EP4097702A1

EP4097702A1 - Method and device for recognising when a mobile terminal falls

Info

Publication number: EP4097702A1
Application number: EP21701277.2A
Authority: EP
Inventors: Juergen Stegmaier; Jan Schnee
Original assignee: Robert Bosch GmbH
Current assignee: Robert Bosch GmbH
Priority date: 2020-01-31
Filing date: 2021-01-19
Publication date: 2022-12-07
Also published as: TW202136780A; DE102020201222A1; WO2021151723A1; CN115053275A; US20230086000A1

Abstract

The method described and claimed below and a device which carries out the method according to the invention are designed to quickly detect the accidental removal of a mobile terminal from a holder and to generate corresponding information which characterises the fall or drop associated with the accident. In order to implement the method according to the invention, rotation rate sensor variables and acceleration sensor variables of the mobile terminal are detected. For this, a rotation or turning of the mobile terminal is recognised by comparing the currently detected and/or integrated rotation rate sensor variables with past values and/or threshold values. In a further step a movement of the mobile terminal is recognised on the basis of the currently detected and/or integrated acceleration variables. A comparison with past values and/or threshold values can optionally also be carried out. An in particular accidental drop of the vehicle and/or falling of the mobile terminal out of the holder is then determined from the recognised rotation and the recognised movement.

Description

description

title

Method and device for detecting the case of a mobile terminal

The invention relates to a method and a device for monitoring and detecting the fall or fall of a mobile terminal, in particular a terminal that falls out of a holder on a vehicle.

State of the art

The use of mobile devices and especially smartphones for various areas of application outside of telephony has increased significantly in recent years. For example, electric bicycles can be controlled using a smartphone that is carried or positioned on the handlebar.

In order to protect the electronics of mobile end devices in the event of a fall or a fall, many such devices already have methods that detect a free fall in order to protect sensitive components, for example by disconnecting these components from the power supply. However, such methods are essentially aimed at recognizing the immediate free fall if the user drops the mobile device while using it.

If such a mobile terminal is now attached to a vehicle, for example to the handlebars of a two-wheeler, recognition of a free fall is often not expedient for recognizing accidents involving two-wheelers. If, for example, the mobile terminal is thrown out of the holder on the two-wheeler, a (flight) movement is to be expected, which only exhibits an essentially free fall in a later phase. The present invention is therefore intended to create a method and a device that recognizes a fall or a fall of a mobile terminal device more quickly as a function of further boundary conditions and under further possible usage situations.

Disclosure of the invention

The method described and claimed below, as well as a device that executes this method according to the invention, is set up to quickly detect the accident-related removal of a mobile device from a holder and to generate corresponding information that characterizes the fall or fall associated with the accident .

To implement the method according to the invention, rotation rate sensor variables and acceleration sensor variables of the mobile terminal are recorded. A rotation or rotation of the mobile terminal is detected by comparing the currently detected and / or integrated yaw rate sensor variables with past values and / or threshold values. In a further step, a movement of the mobile terminal is recognized on the basis of the currently detected and / or integrated acceleration variables. A comparison with historical values and / or threshold values can optionally also be carried out here. The detection of an accident-related fall of the vehicle and / or the fall of the mobile terminal out of the holder then takes place on the basis of the detected rotation and the detected movement. Optionally, the speed and / or the size of the movement can also play a role here in order to finally generate case detection information.

Since there is no normal downward fall when the mobile terminal device is thrown out of the holder, for example the smartphone, the fall situation and thus the accident can be detected more quickly. Due to the special consideration of the rotation in the detection of the fall or the fall of the mobile device, compared to a pure fall detection the possibility to recognize the special situation in an accident of a two-wheeler. In addition, the speed of the rotation and the movement of the mobile terminal out of the holder can be used to classify the fall, which can be helpful for further measures, in particular emergency calls.

In a further development of the invention, the yaw rate sensor variables and / or the acceleration variables are already recorded before the accident or fall or fall to be detected. A plane of movement in which the vehicle or two-wheeler moves can be derived from this. It is thus possible to identify both a longitudinal direction x in which the vehicle is essentially moving forward and a transverse direction y as the lateral direction of movement, which can be identified, for example, when cornering or turning. By detecting the regular movement of the mobile device in the holder on the vehicle or two-wheeler, an atypical deviation in the longitudinal and / or transverse direction can be an indication and thus a trigger for the detection of an accident depending on the mobile device being thrown out of the holder. Optionally, it can be provided that the detection of an atypical rotation about the vertical axis z or an atypical movement of the mobile terminal in the z direction also implies a fall or a fall and can thus lead to the generation of fall information.

The detection of the rotation is particularly advantageous if the method according to the invention integrates the yaw rate variable in at least one spatial direction and thus takes account of the rotation or rotation over time. In the following, a slow rotation can be distinguished from a fast rotation by comparing the integrated rotation variable obtained in this way with a corresponding first threshold value. A minimum rotational speed can thus be associated with the first threshold value, which must be reached in order to recognize the detection of the fall or an associated accident of the vehicle. In addition, it is also possible to classify the accident by taking into account the speed of rotation or rotation, for example, by using a plurality of first threshold values with which the particular integrated rotation variable is compared.

To detect the fall of the mobile terminal or the detection of being thrown out of its holder, the invention provides for the movement of the mobile terminal to be detected as a function of the detected acceleration variables. In the event of a sudden acceleration, it can be assumed that the cause is an unintentional removal of the mobile device from the holder, in particular if this acceleration does not take place in the direction of travel or in the longitudinal direction of the vehicle and / or has atypical values that are typical for a normal Driving activity does not occur. For this purpose, the currently detected or the integrated acceleration variable can be compared with one or more threshold values.

In a special embodiment of the invention it is provided that the acceleration variance is formed in all three spatial directions and the value obtained in this way is compared with a second threshold value. If this shows that the entire acceleration variance exceeds the second threshold value within a specified period, e.g. within 0.1 s, it can be assumed that a sudden acceleration has taken place, which is associated with the mobile device being thrown out of the holder is.

As with the detection of the rotation or rotation on the basis of the yaw rate sensor variables, the spatial acceleration variables in relation to the plane of movement of the vehicle or two-wheeler can also be taken into account when the movement of the mobile terminal device is detected.

To detect the plane of movement of the vehicle or two-wheeler, which at the same time also represents the plane of movement of the mobile terminal, the rotation rate sensor variables and / or acceleration variables of the movement of the vehicle before a possible fall or accident of the vehicle can be taken into account. To detect the rotation or the rotation or the movement of the mobile terminal, the corresponding components in the longitudinal direction or transverse direction are used. Alternatively, however, the corresponding directional components in the direction of the vertical axis z can also be used, since this direction of movement would result in only minor changes in the corresponding sensor variable or its component during normal driving activity of the vehicle.

Based on the detection of the fall or the fall of the vehicle or the hurling of the mobile terminal from the holder, the method can generate a classification of the fall information. For example, in the case of a particularly pronounced rotation or rapid movement, an abrupt fall of the vehicle or two-wheeler can be assumed. In order to request appropriate help, provision can therefore be made for the method to set up a radio link to an emergency based on the case information generated or the severity of the accident identified by the classification. Details about the accident can also be sent here, including GPS data or other information that is available.

Further advantages emerge from the following description of exemplary embodiments or from the dependent claims.

Brief description of the drawings

Figure 1 shows schematically a two-wheeler with a mobile terminal and a coordinate system in which the two-wheeler moves during normal driving activity. The block diagram of FIG. 2 shows a possible implementation of a device according to the invention. The flow charts in FIGS. 3 and 4 describe possible exemplary embodiments of the method according to the invention.

Embodiments of the invention The description of the invention is based on a two-wheeled vehicle in the form of a bicycle 10, although other vehicles such as electric bicycles, motorcycles, e-scooters, prams, scooters or motor vehicles could also be equipped with this invention. In the present case of the bicycle 10, provision is made for a smartphone 20 to be provided as a mobile terminal which is attached to the handlebars of the bicycle 10. The smartphone 20 is used here, for example, as a navigation instrument and / or as a display of the driving dynamics parameters. To carry out the method according to the invention, the smartphone 20 uses the sensor values that are made available by the sensors available in the smartphone 20. The bicycle usually moves forward essentially on the roadway in the longitudinal direction x. When turning and cornering, the plane of movement is spanned by an additional lateral transverse direction y. A movement in the direction of the vertical axis z takes place, for example, in the context of ascents and descents. Further movements, which can have an effect in the direction of the vertical axis, are generated by rotations in the direction of the x-axis or by uneven road surfaces. All of these movements in the direction of the d-axis can be distinguished from one another by characteristic magnitudes of the rate of change, ie the dz / dt. For example, driving up an uphill or downhill slope is associated with a longer time constant than tilting the bicycle to the side, essentially along the x-axis. On the other hand, bumps in the road are characterized by very small movements in the z-direction within a short period of time.

The sensors within the smartphone 20 are aligned with their own coordinate system. By attaching the smartphone to the handlebar, it is therefore necessary to recalibrate the alignment in the coordinate system determined by the movement. The spatially resolved sensor variables of the yaw rate sensor or the acceleration sensor in the smartphone can be used to record this defined coordinate system during normal driving. Any deviations, for example in the z-direction, which go beyond a certain amount, in particular with regard to the time dependency, can thus be assessed as an indication of a fall of the bicycle. Here, as already mentioned above, the order of magnitude in which the rate of change dz / dt is present in the direction of the z-axis, must be taken into account in order to use this movement for the fall detection. It can thus be provided that the change in the z-direction has to be present for a sufficiently long time in order, for example, to distinguish the movement from a rough road surface.

A smartphone 20 is shown schematically in FIG. 2, which has an evaluation unit 100. The evaluation unit 100 has a memory 110 in which various threshold values can be stored. The evaluation unit 100 also detects the spatially resolved sensor variables of a yaw rate sensor 120 and an acceleration sensor 130. In addition, the evaluation unit 100 can also detect other sensor variables if the smartphone has corresponding sensors or these can be read in by external sensors that are attached to the two-wheeler, for example. It is conceivable here, for example, that an inclination sensor supplies corresponding sensor variables about the increase in the ride on the bicycle, in particular the rate of incline. Such additional sensor sizes can increase the accuracy of the subsequent detection of a fall or accident by sharpening the underlying data. Optionally, it can also be provided that the evaluation unit 100 is explicitly informed of a crash that has occurred via a further connection by a separate module 140. In this case, the evaluation unit 100 can derive an even better classification of the accident based on the received sensor variables and, if necessary, forward a message to an emergency center 170. Without this additional crash information from the module 140, the method according to the invention, which is carried out in the evaluation unit 100, can recognize and recognize an accident, a fall or even just the smartphone 20 being thrown out of the holder on the handlebar based on the yaw rate sensor variables and the acceleration variables generate a corresponding case information. This case information can then be forwarded to appropriate contact points 150 or 170 or can also be shown on a display 160. It is conceivable, for example, that a general emergency call 150 is made or a special emergency call point 170 is contacted.

Using the flow chart in FIG. 3, an optional derivation of the coordinate system is to be described, which defines the movement of the bicycle taken into account on the road. To this end, in a first step 200, the spatially resolved yaw rate sensor variables and acceleration variables are recorded during normal driving activity of the vehicle or two-wheeler. Then, in step 220, a movement plane in the preferred x / y direction is derived from the sensor variables recorded in this way. The calibration of the coordinate system of the smartphone can be carried out based on these direction definitions. As an alternative or in addition, the definition of the movement plane can be used to identify whether the smartphone 20 is moving out of this movement plane, for example by being thrown out of the holder on the handlebar.

Optionally, in a further step 240 it can be checked whether the detected sensor variables are sufficient to derive a movement plane in the x / y direction. If this is not the case, e.g. because the bicycle is currently climbing an incline or the sensor data is ambiguous or too fuzzy, the process of acquiring the sensor data can be repeated in step 200.

The method according to the invention for detecting a fall of the bicycle or a fall of the smartphone from its holder is to be described below with reference to the flow chart in FIG. First, in a first step 300 spatially resolved sensor variables for the rate of rotation and the acceleration are recorded. For this purpose, provision is made in particular for the method to run on a smartphone which contains the corresponding sensors for yaw rate and acceleration and the required direction-dependent resolution. In order to obtain reliable and unambiguous sensor values, provision can be made to record a series of acceleration variables, e.g. over 10 samples at a sampling rate of 100 Hz

_ 2 _ _2. _2. _2 o ax, ay, az - ö ax ^T ö ay ^T ö az is the sum of the acceleration variance. If this acceleration variance a ² _a x, _ay , az exceeds a predeterminable third threshold value SW ₃ , an accident, an impact or a collision can be inferred, which is the cause of the smartphone being thrown out of the holder and thus causes the acceleration. If the acceleration variance is less than the third threshold value SW ₃ , the method can be run through again with step 300 or can be ended. In the following step 320, the yaw-rate sensor signals are recorded, at least in the longitudinal direction x and transverse direction y in relation to the plane of movement of the vehicle or its vehicle coordinate system. The yaw rate sensor signals in the direction of the vertical axis z, in particular its rate of change, can optionally be disregarded in order not to trigger any false triggering due to rapid handlebar rotations. The yaw rate sensor variables obtained in this way are integrated in the next step 330 in order to derive the rotation or the rotational movement of the smartphone therefrom. Optionally, the acceleration signals can also be checked in step 330. In addition to the recorded short-term increase in acceleration, a free fall can be recognized from the current acceleration variables also recorded in step 320, for example. For this purpose, for example, the acceleration 2 norm or the vector norm of the acceleration can be generated in order to recognize whether the smartphone is falling. This variable can be compared with a second threshold value SW ₂ (for example 100 mg in 100 ms) in order to derive the falling movement therefrom. In the next step 340, it can be recognized from the individually or jointly integrated yaw rate sensor variables in comparison with corresponding first threshold values SWi _{, x} or SWi _{, y} (based on the individual directional components) or SWi _{, xy} (based on the direction vector in the xy direction), Whether the smartphone is rotating fast enough to detect it being thrown out of the holder and thus a noticeable fall or accident of the bicycle. In addition, the detection of the falling smartphone can be used in step 340 to verify the process. Optionally, a combination of both conditions can also be used, ie the presence of a corresponding rotation and a free fall, with the two individual features being able to be dynamically linked. It can thus be provided that if the acceleration variance is small, a smaller rotation or rotation is detected must to recognize a fall. The same applies to the opposite case, in which a large rotation only requires a small acceleration variance in order to detect the ejection of the smartphone. If the corresponding conditions are not met, ie if insufficient rotation is detected or if the smartphone is not falling, the method can be run through again with step 320. Otherwise, it is determined in step 350 that the rotation or rotation of the smartphone is sufficiently large (e.g. Dg> 360 ° within 1 s, e.g. at a sampling rate of the detection of the sensor variables of 100 Hz) so that it can be assumed that it will be thrown out of the holder . In the optionally following step 360, a termination condition can be defined. The current acceleration signal recorded again is used to determine whether the smartphone has come to rest after being thrown out of the holder. If this is not the case, the method with step 320 can be run through again. This repeated run makes it possible to detect the severity of the collision or the accident by detecting a prolonged fall of the smartphone. Otherwise, case information is generated in the last step 370. This case information can be sent as a message to an emergency service. If the fall is classified, for example by using different threshold values for rotation or acceleration, conclusions can also be drawn about the severity of the accident. In this case, the case information can contain a classification so that different emergency measures are carried out depending on the severity of the accident. This can range from a simple message to an emergency call with the passage of known parameters about the accident.

Optionally, it can also be provided that the method detects a crash by checking an electrical contact in the holder. If the method has such separate information, the method can specialize in the classification of the accident.

Claims

Expectations

1. A method for recognizing a case of a mobile terminal device (20), in particular from a holder, the method for recognizing the case

• Rotation rate sensor variables of the mobile terminal (20) detected, and

• Acceleration variables of the mobile terminal (20) detected, and

• detects a rotation of the mobile terminal (20) as a function of the rotation rate sensor variables, and

• detects a movement of the mobile terminal (20) as a function of the acceleration variables, and

• generates case information as a function of the detected rotation and the detected movement.

2. The method according to claim 1, characterized in that the holder is attached to a vehicle (10), the method

• detects a movement plane of the vehicle as a function of the yaw rate sensor variables or acceleration sensor variables, the movement plane consisting of a longitudinal direction (x) as the preferred direction of movement and a transverse direction (y) as the lateral direction of movement, and

• detects the rotation depending on the yaw rate sensor variables in the longitudinal direction and transverse direction.

3. The method according to any one of the preceding claims, characterized in that the method

• forms at least one rotation variable as a function of an integration of the rotation rate sensor variables in at least one spatial direction and

• detects the rotation as a function of the exceeding of a first threshold value (SWi) by the rotation variable.

4. The method according to claim 2 and 3, characterized in that the method for each direction of the plane of movement

• forms a rotation variable and assigns a first threshold value (SWi _{, X} _{SWi, y} ), and

• detects the rotation as a function of the exceeding of at least one first threshold value (SWi _{, x} , SWi _{, y} ) assigned to the respective rotation variable by the rotation variable.

5. The method according to any one of the preceding claims, characterized in that the method

• detects the movement depending on whether the acceleration value exceeds a second threshold value (SW2).

6. The method according to any one of the preceding claims, characterized in that the method

• forms an acceleration variance from a plurality of directionally resolved acceleration variables, and

• the movement is recognized as a function of the exceeding of a third threshold value (SW ₃ ) due to the acceleration variance.

7. The method according to any one of the preceding claims, characterized in that the method

• detects a movement plane of the vehicle as a function of the yaw rate sensor variables or acceleration variables, the movement plane consisting of a longitudinal direction (x) as the preferred direction of movement and a transverse direction (y) as the lateral direction of movement, and

• detects the movement depending on the acceleration values in the longitudinal and transverse directions.

8. The method according to any one of claims 2 or 7, characterized in that the method

• Rotation rate sensor variables and / or acceleration variables detected during the movement of the vehicle in the movement plane, and • detects the rotation and / or the movement of the mobile terminal as a function of the deviation of the yaw rate sensor variables and / or acceleration variables in the longitudinal direction and transverse direction from a movement of the vehicle in the movement plane.

9. The method according to claim 8, characterized in that the method

_{• derives fifth threshold values (SWs, ®} , SWs. _A ) from the detected yaw rate sensor variables and / or acceleration variables in the movement of the vehicle in the movement plane, which are not exceeded during the movement of the vehicle in the movement plane, and

• detects the rotation and / or the movement of the mobile terminal depending on whether at least a fifth threshold value is exceeded by currently detected or integrated rotation rate sensor variables and / or acceleration variables in the longitudinal and transverse directions.

10. The method according to any one of the preceding claims, characterized in that the method

• A classification of the case information is generated as a function of the detected rotation and / or detected movement of the mobile terminal.

11. The method according to any one of the preceding claims, characterized in that the method

• Establishes a radio link to an emergency call depending on the generated case information.

12. Mobile terminal (20) for attachment to or in a holder on a vehicle, in particular two-wheeler (10), with an evaluation unit (100) which carries out one of the methods in claims 1 to 10, wherein the evaluation unit (100)

• Rotation rate sensor variables of the mobile terminal (20) detected, and

• Acceleration variables of the mobile terminal (20) detected, and • detects a rotation of the mobile terminal (20) as a function of the rotation rate sensor variables, and

• detects a movement of the mobile terminal (20) as a function of the acceleration variables, and • generates case information as a function of the detected rotation and the detected movement.

13. Mobile terminal (20) according to claim 12, characterized in that the mobile terminal (20) has a transmission unit which, depending on the generated case information, a radio connection to a

Emergency call (150, 170) is established.