Sensor device evaluation method

Abstract

A method for evaluating a sensor device having at least one proximity sensor is disclosed. The sensor measurements (S1, S2) of the proximity sensors are monitored (in block 10) and, if the onset of a movement is captured, a timer (t1) is started (in block 30). If a first timer reaches a first target value (tz1) and if the sensor measurements (S1, S2) continuously fulfill a first criterion since the start of the first timer, a first actuation signal is output (in block 30). If further sensor measurements fulfill a second criterion (in block 20) ​​configured for the recognition of a valid execution of a manipulation gesture, a valid operation is confirmed and, if the first actuation signal has already been output, a second actuation signal is output (in block 20). If the first actuation signal has not yet been output, first the first actuation signal is output, followed by the second actuation signal.

Description

[Technical Field]

[0001] The present invention relates to a method for evaluating a sensor device, in particular to a method for using a sensor device having at least one proximity sensor for capturing the spatial proximity of a body, the sensor device further comprising a control and evaluation device coupled to the proximity sensor and having its own signal output. [Background technology]

[0002] Sensor devices of the above type are used in automobiles to recognize operating gestures. For example, such sensor devices, which include capacitive or optical proximity sensors, but sometimes also ultrasonic or radar sensors, are used in vehicles, whereby vehicle functions are deactivated by performing an operating gesture. For example, the operation of doors or hatchbacks, especially the tailgate, can be performed in this manner primarily contactlessly. Contactless means, in this context, that the operator does not need to perform a door lock or unlock the door handle.

[0003] The measured values ​​of the proximity sensor are evaluated in a known manner to determine whether the time signal progression of the data output by the proximity sensor corresponds to a set criterion that characterizes a valid user action command. For example, complex pattern comparisons can be performed, but it is also possible to compare value changes within a specific time period, as well as simple time characteristics of the signal progression. If the proximity sensor is located in the rear area of ​​the vehicle, for example as a capacitive sensor, it is typically assumed that the user must first perform a leg or foot swing toward the vehicle and then back again to express the action command. Such a kick sensor appropriately evaluates whether the proximity sensor first detects a body approach and then a body movement away again within a specific time period. Other gestures and movements can also be used for the action. Numerous implementations of the basic recognition of such action patterns are known in the prior art. Numerous designs of sensor devices with proximity sensors and associated control and evaluation devices are also known.

[0004] For example, US Pat. No. 5,629,999 discloses a corresponding sensor device and an attribution evaluation algorithm. An alternative embodiment in which the time course of the signal of a proximity sensor is subjected to pattern recognition can be seen from US Pat. No. 5,629,999.

[0005] Known systems have in common that the signal curve of the proximity sensor is evaluated and, based on the evaluation, it is determined whether or not a user operation command is actually present. Furthermore, simultaneously with or subsequent to the ongoing evaluation, an authorization request can be made which triggers a wireless request using a vehicle key or other identification means that the operator must carry, and the vehicle function is actually deactivated. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] West German Patent Application Publication No. 102012100960 [Patent Document 2] West German Patent Application Publication No. 102014100974 [Patent Document 3] West German Patent Application Publication No. 102014106939 Summary of the Invention [Problem to be solved by the invention]

[0007] While the basic functions of such operating devices and their operating methods are now widespread and proven, acceptance among users and operators is not always satisfactory. Operators often doubt whether they are performing the operating gesture correctly or whether the vehicle is even ready to detect the performed operating gesture. Numerous improvements have already been proposed to facilitate operation, such as visual indication of the area where the operating gesture should be performed (see, for example, Patent Document 3).

[0008] However, such systems sometimes entail new problems, for example because they require light sources that are not acceptable in vehicles or because they also lose their usefulness in adverse ambient conditions. [Means for solving the problem]

[0009] The object of the invention is to provide an improved method which not only increases the operating comfort of a sensor device but also allows for improved operating safety.

[0010] This problem is solved by a method having the features of patent claim 1.

[0011] According to the present invention, during the recognition process of an operating event, a number of different signals are output at the signal output of the control and evaluation device. This control and evaluation device can typically be connected via its signal output to the vehicle's bus system or another central control unit of the vehicle. It receives the signal received from the control and evaluation device of the sensor device and, if appropriate, taking into account additional signals and criteria, commands subordinate actions, such as unlocking the doors or other adjustments in the vehicle. In response to the central control unit receiving a signal from the control and evaluation device of the sensor device, wireless communication can also be deactivated. However, subordinate actions are not part of the present invention. The reaction to the output signals can be individually selected by the vehicle manufacturer.

[0012] According to the present invention, a first actuation signal is output in addition to a second actuation signal, which in accordance with the present invention signals the recognition of a valid actuation gesture. When a user performs an actuation gesture within the detection range of the vehicle's sensor device and its proximity sensor, the sensor values ​​of the proximity sensor are evaluated to determine whether they represent a validly executed actuation gesture. As described in the prior art, a wide variety of pattern recognition or other evaluations can be considered for this purpose. For example, the evaluation of signal progressions representing actuation gestures such as foot swings or hand approaches can be captured and evaluated by threshold comparison, neural network pattern recognition, and other algorithms. The specific criteria specified also depend on the type of proximity sensor used, which may be configured as a capacitive sensor, for example (although the method can also be used with other types of proximity sensors). This recognition of actual actuation events belongs to the prior art and will not be discussed further herein.

[0013] However, according to the present invention, a first actuation signal is generated and output by the control and evaluation unit before a valid actuation is actually recognized. This first actuation signal may take into account completely different criteria than those used to evaluate a valid complete actuation event. For example, it may be a subset of the criteria also taken into account in the actuation signal evaluation, or it may be a more general criterion that is met in the correct execution of an actuation event, although it may also include some invalid actuation events, if appropriate. To generate the first actuation signal, a timer t1 is started when the control and evaluation unit detects the onset of actuation of the sensor device. Recognition of the onset of actuation may be, in particular, a change in the measured value of the proximity sensor that exceeds a certain deviation from the idle position, for example, exceeding a threshold value at a set distance from the long-term average value of the measured value of the proximity sensor, or a percentage change from the moving average. If such a change in the measured value is detected, the first timer t1 is started, and the proximity sensor continues to capture measured values. When the first timer t1 reaches the first target value tz1 and the measured value continuously satisfies the first criterion since the timer started and until the target value is reached, a first operating signal is generated at the signal output. The first criterion can be a complex criterion, but it can also be a simple continuous threshold comparison, whereby the criterion is not met if the measured value falls back into the range of the long-term average value in the non-operating state. It is also conceivable to check for a continuous monotonic decrease in the measured value of the proximity sensor, although the measured value may also be smoothed or filtered beforehand. In this case, the first criterion may differ from the criterion taken into account for valid operation recognition in terms of data volume and type of criterion. Therefore, a first criterion requiring only a small computational effort can simultaneously perform early recognition of the first criterion and complete monitoring of correct operation. In the present invention, the execution time t1 of the first timer (i.e., the target value tz1) is selected so that this execution time is significantly shorter than the normal operation time. In other words, the target value tz1 is reached before the operation is fully executed during normal operation.

[0014] The subordinate central control unit may further process the first operating signal and consider it as the trigger for multiple processes, which do not yet involve final action. In particular, in response to the first operating signal, information can be provided to the operator, so that the operator knows that an operation evaluation is underway and that the operator's ongoing operation process is being evaluated. This feedback significantly improves the operating comfort for the user, since the user does not know whether the vehicle or sensor device has already transitioned to the running and capturing state until the final release of the operating function. Such a cue to the user may take into account any signal perceptible to the user, such as the operation of the vehicle's signaling device or other vehicle devices (e.g., interior lighting).

[0015] The acquisition of measured values ​​continues during and after the generation of the first actuation signal. This continuation of the acquisition of measured values ​​continues according to the criteria taken into account for the normal recognition of the operating gesture. For such recognition, there is also usually a maximum duration, after which the recognition is interrupted without success. If, during the continued acquisition of measured values, a second criterion configured for the recognition of the valid execution of the operating gesture is met, and thus a valid operation is confirmed by the control and evaluation device, a second actuation signal is output at the signal output of the control and evaluation device following the first actuation signal.

[0016] According to the present invention, a check is then first made to see whether the first actuation signal has actually already been generated. This ensures that the first actuation signal precedes the second actuation signal whenever it is generated. This ensures that the operator receives a consistent sense of operation, i.e., that the release of the actuation is never recognized when the first actuation signal was not generated. Such a check is necessary because, as mentioned above, the criteria for generating the first actuation signal may differ from the criteria for recognizing successful operation. Because the first actuation signal is generated based on an earlier evaluation, it is entirely possible that the earlier evaluation did not meet the first criterion for generating the actuation signal, whereas a later evaluation reveals that a valid actuation did indeed occur. If the first criterion is, for example, a simple threshold comparison that checks whether the measured value is persistently above or below a set threshold during the execution time of the first timer, a single deviation in value may already result in a failure of validation of that criterion. For example, if a zero value is obtained for any reason in the signal transmission, the first criterion may be deemed not to have been met. A more complex evaluation, using appropriate smoothing and filtering, to generate the second control signal for the actual correctly executed complete operation may eliminate such errors and confirm that a valid operation indeed exists. In this case, even though the first criterion was not met up until time tz1, a first control signal is generated and output later, followed by a second control signal. As a result, it is always guaranteed that the second control signal is only output together with the preceding first control signal. In other words, if the central control unit deactivates a technical reaction in response to the first control signal, it can always be trusted that this execution also occurs before the actual operating operation.

[0017] According to the invention, the first and second operating signals are different, so that the subordinate central control unit receiving the signals from the control and evaluation unit can always distinguish between the operating signals, which can be any distinction in signal coding, frequency, signal level, etc.

[0018] It is particularly preferred if the first operating signal and the second operating signal differ in terms of their signal lengths.

[0019] Length coding of the signals allows for particularly simple and reliable transmission within the signalling system of a vehicle, for example via a bus system.

[0020] In a preferred embodiment of the invention, the first criterion comprises a condition according to which the measured value does not exceed a set first threshold value.

[0021] This criterion checks whether the threshold value is crossed within the execution time of the first timer t1. For example, the first rise or fall of the measured value above or below the threshold value can be used as a criterion for starting the timer t1, i.e., for recognizing an initiating maneuver event. Thereafter, until the end of the first timer t1, it is checked whether the signal again falls or rises toward the initial level. If this is not the case, i.e., if the signal does not again exceed the threshold value for the set time, the first maneuver signal is generated, if appropriate, after checking whether further conditions are met. The advantage of such a simple threshold check is the low computational requirements imposed on the evaluation and calculation. To design a corresponding system as simply as possible, low computational requirements are advantageous, especially since the actual, later recognition of a maneuver event may require all available resources in order to be able to perform a rapid evaluation. Furthermore, it has been shown that a simple threshold comparison can correctly recognize a substantial portion of the initiating maneuver event, although the threshold value is determined empirically and depending on the vehicle model.

[0022] In a preferred embodiment of the present invention, the sensor device includes at least two proximity sensors, each of which provides a measurement value, both of which are considered in the evaluation for generating the first actuation signal. That is, the sensor values ​​of both proximity sensors are considered until the first timer t1 reaches its target value, which allows for a more precise and reliable early evaluation for generating the first actuation signal. For example, both measurement value series can be compared with a threshold value, with each proximity sensor being assigned a specific threshold value for the comparison. In conventional sensor devices used, for example, in the rear area of ​​a vehicle, multiple proximity sensors, usually in the form of capacitive proximity sensors, are located at various positions on the vehicle shell. For example, a first proximity sensor is located in the bumper, while a second proximity sensor is located further below it, toward the center of the vehicle. When a foot swing is performed in this area, both proximity sensors detect signal changes, but with a time shift due to their positions. As a first criterion, a simple value comparison may then be taken into account, for example, for both proximity sensors, but it is also possible to check the time course of the measurement values ​​of the proximity sensors, for example whether both proximity sensors show an increasing or decreasing course until the first target value is reached by timer t1.

[0023] In a preferred embodiment of the present invention, the timer t1 is not only taken into account in the evaluation for generating the first actuation signal, but is continuously monitored thereafter. The achievement of the second target value TZ2 by the timer t1 can then be used as a time limit for recognizing a valid actuation event. That is, if the control and evaluation device does not recognize the presence of a valid actuation event by the second target value TZ2, resulting from the complete execution of a correct actuation gesture, the actuation event is discarded. In this way, a consistent maximum duration for possible acts is established that is clear and understandable to the user.

[0024] It is advantageous if the control and evaluation device is operated so that the signals output at the signal output section are transmitted with a minimum time interval TD. In this case, the control and evaluation device ensures that a minimum delay is observed, even when multiple signals are output simultaneously or one after the other, ensuring accurate signal transmission within the vehicle system at all times. This is particularly important when the first actuation signal and the second actuation or malfunction signal are generated almost simultaneously. In any case, the delay in the operation of the control and evaluation device ensures that a minimum time interval is observed between the first actuation signal and the second actuation or malfunction signal. This is particularly important when the first actuation signal and the second actuation signal are generated almost simultaneously. As described above, if an actuation is recognized and the first actuation signal has not yet been output before, the first actuation signal is always compensated for. In this case, too, the delay in the operation of the control and evaluation device ensures that a minimum time interval is observed between the first actuation signal and the second actuation signal.

[0025] It is particularly preferred that if a first operating signal is output but then no fully effective operation is recognized and accordingly a second operating signal is not generated because the measured value does not fulfill the second criterion, a malfunction signal different from the first and second operating signals is output.

[0026] That is, the malfunction signal is output each time a first operating signal is sent but an effective operation is not subsequently confirmed. This ensures that the action generated by the first operating signal in the vehicle or downstream to the operator is canceled, so that a consistent operating sequence and impression is always produced for the user. For example, if the first operating signal is used to signal the operator of ongoing operation recognition, a corresponding malfunction signal can be used to inform the operator of unsuccessful detection. This increases operator support, because the operator can always understand whether the operation is progressing with respect to its capture, whether the operation was effective, or whether the recognition of the operation was unsuccessful.

[0027] It is particularly preferred if the first operating signal is used to inform the operator of the progress of the evaluation method by means of an acoustic or optical signal, the aim of this process being an understandable operator guide, since by means of such optical or acoustic feedback the user is always informed about the current progress of the method.

[0028] In a modified form of the method, in addition to or as an alternative to the optical or acoustic cue in response to the first operating signal, the first operating signal may be used as a trigger to disable wireless radio communication regarding the authorization request of an ID transponder carried by the operator.

[0029] Since the first actuation signal precedes the second actuation signal for signaling successful opening, this time saving can be used to initiate a wireless request of the ID transponder, which must in any case precede the later release of a vehicle function, in particular door opening. When the first actuation signal is used for this purpose, it results in improved comfort and support. [Brief explanation of the drawings]

[0030] The invention is explained in more detail below with the help of the accompanying drawings.

[0031] [Figure 1a] 1 shows a rear view of a vehicle for the implementation of the method according to the invention; [Figure 1b] FIG. 1b shows a schematic side view of the vehicle from FIG. 1a. [Figure 2] FIG. 1 shows a flow chart of an embodiment of a method according to the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0032] 1a and 1b show a vehicle 1 in which proximity sensor electrodes 2, 3 are arranged in the rear region. These proximity sensor electrodes are connected to a control and evaluation device 4, which controls the proximity sensor electrodes, which are capacitive electrodes, and calculates their respective capacitances. This control device 4 is also connected to a central control device 5 of the vehicle. The control and evaluation device 4 is responsible for controlling the electrodes 2, 3 and for signal evaluation, i.e., for calculating the signal response and assigning it to an actuation signal. The possibly generated actuation signal is transmitted from the control and evaluation device 4 to the central control device 5, which can perform the tailgate closing function and electrical opening.

[0033] Electrode 2 is positioned in the lower rear region with its capture area 2a facing downwards as shown in Figure 1b, and electrode 3 is positioned with its capture area 3a facing rearwards.

[0034] FIG. 1b shows the user's legs 6a and 6b in two different positions. In position 6a, the user is standing behind the rear of the vehicle. The user's legs are captured in capture area 3a by sensor arrangement 3, if applicable, but not in capture area 2a by sensor arrangement 2. However, if the user approaches the tailgate and moves their feet into capture area 2a, as shown in position 6b, capture in area 3a and thus in area 2a is also possible. Effective actuation recognition requires that sensors 2 as well as 3 provide a temporal signal sequence that matches criteria stored in control and evaluation unit 4. For example, this may take into account how long the user's legs need to remain in position 6b to recognize a successful actuation, and how the measured values ​​of sensors 2 and 3, respectively, change over time. How such recognition proceeds and how the appropriate second actuation signal is generated is described in detail in the prior art. The control and evaluation device may perform, inter alia, pattern or threshold comparisons or may also include neural networks to distinguish actual operations from disturbing signals due to other objects or ambient conditions.

[0035] However, according to the invention, the first actuation signal is preceded by a second actuation signal that signals the success of the operation to the central control device 5. To generate the first actuation signal, once the actuation to be initiated is recognized, a timer t1 is first started, which in this example may be started as soon as the proximity sensor electrodes 3 and 2 detect the approach of an object, indicated by an increase in measurement values ​​above their assigned thresholds.

[0036] 1a and 1b serve to clarify a system that can be used to carry out the method according to the invention, whereas FIG. 2 shows a flow chart of the method according to the invention according to a first embodiment.

[0037] In the first part of the method according to the present invention, shown in block 10 of FIG. 2, the control and evaluation device 4 monitors the signals S1 and S2, each assigned to one of the proximity sensor electrodes 2 or 3. This monitoring continues in a loop until it is determined that the measured values ​​at both proximity sensors 2 and 3 exceed the assigned thresholds THR1 and THR2. Exceeding these thresholds indicates the possible beginning or initiation of an operational event. The capacitances captured by the proximity sensor electrodes 2 and 3 then change significantly compared to their previous state (idle state or moving average), indicating the proximity of a user. If this condition is met, i.e., if the assigned thresholds THR1 and THR2 are exceeded at both proximity sensor electrodes 2 and 3, process block 30 is executed.

[0038] Process block 30 illustrates how the first actuation signal is generated and the associated criteria in this exemplary embodiment of the invention. First, timer t1 is set to zero. Then, during the execution time of timer t1, i.e., for a time shorter than the target value tz1, it is checked whether the signals S1 and S2, i.e., the measured values ​​of the proximity sensor electrodes 2 and 3, subsequently do not again exceed the assigned threshold and rise or fall toward their initial level. While reference is made herein to falling and rising sensor measured values, this is only relevant for the specific exemplary embodiment. Whether proximity is represented by a falling or rising measured value depends on the signal display of the proximity sensor electrodes and the type of circuit. Process block 30 checks whether the signal data S1 and S2 remain on the same side of the assigned threshold and do not again exceed these thresholds during the execution time of timer t1. If this is the case, the first actuation signal is generated at the signal output of the control and evaluation device. If this is not the case, the first actuation signal is not generated. In any case, after the execution time of timer t1 has expired, the process returns to block 20. There, regardless of the previous or parallel check in block 30, the presence of a valid operating event is checked based on the proximity sensor measurements S1 and S2. The time required for this can be significantly longer than time tz1, and accordingly, additional measurement values ​​can be taken into account compared with the process from block 30. The evaluation of such a valid operating event can be performed based on complex criteria and with significantly greater computational effort, for example, by pattern comparison or by feeding stored measurement values ​​for a specific time range into a neural network. A valid operating event can also be recognized using multiple threshold comparison criteria. If a valid operating event is recognized in block 20, it is checked whether a first operating signal has been sent. If a valid operating signal was not output in the previous or parallel check in block 30, the first operating signal is output first.A second actuation signal is then output, which indicates the recognition of a valid actuation event, with the control and evaluation device inserting a predetermined minimum time interval between the first and second actuation signals.

[0039] This procedure therefore ensures that the first actuation signal always precedes the second actuation signal, even if the first actuation signal was not sent during the recognition in block 30.

[0040] However, if it is determined in block 20 that a valid actuation signal has not been recognized, it is likewise first checked in block 30 whether a first actuation signal has been generated. If this is not the case, the process ends and the measured values ​​S1 and S2 are monitored again. However, if a first actuation signal has been transmitted in block 30, a malfunction signal is now output from the control and evaluation device. Then, the process returns to monitoring the sensors.

[0041] The reaction of the central control unit 5 to the first actuation signal, on the one hand, and the second actuation signal, on the other hand, depends on the intended use and the respective vehicle manufacturer that incorporates the corresponding system. As already mentioned above, the first actuation signal can be used, inter alia, to signal the user to check their operation in progress. Alternatively, the first actuation signal can be used to include an identification means carried by the user, such as a remote key, in a wireless communication. In such a wireless communication, for example, the distance to the valid vehicle key can be checked by the vehicle while the actual operation recognition is still in progress. Similarly, a malfunction signal can be used to send an appropriate report to the user or the carried identification means and, if appropriate, to interrupt the wireless communication again.

Claims

1. A method for evaluating a sensor device having at least one proximity sensor (2, 3) for detecting the spatial proximity of a body (6a, 6b) and at least one control and evaluation device (4) coupled to the proximity sensor and having a signal output, comprising: repeatedly capturing the sensor measurements of the proximity sensors (2, 3) by the control and evaluation device; If the sensor measurement characterizes the onset of operation of the sensor device, - starting a first timer t1; - repeatedly capturing the sensor measurements of the at least one proximity sensor (2, 3) by the control and evaluation device, a first actuating signal is output at the signal output of the control and evaluation device (4) if the first timer reaches a first target value tz1 and if the sensor measured values ​​continuously fulfill a first criterion since the start of the first timer; - continuously capturing the sensor measurements of the at least one proximity sensor by the control and evaluation device (4), - if the sensor measurements satisfy a second criterion, which is configured for the recognition of a valid execution of a manipulation gesture, a valid manipulation is confirmed by the control and evaluation device (4); and if a first operating signal has already been output, a second operating signal is output at the signal output unit; - if a first actuation signal has not yet been output, first the first actuation signal is output at the signal output of the control and evaluation device (4) and then the second actuation signal is output at the signal output, the first actuation signal and the second actuation signal are characteristically distinct steps and Including, The first criterion includes a condition whereby the sensor measurement value does not exceed a set first threshold.

2. The method of claim 1 , wherein the first operating signal and the second operating signal differ in their signal lengths.

3. 3. The method according to claim 1, wherein the sensor device comprises at least two proximity sensors (2, 3), each of which supplies a sensor measurement value, and wherein a first operating signal is output at the signal output unit when the first timer reaches a first target value and when the sensor measurement values ​​of all proximity sensors (2, 3) continuously fulfill a first criterion assigned to each of them since the start of the first timer.

4. 4. The method of claim 3, wherein the first criterion respectively assigned to each proximity sensor is a specific threshold value that the sensor measurement value of the respective proximity sensor (2, 3) must not exceed.

5. 5. The method according to claim 1, wherein if the sensor measurement values ​​do not meet the second criterion, an invalid operation is confirmed by the control and evaluation device and, if a first operating signal has already been output, a malfunction signal is output at the signal output.

6. 6. The method according to claim 1, wherein the second criterion includes a condition according to which a valid execution of the manipulation gesture must be recognized by the timer t1 within an execution time of the timer t1 and before a second target value tz2 is reached.

7. 7. The method according to claim 1, wherein the control and evaluation device delays the output of the signals at the signal output section, if necessary, in such a way that a minimum time interval td is observed between the signals.

8. 8. The method according to any one of claims 1 to 7, wherein the first operating signal and / or the malfunction signal is received by a processing unit and used as a trigger for disabling an optical or acoustic signaling device.

9. 9. The method according to claim 1, wherein the first operation signal is received by a processing unit and used as a trigger to release wireless radio communication related to an authorization request of an ID transponder carried by an operator.

Images