Method for operating a seat identification device and identification device - Patents.com

Abstract

The present invention relates to a method for operating an identification device (10) for a vehicle seat (12), wherein an identification of a child car seat or an adult car seat on the seat (12) is performed using an electronic computer (24) of the identification device (10), an airbag device for the seat (12) is activated in response to the identification, a relative variation (34) is determined from a ratio of a pressure variation in the seat (12) to an acceleration variation in the acceleration of the vehicle while the vehicle is moving, and the identification and activation of the airbag device are performed in response to the relative variation (34), wherein a speed variation (30) of a speed (28) of the vehicle is determined using the electronic computer (24), and a decision is made as to whether to perform the identification while the vehicle is moving in response to the determined speed variation (30). The present invention further relates to an identification device (10).

Description

[Technical field]

[0001] The present invention relates to a method for operating an identification device for a vehicle seat according to the preamble of claim 1. Furthermore, the invention relates to an identification device. [Background technology]

[0002] Methods are already known from the prior art for identifying a person on a seat. In particular, the person on the seat can be classified as, for example, a child in a child seat or an adult, where adult is understood in particular to mean a person who can sit on the seat without a booster seat. It is further known from the prior art that, for example, an airbag device can be appropriately deactivated when a child seat is detected on the seat. This increases safety, in particular for a child in a child seat, since the deployment of the airbag is prevented if a child seat is detected. For this purpose, so-called static and dynamic methods are also known from the prior art. In the static method, the pressure on the seat is simply recorded and depending on this pressure it is determined whether or not a child seat is present on the seat. In the dynamic method, the inherent motion of the vehicle, in particular the acceleration of the vehicle, is also taken into account, so that an improved detection of a child seat during travel can likewise be achieved.

[0003] US Patent Application Publication No. 2003004628(A1) describes a weight-based method for characterizing occupants that reliably distinguishes between children, small adults, and tightly secured child seats based on the variance of sensed occupant weight and the variation in vehicle acceleration. The weight variance and acceleration variation are used to determine a relative or normalized variance that compensates for the effects of driving the vehicle on rough road surfaces. An occupant is characterized as a child seat if the normalized variance is below a first threshold for each specified interval, and as a child or small adult if the normalized variance is above a second threshold for each specified interval.

[0004] EP 1 470 968 A1 includes an occupant detection system for a vehicle, which comprises at least one pressure sensor arranged under the foam of a vehicle seat, at least one temperature sensor and an electronic control and / or evaluation device to which the sensors are connected. In particular, means are provided for adjusting the time response of the output signal of a temperature sensor arranged remotely from the pressure sensor or the seat foam, which occurs upon a change in the ambient temperature, to the time response of the temperature prevailing within the pressure sensor or the seat foam. Summary of the Invention [Problem to be solved by the invention]

[0005] It is an object of the present invention to provide a method and an identification device by which an improved identification or classification of persons on a seat can be performed. [Means for solving the problem]

[0006] This object is solved by a method and an identification device according to the independent claims. Advantageous embodiments are set forth in the dependent claims.

[0007] One aspect of the invention relates to a method for operating an identification device for a seat of a motor vehicle, comprising: using an electronic computer of the identification device, an identification of a child seat on the seat or an adult on the seat is performed; in response to the identification, an airbag device on the seat is activated; a relative variation is determined from the ratio of a pressure variation of pressure on the seat during a movement of the motor vehicle to an acceleration variation of the acceleration of the motor vehicle; and in response to the relative variation, an identification is performed and the airbag device is activated.

[0008] It is intended that a speed variation of the speed of the vehicle is determined using the electronic computer and depending on the determined speed variation it is decided whether or not to perform identification during the movement of the vehicle.

[0009] This allows for improved child seat vs. adult discrimination or determination.

[0010] In particular, the invention solves the problem that the decision criteria, i.e. the relative variations, of the dynamic algorithms can unintentionally increase in highly dynamic driving styles, for example with a child seat installed, which in particular include rapid acceleration and deceleration maneuvers as well as successive acceleration and deceleration maneuvers, since pressure variations are more strongly affected than acceleration variations, especially in the z-direction of the vehicle.

[0011] In order to identify the relevant situation as clearly as possible, it is considered advisable to analyze the speed fluctuations. In that case, the calculation can be parameterizable, in particular, via the speed values ​​used for the calculation of the fluctuations. Furthermore, a filtering of the calculated values ​​can be realized, for example, by a moving average value. Here, if the speed fluctuations exceed a parameterizable threshold value, at least for the duration of the exceedance, a corresponding reaction can be performed, for example a reset of the relative fluctuations to an existing parameterizable starting value. Furthermore, for stabilization, a hysteresis function or a similar function can be implemented, for example an extension of the reaction by a parameterizable period.

[0012] This has the particular advantage that in relevant situations, such as rapid acceleration and deceleration maneuvers, a corresponding acceleration change can be identified. For example, evaluating the absolute pedal position alone does not allow this change to be identified, as is the case in the prior art. Identification based on the pedal position, for example, can lead to false positive situations. For example, in the case of driving downhill with a hard brake pedal, a corresponding situation will be detected. Furthermore, in the case of driving uphill with a hard accelerator pedal, a corresponding situation will likewise be detected. Furthermore, false negatives can be determined based on the pedal position. For example, in the case of a change in acceleration below an absolute threshold, a corresponding false negative can be detected.

[0013] According to an advantageous embodiment, a current starting value for the relative variation is determined when a predefined speed threshold is exceeded. In particular, this predefined speed may be, for example, less than 4 kilometers per hour. Moreover, the relative variation is appropriately determined, for example, using a so-called static algorithm that only considers the current pressure. This allows a reliable generation of a starting value for the relative variation, so that the relative variation is then dynamically determined based on the current starting value during the movement of the vehicle, thereby allowing an appropriate identification of the person.

[0014] It is also advantageous if the identification based on the determined current relative variation is suppressed when a predefined threshold for the speed variation is exceeded, thereby making it possible, for example, to suppress erroneous identification in relevant situations, so that during the suppression, for example during rapid acceleration or changes in acceleration, erroneous identification can be eliminated, in this way improving the identification of people throughout the entire journey can be achieved.

[0015] It has further turned out to be advantageous if the starting value of the relative variation is used when the speed variation exceeds the threshold value, in other words if the speed variation exceeds the threshold value, the starting value of the relative variation is used, the relative variation is thus reset and determined again, thereby providing a reliable algorithm for determining the occupant of the seat.

[0016] In a further advantageous embodiment, the speed fluctuation is determined as a function of a filtering of the speed value and / or as a function of a number of speed values. The determination of the speed fluctuation can thus be parameterizable. The individual speed values ​​can also be smoothed beforehand and used to determine the speed fluctuation. Furthermore, the filtering of the calculated values ​​can be realized, for example, by a moving average value.

[0017] It is further advantageous if a steering angle fluctuation of the steering angle is additionally determined and depending on the determined steering angle fluctuation it is decided whether or not a recognition is performed during the movement of the motor vehicle, whereby an additional detection of the corresponding driving situation can be realized. The determination of the steering angle fluctuation is carried out in particular in the same way as the determination of the speed fluctuation.

[0018] It is likewise advantageous if control signals of assistance systems of the motor vehicle are additionally transmitted to the identification device and, depending on the transmitted control signals, it is decided whether or not to perform the identification during the movement of the motor vehicle. This allows, in particular, additional detection of unstable / dynamic driving situations. For example, an anti-lock braking system as an assistance system can transmit a corresponding intervention as a control signal, and then the identification is suppressed in such situations. Furthermore, pre-safe operation requirements can also be used for this purpose. Furthermore, an electronic stabilization program as an assistance system can also transmit a corresponding intervention as a control signal to the identification device.

[0019] In a further advantageous embodiment, the current pressure on the seat is detected using a pressure sensor in the seat and the pressure variation is determined using the electronic computer depending on the detected current pressure. For example, a pressure sensor may be arranged in a pressure mat of the seat, so that the pressure variation can be determined reliably.

[0020] It has further proved to be advantageous if the airbag device is deactivated when a child seat is detected and if an adult is detected, the airbag device is activated. An adult is considered in this specification in particular as a person who does not require a booster seat. An adult may also be a young person who does not require a seat support, so to speak. Thus, when deactivating an airbag, for example a passenger airbag, it is possible to prevent the airbag from being activated when a child seat is detected, which would result in injury to a child in the child seat.

[0021] A further aspect of the invention relates to an identification device for a seat of a motor vehicle, for identifying a child seat or an adult on said seat, comprising at least one electronic computer, said identification device being adapted to implement the method according to the previous aspect, in particular the method being implemented using the identification device.

[0022] A further aspect of the invention relates to a motor vehicle, in particular a passenger car, comprising an identification device according to the previous aspect.

[0023] Further advantages, features and details of the invention will become apparent from the following description of preferred exemplary embodiments and from reference to the drawings, in which: The features and combinations of features mentioned in the above description and those mentioned in the following description of the drawings and / or shown only in the drawings can be used not only in the respective combinations described, but also in other combinations or alone, without departing from the scope of the invention. [Brief description of the drawings]

[0024] [Figure 1] FIG. 1 is a schematic perspective view of one embodiment of an identification device. [Diagram 2] 1 is a schematic graph including a record of a vehicle's speed and associated speed fluctuations. [Diagram 3] 2 is a schematic graph according to one embodiment of the method; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0025] In the drawings, the same elements or elements with the same function are provided with the same reference numbers.

[0026] 1 shows a schematic perspective view of an identification device 10 for a motor vehicle (not shown). The identification device 10 is in particular configured for a seat 12 of a motor vehicle. The seat 12 in turn comprises in particular a backrest 14, a cover 16, a foam padding 18 and a pressure sensor 20. Furthermore, the pressure sensor 20 is in particular formed from at least one silicone-filled mat 22. Furthermore, the identification device 10 comprises at least one electronic calculator 24 equipped with a pressure sensor and a temperature sensor. The seat 12 further comprises a spring base 26.

[0027] FIG. 2 shows a schematic graph of a vehicle's speed 28 and the corresponding determined speed fluctuations 30.

[0028] In the indicated range, relevant situations 32 in which a sudden braking maneuver is performed can be particularly shown here, which are indicated in particular by a drop in the speed curve. These relevant situations 32 can also be seen as spikes in the speed variation curve.

[0029] In a method for operating the identification device 10 of a vehicle seat 12, an identification of a child seat on the seat 12 or an adult on the seat 12 is performed using the electronic computer 24 of the identification device 12, and an airbag device (not shown) of the seat 12 is activated in response to the identification. A relative variation 34 (FIG. 3) is determined from the ratio of the pressure variation of the pressure on the seat 12 during the movement of the vehicle to the acceleration variation of the acceleration of the vehicle, and an identification is performed and the airbag is activated in response to the relative variation 34.

[0030] It is provided that the speed fluctuations 30 of the speed 28 of the motor vehicle are determined using the electronic calculator 24 and that depending on the determined speed fluctuations 30 it is decided whether or not to perform a discrimination during the movement of the motor vehicle. Figure 2 particularly shows that the discrimination is suppressed in the area of ​​relevant conditions 32. In particular, for this purpose it is provided that the discrimination based on the determined current relative fluctuations 34 is suppressed, for example when a predefined threshold value 36 for the speed fluctuations 30 is exceeded.

[0031] It may further be specifically contemplated that the velocity fluctuations 30 are defined as a function of filtering of the velocity values ​​and / or as a function of multiple velocity values.

[0032] Thus, in particular, FIG. 2 shows a strong and simple brake. This behavior is detected and subsequently the identification is suppressed. This is because, in particular, in a highly dynamic driving style, such as for example hard braking, the relative fluctuations 34 can increase unintentionally. The reason is that, in particular in the z-direction, the influence on the pressure fluctuations is relatively greater than the acceleration fluctuations. In particular, an analysis of the speed fluctuations 30 has proven to be expedient in order to identify the relevant situation 32 as clearly as possible. This allows the decision to be parameterizable, for example via a number of speed values, in particular previously smoothed speed values, used for the calculation of the speed fluctuations 30. Furthermore, a filtering of the calculated values ​​can be realized, for example by a moving average value. If the speed fluctuations 30 exceed a parameterizable threshold value, in particular the threshold value 36, at least for the duration of the exceedance, a corresponding reaction can be performed, for example a resetting of the relative fluctuations 34 to an existing parameterizable starting value. Furthermore, for stabilization, a hysteresis function or a similar function can be implemented, for example an extension of the reaction by a parameterizable period.

[0033] The method according to the invention can also be used for stabilization when only static algorithms are executed. Furthermore, a steering angle variation of the steering angle can additionally be determined and, depending on the determined steering angle variation, it can be determined whether or not the identification is performed during the movement of the vehicle. Thereby, a further detection of a corresponding driving situation can be realized. The determination of the steering angle variation is in particular performed similarly to the determination of the speed variation. Additionally, control signals of the assistance systems of the vehicle can be transmitted to the identification device 10 and, depending on the transmitted control signals, it can be determined whether or not the identification is performed during the movement of the vehicle. Thereby, in particular unstable / dynamic driving situations can additionally be detected. For example, a corresponding intervention can be transmitted as a control signal by an anti-lock braking system as an assistance system and then the identification is suppressed in such a situation. Furthermore, pre-safe operation requirements can also be used for this purpose. Furthermore, an electronic stabilization program as an assistance system can also transmit a corresponding intervention as a control signal to the identification device 10.

[0034] Fig. 3 shows a further schematic graph with the relative variation 34. In particular, Fig. 3 shows a filtered relative variation 38, a starting value 40 of the relative variation 34, a threshold value 42 for the relative variation 34 for detecting a child seat, and a threshold value 44 for the relative variation 34 for detecting a person, in particular an adult. In this case, in particular, an adult is identified as being seated in the seat 12 during a vehicle movement. The starting value 40 for the relative variation 34 is determined in particular when the speed is less than 4 km / h. If the speed is more than 4 km / h, the parameterizable starting value 40 is output. In this case, in particular, it is shown that if the relative variation 34 exceeds the threshold value 44, the corresponding airbag device is switched on. If the relative variation 34 is below the threshold value 42, the airbag device is switched off.

[0035] The speed fluctuation 30 is determined in a similar manner to the pressure and acceleration fluctuations, in particular from 4 kilometers per hour. For this, a corresponding fluctuation range and a corresponding pre-filtering, for example via a filtering device, are required. Here, it is provided that if the speed fluctuation 30 exceeds a corresponding threshold value 36, a reset of the relative fluctuation 34 to a starting value 40 is performed, which is particularly illustrated by the arrow 46. This allows a safe state to be established. The speed fluctuation 30 can be output in raw frames. For example, instead of the relative pressure, a direct output for a test drive is meaningful.

[0036] The idea according to the invention therefore generally presents an improved person detection and classification using the pressure sensor 20 in the seat 12, where speed variations 30 above a threshold 36 do not use the corresponding signal or use it as an exclusion from the current evaluation and initially reset the parameters, thus preventing erroneous evaluations during changes in the running motion and stabilizing the decision algorithm. As an important feature of the method, it is envisaged that in particular if the speed variations 30 exceed the threshold 36, the measurements are truncated or ignored, thereby allowing a better and more stable evaluation of the person detection and classification related to the running motion than is possible, for example, via the pedal position alone. Thus, if the speed variations 30 exceed the threshold 36, the corresponding parameters are skipped and reset and the speed variations 30 are analyzed and used. [Explanation of symbols]

[0037] 10 Identification device 12 seats 14 Backrest 16 Cover 18 Foam Pad 20 Pressure Sensor 22 Silicone Filling Mat 24 Electronic computer 26 Spring Mat 28 speed 30 Speed ​​Fluctuation 32 Related circumstances 34 Relative Fluctuations 36 Threshold 38 Filtered relative variation 40 starting value 42 Threshold 44 Threshold 46 Arrow

Claims

1. A method for operating an identification device (10) in a vehicle seat (12), comprising: determining a relative change (34) representing a characteristic of how the pressure changes with respect to the change in acceleration based on a change in pressure on the seat (12) and a change in acceleration of the vehicle while the vehicle is moving; a speed variation (30) of the speed (28) of the vehicle is determined using an electronic computer (24) of the identification device (10), and if the determined speed variation (30) does not exceed a predefined threshold (36), an identification of a child seat on the seat (12) or an adult on the seat (12) is carried out using the electronic computer (24), An airbag device is switched on or off depending on the relative variation (34) and the result of the identification. Furthermore, the performance of said identification is inhibited during said movement of said vehicle if said determined speed fluctuation (30) exceeds said predefined threshold (36).

13. A method for operating a seat identification device, comprising:

2. A starting value (40) for said relative variation (34) is determined when the velocity falls below a predetermined threshold.

2. A method for operating a seat identification device according to claim 1.

3. When the speed variation (30) exceeds the predetermined threshold (36), the starting value (40) of the relative variation (34) is used. A method for operating a seat identification device according to claim 2.

4. The speed fluctuation (30) is determined in response to a filtering process that generates a moving average of the speed values ​​and in response to a plurality of smoothed speed values. A method for operating a seat identification device according to any one of claims 1 to 3.

5. Additionally, a steering angle variation of the steering angle is determined, The performance of the identification is also inhibited during the movement of the vehicle when a predetermined threshold for the steering angle variation is exceeded. A method for operating a seat identification device according to any one of claims 1 to 4.

6. Additionally, when the assistance system of the vehicle detects at least one of an unstable driving state and a driving state involving a sudden speed change, a control signal is transmitted to the identification device (10), and even when the control signal is transmitted, the identification is inhibited from being performed during the movement of the vehicle. A method for operating a seat identification device according to any one of claims 1 to 5.

7. A current pressure on the seat (12) is sensed using a pressure sensor (20) in the seat (12), and an amount of change in the pressure is determined using the electronic computer (24) in response to the sensed current pressure. The seat identification device according to any one of claims 1 to 6 is operated. How to.

8. When a child seat is identified, the switch of the airbag device is turned off, and when an adult is identified, the switch of the airbag device is turned on. A method for operating a seat identification device according to any one of claims 1 to 7.

9. An identification device (10) for a seat (12) of a motor vehicle for identifying a child seat or an adult on said seat (12), said device comprising at least one electronic computer (24), The identification device (10) is adapted to carry out the method according to any one of claims 1 to 8. An identification device (10).

Images