximate area may be inferred from the accident description and/or sketches on a police report.
The UDA algorithm makes the following assumptions: bumpers are aligned in front-front, front-rear, and rear-rear type collisions; the damage width for the unknown damage vehicle matches the damage width of the vehicle with known damage (note also that the damage width is the extent of crush or contact damage as measured parallel with the ground and perpendicular to the primary point of impact (as seen in
To account for uncertainties in the variables used in the UDA algorithm, in some embodiments a Monte Carlo simulation is performed. In the Monte Carlo simulation, the steps of the UDA algorithm are conducted a predetermined number of times (e.g., between approximately 10,000 and 50,000 runs, which may be user controlled). For each of these individual runs of the UDA process, each input variable is randomly sampled within a range of its nominal value. This results in a distribution of ΔV values for both vehicles, which may be stored in a given non-transitory storage and further output to an end user entity, such as via display of a report on one or more displays of a given computer system.
Referring now to
Still with reference to
If additional simulations are determined to be performed, control passes to block 250 where a collision force may be calculated on the known damage vehicle based on crush information and stiffness characteristics of the vehicle. Thereafter, control passes to block 260, where a crush depth may be calculated for the unknown damage vehicle based on the calculated collision force for the known damage vehicle and information of the unknown damage vehicle (including stiffness characteristics of the vehicle).
Referring still to
The following example demonstrates how a UDA algorithm in accordance with an embodiment can be applied to a typical accident scenario. Assume a 1997 Mercedes C230 sedan rear ends a 2000 Ford F150 pickup. The Mercedes vehicle is owned by an insured party, and herein is the first party vehicle. There is a repair estimate and photographs of the Mercedes. The Ford vehicle is a third party vehicle and there are no post-accident photographs. Information regarding both vehicles (year, make and model) is entered into a computer system including impact severity determination logic as described herein, via a user input device. Assume that the primary point of impact for the Mercedes is “front” and the primary point of impact for the Ford is “rear”. The police report suggests that this is an inline rear end collision with no offset (as shown in
The post-impact photographs of the Mercedes suggest a crush pattern of 1-3 inches across the front end. The police report suggests that some damage extends across the full width of the rear end of the Ford. The user enters the crush profile for the Mercedes and indicates the approximate damage area for the Ford.
When the user runs the analysis, the UDA algorithm calculates the collision force on the Mercedes, given its stiffness characteristics and the crush profile. Using this force value and the stiffness characteristics of the Ford, the algorithm then calculates the crush depth to the Ford required to satisfy Newton's third law. Finally, the algorithm calculates the total energy absorbed in the collision, and the collision severity for each vehicle. This collision severity, which may be part of a report provided to a user, may be used as the basis for a biomechanical analysis for occupants of one or both of the vehicles.
Referring now to
Impact severity determination logic 300 includes an input processing logic 310. In various embodiments, input processing logic 310 is configured to receive user input of information regarding a collision, including the various information available for the known damage vehicle and the unknown damage vehicle. Still further, input processing logic 310 may manipulate and process this information into an appropriate format for use in a Monte Carlo simulation module 320. In the embodiment shown, Monte Carlo simulation module 320, which in embodiments may be implemented as one or more processors, microcontrollers, signal processors, or so forth configured to execute instructions stored in a non-volatile storage medium, includes various logics. Specifically, Monte Carlo simulation module 320 includes a collision force determination logic 322, a crush depth calculation logic 324, an energy absorption calculation logic 326, and an impact severity calculation logic 328. These various constituent logics of Monte Carlo simulation module 320 may be configured to perform a UDA, as described above, e.g., with regard to
Upon completion of a Monte Carlo simulation, the simulation results, which may include various calculated values, including collision force, crush depth, energy absorption, and impact severity, may be provided to a report generation logic 330. Report generation logic 330 may be configured to generate a report. In an embodiment, the report may include various entries each associated with a given run of the Monte Carlo simulation. Thereafter, report generation logic 330 provides the generated report to a report output logic 340. In various embodiments, report output logic 340 may be configured to store the report in a non-transitory storage, such as a mass storage device of a system, e.g., a server system of an insurance company or other end user entity. Still further, report output logic 340 may be further configured to provide the report in a human-readable format for display on an output device, such as a display of the system. Understand while shown at this high level in the embodiment of
Referring now to
As further shown in
Still with reference to
While the present invention has been described with respect to a limited number of embodiments, those skilled in the art will appreciate numerous modifications and variations therefrom. It is intended that the appended claims cover all such modifications and variations as fall within the true spirit and scope of this present invention.
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Number | Date | Country | |
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20160178465 A1 | Jun 2016 | US |