System and method for determining whole-body vibrations

Abstract

System (1) for determining whole-body vibrations, the system comprising at least a sensor (2) for measuring accelerations of a vehicle seat (7) in the x, y and z directions, a transmission unit (4) for transmitting acceleration values ​​measured by the sensor to a computing unit (3) for determining a value of a previous exposure using the acceleration measurements, a storage unit (6) and a display unit (5), wherein at least one sensor (2), the transmission unit (4) and the computing unit (3) are arranged within the vehicle seat (7), characterized by the fact that the display unit (5) comprises at least one display area (13) by means of which a recommended action can be displayed to reduce instantaneous exposure, wherein the transmission of the acceleration measurements to the computing unit (3) is a wireless transmission, wherein the wireless transmission is at least one of WLAN, NFC, Bluetooth or a combination thereof.

Description

[0001] The invention relates to a method and a system for determining whole-body vibrations.

[0002] Whole-body vibration generally refers to mechanical vibrations which, when transmitted to a worker's body, pose a risk to the worker's health and safety, particularly to the worker's back and spine. This is especially relevant in work environments where the worker is seated in a vehicle and the seat is subject to vibrations. Examples include truck drivers, farmers, and forklift operators.

[0003] Whole-body vibration measurements are necessary and should be observed in accordance with Regulation (EC) No 2002 / 44 / EC of the European Parliament and of the Council, and in accordance with the German implementation of the Ordinance on the Protection of Employees from Hazards due to Noise and Vibration (LärmVibrationsArbSchV). The limit value or exposure limit A(8) is 1.15 m / s². 2 in the x-direction and y-direction and at 0.8 m / s 2 in the z-direction. The trigger value is 0.5 m / s. 2 However, it should be noted that different limit values ​​A(8) and trigger values ​​exist in different countries.

[0004] US 2009 / 0 188 323 A1 shows a monitoring system for machine vibrations.

[0005] US 2008 / 0258522A1 relates to a method and apparatus for analyzing the effects of vibrations from a vehicle that are transmitted to a person.

[0006] US 2008 / 0 000 301 A1 is directed to a method for measuring vibrations.

[0007] WO 2013 / 083 943 A2 shows a whole-body vibration management device.

[0008] US 8 108 132 B2 concerns component vibrations based on a cylinder deactivation control system.

[0009] US 2006 / 0 185 434 A1 concerns a dosimeter.

[0010] EP 1 672 336 A1 shows a system for monitoring mechanical vibrations.

[0011] EP 1 645 230 A2 relates to an exposure measuring device for a work tool.

[0012] US 2008 / 0 134 794 A1 shows a dosimeter for body vibrations.

[0013] WO 2015 / 138 416 A1 concerns health surveillance.

[0014] GB 2 490 090 A indicates a motion sensor.

[0015] US 2015 / 0308926A1 concerns a vibration analysis method.

[0016] DE 10 2007 006 046 A1 shows a system for measuring and recording movements in a work vehicle.

[0017] EP 1 985 980 A2 relates to a method for evaluating vibrations of a vehicle acting on a person.

[0018] The object of the invention is therefore to provide a method and a system for determining whole-body vibrations.

[0019] This problem is solved according to the features of claims 1 and 2. Advantageous embodiments of the invention are found in the dependent claims.

[0020] The core idea of ​​the invention is to provide a method for determining whole-body vibrations, which comprises the following process steps: a) Measuring the accelerations of a vehicle seat in the x, y and z directions using at least one sensor; b) Transferring measured acceleration values ​​to a computing unit using a transmission unit; c) Determining a value of previous whole-body vibration exposure using the computing unit and acceleration measurements.

[0021] The x, y and z directions correspond to the longitudinal direction, the lateral direction and the vertical direction of the vehicle seat.

[0022] The at least one sensor is designed and intended to measure accelerations in the respective direction. It is conceivable that one sensor measures all directions or that a separate sensor is provided for each direction; that is, in particular, that three sensors are provided.

[0023] The term "previous exposure" refers to the total exposure the driver has received to date. In essence, this means that all previous exposure values ​​are summed and continuously updated over time. Exposures are determined from the acceleration measurements and then totaled. This allows for easy verification of the total exposure the driver has received since starting work and the remaining total exposure.

[0024] According to a preferred embodiment, the acceleration measurements are continuous. This means that acceleration measurements are taken at regular intervals, with a time interval between 1 ms and 10 ms, preferably between 1 ms and 5 ms, and most preferably between 1 ms and 2 ms. Such a measurement method therefore makes it possible to obtain the most accurate possible result for the exposure to date.

[0025] It is advantageous if the acceleration measurements are transmitted wirelessly to the processing unit, where the wireless transmission is at least one of WLAN, NFC, Bluetooth or a combination thereof. Bluetooth is particularly preferred.

[0026] This is particularly advantageous when the processing unit is located in a mobile device, such as a smartphone, tablet, or laptop. Wireless transmission makes it especially easy to transfer the recorded acceleration measurements to the processing unit.

[0027] According to another preferred embodiment, the method includes a further process step: d) Determining a value of instantaneous whole-body vibration exposure using the computing unit and acceleration measurements.

[0028] Instantaneous exposure refers to the current exposure associated with the force acting upon the vehicle, which is accompanied by acceleration. This can indicate, for example, that particularly high exposure levels are being reached in the current driving situation and should be avoided. It is also conceivable that instantaneous exposure can be used to determine how long a driver can be exposed to such a level of exposure before the limit value is exceeded.

[0029] According to another preferred embodiment, the method includes a further process step: e) Storing the acceleration measurements, the values ​​of the previous exposure and, if applicable, the current exposure in a storage unit.

[0030] Saving the respective values ​​allows for an evaluation; this is particularly advantageous if the limit value is exceeded and an improvement in working conditions becomes necessary.

[0031] The procedure includes a further procedural step: f) Displaying the value of previous exposure and, where applicable, current exposure by means of a display unit.

[0032] It is particularly advantageous that the previous exposure value is the last determined previous exposure value, so that the most accurate value possible is displayed.

[0033] Furthermore, the underlying problem is solved by a system for carrying out a method according to the invention, wherein the system comprises at least one sensor, one computing unit, one transmission unit, one storage unit and one display unit.

[0034] In particular, the at least one sensor is designed and intended to record the acceleration of a vehicle seat in the x, y, and z directions. The processing unit is designed and intended to determine or ascertain the values ​​of the previous and, if applicable, current exposure. The transmission unit is designed and intended to transmit the recorded acceleration measurements to the processing unit. The storage unit is designed and intended to store the acceleration measurements, the values ​​of the previous exposure, and, if applicable, the current exposure. The display unit is designed and intended to display the value of the previous exposure and, if applicable, the current exposure.

[0035] Furthermore, a computing unit is preferably provided which is designed and intended to determine previously achieved A(8) values ​​in the x-direction, y-direction and z-direction using the measured accelerations in the x-direction, y-direction and z-direction, which can be used, for example, with A(8) x , A(8) y and A(8) z The determined A(8) values, as already mentioned, represent a calculation of the exposure achieved so far; that is, the A(8) values ​​indicate the previous vibration exposure. The computing unit can be integrated into the vehicle seat or commercial vehicle seat, or it can be located outside the vehicle seat or commercial vehicle seat.

[0036] Preferably, the system further comprises a transmission unit designed and intended to transmit the acceleration values ​​measured by the sensor to the processing unit. Wireless transmission via WLAN, NFC, or Bluetooth is provided by the transmission unit. Like the processing unit, the transmission unit is either integrated into the vehicle seat or commercial vehicle seat, or located outside of it.

[0037] The system features a display unit designed and configured to show specific values ​​determined from the acceleration values. These values ​​could include, for example, the exposure reserve, indicating the permissible level of vibration exposure. The reserve value is calculated by subtracting the previous exposure from the exposure limit. Another value could be the current exposure, calculated by subtracting the previous exposure from the current exposure.

[0038] Furthermore, assuming exposure is normalized to an eight-hour day, it is conceivable that the time until the trigger value or exposure limit is reached can be calculated. This time naturally depends on the current and previous exposure levels.

[0039] Preferably, the current and previous exposure values ​​are displayed using a gauge similar to a fuel gauge, with the start of work indicating a full tank and the trigger value indicating a remaining tank, similar to a fuel reserve. When the exposure limit is reached, the tank is empty. Furthermore, recommendations can be displayed for influencing vibration exposure, such as prompting the driver to slow down or adjust the damper settings.

[0040] The system preferably also includes a storage unit for recording measured values ​​of acceleration, current exposure, and historical exposure. This allows the values ​​to be re-evaluated at a later time to improve vibration protection measures. Furthermore, a reliable display and calculation of current and historical exposure can be provided.

[0041] The at least one sensor is arranged within a vehicle seat. "Within" means, in particular, that the at least one sensor is concealed by parts of the vehicle seat and is not detectable from the outside. More preferably, the at least one sensor is arranged within a seat section of the vehicle seat. This makes it possible to record the accelerations of the vehicle seat as accurately as possible.

[0042] The transmission unit is also located within the vehicle seat. The transmission unit is in signal communication with at least one sensor.

[0043] Further advantageous embodiments are described in the dependent claims.

[0044] Further objectives, advantages and expediencies of the present invention can be found in the following description in conjunction with the drawings. These show: Fig. 1 System for carrying out a method according to one embodiment; Fig. 2 Methods for determining whole-body vibrations according to one embodiment; Fig. 3 Determination of exposure; Fig. 4 possible displays of a display unit; Fig. 5. Graphic overview of the exhibition.

[0045] In the figures, identical components are to be understood by their corresponding reference symbols. For clarity, some components may not have a reference symbol in the figures, but are labeled elsewhere.

[0046] The Fig. Figure 1 shows a system 1 with at least one sensor 2, which is integrated into a vehicle seat 7, whereby it is also conceivable that the sensor 2 is merely connected to the vehicle seat 7. Preferably, however, the at least one sensor 2 is arranged inside the vehicle seat 7. In the present case, in the Fig. 1 of which at least one sensor 2 is arranged in a seat part 14 of the vehicle seat 7.

[0047] Furthermore, a computing unit 3, a transmission unit 4, a storage unit 6 and a display unit 5 of the system 2 are provided.

[0048] The at least one sensor 2 is designed and intended to detect acceleration in the x, y, and z directions, that is, in this case, accelerations acting on the vehicle seat 7 and, accordingly, on the person sitting on the vehicle seat 7. It is also conceivable that three sensors 2 are provided, each of which can detect an acceleration in a specific direction x, y, z.

[0049] The acceleration values ​​recorded by sensor 2 are subsequently transmitted by a transmission unit 4 to the processing unit 3. The transmission unit 4 and the processing unit 3 are preferably wirelessly connected, for example via WLAN, NFC, or preferably Bluetooth. Furthermore, the transmission unit 4 is connected to the at least one sensor 2, and preferably the transmission unit 4 is located within the vehicle seat 7.

[0050] The processing unit 3 processes the acceleration values ​​in such a way that the previous exposure and / or the current exposure can be determined. The previous exposure value describes the vibrations to which the worker has been exposed, and the current exposure value describes the vibrations to which the worker is currently exposed.

[0051] The values ​​of the current exposure or the previous exposure can be displayed to the worker using the display device 5, giving him an overview of the current and previous exposure.

[0052] Furthermore, a storage unit 6 is shown, which is in signal-technical connection with the transmission unit 4 and the computing unit 3, wherein at least the values ​​of the measured accelerations and the current and previous exposure can be stored in the storage unit 6.

[0053] The Fig. 2 apparently a possible method for determining whole-body vibrations according to an embodiment, comprising the method steps: S1) Measuring accelerations in the x-direction, y-direction and z-direction using the sensor, S2) Transmitting the measured accelerations to a computing unit by means of a transmission unit, S3) Determining the value of the previous exposure and, if applicable, the current exposure using the computing unit, S4) Displaying the values ​​of previous exposure and, if applicable, current exposure using the display unit.

[0054] In the following Fig. Section 3 describes in more detail the determination of the previous exposure or the current exposure, which corresponds in particular to procedure step S3.

[0055] First, the acceleration values ​​recorded by at least one sensor 2, in the x, y and z directions, are a x , a y and a z by means of a weighting W d for x and y directions and a weighting W k Weighted in the z-direction. Frequencies corresponding to the body's natural frequencies are given greater weight.

[0056] Subsequently, the weighted acceleration values ​​a x , a y and a z the mean squares of the weighted values ​​are determined and multiplied by a wx , a wy and a wz This is referred to as square averaging. A square averaging is used here to give more weight to the upper peaks.

[0057] Using these weighted values ​​a wx , a wy and a wz The respective exposure values ​​A(8) x , A(8) y and A(8) zdetermined using the following calculation formula: Al(8)=kl1T0∑iawli2 Ti where I = x, y, z and T i denotes a measurement time. Furthermore, k denotes l a weighting factor for the respective direction, where k x = k y = 1.4 and k z = 1.0. Here, T0 is a time normalization and equals eight hours or the respective time of a shift.

[0058] From the obtained values ​​A(8) x , A(8) y and A(8) z A single value is determined which corresponds to the maximum value of the previous exposure, that is, which value is closer to the exposure limit for the respective direction.

[0059] The individual steps are described in the Fig. 3 labelled S10, S20, S30 and S40.

[0060] One preferred display is the Fig. 4 can be seen, which represents the display unit 5, by means of which various values ​​are displayed.

[0061] The value displayed on the left side corresponds to the remaining available vibration absorption, calculated by subtracting the previous exposure value from the exposure limit.

[0062] On the right side, you can see the instantaneous exposure value, which has a first range of 8 and a second range of 9. The first range of 8 represents instantaneous exposure values ​​that are considered not particularly high. Values ​​in the second range of 9 indicate significant instantaneous exposure, and values ​​above the second range of 9, in a third range of 10, are dangerous to the health and safety of the worker.

[0063] Furthermore, a first display area 11, a second display area 12, and a third display area 13 are visible. The first display area 11 indicates the remaining travel time until the trigger value AL is reached, taking into account the current exposure. If the current exposure changes, the remaining travel time also changes. For example, if the current exposure increases, the remaining travel time decreases. The second display area 12 indicates the remaining travel time until the exposure limit value EL is reached, and this time also depends on the current exposure. Optionally, the third display area 13 can show a message recommending a specific action to the worker to reduce the current exposure.Possible prompts include “adjust speed” or “adjust damper setting”, with examples of such prompts being “drive slower”, “drive faster”, “use softer damping” or “use harder damping”.

[0064] The Fig. Figure 5 shows an example graph with the course of the driving time until reaching the trigger value AL, the driving time until reaching the exposure limit value EL, and the current exposure a. wz in the z-direction and the previous exposure A(8).

[0065] All features disclosed in the application documents are claimed to be essential to the invention, provided that they are novel individually or in combination compared to the prior art. Reference symbol list 1 system 2 Sensor 3 Computing Unit 4 transmission unit 5 Display unit 6 storage units 7 vehicle seats 8 first area 9 second area 10 third area 11 first display area 12 second display area 13 third display area 14 Seat section

Claims

[1] System (1) for determining whole-body vibrations, the system comprising at least a sensor (2) for measuring accelerations of a vehicle seat (7) in the x, y and z directions, a transmission unit (4) for transmitting acceleration values ​​measured by the sensor to a computing unit (3) for determining a value of a previous exposure using the acceleration measurements, a storage unit (6) and a display unit (5), wherein at least one sensor (2), the transmission unit (4) and the computing unit (3) are arranged within the vehicle seat (7), characterized by , that the display unit (5) comprises at least one display area (13) by means of which a recommended action can be displayed to reduce instantaneous exposure, wherein the transmission of the acceleration measurements to the computing unit (3) is a wireless transmission, wherein the wireless transmission is at least one of WLAN, NFC, Bluetooth or a combination thereof. [2] Method for determining whole-body vibrations using a system (1) according to claim 1, comprising the method steps: a) Measuring accelerations of a vehicle seat (7) in the x, y and z directions using at least one sensor (2); b) Transmitting measured acceleration values ​​to a computing unit (3) by means of a transmission unit (4), wherein the at least one sensor (2), the transmission unit (4) and the computing unit (3) are arranged inside the vehicle seat (7); c) Determining a value of a previous exposure to whole-body vibration using the computing unit (3) and the acceleration measurements, wherein the step of transmitting the measured acceleration values ​​to the computing unit (3) is a wireless transmission, wherein the wireless transmission is at least one of WLAN, NFC, Bluetooth or a combination thereof, further comprising the step of: Displaying the value of an instantaneous exposure using a display unit (5), wherein the display unit (5) includes at least one display area (13) by means of which a recommended action can be displayed to reduce the instantaneous exposure. [3] Method according to claim 2, characterized by that measuring accelerations is a continuous measurement. [4] Method according to one of claims 2 or 3, characterized by that the procedure includes a further procedural step: d) Determining a value of instantaneous whole-body vibration exposure using the computing unit (3) and the acceleration measurements. [5] Method according to any one of claims 2-4, characterized by that the procedure includes a further procedural step: e) Storing the acceleration measurements, the value of the previous exposure in a storage unit (6). [6] Method according to claim 4, characterized by that the procedure includes a further procedural step: e') Storing the current exposure in the storage unit (6). [7] Method according to any one of claims 2-6, characterized by that the procedure includes a further procedural step: f) Displaying the value of the exposure to date using the display unit (5).

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