EP3544862A1

EP3544862A1 - Method and parameter module for detecting the type and/or severity of a collision of a vehicle with a collision object.

Info

Publication number: EP3544862A1
Application number: EP17778284.4A
Authority: EP
Inventors: Heiko Freienstein; Jochen Wieland; Josef Kolatschek
Original assignee: Robert Bosch GmbH
Current assignee: Robert Bosch GmbH
Priority date: 2016-11-28
Filing date: 2017-10-04
Publication date: 2019-10-02
Also published as: US20190344739A1; WO2018095626A1; JP2019535587A; DE102016223541A1; CN110023149A

Abstract

Method for detecting the type and/or severity of a collision of a vehicle (1) with a first mass (m₁) with a collision object (2) of a second mass (m₂) in an early phase of the collision in order to trigger suitable safety measures comprising the following steps: acquisition of surroundings data on the surroundings of the vehicle (1), detection and determination of the location of the collision object (2) from the surroundings data, extraction of at least one reference feature (4), not lying in a direct collision area (5), of the collision object (2) for the further observation of a relative speed (V_r) between the reference feature (4) of the collision object (2) and the vehicle (1), repeated successive determination of a current speed (V_{1, n}) of the vehicle (1) and determination of a change in the speed of the vehicle (Delta V₁), repeated successive determination of a current relative speed (V_r,n) between the vehicle (1) and reference feature (4), and determination of a change in the speed of the collision object (Delta V_r), estimation of a mass ratio (m₁/m₂), effective during the collision, between the mass (m₁) of the vehicle (1) and the mass (m₂) of the collision object (2) from the determined changes (Delta V₁, Delta V_r) in the speeds of the vehicle (1) and of the collision object (2).

Description

description

title

Method and parameter module for detecting type and / or

Gravity of a collision of a vehicle with a collision object

The present invention relates to a method for detecting the type and / or severity of a collision of a vehicle, in particular of a motor vehicle, with a collision object for triggering suitable safety measures. In particular, the invention also relates to a parameter module for estimating the absolute mass of a collision object in an early phase of a collision with a vehicle or the ratio of a mass of a vehicle to a mass of a collision object.

Modern motor vehicles are equipped with extensive sensors and monitoring equipment with the aim of increasing safety for the vehicle occupants. Even with the development of autonomous vehicles, which participate in the traffic without driver intervention, ever better systems have been developed for acquiring environmental data of the surroundings of the vehicle. In the present invention, it is assumed that a vehicle with extensive sensors and means for generating

Environment data of its environment is equipped. In particular, these may be video cameras, radar systems, lidar systems and / or ultrasound systems. It is also known to use such systems, not (anymore)

anticipate avoidable collisions as early as possible, estimate their course and severity, and timely in the event of an accident

Safety systems of the vehicle, such as belt tensioners,

Seat adjustments and / or airbags trigger. In such systems, it is also common to have accidents in terms of their severity and / or their course in to classify different categories, which then lead to different sequences of security measures.

Against this background, a method according to claim 1 for detecting the type and / or severity of a collision of a vehicle with a collision object in an early phase of the collision to trigger appropriate security measures is provided according to the invention. A parameter module according to claim 9 is also included in the invention.

A hitherto difficult parameter to consider in the collision of a vehicle with a collision object is the mass nri2 of the collision object or the ratio of mass rru of the vehicle to mass nri2 of the collision object. The knowledge of the involved masses or of the mass ratio is of great importance for predicting the accident as accurately as possible, because this information can be used to make more accurate forecasts of expected loads on the vehicle occupants based on the physical laws of (plastic) impact. The advantage which results from an approximate knowledge of the mass of the collision object, at least in relation to the mass of the own vehicle, is independent of the other accident occurrence, so that an application in principle for all types of collisions and all impact directions is advantageous. Of particular importance in the following considerations, however, is an accident involving the front of the vehicle, such as an impact directly from the front or obliquely from the front with full or partial overlap of the front of the vehicle and collision object. The following

Considerations apply exactly only to a head-on collision with complete coverage, but can be qualitatively transferred to other accident situations at different angles with different coverage. In any case, at least one estimated value for the mass nri2 of the

Collision object or the mass ratio of vehicle and

Collision object, with the help of which the expected accident can be better assessed and categorized, resulting in a more targeted

Application of security measures. In the described method, it is assumed that existing systems for scanning the environment or for detecting environmental data of the vehicle due to existing evaluation systems speed and direction of vehicle and objects to each other recognize and evaluate, so that potential collision objects can be identified. The

Detection of environmental data in step a) of the method can be done for example via sensors. It is possible that the described method is carried out in a control unit which receives such environmental data via signal inputs from external (out-of-module) sensors.

In general, of course, the goal is to avoid collisions by suitable steering and / or braking maneuvers, but this is not always possible. According to the method described, an object with which a collision is to be expected should not only be detected and localized (step b), but the scanning system for acquiring environmental data should be at least one reference feature of the

Select a collision object (step c) to perform further observations using this feature (step d) and subsequent steps). Detection, localization and further observation of

Collision objects in the individual process steps initially always takes place in a fixed vehicle permanently assigned to the reference system. This means that a relative localization of the collision object takes place starting from the motor vehicle and thus a relative position (relative to the motor vehicle) is determined. In steps e) and d), absolute velocities are then calculated in an absolute, stationary reference system, in which the motor vehicle also moves. This is done by converting the relative

Observations in the reference system assigned to the vehicle into the absolute reference system, this conversion being able to take place with the aid of the speed of the motor vehicle (known from step d). The reference feature should lie in an area of the collision object that can be well observed before and even in the early phase of the collision, that is, for example, is not very deep on the front of the collision object. If the collision object is a vehicle, which will be the case in most cases, z. B. a lower lateral boundary of a windscreen (beginning of the A-pillar) as a reference feature. Many others for a safe Image processing suitable features can be stored in a security system. A scanning system for acquiring environmental data may in this way be concentrated on one or more reference features, such that the relative speed between the vehicle and the collision object is determined by repeated distance measurement with reference to at least one

Reference feature can be determined. At the same time is the current

Speed of the vehicle from its sensors (eg, measurement of wheel speed or time integration of measured accelerations) known. This means that from the measured relative speed and the known speed of the vehicle, the speed of the collision object can be determined. As soon as the vehicle and the collision object touch each other, the deformation begins at both, so that in a first approximation one can physically speak of a plastic shock. The vehicle and the collision object become slower, in proportion to their masses. By measuring the relative speed even in the early phase of the collision, that is, by repeatedly measuring the

Speed of the vehicle and the relative speed between the vehicle and collision object at known time intervals, therefore, the mass ratio between the two collision partners can be determined more accurately (with each repetition of the measurements or increasing time interval between the measurements increases the accuracy of

Measurement results). If the mass rru of the vehicle is known, the mass nri2 of the collision object can even be determined absolutely from the mass ratio. From the measured before the collision

Initial speeds of the vehicle and collision object (and possibly the collision angle) can thus also be determined the expected final speeds of both collision partners at the end of the collision and thus the severity of the accident from the perspective of the vehicle already in the early phase of the collision. This allows appropriate safety measures to be initiated in a suitable time sequence (or not to be triggered in the event of less serious accidents). Typically, in the early phase of the collision, a measure of the type and / or severity of the collision from the perspective of the vehicle based on the determined

Mass ratio measured before the collision

Initial speeds and numerous other data of the Security system of the vehicle determined to trigger this measure appropriate security measures at appropriate times.

In a preferred embodiment of the method, the environmental data is obtained by at least one of the following methods: video surveillance,

Lidar monitoring, radar monitoring, ultrasound monitoring. Such monitoring systems are used in modern vehicles

Driver assistance systems used individually or in combination and serve so far to increase driving safety and for the early classification of expected collisions. Video systems, but also increasingly the other mentioned systems, are suitable for extracting reference features and for measuring relative velocities. This can be done by

Image processing method and / or for example by measurements on the basis of the Doppler effect done.

This makes it possible, in a preferred embodiment of the method described, to select at least one reference feature on the potential collision object for further observation and to repeatedly measure its current relative speed to the vehicle. In the most favorable situation for the described method, in which a potential collision object already before

Collision can be observed, thus quite accurate statements on the expected accident events are possible.

Thus, the current speed of the vehicle can preferably be determined repeatedly before and during the collision from the sensors for speed, speed, acceleration and the like present in the vehicle. This allows to determine the absolute speeds of both vehicles from relative speed to the collision object and the vehicle's own speed and to draw further conclusions from this.

In a preferred embodiment is from the effective

Mass ratio of vehicle and collision object at approximately known mass rru of the vehicle also calculates the absolute mass nri2 of the collision object, whereby the kinematics of the collision is calculated on the assumption of a plastic shock substantially according to the pulse conservation law and Determination of the measure of the nature and / or severity of the collision can be used. It is immediately obvious that the collision with an object of large mass can have more serious consequences for the occupants of a vehicle than the collision with a small-mass object. For this reason, the early determination of the mass ratio or the mass of the

Collision object in the early phase of the collision before coordinated triggering security measures a significant advantage for the safety of the

Vehicle occupants.

Due to the fact that the processing of large amounts of environmental data, as they occur in the scanning of the environment of a vehicle, requires a considerable amount of computing, is in a preferred

Embodiment of the method in case of a finding of a

imminent collision data processing on the for the

Collision processing focused on important operations. This means that all uses of the environment data are switched off, not for the

Detection of the type and / or severity of the collision are needed. This provides additional computational capacity for the calculations to be performed before and during the early stages of the collision, allowing such complex tasks as extracting and tracking reference features and calculating deceleration speed of both collision partners to be performed so quickly that safety measures are triggered in a timely manner. Preference is given to the current speed of the vehicle (step d) and the

Determining the current relative speed between the reference feature and the vehicle (step e) performed several times at equal intervals during the collision, in each case also the changes of the two

Speeds are determined per unit time, so that with each measurement results in an increasingly accurate measure of the nature and / or severity of the collision from the vehicle's point of view. It should be noted that the entire observation takes place only in a short period of time, usually less than a second, which is why the time intervals for the speed measurements should be in the range of a few milliseconds. As far as metrologically possible, it is of particular advantage if at least two reference features are selected and observed on the collision object, because this increases the measurement accuracy and / or information about further parameters of the collision and a possible rotation of the

Collision object can be included in the determination of the degree of the type and / or severity of the collision. For example, when using the two lower ends of the A-pillars of a vehicle as reference features collision angle and / or rotation of the collision partners to each other can be determined.

In order to determine a measure of the type and / or severity of the collision (step g), an estimate of an effective mass mass ratio between mass of the vehicle and mass of the collision is first of all taken in document f)

Collision properties. Subsequently, target measures can be triggered in step h) based on the estimated severity of the collision.

Environmental data of the surroundings of the motor vehicle are used in different ways or by different systems in the vehicle, whereby in case of an imminent collision (all or some)

Uses of the environment data are switched off, not for the

Detection of the type and / or severity of the collision and the consequent measures are needed. This serves, in particular, to provide computing capacity for the invoices to be carried out before and during the early phase of the collision (described here).

The determination of the current speed of the vehicle and the

Determining the current relative speed between reference feature and vehicle are preferably multiple, in particular in same

Time intervals performed during the collision, in each case the change of the two speeds per unit time are determined.

This creates an increasingly accurate measure of the nature and / or severity of the collision from the vehicle's point of view.

In step c), at least two reference features are preferably extracted at a collision object and observed in the subsequent steps. As a result, the measurement accuracy is increased and / or it is possible

Include information about other parameters of the collision and a possible rotation of the collision object in the determination of the measure of the type and / or severity of the collision. Higher measurement accuracy can be achieved, for example, by taking into account two or more reference features for correction. For example, a rotation may be detected based on differences in the speeds of two reference features on a collision object.

Also described herein is a controller according to claim 9. It is for estimating the absolute mass nri2 of a collision object in an early phase of a collision with a vehicle or the ratio a mass mi of a vehicle relative to a mass nri2 of a collision object in an early phase of a collision, wherein the module corresponds to a system in the

Vehicle is assigned to trigger appropriate safety measures in a collision, wherein further the module inputs for measured values of at least one first measuring device for repeatedly determining the relative

Speed between the vehicle and collision object before and during the early phase of the collision and at least one second measuring device for repeatedly determining the absolute speed of the vehicle and wherein the control unit for estimating the mass nri2 of

Collision object or the mass ratio of vehicle and collision object from the change of the absolute speed of

Vehicle and the relative speed to the collision object in the early phase of the collision based on the pulse conservation theorem is designed. The particular advantages shown for the method described and

Design features are applicable to the described controller and transferable. Such a controller is suitable as part of a security system of a

Power vehicle and contributes important information to classify a collision, so that appropriate security measures can be triggered. The second mass nri2 or the ratio determined by the parameter module The masses of motor vehicle and collision object are essential parameters for the expected course of a collision, so with Help the parameter module a more accurate prediction of expected loads on the occupants of the motor vehicle and on appropriate

Safety measures can be taken. The method described and its environment are described below with reference to

Drawing explained in more detail. Show it:

Fig. 1: schematically a situation shortly before collision of a vehicle with a collision object and

2 shows an exemplary flow chart for the method.

1 shows a schematic representation of a constellation shortly before the collision of a motor vehicle 1 with a collision object 2. The motor vehicle 1 has the initial speed Vi.o and the mass rru. The collision object, in the present case also exemplified as a motor vehicle, has the initial velocity V2, o and the mass nri2. Before the collision, the two collision partners still have a certain distance and a spatial arrangement to each other. The area directly affected by a collision (which thereby deforms) is referred to below as the collision area 5. The vehicle 1 has at least one first measuring device 3 for acquiring surroundings data of the surroundings of the vehicle 1. Typically, this involves a camera, an ultrasound or laser system or a radar device. Preferably, a laser scanning system for detecting environmental data is used because it can also provide data on the relative movement between the vehicle 1 and collision object 2, for example by measuring the Doppler effect, simultaneously with data about the direction of an object. Under favorable conditions, the first measuring device 3 delivers extensive data about a potential collision object 2 even before a collision. It is assumed in the present considerations that driver assistance systems or systems for autonomous driving present in the vehicle 1 recognize potential collision objects 2 at an early stage and foresee a collision can. If a potential collision object 2 is detected, then Help the first measuring device 3 identified at least a first reference feature 4 on the collision object 2 and extracted for a more accurate observation. Since this first reference feature 4 should also be observed during the collision, it should not be located in the immediate collision area 5, which deforms first in a collision. As suitable

Reference feature offers, for example, a lower corner of a lateral boundary of a windshield, a so-called A-pillar of a motor vehicle. For a higher accuracy of the further measurements, a second reference feature 12 and further reference features depending on the performance of the data processing in the vehicle 1 can be consulted.

In any case, the relative distance 6 between the first measuring device 3 and the first reference feature 4 (and, of course, other reference features) can be measured quite accurately before and during the course of a collision. This is done before and especially during the collision in preferably the same time intervals. A second measuring device 9 in the vehicle 1 allows at any time, the absolute

Speed of this vehicle to measure. For this purpose, several different systems can be used. As a result, the speed data Vi, o, Vi, i, Vi, ₂ ... Vi, _n at the times 0, 1, 2 .... n are available at an input 13. Likewise, the controller 7 at an input 14 for environmental data information about the distance 6 between the first

Measuring device 3 and first reference feature 4 available. In most cases, data about the relative velocity V _r , o, V _r , i, V _{r> 2} ... VR, _n are already available or can be calculated from the temporal sequence of these data.

An essential objective of the described system is to assist the safety system of a vehicle 1 in assessing the severity of a collision with additional information so that safety measures can be initiated in a timely and appropriate manner. For the assessment of a collision, it is not only important to be able to estimate the geometric data of a collision course, such as impact angle, impact velocity and impact time, but of great importance is also the mass m _{2 of} the collision object 2 and the ratio of the mass rru of the vehicle to the mass m _{2 of} the collision object 2

Essentially of a plastic shock, so deform the Collision partners in the collision area 5 and are both slower. Simply put, the difference of the speed decrease (ie the negative acceleration of both collision partners) can be used to calculate the

Calculate mass ratio, with the assumption that the mass rru of the vehicle 1 is known, the absolute masses of both

Have vehicles calculated. For the course of the collision, it is basically only on the ratio of the two masses. As will be explained below with reference to the corresponding formulas, it is therefore possible to calculate in the early phase of a collision, typically in the first 10 to 100 milliseconds from the speed decrease of the two collision partners 1, 2, which final velocity Vend vehicle 1 and collision object 2 after the collision have (at a plastic shock both have the same speed at the end), from which also the expected load for the occupants of the vehicle 1 can be estimated better. The control unit 7 therefore controls data about the mass ratio of the collision partners to the system 8

Triggering of safety measures, whereby the course and consequences of the collision can be estimated more accurately and safety elements can be triggered in a suitable manner. In particular, for example, belt tensioners 10 and / or airbags 11 can be triggered.

Fig. 2 illustrates the sequence of the method in the control unit 7. From the first measuring device 3 ambient data are forwarded to the input 14 for environmental data, including data on the relative velocity V _r , n between the vehicle 1 and collision object 2 too short consecutive time points 0th , 1, 2, ... n. Where V _r , o is the last one measured before the collision

Relative speed, while the following speeds are measured in the early phase of the collision. From the second measuring device 9 of the vehicle 1 speed data to the input 13 for

Speed data forwarded. This data represents one

Velocity determination 15, from which speeds Vi, o,

Vi, i, Vi, 2 .... Vi, _n at the times 0, 1, 2 ... n are selected or calculated. From a relative velocity determination 16 and the

Speed determination 15, the data becomes a

Absolutgeschwindigkeitsbestimmung 17 forwarded, with the

Absolute velocity V2 from the difference of relative velocity V _r and Speed Vi results. In the absolute velocity determination 17, the speed Vi, o, Vi, i... Vi, _{n of} the vehicle 1 and the speed V2, o, V2, i, are present for each time t = 0, 1, 2. ... V2, _{n of} the collision object 2 are available. In an acceleration determination 18, the speed differences to the preceding time point t = 0, 1, 2,... N-1 can therefore be determined at each time t = 1, 2,. If necessary can also

Speed differences over longer periods of time to increase the accuracy of measurement are determined or the individual calculated values are analyzed at different times. Overall, the acceleration determination 18 results in a negative acceleration for both collision partners, so that, assuming the physical laws of a plastic (or at least partially plastic) impact, the ratio mi / m2 of the masses involved is estimated in a mass (ratio) determination19 can. This ratio is passed to the system 8 for triggering safety measures, whereby the mass ratio or, if the mass rru of the vehicle 1 is known, both absolute masses of the collision partners can be taken into account in the considerations of severity S of a collision. The calculations described are made in a simplified representation according to the following formulas:

V2, _n = V _{r> n} - Vi, _n with time n = 0, 1, 2 ... n

Delta Vi, _n = Vi, _n - Vi, _n -i with time n = 1, 2 n

Delta V2, _n = V2, _n - V2.ni with time n = 1, 2 n

mi * Vi, o + m ₂ * V ₂ , o = (rru + m ₂ ) * V _en d

S = m2 / (mi + m ₂ ) * (Vi, o - V ₂ , o) with

Vend = final velocity of both collision partners after collision Delta = deceleration

S = measure of the severity of a collision

The method described makes it possible to obtain a system for triggering safety measures in a vehicle 1 with a collision object 2 in the early phase of a collision data that contains an estimate of the collision object 2 Enable mass ratio between the vehicle 1 and collision object 2, allowing a more accurate early estimation of the collision consequences for occupants of the vehicle 1, which is a better timing and coordination of security measures, in particular the triggering seat adjusters, seatbelt tensioners and / or airbags is enabled.

Claims

claims

1. A method for detecting the type and / or severity of a collision of a vehicle (1) of a first mass (rru) with a collision object (2) of a second mass (nri2) in an early phase of the collision to trigger appropriate security measures with the following steps:

a) detection of environmental data of an environment of the vehicle (1), b) detection of the collision object (2) from the environmental data,

c) Extraction of at least one not in a direct collision area

(5) lying reference feature (4) of the collision object (2) for further observation of a relative velocity (V _r ) between reference feature (4) of the collision object (2) and vehicle (1),

d) Determining a current speed (Vi, _n ) of the vehicle (1) several times consecutively and determining a change in the vehicle speed

Speed of the vehicle (Delta Vi),

e) repeated successive determination of a current relative speed (V _r , n) between the vehicle (1) and reference feature (4) and determination of a change in the velocity of the collision object (delta V _r ),

f) estimation of a mass ratio effective in the collision between mass (rru) of the vehicle (1) and mass (nri2) of the collision object (2) from the determined changes (delta Vi, delta V _r ) of the speeds of vehicle (1) and collision object (2),

2. The method of claim 1, wherein subsequent to step f), the following method steps are performed:

g) determining a measure of the type and / or severity (S) of the collision from the perspective of the vehicle (1) on the basis of the determined mass ratio (mi / m2), the initial velocity (Vi, o) of the collision measured before the collision

Vehicle (1) and the initial relative speed (V _r , o) between the vehicle (1) and collision object (2),

h) Initiate at least one appropriate safety measure at the appropriate time, depending on the nature or severity of the collision.

3. The method of claim 1, wherein the environmental data of the environment are obtained by at least one of the following methods: video surveillance, lidar monitoring, radar surveillance, ultrasound monitoring.

4. The method of claim 1 or 2, wherein in a potential collision object (2) at least one of the environment data identifiable reference feature (4) selected for further observation and the current relative speed (V _{r> n} ) to the vehicle (1) is repeatedly measured ,

5. The method according to any one of the preceding claims, wherein the current speed (Vi, _n ) of the vehicle (1) before and during a collision from existing in the vehicle (1) sensors for speeds, speed, accelerations and the like repeatedly determined.

6. The method according to any one of the preceding claims, wherein from the effective mass ratio is calculated at an approximately known mass (rru) of the vehicle (1) and the absolute mass (nri2) of the collision object (2), whereby the kinematics of the collision is calculated on the assumption of a plastic shock substantially to the momentum conservation law and to determine the measure of the Type and / or severity (S) of the collision can be used.

7. The method according to any one of the preceding claims, wherein

Environmental data of the environment in different ways or from

different systems in the vehicle (1) are used, wherein in the event of an impending collision detection of environment data are turned off, which are not required for the detection of the nature and / or severity of the collision or the collision following measures.

8. The method according to any one of the preceding claims, wherein the determination of the current speed (Vi, _n ) of the vehicle (1) and the determination of the current relative speed (V _r , _n ) between reference feature (4) and vehicle (1) several times in the same Time intervals during the collision in each case also the change of the two speeds (delta Vi, delta V _r ) per unit of time is determined.

9. The method according to any one of the preceding claims, wherein in step c) at least two reference features (4, 12) are extracted at a collision object (2) and observed in the subsequent steps.

10. Control unit (7) for estimating the absolute mass (nri2) of a

Collision object (2) in an early phase of a collision with a vehicle (1) or the ratio (mi / m2) of a mass (rru) of a vehicle (1) in relation to a mass (nri2) of a collision object (2) in one Early phase of a collision, wherein the module (7) is associated with a system (8) in the vehicle (1) for triggering appropriate security measures on security elements (10, 11) in a collision, wherein further the module (7) inputs (13 , 14) for measured values of at least one first measuring device (3) for the repeated determination of the relative speed (V _r , _n ) between vehicle (1) and collision object (2) before and during the early phase of the collision and at least one second measuring device (9) repeated determination of the absolute velocity (Vi, _n) of the vehicle (1), and wherein the module (7) for estimating the mass (nri2) of the collision object (2) or the mass ratio (ml / m2) of the vehicle (1) and Kollisionsobjek t (2) from the change of the absolute speed (Delta Vi) of the vehicle (1) and the relative speed (Delta V _r ) to the collision object (2) in the early phase of the collision based on the momentum conservation law.