Safety device and method for detecting an emergency situation of a person

Abstract

The aim of the invention is to better prevent false activations in a safety device which detects an emergency situation of a person wearing the safety device via the movement state. This is achieved in that the acceleration (B) of the person (2) wearing the safety device (1) is detected by means of an acceleration sensor (4) on the safety device (1), and the detected acceleration (B) is analyzed by an analysis unit (5) in order to detect an emergency situation of the person (2) from the acceleration (B) time curve produced from the detected acceleration (B). In the event of a detected emergency situation, a safety action is initiated by the analysis unit (5), wherein the analysis unit (5) initiates the safety action for the produced acceleration (B) time curve after a period of time (TD), said period of time (TD) being set on the basis of the detected acceleration (B).

Description

[0001] Safety device and method for detecting a person's emergency situation

[0002] The present invention relates to a safety device for detecting an emergency situation of a person wearing the safety device. An acceleration sensor is provided on the safety device to detect an acceleration, preferably in 3D space, of the person wearing the safety device. An evaluation unit is provided on the safety device to evaluate the detected acceleration in order to detect an emergency situation of the person from a resulting temporal progression of the acceleration. The evaluation unit triggers at least one configured safety action in the event of a detected emergency situation. The invention also relates to a corresponding method for detecting an emergency situation of a person wearing the safety device.

[0003] When a person works in a safety-critical environment, safety devices are sometimes used that use motion sensors to detect critical or emergency situations. Examples of safety-critical environments include electrical systems, electrical power transmission systems, industrial facilities, etc. For example, in the event of a person suffering cardiac arrest, help must be called as quickly as possible. Minutes, or even seconds, can separate the person's death from rescue. If someone is otherwise seriously injured, help must also be called, but it is not quite as time-critical as in the case of cardiac arrest. This is particularly important if the person is working alone.The safety device worn by the person often detects such emergency situations with the help of motion sensors, such as position or acceleration sensors. A motion sensor detects a specific state of movement, for example, immobility, a person lying down, etc. When a certain state of movement is detected, such a safety device triggers a pre-alarm - usually an acoustic one. If there is no response to the pre-alarm, for example, by a noticeable movement or the pressing of a button on the safety device, then an alarm is triggered and help is called, for example through acoustic and / or visual signals, by sending text messages, by sending emails, or by voice calls. However, pre-alarms can occur very frequently, even when there is no critical situation.If, for example, a person is sitting at a desk or in a meeting, a state of inactivity can be mistakenly identified as a critical state of movement, triggering a pre-alarm or even an alarm. This becomes annoying sooner or later. A common reaction of the person wearing the safety device is to deactivate the safety function of the safety device or the entire safety device. If the person forgets to switch the safety function or the safety device back on, a potential danger arises because critical situations can no longer be detected. A known workaround for this problem is to combine immobility with a position sensor. Immobility is only reported if the person is lying down or is at a certain angle.However, there is no guarantee that a person will actually end up lying horizontally after a fall, nor is there any guarantee that a particular emergency situation, such as a heart attack, will occur in a particular position of the person, for example in a more or less sitting position.

[0004] There is therefore a need to improve a safety device and a method that detects an emergency situation of a person wearing the safety device via a movement state in this respect, in particular by better suppressing false triggering.

[0005] For this purpose, the evaluation unit is designed to trigger the safety action for the resulting temporal progression of the acceleration after a period of time and to set the period of time as a function of the detected acceleration.

[0006] By setting the time period based on the person's acceleration, i.e., their current state of motion, it's easier to respond to situations where a certain state of motion exists, even though the person isn't in an emergency. Previously, a fixed relationship between acceleration and time period was required. This required a compromise, which, however, led to false triggering in certain situations. The inventive approach makes the time period dependent on the acceleration and can thus be better adapted to current states of motion, making false triggering easier to avoid.

[0007] It is advantageous if the evaluation unit sets the time period shorter, the lower the currently detected acceleration is. This is based on the idea that at low accelerations, for example, when the person is (almost) motionless, it is more likely that an emergency situation is present for the person than at higher accelerations. If accelerations are expected due to a person's normal movement, it can be concluded that no emergency situation exists at all. This can be reflected by the time period, and the triggering behavior of the safety device can thus be specifically configured.

[0008] In an advantageous embodiment, a first acceleration threshold is provided in the evaluation unit, to which a time period is assigned. The evaluation unit triggers the safety action if the detected acceleration falls below the first acceleration threshold during the time period assigned to the acceleration threshold. This is particularly easy to implement because only an acceleration threshold with an associated time period needs to be specified. A comparison of the detected acceleration with an acceleration threshold is also easy to implement.

[0009] To refine the triggering behavior, the evaluation unit can be provided with a first acceleration threshold and a second acceleration threshold, each of which is assigned a time period. The evaluation unit triggers the safety action if the detected acceleration falls below the first acceleration threshold during the time period assigned to the first acceleration threshold or if the detected acceleration falls below the second acceleration threshold during the time period assigned to the second acceleration threshold. Each acceleration threshold can also be assigned its own safety action in order to trigger different safety actions.

[0010] In a particularly advantageous embodiment, the security device also features a motion sensor that detects a motion signal characterizing the movement state, which is different from the acceleration. The evaluation unit also sets the time period based on the detected motion signal. This allows the time period to be further influenced. The underlying idea is that acceleration may be uncritical in combination with a certain motion signal, which, for example, reflects a person's orientation, but can very well be critical in combination with another motion signal. This allows false triggering to be further suppressed.

[0011] This can be implemented by the evaluation unit setting at least one acceleration threshold value depending on the motion signal.

[0012] The present invention will be explained in more detail below with reference to Figures 1 to 6, which show exemplary, schematic and non-limiting advantageous embodiments of the invention.

[0013] Fig.1 a person with safety device,

[0014] Fig.2 a person with safety device in an emergency situation,

[0015] Fig.3 an example of a relationship between acceleration and time,

[0016] Fig.4 triggering when an acceleration threshold is undershot,

[0017] Fig.5 a triggering due to a time period resulting from a temporal progression of the acceleration and

[0018] Fig.6 a person with security device with an additional motion sensor.

[0019] The invention relates to a safety device 1 for detecting an emergency situation of a person 2 wearing the safety device 1, as shown in Fig. 1. An emergency situation is a situation in which there is a danger to the health of the person 2, for example after an accident or a health emergency. The safety device 1 is, for example, arranged on an item of clothing 7, for example a shirt, T-shirt, sweater, trousers, etc., of the person 2 or is inserted into a pocket of the item of clothing 7 or is otherwise worn by the person 2. The safety device 1 can also be integrated into the item of clothing 7, for example as an intelligent item of clothing with integrated electronics. The person 2 works, for example, on a system 3, for example an energy distributor or a system for generating, distributing or transmitting electrical energy.Installation 3 may be located in a very remote location, for example a power pylon of an energy supply network.

[0020] An acceleration sensor 4 and an evaluation unit 5 are provided on the safety device 1. The acceleration sensor 4 detects the movement state of the person 2 wearing the safety device 1, preferably in three-dimensional space. The acceleration sensor 4 can be integrated into the safety device 1, but can also be present as a separate component and connected to the evaluation unit 5 in a suitable manner.

[0021] The state of motion is generally understood to mean the position (location), orientation, speed and / or acceleration of person 2, usually in 3-dimensional space.

[0022] The evaluation unit 5 can be a microprocessor-based hardware device running corresponding software. However, the evaluation unit 5 can also be implemented as an integrated circuit, such as a field-programmable gate array (FPGA) or an application-specific integrated circuit (ASCI). Other implementations are also conceivable.

[0023] The acceleration sensor 4, for example, determines the accelerations in 3-dimensional space. The acceleration sensor 4, for example, provides three linear acceleration values ​​for the translational movement in the three spatial directions, but can also, or additionally, provide three rotational acceleration values ​​for the rotational movement. From this, a linear acceleration of person 2 in space can be determined, but also, alternatively or additionally, a rotational acceleration state. The acceleration is usually related to a reference position or reference orientation, for example, to a reference coordinate system. When an acceleration B of person 2 is mentioned below, this means a linear acceleration in space (or also divided into the three spatial directions) and / or a rotational acceleration state of person 2.

[0024] A so-called inertial measuring unit is often used to record a state of motion. An inertial measuring unit provides three linear acceleration values ​​for the translational movement and three angular velocities for the rotation rates of a body (here, person 2). From these measured values, the speed of person 2 in space (e.g., by integrating the linear accelerations), the position of person 2 in space (e.g., by integrating the linear accelerations twice), and the orientation of person 2 in space (by integrating the angular velocities) can be determined—in other words, a complete state of motion of person 2. The acceleration sensor 2 is advantageously designed as an inertial measuring unit.

[0025] The evaluation unit 5 receives the acceleration B characterizing the movement state of the person 2 from the acceleration sensor 4 and evaluates it in order to detect an emergency situation of the person 2 wearing the safety device 1 based on the movement state. If an emergency situation is detected, the safety device 1, e.g., the evaluation unit 5, triggers at least one configured safety action.

[0026] The security action can, for example, include triggering an acoustic and / or visual alarm, but also signaling an alarm to a security center or security personnel configured in the security device 1, or to an emergency service, for example, by sending a text message, an email, or a voice call, etc. The security device 1 therefore naturally also includes a suitable communication interface for triggering the alarm. The communication interface also depends on the type of security action and alarm.

[0027] The evaluation unit 5 is configured to trigger the safety action after a time period TD, wherein the evaluation unit 5 sets the time period TD depending on the detected acceleration. The time period TD is thus adapted to the movement state of the person 2 in order to avoid unwanted false triggering as far as possible. The inventive idea is that an emergency situation will only manifest itself with small accelerations, i.e. when the person 2 moves little or not at all. If, on the other hand, higher accelerations B occur, for example as part of the person's normal movement, it can generally not be assumed that the person 2 is in an emergency situation, or it can be assumed that the person 2 is still able to call for help.

[0028] At low accelerations B, the evaluation unit 5 should trigger the safety action more quickly than at higher accelerations B. Therefore, the time period TD in the evaluation unit 5 is set shorter at low accelerations B than at higher accelerations B. If a certain acceleration B or an acceleration less than a certain acceleration B occurs during the time period TD, the safety action is triggered. At higher or normal accelerations B, the time period TD can become very long, or even approach infinity.

[0029] This can of course be implemented in different ways, as explained below.

[0030] In an advantageous embodiment, the evaluation unit 5 checks whether the acceleration B falls below a predetermined acceleration threshold value BS1 during the time period TD.

[0031] The time period TD can be assigned to the acceleration threshold BS1, for example, by configuring the evaluation unit 5. If the detected acceleration B falls below the acceleration threshold BS1, a check is performed to determine whether the acceleration B falls below the acceleration threshold during the time period TD assigned to the acceleration threshold BS1. Of course, several different acceleration thresholds BS1, BS2 can also be provided, each of which is assigned a time period TD.

[0032] For example, person 2 may be lying motionless on the ground due to an accident, as shown in Fig.2. In such a state of movement, the acceleration sensor

[0033] 4 only very low accelerations B are recorded, for example, less than a first acceleration threshold BS1 of 25 mg (milli-g, i.e. thousandths of the acceleration due to gravity g). Even if person 2 is motionless, it can be assumed that small accelerations B are recorded, either due to the measurement noise of the acceleration sensor 4 or due to vibrations of the floor on which person 2 is lying. Therefore, a lowest acceleration threshold BS1 should take such influences into account. Due to the motionlessness, this indicates a serious incident and a serious emergency situation for person 2. In this case, the time period TD of the undershoot can be set short, for example, to 60 s (seconds). If this state of movement does not change during the time period TD, the evaluation unit

[0034] 5 the configured safety action is triggered, for example, the sending of an alarm, for example to an emergency service. If, on the other hand, an acceleration B less than a second acceleration threshold BS2 of 100 mg is detected, it can be assumed that person 2 is moving slightly, for example due to breathing. In this case, the second time period TD2 of the undershoot can be set somewhat longer, for example to 300 s (seconds). Above the second acceleration threshold BS2, for example, no safety action is triggered at all or only an alarm is triggered for a colleague, or further acceleration thresholds above the second acceleration threshold BS2 can be specified.

[0035] Fig. 3 shows another embodiment of a relationship between the acceleration and the time duration TD. Shown are three different first movement signals B1, B2, B3, each of which is assigned a time duration TD. In this example, there is a continuous (here linear) region and discrete regions of the assignment. For the smallest accelerations B, less than an acceleration threshold value BS1, the acceleration threshold value BS1 is again assigned a time duration TD, which must be taken into account for accelerations B1 below the acceleration threshold value BS1. For larger accelerations B3, the time duration TD is continuously dependent on the acceleration B3, i.e. each acceleration B3 is assigned a time duration TD according to a defined relationship. If the acceleration B3 is below the acceleration threshold value BS3, the time duration TD is set to the value resulting from the acceleration B3.For average accelerations B2, a mixture of a discrete and continuous assignment is provided, from which the time period TD is derived.

[0036] The relationship between the acceleration B and the time period TD, for example as shown in Fig.2 or Fig.3, is stored in a suitable manner in the evaluation unit 5, for example in tabular form, as a mathematical function, discretely or continuously.

[0037] In this embodiment, a time period TD is set based on a currently detected acceleration B and then a check is carried out to determine whether the acceleration B has a specific temporal profile in this time period, for example, whether it is less than a specific acceleration threshold value BS. In other words, at the triggering time U of the safety action, the past acceleration profile in the past time period TD has thus adopted a specific temporal profile, for example, less than a specific acceleration threshold value BS. The past time period TD is the time period immediately before the triggering time U. This is illustrated by way of example in Fig. 4, which shows the acceleration B over time t. At the triggering time U of the safety device 1, the acceleration B was less than an acceleration threshold value BS during the time period TD, which, as described above, depends on the acceleration B.

[0038] In another embodiment, the time period TD is not determined as such, but rather the time period TD results from the temporal acceleration curve and is set in this way in the evaluation unit 5. The time period TD is therefore also dependent on the detected acceleration B.

[0039] In a possible embodiment, according to Fig.5, the safety device 1 is triggered due to a time period TD resulting from a temporal progression of the acceleration B.

[0040] For example, an acceleration effect W is determined from the acceleration B recorded at each point in time (preferably in time-discrete sampling steps), for example as the inverse 1 / B of the acceleration B, possibly also weighted, for example to take small accelerations into account even more. The acceleration effects W at each point in time are added together over a predetermined time window to form an acceleration sum ZB. The time window is a predetermined observation period, but can also be the entire time period since switching on the safety device 1. At the same time, a predetermined acceleration effect W is subtracted from the current acceleration sum ZB at each point in time, whereby the acceleration sum ZB cannot be negative.For large accelerations B, the reciprocal is small and the acceleration sum ZB will be low or even zero, especially because an acceleration effect W is also subtracted in each period. However, if the current acceleration B is small, the reciprocal is large and the acceleration sum ZB increases sharply, especially if the acceleration B remains low for a longer period, for example, if person 2 is motionless. If the acceleration sum ZB exceeds a predetermined limit BG, the safety action is triggered. This results in the time period TD as the period before the triggering time U during which the acceleration B had low values. The effect is thus the same as in the embodiment shown in Fig. 4.

[0041] It is obvious that in such a configuration, acceleration B can also be evaluated in a manner other than with an acceleration sum ZB. For example, a moving average could be determined over a time window. If the average is less than a threshold value, the safety action could be triggered. Likewise, the area under the acceleration during a time window could be evaluated, for example, as an integral.

[0042] In this embodiment, the time period TD thus results from a past acceleration curve, whereby the time period TD becomes shorter the lower the acceleration B is in the past acceleration curve. The past acceleration curve is the temporal profile of the acceleration B in a predetermined time window before the current time. The time period TD can additionally depend on a second motion signal B2, which is different from the first motion signal B1, as explained with reference to Fig. 6.

[0043] In this exemplary embodiment, the safety device 1 comprises a motion sensor 6 that detects a movement state of the person 2 wearing the safety device 1. The motion sensor 6 detects a movement signal B2 that differs from the detected acceleration B. The second movement signal B2 is transmitted to the evaluation unit 5 and evaluated therein.

[0044] The motion sensor 6 is, for example, a position sensor that provides a motion signal B2 that characterizes the orientation of the person 2 in 3-dimensional space.

[0045] If the acceleration sensor 4 is designed as an inertial measuring unit that can also provide a position or orientation of the person 2 in space, the acceleration sensor 4 can of course also function simultaneously as a motion sensor 6. The acceleration sensor 4 and the motion sensor 6 are thus integrated into one sensor.

[0046] If the detected acceleration B falls below a specified acceleration threshold BS, the additional motion signal B2 can also be checked. If the motion signal B2 is within a specified signal range, a specific time period TD is set. If the motion signal B2 is outside the specified signal range, a different time period TD is set, as indicated in Fig. 6. Of course, multiple signal ranges are also possible, each of which is assigned a specific time period TD.

[0047] In the case of a position sensor as the second motion sensor 6, the signal range (position range) can be set, for example, to a range of -45° to +45° (relative to a horizontal plane). If the acceleration B falls below an acceleration threshold BS (e.g., 100 mg in the above embodiment), the time period TD is set to 60 s if an orientation of person 2 is also detected within the position range. If the orientation is outside the position range, the time period TD is set to 300 s.

[0048] The time period TD therefore depends not only on the detected acceleration B, but also on the further movement signal B2.

[0049] Furthermore, it is conceivable that the at least one acceleration threshold BS depends on the second motion signal B2. In this case, it is possible to provide different acceleration thresholds BS for acceleration B, depending on a current motion signal B2. For example, a different acceleration threshold BS could be provided when person 2 is lying down compared to a motion state in which person 2 is standing or sitting. The lying position of person 2 can again be determined, for example, by a position range of -45° to +45°.

Claims

Patent claims 1 . Safety device for detecting an emergency situation of a person (2) wearing the safety device (1), wherein an acceleration sensor (4) is provided on the safety device (1), which detects an acceleration (B), preferably in 3-dimensional space, of the person (2) wearing the safety device (1), wherein an evaluation unit (5) is provided on the safety device (1), which evaluates the detected acceleration (B) in order to detect an emergency situation of the person (2) from a resulting temporal profile of the acceleration (B), and the evaluation unit (5) triggers at least one configured safety action in the event of a detected emergency situation, characterized in that the evaluation unit (5) is configured to trigger the safety action for the resulting temporal profile of the acceleration (B) after a time period (TD) and to set the time period (TD) as a function of the detected acceleration (B).

2. Safety device according to claim 1, characterized in that the evaluation unit (5) sets the time period (TD) to be shorter, the lower the currently detected acceleration (B) is.

3. Safety device according to claim 1 or 2, characterized in that a first acceleration threshold value (BS1) is provided in the evaluation unit (5), to which a time period (TD) is assigned, and the evaluation unit (5) triggers the safety action if the detected acceleration (TD) falls below the first acceleration threshold value (BS1) during the time period (TD) assigned to the acceleration threshold value (BS1).

4. Safety device according to claim 1 or 2, characterized in that a first acceleration threshold value (BS1) and a second acceleration threshold value (BS2) are provided in the evaluation unit (5), each of which is assigned a time period (TD), and the evaluation unit (5) triggers the safety action if the detected acceleration (B) falls below the first acceleration threshold value (BS1) during the time period (TD) assigned to the first acceleration threshold value (BS1) or if the detected acceleration (B) falls below the second acceleration threshold value (BS2) during the time period (TD) assigned to the second acceleration threshold value (BS2).

5. Safety device according to claim 1 or 2, characterized in that a first acceleration threshold value (BS1) and a second acceleration threshold value (BS2) are provided in the evaluation unit (5), each of which is assigned a time period (TD), and the evaluation unit (5) triggers a first safety action if the detected acceleration (B) during the time period assigned to the first acceleration threshold value (BS1) time period (TD) falls below the first acceleration threshold value (BS1) or the evaluation unit (5) triggers a second safety action if the detected acceleration (B) falls below the second acceleration threshold value (BS2) during the time period (TD) assigned to the second acceleration threshold value (BS2).

6. Safety device according to claim 1 or 2, characterized in that the evaluation unit (5) is designed to trigger a safety action on the basis of a time period (TD) resulting from a temporal progression of the acceleration (B).

7. Safety device according to one of claims 1 to 6, characterized in that a motion sensor (6) is provided on the safety device (1), which detects a motion signal (B2) characterizing the state of motion, which is different from the acceleration (B), and in that the evaluation unit (5) additionally sets the time period (TD) as a function of the detected motion signal (B2).

8. Safety device according to claim 7, characterized in that the evaluation unit (5) sets at least one acceleration threshold value (BS1, BS2) as a function of the movement signal (B2).

9. Security device according to claim 7 or 8, characterized in that the motion sensor (6) is a position sensor and the motion signal (B2) indicates an orientation of the person (2), preferably in 3-dimensional space.

10. Method for detecting an emergency situation of a person (2) with a safety device that the person (2) wears, wherein an acceleration (B), preferably in 3-dimensional space, of the person (2) wearing the safety device (1) is detected by an acceleration sensor (4) on the safety device (1), and the detected acceleration (B) is evaluated by an evaluation unit (5) in order to detect an emergency situation of the person (2) from a temporal profile of the acceleration (B) resulting from the detected acceleration (B), and in the event of a detected emergency situation, at least one configured safety action is triggered by the evaluation unit (5), characterized in that the evaluation unit (5) triggers the safety action for the resulting temporal profile of the acceleration (B) after a time period (TD), wherein the time period (TD) is set as a function of the detected acceleration (B).

11. Method according to claim 10, characterized in that the time period (TD) is set shorter, the lower the currently detected acceleration (B) is.

12. Method according to claim 10 or 11, characterized in that the safety action is triggered when the detected acceleration (B) during a pre- the time period (TD) assigned to the given acceleration threshold value (BS1) falls below the first acceleration threshold value (BS1).

13. The method according to claim 10 or 11, characterized in that the safety action is triggered when the detected acceleration (B) falls below the first acceleration threshold (BS1) during a first time period (TD) associated with a predetermined first acceleration threshold (BS1) or when the detected acceleration (B) falls below the second acceleration threshold (BS2) during a second time period (TD) associated with a predetermined second acceleration threshold (BS2).

14. The method according to claim 10 or 11, characterized in that a first safety action is triggered when the detected acceleration (B) falls below the first acceleration threshold (BS1) during a first time period (TD) associated with a predetermined first acceleration threshold (BS1) or a second safety action is triggered when the detected acceleration (B) falls below the second acceleration threshold (BS2) during a second time period (TD) associated with a predetermined second acceleration threshold (BS2).

15. Method according to claim 10 or 11, characterized in that a safety action is triggered on the basis of a time period (TD) resulting from a temporal progression of the acceleration (B).

16. Method according to one of claims 10 to 15, characterized in that a movement signal (B2) characterizing the movement state of the person (2) is detected with a movement sensor (6), which is different from the acceleration (B), and in that the time period (TD) is additionally set as a function of the detected movement signal (B2).

17. The method according to claim 16, characterized in that at least one acceleration threshold value (BS1) is set as a function of the movement signal (B2).