RU2501080C1 - Method of checking operating efficiency of system installed on vehicle in configuration of additional equipment for determining time and severity of accident - Google Patents

Abstract

FIELD: information technology.

SUBSTANCE: operating efficiency of a vehicle system is determined by creating a computer model of the vehicle, which provides the required confidence level, and performing numerical simulation of processes occurring in the vehicle during different accident scenarios.

EFFECT: checking operating efficiency of a system at the development stage without full-scale testing.

15 cl, 4 tbl, 8 dwg

Description

FIELD OF THE INVENTION

The invention relates to the field of development of automotive systems designed to determine the moment of an accident and the severity of an accident in an automatic mode. These systems can be used in the construction of emergency call systems and other systems designed to ensure transport safety.

The invention is used to verify the effectiveness of the operation of an automotive system at the stage of its development, installed on a vehicle (TS) in the configuration of additional equipment to determine the moment and severity of an accident in a traffic accident (accident).

State of the art

Known automotive systems designed to determine the moment and severity of an accident in automatic mode, installed on a vehicle:

- in the configuration of standard equipment, in which the system is installed on the assembly line of the vehicle manufacturer;

- in the configuration of additional equipment, in which the system is installed at service (installation) stations authorized by the established procedure to carry out the indicated works, or at the site of the vehicle manufacturer or dealer of the vehicle manufacturer after the vehicle is manufactured (manufactured) at the main assembly plant.

The developers of automotive systems designed to determine the moment and severity of an accident in an accident have an important task - to develop a method for determining the moment and severity of an accident and to test created automobile systems in terms of verifying the effectiveness of their functioning.

At present, both in Russia and abroad there are no uniform standardized criteria characterizing the events that occur during the operation of the vehicle, leading to a high probability of significant damage to the life and health of people in the vehicle cabin during an accident. These standards require the use of full-scale tests.

Overseas, a series of standards have been developed that regulate full-scale testing of a car, with the aim of assessing its safety for both the driver and passengers, and for pedestrians. These include:

- New United States Car Assessment Program (USNCAP);

- New European Car Assessment Program (EUNCAP);

- New Japan Car Assessment Program (Japan New Car Assessment Program-JNCAP);

- Federal safety standards TS (Federal Motor Vehicle Safety Standards);

- Tests of The Insurance Institute for Highway Safety, IIHS.

In accordance with the EUNCAP standard, the vehicle safety rating is established based on the results of field tests designed to determine the behavior of the vehicle in terms of ensuring:

- protection of adult passengers;

- child protection;

- pedestrian safety;

- active vehicle safety.

To calculate the EUNCAP safety rating, it is necessary to conduct and process the results of the following field experiments:

- frontal crash test: 64 km / h, overlap - 40%, deformable barrier;

- lateral crash test: 50 km / h, deformable barrier;

- Imitation of a pedestrian collision at a speed of 40 km / h. During the “shelling” of the bumper, hood and windshield with dummies of the head and legs, the overloads of the “knees”, the bending moments of the “hips” and the criterion for injuring the “head” —HIC;

- hit the pillar at a speed of 29 km / h (only for cars with special pillows to protect the head);

To calculate the rating in accordance with the IIHS methodology, it is required to conduct and process the results of the following field experiments:

- frontal crash test: 64 km / h, at an angle, deformable barrier;

- lateral crash test: 50 km / h, deformable barrier;

- a blow to the rear of the car: 32 km / h;

- bumper tests: front and rear collisions across the entire width at a speed of 9.6 km / h, as well as front and rear collisions of the corner at a speed of 4.8 km / h;

- roof strength tests.

To conduct tests in accordance with these standards, it is necessary to purchase vehicles of the corresponding category, anthropomorphic mannequins (Hybrid III, Crabi for front crash tests, ES-2, SID-II for side crash tests, BioRID for rear collisions), which allow with a high degree of accuracy to determine the behavior of the human body in a collision and to assess injuries and their severity. After testing, the front crash test, side crash test, and a hit in the post state of the vehicle after the test does not allow the use of this vehicle for subsequent tests.

The use of models of mannequins allows you to accurately determine the likelihood of injury and their location on the human body. Including to assess the possible injury caused by subsequent collisions. The disadvantages include the fact that the analysis is carried out on a mannequin that does not reflect the complexion of a particular person. Most often, an anthropomorphic mannequin has some average statistical characteristics (height, weight). The position of the dummy is strictly regulated by the rules, however, in a real situation, the passenger can be located in the vehicle seat differently, in which case the movement of the body and the collision point will be different. Despite this, mannequins are widely used in testing, and their characteristics are constantly improving, allowing you to simulate the work of muscles, ligaments, and evaluate injuries of internal organs.

In addition, during testing, in accordance with the above standards, the vehicle speed and other test parameters remain unchanged, which limits the ability to determine the effectiveness of the system to determine the moment and severity of an accident when circumstances of an accident occur, including changes in vehicle speed and trajectory before an accident; vehicle collision angle with a fixed obstacle; the angle of collision of the vehicle with other vehicles involved in the accident; speeds of other vehicles involved in an accident; the degree of overlap in the collision of several vehicles involved in an accident, and other parameters.

All these standards require expensive full-scale tests involving certified organizations, which is a significant limitation when solving the problem of verifying the effectiveness of the system installed on the vehicle in the configuration of additional equipment to determine the moment and severity of the accident.

SUMMARY OF THE INVENTION

The objective of the invention is to determine the efficiency of the automotive system at the stage of its development, installed on the vehicle in the configuration of additional equipment, to determine the time and severity of the accident.

The task is achieved by creating a computer model of the vehicle, which provides the necessary level of reliability, and by numerically simulating the processes occurring in the vehicle under various accident scenarios, various speeds of the vehicle, the trajectory of the vehicle, the angle of collision of the vehicle with fixed obstacles, the angle of collision of the vehicle with other vehicles involved in an accident; speeds of other vehicles involved in an accident; the degree of overlap in the collision of several vehicles, etc.

The invention allows to reduce financial costs allocated for testing by at least 5 times due to the use of numerical modeling tools and eliminating the need for full-scale tests at the development stage with the involvement of certified organizations.

The proposed method is recommended to be used at the stage of development of automotive systems designed to determine the moment and severity of an accident installed on vehicles in the configuration of additional equipment, followed by full-scale tests at the final stages in order to confirm the results of the numerical simulation.

The invention is carried out by sequentially performing the following procedures:

1. Development of a computer model of the vehicle;

2. Determining the moment and severity of the accident, taking into account the technical characteristics and method of installing the system installed on the vehicle in the configuration of additional equipment to determine the moment and severity of the accident;

3. Calculation of the assessment of the degree of danger of acceleration for persons in the vehicle cabin;

4. Determination of numerical modeling tools and preparation of a numerical simulation environment for modeling in accordance with various accident scenarios;

5. Development of a program and methodology for testing to verify the effectiveness of the functioning of the automotive system;

6. Carrying out numerical modeling;

7. Analysis of the results of numerical modeling.

Brief Description of the Drawings

Figure 1 - image of a spatial-geometric model of the vehicle using computer simulation;

Figure 2 - image of the thickness of the vehicle is less than 0.8 mm;

Figure 3 - image of the thickness of the vehicle from 0.8 mm to 1.5 mm;

Figure 4 - image of the thickness of the vehicle from 1.51 mm to 2.5 mm;

Figure 5 - image of the thickness of the vehicle more than 2.5 mm;

6 is a diagram of the installation location of the event detection sensor;

7 is a graph of the Wayne-State curve, which uses information on the nature of the change in acceleration over time at various points in the body of a person inside the vehicle at the time of the accident;

Fig. 8 is a schematic representation of an assessment of a theoretical head impact speed.

The implementation of the invention

The development of a computer model of the vehicle should be carried out subject to the requirement to ensure a sufficient degree of compliance of the results of the numerical simulation of the accident scenario with the results of the corresponding field tests conducted under controlled conditions in accordance with the established program and methodology for field tests.

Most of the car body parts are made from steels of various grades by stamping, or for particularly important parts where high strength is required, by hydroforming. The continuity and composition of the structural element made of steel according to these technologies allows us to consider the material as a homogeneous isotropic medium and to use elastic-plastic models of materials with isotropic hardening taking into account the dependence on the strain rates to describe the stress-strain behavior of steel structures subject to large plastic deformations.

The development of the vehicle model is carried out in accordance with the standards of the Federal Highway Administration (FHWA), the National Crash Analysis Center (NCAC), the National Highway Traffic Safety Administration (NHTSA) and University named after George Washington, USA (The George Washington University - GWU, USA).

In order to ensure the completeness and comprehensiveness of numerical simulation is provided:

- maximum detailing of vehicle models;

- Models are verified to achieve the most reliable similarity between prototypes and real vehicles participating in virtual tests.

When developing a vehicle model, the following are taken into account:

- characteristics of the materials used, taking into account the elastoplastic behavior of the materials and fracture;

- characteristics of the joints of sheet body parts using a mathematical model of welding with a given tensile strength;

- characteristics of the connection of engine elements, brakes, suspensions and some elements of the body (door, hood) using a mathematical model of the bolted connection without taking into account the destruction;

- vehicle tire pressure and vehicle tire grip characteristics.

To implement the invention, it is necessary to create a spatial geometric model of the vehicle (Figure 1), for example, with the following characteristics:

- vehicle weight 1220 kg (total weight 1500 kg);

- main dimensions: height 1660 mm, width 1695 mm, length 4115 mm, base 2410 mm;

- ground clearance 200 mm;

- track front / rear wheels, mm - 1460/1465;

- engine location - front, transverse;

- the sheet metal thickness of the body parts is from 0.5 to 2.5 mm (the metal thickness of the main body parts is selected in accordance with the values of the thickness of the stamped body parts adopted in serial production of the vehicle by the manufacturer) (in figure 2, figure 3, figure 4 , Fig.5 shows the location of the thicknesses of the main elements of the body):

- front suspension - suspension strut, wishbone, wishbone;

- rear suspension - trailing arm, wishbone, wishbone. Permanent four-wheel drive;

- braking mechanisms: front - ventilated discs, rear - drum;

- The model takes into account the door safety bars installed on the car.

- tire size: 215/70 R16 (standard equipment).

The main characteristics of the created computer model of the vehicle are presented in table 1.

Table 1 Number of solid elements (pcs.) Number of nodes (3 degrees of freedom in a node) (pcs.) The total number of degrees of freedom (pcs.) 22661 67983 2640717 The number of shell elements (pcs.) Number of nodes (6 degrees of freedom in a node) (pcs.) 427735 2572734 Number of beam elements (pcs.) 1054

The determination of the moment and severity of an accident occurs when a three-axis acceleration sensor is used as a sensor for determining an accident event.

The technical characteristics of the sensor are accuracy, resolution when measuring the acceleration value along three axes (x, y, z) and the frequency of updating information.

Subject to the use of other sensor (s) as a sensor for determining the event of an accident, the technical characteristics of the sensor are determined based on the constructive implementation of the sensor.

The figure 6 presents the drawing of the vehicle (top view). In the case of using the acceleration sensor as a sensor for determining the event of an accident, this sensor is recommended to be installed along the longitudinal axis of the vehicle (Y = 0) at the most reinforced place of the floor panel, away from deformable parts of the vehicle body. This arrangement provides the application of the same criteria when hitting the right and left sides of the vehicle, which greatly simplifies the configuration of the car system. Recommended installation locations in the sensor vehicle are indicated by points 1, 2, 3 (Fig.6).

When choosing the location of the sensor for determining the event of an accident, it is necessary to ensure sufficient space around the sensor so that significant deformations of the body elements do not damage the sensor and do not adversely affect its performance.

Determining the moment and severity of the accident implies the possibility of executing this procedure in conjunction with the numerical simulation of the processes occurring in the vehicle during an accident, using information from the system that provides numerical simulation as input.

The calculation of the assessment of the degree of danger of acceleration for people in the vehicle’s cabin is based on the analysis of the occupational hazard of passengers and the driver, which is carried out according to two main types of criteria.

The first type includes criteria that use information on the nature of the change in acceleration over time at various points in the body of a person inside the vehicle at the time of the accident. The acceleration curve determines the overload that can lead to bone fractures, as well as other injuries caused by a sharp acceleration of the body. The criteria of the first type are based on the Wayne-State curve, which describes the dependence of the threshold overload value at which concussion does not occur on the duration of exposure.

Figure 7 shows an example, if an overload of 80g (g is the acceleration of gravity) acted on a person for 3 ms, then postponing 3 ms on the abscissa of the Wayne-State curve and 80g on the ordinate, we get a point below threshold curve. Thus, this effect can be considered safe (in accordance with the UNECE Passive Safety Rules No. 12 and 21).

An analysis of the trauma of parts of the human body must be performed according to the following criteria:

- Head injury criterion (Head Injury Criteria - HIC);

- Criterion for neck injury (Neck Injury Criterion - NIC);

- The degree of chest injury (Thorax Trauma Index - TTI);

- Severity Index Severity Index (SI) (determines the severity of a chest injury based on the Wayne State relationship).

A common technique for measuring the likelihood of an injury from overload when hitting a head is the Head Injury Criteria (HIC). The criterion for head injury is the maximum integral of acceleration (deceleration), taken over a period of not more than 36 ms, at which the acceleration reaches its peak value with a certain coefficient. Calculation of the value The head injury criterion is performed on a time interval that includes the first peak of acceleration. If there is a second peak of accelerations on the graph, which is possible due to head contact with car elements, the value “Head injury criterion” should be calculated for this section of the graph.

The second type of criteria requires the use of special sensors that measure displacements, forces and moments at various points of the mannequins used in field tests of the vehicle. Further, by the magnitude of the greatest force impact, the possibility of a bone fracture, rupture of ligaments or muscle damage is determined. These criteria include:

- The normalized neck injury criterion (Normalized Neck Injury Criteria - Nij);

- The magnitude of the moment relative to the occipital part (Total Moment about Occipital condyle - MOC);

- The magnitude of the moment relative to the lower part of the neck (Total Moment - MTO);

- The speed of compression of the chest (Velocity of Compression - VC);

- A criterion for the degree of breast deformity (Thorax Performance Criterion - THPC);

- The amount of compression of the chest (Thoracic Compression Criterion - ThC);

- The value of the offset ribs (Rib Deflection Criterion - RDC).

This method uses mathematical models of mannequins that are fully consistent with their physical counterparts, and are also certified.

In the implementation of the invention, it is possible to use a simplified approach to assess events that occur during operation of the vehicle, leading to a high probability of significant damage to the life and health of people in the vehicle’s cabin, based on the use of ASI criteria (Acceleration Severity Index - acceleration hazard index) and THIV (Theoretical Head Impact Velocity). These approaches consider the behavior of the human body as a freely moving object with an initial speed and acceleration equal to the speed and acceleration of the vehicle until the moment of collision.

The Acceleration Hazard Index ASI is designed to evaluate the measurement of the trauma of a person sitting in a car near the point of impact, with a possible impact on the internal elements of the car and is a function of time calculated by

$$\begin{array}{l}\mathrm{At}R\mathrm{but}\mathrm{at}nen\mathrm{and}e\mathrm{one}\\ ASI\left(t\right)=\sqrt{\left[{\left(\frac{{\overline{a}}_x}{{\widehat{a}}_x}\right)}^2+{\left(\frac{{\overline{a}}_y}{{\widehat{a}}_y}\right)}^2+{\left(\frac{{\overline{a}}_z}{{\widehat{a}}_z}\right)}^2\right]}\end{array}$$

Where:

, $${\overline{a}}_y$$

и $${\overline{a}}_z$$

- предельные значения для компонентов ускорения вдоль связанных с телом осями координат х, у и z; $${\overline{a}}_x$$

, $${\overline{a}}_y$$

and $${\overline{a}}_z$$

- limit values for acceleration components along the x, y, and z coordinate axes associated with the body;

, $${\widehat{a}}_y$$

и $${\widehat{a}}_z$$

- компоненты ускорения рассматриваемой точки Р транспортного средства, усредненные на промежутке интервала времени δ=50 мс. $${\widehat{a}}_x$$

, $${\widehat{a}}_y$$

and $${\widehat{a}}_z$$

- acceleration components of the considered point P of the vehicle, averaged over the interval of the time interval δ = 50 ms.

Equation 1 is the simplest possible equation for the interaction of three variables x, y and z. If any two components of the acceleration of the vehicle are equal to zero, ASI reaches its limit value of 1, if the third component of the acceleration reaches its limit value. If two or three components are not equal to zero, the ASI may be 1 if the individual components are significantly below the limit values. Extreme accelerations are interpreted as values below which the risk of passenger injury is very small (minor injuries, if any). In equation (1), ASI is a dimensionless quantity, it is a scalar function of time, and in general for the TS point under consideration, it has only positive values.

Equation 2 is a low-pass filter that takes into account the fact that vehicle accelerations can be communicated to the passenger’s body through relatively soft contacts that cannot transmit the highest frequencies:

$$\begin{array}{l}\mathrm{At}R\mathrm{but}\mathrm{at}nen\mathrm{and}e2\\ {\overline{a}}_y\left(t\right)=\frac{\mathrm{one}}{\delta }{\displaystyle \underset{t}{\overset{t+\delta }{\int }}{a}_{y}dt}\end{array}$$

For passengers wearing seat belts, the following acceleration limits are typically used:

, $${\widehat{a}}_y=9g$$

, $${\widehat{a}}_z=10g$$

$${\widehat{a}}_x=12g$$

, $${\widehat{a}}_y=9g$$

, $${\widehat{a}}_z=10g$$

Where:

g = 9.81 m / s ² - reference value for acceleration;

, $${\widehat{a}}_y$$

и $${\widehat{a}}_z$$

- компоненты ускорения рассматриваемой точки Р транспортного средства. $${\widehat{a}}_x$$

, $${\widehat{a}}_y$$

and $${\widehat{a}}_z$$

- acceleration components of the considered point P of the vehicle.

Thus, we can conclude that the more the ASI exceeds one, the greater the risk for the passenger at this point to get injured. Therefore, the maximum value reached by ASI during a collision is taken as a separate measure of the degree of danger, or according to

$$\begin{array}{l}\mathrm{At}R\mathrm{but}\mathrm{at}nen\mathrm{and}e3\\ ASI=\max \left[ASI\left(t\right)\right]\end{array}$$

The concept of a safety assessment based on Theoretical Head Impact Velocity is used to assess the degree of a passenger’s blow to the head, for vehicles equipped with a passive safety system in the form of seat belts, in an accident. In the framework of this concept, a passenger (passenger's head) is considered as a freely moving object, which, like a car, changes its speed when it collides with a barrier or obstacle, continuing to move until it collides with any surface inside the car.

The module of the velocity vector of the theoretical head is used to estimate the degree of rigidity of the vehicle’s impact on the obstacle. This implies that after the collision, the head remains in contact with the surface for the rest of the time. And it has the same acceleration characteristics as the vehicle itself during the rest of the time of contact interaction with the barrier.

At the beginning of the contact of the vehicle with the barrier, both the vehicle and the theoretical head have the same horizontal speed V ₀ , while the movement of the vehicle is exclusively translational. It is assumed that during the impact the vehicle moves only in the horizontal plane, since high levels of slope, roll or vertical movement are not so significant if the machine does not roll over.

On Fig (1 - the origin, 2 - the position of the theoretical head) shows the coordinate system TC - 1 _xy , where x is the longitudinal axis, y is the transverse axis. The origin of coordinates (indicated by 1 in FIG. 8) is a vehicle point close to, but not necessarily coinciding with, the center of gravity. The accelerations of point 1 will be used to analyze the behavior of the vehicle in assessing the theoretical speed of a head strike.

An example of assessing the theoretical speed of a head strike (Fig. 8 point 2)

и $${\ddot{y}}_c$$

- ускорения точки 1 (в м/с²) вдоль осей ТС х и у соответственно, а ψ - скорость рыскания (в радианах в секунду, $$\ddot{x}$$

- положительное вперед, $$\ddot{y}$$

- положительное в правую сторону и ψ - положительное по часовой стрелке, если смотреть сверху);- let be $${\ddot{x}}_c$$

and $${\ddot{y}}_c$$

- accelerations of point 1 (in m / s ² ) along the axes of the vehicle x and y, respectively, and ψ is the yaw rate (in radians per second, $$\ddot{x}$$

- positive forward $$\ddot{y}$$

- positive to the right side and ψ - positive clockwise, when viewed from above);

- the coordinate system of the earth is OXY, horizontal, the X axis is aligned with the speed V ₀ , and the origin 0 coincides with the initial position of the base point 1 of the vehicle. X _c (t) and Y _c (t) are the earth coordinates of the starting point of the TS C, and X _b (1) and Y _b (t) are the earth coordinates of the theoretical head (2).

Using the assumptions and hypotheses discussed above, the movement of the vehicle and the theoretical head is calculated as follows.

The conditions for calculating the movement of the vehicle at the initial time t = 0 are:

$$\{\begin{array}{l}{X}_c=0Y_c=0\psi ={\psi }_0\\ {\dot{X}}_c=V_0{\dot{Y}}_c=0\dot{\psi }=0\end{array}$$

In experiments, the yaw angle ψ can be measured from the records of the corresponding ceiling chamber, either by calculating the yaw rate integral ψ, or in another suitable way. For example, when using a sensor associated with the vehicle coordinate system, the angle can be measured using an additional sensor combined with a gyroscope.

Vehicle speed and position are calculated by integration over

$$\begin{array}{l}\mathrm{At}R\mathrm{but}\mathrm{at}nen\mathrm{and}e\mathrm{four}\\ \{\begin{array}{cc}{\dot{X}}_c=\Delta {\dot{X}}_c+V_0& \Delta {\dot{X}}_c={\displaystyle {\int }_0^t{\ddot{X}}_{c}dt}\\ {\dot{Y}}_c=\Delta {\dot{Y}}_c& \Delta {\dot{Y}}_c={\displaystyle {\int }_0^t{\ddot{Y}}_{c}dt}\end{array}\end{array}$$

$$\{\begin{array}{c}{X}_c={\displaystyle \underset{0}{\overset{t}{\int }}\Delta {\dot{X}}_{c}dt}+V_{0}t\\ Y_c={\displaystyle \underset{0}{\overset{t}{\int }}\Delta {\dot{Y}}_{c}dt}\end{array}$$

The initial conditions for calculating the movement of the theoretical head relative to the ground at the initial time t = 0 are:

$$\{\begin{array}{cc}{X}_b=x_0\cos \psi =X_0& Y_b=x_0\sin \psi =Y_0\\ {\dot{X}}_b=V_0& {\dot{Y}}_b=0\end{array}$$

If the theoretical head continues to move uniformly, then apply

$$\begin{array}{l}\mathrm{At}R\mathrm{but}\mathrm{at}nen\mathrm{and}e5\\ \{\begin{array}{c}{X}_b=V_{0}t+X_0\\ Y_b=Y_0\end{array}\end{array}$$

The speed of the theoretical head relative to the vehicle is calculated by

$$\begin{array}{l}\mathrm{At}R\mathrm{but}\mathrm{at}nen\mathrm{and}e6\\ \{\begin{array}{c}{V}_x\left(t\right)=\Delta {\dot{X}}_c\cos \psi +\Delta {\dot{Y}}_c\sin \psi +y_b\dot{\psi }\\ V_y\left(t\right)=-\Delta {\dot{X}}_c\sin \psi +\Delta {\dot{Y}}_c\cos \psi -x_b\dot{\psi }\end{array}\end{array}$$

The coordinates of the theoretical head relative to the coordinate system of the vehicle are calculated using

$$\begin{array}{l}\mathrm{At}R\mathrm{but}\mathrm{at}nen\mathrm{and}e7\\ \{\begin{array}{cc}{x}_b\left(t\right)=\Delta X_b\cos \psi +\Delta Y_b\sin \psi & \Delta X_b=X_0-{\displaystyle {\int }_0^t\Delta \dot{X}dt}\\ y_b\left(t\right)=-\Delta X_b\sin \psi +\Delta Y_b\cos \psi & \Delta Y_b=Y_0-{\displaystyle {\int }_0^t\Delta \dot{Y}dt}\end{array}\end{array}$$

Figure 9 shows the position of the theoretical head before impact (2) about one of the three conventional surfaces inside the vehicle. It is assumed that the conditional impact surfaces inside the vehicle are flat and located perpendicular to the axes of the vehicle x and y.

Distances to such surfaces from the initial position of the head (distance to the impact): forward D _x and sideways D _y . Figure 9 shows a head punch on the left inner side of the vehicle (3).

The free movement time of the theoretical head is the shortest time T, for which one of the following three is satisfied:

$$\begin{array}{l}\mathrm{At}R\mathrm{but}\mathrm{at}nen\mathrm{and}e8\\ x_b\left(T\right)=D_x+x_0;\mathrm{and}l\mathrm{and}{y}_b\left(T\right)=D_y;\mathrm{and}l\mathrm{and}{y}_b\left(T\right)=-D_y\end{array}$$

Where:

D _x = 0.6 m; D _y = 0.3 m - recommended values of distances to impact.

Note that the yaw angle ψ is necessary for converting the results from the coordinate system associated with the earth to the coordinate system associated with the vehicle. When installing a three-axis acceleration sensor on a vehicle according to Equations 8, yaw sensor readings are not required.

Finally, the impact velocity of the theoretical head is the relative velocity over time T and is calculated using

$$\begin{array}{l}\mathrm{At}R\mathrm{but}\mathrm{at}nen\mathrm{and}e9\\ THIV=\sqrt{V_x^2\left(T\right)+V_y^2\left(T\right)}\end{array}$$

One of the main advantages of the above criteria for the Acceleration Hazard Index (ASI), theoretical head impact speed (THIV) is their independence from the location of passengers and the driver, as well as the use of information only about the movement and effects of the tested vehicles. This allows you to evaluate the occurrence of an emergency and the severity of potential injuries of people in the vehicle’s cabin using modern sensors that measure speed and acceleration in the coordinate system associated with the vehicle.

The calculation of the assessment of the degree of danger of acceleration for people in the vehicle’s cabin is based on the requirements of the subject area and suggests the possibility of executing an appropriate method of data processing in conjunction with a numerical simulation of the processes occurring in the vehicle during an accident using information from a system that provides numerical modeling, as input.

The difference in the implementation of the method of processing data coming from a system that provides numerical simulation, in the case of implementing the method for determining the moment and severity of an accident and in the case of implementing the method of calculating the assessment of the degree of danger of acceleration for people in the vehicle’s cabin, is that in the first In this case, a method is used that is optimized for use on the target automotive software and hardware platform (limited RAM and limited computing resources), and in the second case, they can spolzovat computing resources significantly greater power, the use of which is necessary to ensure that the numerical simulation.

As the target automotive hardware platform should be considered a hardware platform of class ARM7 or higher, with at least 137 Kbytes of free ROM memory and 100 Kbytes of RAM memory.

Multiprocessor systems built on the basis of Intel Xeon X5570 class processors 2.93 GHz or higher with a disk space of 300 Gb and a RAM capacity of 200 Gb or more should be considered as a computational resource necessary to ensure the performance of numerical simulation.

When determining the means of numerical modeling, it is taken into account that the problem under consideration has:

- physical non-linearities, by taking into account the elastoplastic properties of the materials of the vehicle body model;

- contact non-linearities, since numerous contact interaction is considered by modeling the processes of slipping, sticking, the exit of areas from contact interaction and repeated contact interaction.

When implementing the invention, a finite element analysis system ABAQUS was used. ABAQUS is a world-class software package in the field of finite element strength calculations, with which you can get accurate and reliable solutions for the most complex linear and nonlinear engineering problems. The ABAQUS software package is developed on a modular basis. It consists of two main modules - ABAQUS / Standard and ABAQUS / Explicit solvers, ABAQUS / CAE pre-postprocessor and modules that take into account the characteristics of various disciplines. Simulia Abaqus software package (ABAQUS 6.9. Year of release: 2009. Version: 6.9. Developer: Dassault Systems) is a completely parallel code and can be used on all computing platforms, including multicore computing systems and clusters.

When implementing the invention, it is possible to use other systems of finite element analysis, if these systems provide numerical simulation with the necessary degree of reliability.

During numerical simulation, impact interaction between individual vehicles and between vehicles and elements of the road infrastructure is simulated, which is dynamic and fast-flowing, which requires the application of explicit methods for solving the dynamics equation. Explicit methods for solving the dynamics equation are called methods that are not related to solving systems of equations, but using recurrence relations that express displacements, velocities, and accelerations at this step through their values in the previous steps.

Preparation of a numerical simulation environment for modeling in accordance with certain accident scenarios provides the possibility of numerical simulation taking into account all the defined accident scenarios; the ability to automate the process of conducting numerical modeling, collecting and processing the results of numerical modeling.

Taking into account the technical features of the selected means of numerical simulation, a program and test procedure are being developed that should be used to perform the following procedures when conducting and analyzing the results of numerical modeling.

The test program and methodology should include:

- a list of technical characteristics and functional properties to be confirmed during testing;

- conditions, procedure and methods for testing and processing the results;

- acceptance criteria based on test results;

- a description of the tests (methods, test procedures).

The set of tests performed at the stage of autonomous preliminary tests should provide:

- a full check of the procedure for determining the event and the severity of an accident;

- checking the reliability and stability of the functioning of the procedure for determining the event and the severity of an accident.

Numerical modeling is carried out in accordance with the test program and methodology.

The results of numerical simulation should be recorded in order to enable subsequent processing and analysis of the results of numerical simulation.

Table 2 and Table 3 presents the calculated cases for a frontal collision, side collision and rear impact of the vehicle in the event of an accident, processed during computer simulation as part of the application of the method.

table 2 Design cases for frontal collision Design Option No. Vehicles Overlap Impact Speed, km / h V1 V2 one Frontal strike TS1-TS2 one hundred% eighteen eighteen 2 32 32 3 64 64 four 40% eighteen eighteen 5 32 32 6 64 64 7 small eighteen eighteen 8 32 32 9 64 64 10 TS1-TS1 one hundred% eighteen eighteen eleven 32 32 12 64 64 13 40% eighteen eighteen fourteen 32 32 fifteen 64 64 16 small eighteen eighteen 17 32 32 eighteen 64 64 19 TC2-TC2 one hundred% eighteen eighteen twenty 32 32 21 64 64 22 40% eighteen eighteen 23 32 32 24 64 64 25 small eighteen eighteen 26 32 32 27 64 64 28 Rear kick TC1-TC2 one hundred% 80 0 29th fifty% 80 0 thirty TC1-TC1 one hundred% 80 0 31 fifty% 80 0 32 TS2-TS2 one hundred% 80 0 33 fifty% 80 0

Table 3 Design cases for side impact Design Option No. Cars Point of impact Impact Speed, km / h V1 V2 34 Side kick TS1-TS2 central rack 62 0 35 32 0 36 front wheel 62 0 37 rear wheel 62 0 38 driver's door 62 0 39 32 0 40 backdoor 62 0 41 32 0 42 TS2-TS1 central rack 62 0 43 32 0 44 front wheel 62 0 45 rear wheel 62 0 46 driver's door 62 0 47 32 0 48 backdoor 62 0 49 32 0 fifty TS1-TS1 central rack 62 0 51 32 0 52 front wheel 62 0 53 rear wheel 62 0 54 driver's door 62 0 55 32 0 56 backdoor 62 0 57 32 0 58 TS2-TS2 central rack 62 0 59 32 0 60 front wheel 62 0 61 rear wheel 62 0 62 driver's door 62 0 63 32 0 64 backdoor 62 0 65 32 0

The analysis of the results of numerical modeling is carried out in accordance with the established program and test procedure and allows us to conclude whether the output data obtained when the method for determining the moment and severity of the accident corresponds to the output data obtained when calculating the assessment of the degree of danger of acceleration for people located in the vehicle cabin during testing in accordance with certain accident scenarios.

Table 4 provides a brief description of the implementation process of the invention for specific vehicles (Toyota RAV4 and BMW 1 Series)

Table 4 No. p / p Job title Work result one Development of a computer model of the vehicle Computer models of the Toyota RAV4 and BMW 1 Series vehicles have been developed. The characteristics of one of the developed computer models of the vehicle and the corresponding graphic images are given earlier. 2 Choosing a method for determining the moment and severity of an accident An algorithm for determining the accident event and a criterion for assessing the severity of an accident for use in automotive systems installed in the configuration of additional equipment is developed. A detailed discussion of the algorithm for determining the event of an accident and the criteria for assessing the severity of an accident is not the subject of this application for invention 3 The choice of method for assessing the degree of danger of acceleration for persons in the vehicle cabin Calculation of parameter ASI15 and comparison of the calculated parameter with a threshold value is selected as a method for assessing the degree of danger of acceleration for people in the vehicle’s cabin. The methodology for calculating the ASI15 parameter is defined earlier in the document four The choice of numerical modeling tools and the preparation of a numerical simulation environment The software package Simulia Abaqus is selected as a means of numerical simulation. Information about the software package Simulia Abaqus presented earlier. The scenarios of road accidents that are used during the numerical simulation are determined. Information on selected accident scenarios is presented earlier. 5 Development of a test program and methodology Programs and test procedures have been developed. Requirements for programs and techniques presented earlier 6 Analysis of the results of numerical simulation As a result of the analysis of the results of numerical simulation, it was concluded that the algorithm used to determine the event and the severity of an accident gives correct results when conducting numerical simulation in all given scenarios

Claims (15)

1. A method of checking the effectiveness of the operation of the automotive system at the development stage, installed on the vehicle in the configuration of additional equipment to determine the moment and severity of the accident, including
the procedure for developing a computer model of a vehicle;
the procedure for determining the moment and severity of an accident, taking into account the technical characteristics and method of installing the system installed on the vehicle in the configuration of additional equipment to determine the moment and severity of the accident;
the procedure for calculating the assessment of the degree of danger of acceleration for persons in the cab of the vehicle;
the procedure for determining numerical modeling tools and preparing the numerical simulation environment for modeling in accordance with various accident scenarios;
the procedure for developing a program and methodology for conducting tests to verify the effectiveness of the functioning of the automotive system;
numerical simulation procedure;
the procedure for analyzing the results of numerical modeling. 2. The method according to claim 1, in which the procedure for developing a computer model of a vehicle is carried out with maximum detail. 3. The method according to claim 1, in which the determination of the moment and severity of the accident occurs subject to the use of a three-axis acceleration sensor and its installation along the longitudinal axis of the vehicle. 4. The method according to claim 3, in which determining the moment and severity of the accident suggests the possibility of performing this procedure in conjunction with numerical simulation. 5. The method according to claim 1, in which the calculation of the assessment of the degree of danger of acceleration for people in the vehicle’s cabin is based on the analysis of the injuries of parts of the body of passengers and the driver. 6. The method according to claim 5, in which the calculation of the degree of danger of acceleration for people in the vehicle’s cabin is made based on information about the nature of the change in acceleration over time at various points in the body of a person inside the vehicle at the time of the accident. 7. The method according to claim 5, in which the analysis of the injuries of the body parts of the passengers and the driver is carried out according to the criteria for injuring the head, neck, degree of injury to the chest, severity of the injury. 8. The method according to claim 5, in which the calculation of the degree of danger of acceleration for persons in the vehicle’s cabin is performed using a mathematical model of the manikin, measuring displacements, forces and moments at various points on the manikin. 9. The method according to claim 5, in which the calculation of the assessment of the degree of danger of acceleration for persons in the vehicle’s cabin is performed using the index of the degree of danger of acceleration and the theoretical speed of the head. 10. The method according to claim 5, in which multiprocessor systems based on processors of the Intel Xeon X5570 class 2.93 GHz or higher with a disk space of 300 Gb and or more of RAM are used as the computing resource necessary for numerical simulation. 200 Gb. 11. The method according to claim 1, in which during the procedure of numerical simulation simulate the impact interaction between individual vehicles and between vehicles and road infrastructure elements. 12. The method according to claim 10, in which various scenarios of accident, vehicle speeds, vehicle paths, collision angles of vehicles with fixed obstacles, angles of collision of vehicles with other vehicles involved in traffic accidents are used to carry out numerical simulation; speeds of other vehicles involved in an accident; degree of overlap in the collision of several vehicles. 13. The method according to claim 10, in which the procedure for numerical simulation, collection and processing of simulation results is automated. 14. The method according to claim 1, in which the program and methodology for testing to verify the effectiveness of the operation of the automotive system is carried out on the basis of a list of technical characteristics and functional properties to be confirmed during testing; conditions, order and methods of testing and processing the results. 15. The method according to claim 1, in which the analysis of the results of numerical simulation is carried out to determine the conformity of the output data obtained when determining the moment and severity of the accident to the output data obtained by calculating the assessment of the degree of danger of acceleration for people in the vehicle cabin.

Images