Procedure for adjusting particulate matter measurements

Abstract

Method for adapting particulate matter measured values ​​detected by a sensor (13) for detecting particulate matter within a motor vehicle (30), comprising the following steps: - Recording of fine dust measured values ​​using the sensor (13), - detecting at least one condition parameter of the motor vehicle (30), - Adjusting the recorded particulate matter measurement values ​​using a correction factor depending on the at least one recorded condition parameter.

Description

[0001] The present invention relates to a method and a device for adjusting particulate matter measured values ​​detected by a particulate matter sensor within a motor vehicle. The invention also relates to a motor vehicle.

[0002] In the future, motor vehicles will be equipped with a built-in sensor for detecting particulate matter, in particular to display the particulate matter concentration inside the vehicle and / or in the environment outside the vehicle in real time. Certain challenges arise when using sensors to accurately estimate particulate matter pollution or concentration, particularly in connection with sensors that use optical detection of particulate matter. Most sensors are calibrated for a specific range of particulate matter concentrations. Within this range, the sensors react differently, for example, depending on whether they are fixed measuring or monitoring stations, or depending on a specific calibration device used, which is usually designed for high-precision or laboratory-quality measurements.

[0003] Sensors for detecting particulate matter are sensitive to changes in environmental conditions, particularly temperature, humidity, and vibration changes, as well as changes in the operating conditions of air conditioning systems, such as the use of recirculated or fresh air supply, or the presence of open or closed windows, etc. Taking into account the various possible applications, one challenge is to develop a control mechanism so that particulate matter pollution can be read as precisely as possible using the sensors.

[0004] It is also possible that a vehicle occupant themselves contributes to a change in the particulate matter concentration inside the vehicle, for example, by smoking, for example, conventional cigarettes or e-cigarettes. In this case, the type, size, and concentration of the aerosols may differ from aerosols resulting from sources outside the vehicle. In this case, it is not desirable to inform the vehicle occupant of a particulate matter concentration value caused by them, but there is currently no reliable method to distinguish whether the particulate matter was intentionally generated or not.

[0005] Document US 9 688 194 B2 describes a method for evaluating particulate matter measurements using particulate matter sensors in connection with motor vehicles. Document US 2018 / 0 037 093 A1 discloses a method for improving air quality in a vehicle interior. Document US 6 206 775 B1 describes an air conditioning system with a pollution sensor. Further prior art can be found in the documents OTT, Wayne; KLEPEIS, Neil; SWITZER, Paul: Air change rates of motor vehicles and invehicles pollutant concentrations from secondhand smoke. In: Journal of exposure science and environmental epidemiology, Vol. 18, 2008, No. 3, pp. 312-325. - ISSN 1559-0631 and SZWABOWSKI, Steven J. [et al.]: In-vehicle ambient condition sensing based on wireless internet access.In: Intelligent vehicle initiative (IVI) technology advanced controls and navigation systems, 2010: held during the SAE 2010 world congress, held April 13-15, 2010 in Detroit, Michigan, USA. Warrendale, Pa.: SAE International, 2010 (SAE special publication; 2264). S.37-43. - ISBN 978-0-7680-3402-8 offenbart.

[0006] Against the background described, the object of the present invention is to provide a method and a device for adjusting particulate matter measured values ​​detected by a sensor for detecting particulate matter within a motor vehicle. A further object is to provide an advantageous motor vehicle. These objects are achieved by a method for adjusting detected particulate matter measured values ​​according to claim 1, a device for adjusting detected particulate matter measured values ​​according to claim 9, and a motor vehicle according to claim 10. The dependent claims contain further advantageous embodiments of the invention.

[0007] Sensors for detecting particulate matter installed inside a motor vehicle are capable of measuring high-resolution data on particulate matter concentrations. However, this data must be correctly interpreted, as changes in the signals may be due to the vehicle's operating conditions. For example, the windows may be open or closed, and sources of various types of particulate matter, such as particles caused by smoking, may be present inside the vehicle. Furthermore, the operating conditions of the air conditioning system, particularly a switched-on fan, the use of recirculation, the opening of doors, etc., influence the measured particulate matter levels. Environmental conditions also influence the measurement.

[0008] To address this situation, the present invention uses a correction factor to adjust the measured particulate matter values ​​under specific conditions. The signals output by the sensor can be adjusted. The adjusted signals can then be forwarded to a human-machine interface or an HMI display.

[0009] The method according to the invention for adjusting particulate matter measured values ​​detected, in particular measured, within a motor vehicle by means of a sensor for detecting particulate matter, in particular for measuring particulate matter, comprises the following steps: Particulate matter measured values, for example, particulate matter concentration values, are detected by the sensor. At least one condition parameter of the motor vehicle is detected. The detected particulate matter measured values ​​are adjusted using a correction factor depending on or based on at least one detected condition parameter.

[0010] The method according to the invention has the advantage that the measured particulate matter values ​​can be adapted to specific conditions inside and / or outside the motor vehicle. This particularly applies to conditions that result in a temporary increase in particulate matter concentration or those caused by a vehicle occupant. Furthermore, a precise measurement of the particulate matter concentration in the air inside the passenger compartment is possible, which, in particular, reflects the particulate matter exposure actually relevant to the user.

[0011] In an advantageous variant, the rate of change of the recorded particulate matter measurements is determined, for example, calculated, and the recorded particulate matter measurements are adjusted if the rate of change exceeds a specified threshold. This makes it possible to adjust the particulate matter measurements only if a sudden or abrupt change in the recorded particulate matter measurements occurs, which can be assumed not to represent the actual particulate matter pollution in the ambient air or the air inside the passenger compartment.

[0012] The adjusted particulate matter measurements can be output via a human-machine interface (HMI), for example, via an HMI display. This has the advantage that a user, especially a driver or other vehicle occupant, is only shown those particulate matter measurements that actually represent relevant particulate matter pollution. The display also allows the user to be informed about the current particulate matter pollution level and, if necessary, take measures to either reduce the particulate matter pollution or protect themselves from it.

[0013] In a further variant, the motor vehicle may include an air conditioning system. In this case, at least one parameter of the operating state of the air conditioning system (HVAC parameter) can be recorded as a state parameter of the motor vehicle.

[0014] In an advantageous variant, the temperature, in particular the temperature inside / or outside the motor vehicle, and / or the air humidity are recorded. In addition or alternatively, the current location of the motor vehicle or the position can be recorded as a status parameter, for example using GPS. Furthermore, the operating status of the vehicle doors, i.e. whether and to what extent the vehicle doors are open or closed, and / or the operating status of the windows, i.e. whether and to what extent they are open or closed, can be recorded. Advantageously, in addition to or alternatively to the aforementioned characteristics, the operating status of the fan can be recorded. Since the aforementioned characteristics may influence the measurement result of the particulate matter measured by the sensor, recording and taking into account the aforementioned characteristics is advantageous with regard to adjusting the recorded particulate matter measured values.

[0015] Advantageously, it is possible to record whether smoking is currently taking place in the vehicle as a status parameter. This can involve smoking tobacco or other smoking products and / or vaping, i.e., smoking e-cigarettes. Since smoking by vehicle occupants alters or distorts the recorded particulate matter measurements with regard to the particulate matter actually present in the ambient air, it is advantageous to take the fact of smoking inside the vehicle into account accordingly. Typically, the user is not primarily interested in being notified of self-inflicted particulate matter pollution, but rather would like to be notified of the particulate matter pollution in the ambient air.

[0016] In an advantageous variant, the vehicle interior and / or the surroundings of the motor vehicle are at least partially recorded using a camera. The recorded data can be evaluated with regard to possible causes of increased particulate matter pollution. The recorded particulate matter measured values ​​can then be adjusted depending on the result of the evaluation. The use of a camera is particularly suitable for detecting whether smoking is currently taking place in the motor vehicle. The camera can be used in particular to determine whether there are sources of temporarily increased particulate matter concentrations in the vehicle's surroundings. This could, for example, be a motor vehicle driving ahead that emits exhaust gases with increased particulate matter pollution.

[0017] In an advantageous variant, the correction factor is adjusted depending on the at least one recorded condition parameter. This can occur continuously, at set times or at set intervals, or at times selected by a user. The immediate adjustment of the correction factor has the advantage that the recorded particulate matter measurements do not have to be first analyzed with regard to a rate of change, but rather an adjustment can be made immediately if specified condition parameters are present. In this context, for example, specified or previously defined correction factors can be used for certain condition parameters. The immediate adjustment of the correction factor therefore has the advantage that a particularly rapid adjustment can be made.

[0018] The device according to the invention for adjusting particulate matter measured values ​​detected, in particular measured, within a motor vehicle by means of a sensor for detecting particulate matter, in particular by means of a sensor for measuring particulate matter, is characterized in that it comprises a sensor for detecting particulate matter measured values. Furthermore, the device comprises a device for detecting at least one condition parameter of the motor vehicle. The device according to the invention also comprises a control device designed to carry out a method according to the invention described above.

[0019] The sensor can be designed, in particular, to detect the particulate matter concentration. The control device can be designed, in particular, to determine, in particular calculate, the rate of change of the detected particulate matter measured values. Additionally or alternatively, the control device can be designed to adjust the correction factor depending on the at least one detected state parameter. The device according to the invention basically has the same advantages and features as the previously described method according to the invention.

[0020] The motor vehicle according to the invention comprises a sensor for detecting particulate matter within the motor vehicle. The motor vehicle is designed to carry out a method according to the invention described above. Additionally or alternatively, the motor vehicle according to the invention can comprise a previously described device according to the invention. The motor vehicle according to the invention has the same advantages and features as the method according to the invention described above and the device according to the invention already described. The motor vehicle can be, for example, a passenger car or a truck.

[0021] The invention will be explained in more detail below using exemplary embodiments with reference to the accompanying figures. Although the invention is illustrated and described in more detail by the preferred embodiments, the invention is not limited to the disclosed examples, and other variations may be derived therefrom by those skilled in the art without departing from the scope of the invention.

[0022] The figures are not necessarily detailed or to scale and may be enlarged or reduced to provide a better overview. Therefore, the functional details disclosed herein are not to be interpreted in a limiting sense, but merely as an illustrative basis for teaching one skilled in the art how to variously employ the present invention.

[0023] As used herein, the term "and / or," when used in a series of two or more elements, means that any of the listed elements may be used alone, or any combination of two or more of the listed elements may be used. For example, if a composition is described as containing components A, B, and / or C, the composition may contain A alone; B alone; C alone; A and B in combination; A and C in combination; B and C in combination; or A, B, and C in combination. Fig. 1 schematically shows a first embodiment of the method according to the invention in the form of a flow chart. Fig. 2 schematically shows a further variant of a method according to the invention in the form of a flow chart. Fig. 3 schematically shows a device according to the invention for adapting particulate matter measurement values ​​recorded by means of a sensor for detecting particulate matter within a motor vehicle. Fig. 4 shows schematically a motor vehicle according to the invention.

[0024] The Fig. 1 schematically shows a first embodiment of the method according to the invention in the form of a flow chart. The method begins at step 1. At step 2, particulate matter measurements are recorded using a sensor. The recorded measurements can be output by the sensor. At step 3, it is examined whether the rate of change of the recorded particulate matter measurements exceeds a specified threshold value. The rate of change is preferably determined, in particular calculated, from the particulate matter measurements output by the sensor at step 2. If the rate of change does not exceed the specified threshold value, at step 4, the particulate matter measurement recorded by the sensor or the measured values ​​are output to a display device. At step 5, the recorded measurements are displayed as particulate matter concentration values ​​on a display, in particular a display arranged inside a motor vehicle.

[0025] If the rate of change exceeds the specified threshold, the affected measured values ​​are flagged in step 6. Furthermore, at least one condition parameter of the motor vehicle is recorded in step 6. In this context, various vehicle system data, GPS data, the operating status of the air conditioning system, and other condition parameters of the motor vehicle mentioned above can be recorded. In step 7, at least one recorded particulate matter measured value, preferably the particulate matter measured values ​​flagged in step 6, is adjusted using a correction factor depending on at least one of the recorded condition parameters.

[0026] Subsequently, in step 8, the observation or monitoring of the recorded particulate matter measurements continues, with their rate of change being checked. In step 9, it is checked whether the rate of change continues to exceed the specified threshold. If this is the case, the process continues with step 6. If this is not the case, the particulate matter concentration estimate is updated in step 10. In other words, the values ​​adjusted using the correction factor are output to a display device. In step 5, the corrected particulate matter measurements are subsequently displayed as particulate matter concentration values. The process ends with step 11.

[0027] A sensor for detecting particulate matter measurements is typically calibrated relative to specific reference devices. This standard calibration may be limited in that it is unable to account for the dynamics of the detected particles or the type of particles. The present invention addresses this situation. Two types of control can be distinguished. The first involves active adjustment using data read from the sensor. The second variant involves passive adjustment of the read measurement data.

[0028] In the first variant, particulate matter measurements are recorded using a sensor. Furthermore, data from other vehicle systems, particularly vehicle condition parameters, are recorded. This can include the state of the windows (open or closed), the state of the doors (open or closed), the operating state of the air conditioning system (especially the use of recirculated air and / or fan), the ambient temperature, the vehicle interior temperature, the humidity, and so on. For example, if the position of the windows (open or closed) is taken into account, this condition can be used as an example to estimate whether a certain change in the recorded particulate matter measurements is attributable to this.For example, if a rate of change in the recorded particulate matter measurements exceeds a threshold, the position of the windows can be identified as a possible cause, and the measured value can be adjusted accordingly. This can be achieved, in particular, with the help of a correction factor. This allows the estimated particulate matter measurement value to be corrected in real time. The corrected value can then be displayed to a user.

[0029] In addition to the aforementioned operating conditions, a vehicle position determined by GPS can also be used as a vehicle condition parameter. Higher levels of particulate matter can occur, for example, due to driving through a tunnel, overtaking a truck, passing a construction site, etc. In order to assess the cause of the poor air quality, at least one photo can be taken using a camera and evaluated with regard to possible causes of increased particulate matter pollution. In this way, further fine-tuning or adaptation of the output signal with regard to the actual particulate matter concentration is possible. The device and method according to the invention have the advantage that sensors that are typically already present in a vehicle or data already recorded in another context can be used.

[0030] A second variant involves passive adjustment of the recorded particulate matter measurements. In this variant, the correction factor is applied directly based on inputs from recorded vehicle condition parameters, such as the operating status of the air conditioning system, the position of the windows and / or doors, etc., without having to wait for further evaluation of the concentration values ​​recorded by the particulate matter sensor. For example, correction factors can be saved for different situations and operating states of the vehicle. The respective factor can then be used directly to adjust the recorded particulate matter measurements. The value corrected in this way for an estimated particulate matter concentration can then be displayed to a user.

[0031] The Fig. Figure 2 schematically shows a further variant of a method according to the invention in the form of a flow chart. The method begins at step 31. At step 32, the particulate matter sensor is put into operation. At step 33, measured values ​​are acquired by the particulate matter sensor. At step 34, particulate matter sensor output signals are generated. For this purpose, measurement data 35 from the particulate matter sensor are input, and a raw data stream is generated as a function of time, for example, one signal per second, P_raw(t) in, for example, micrograms per cubic meter (µg / m 3 ) is issued.

[0032] This data stream is examined for possible errors in step 36. If no errors are present, the raw data stream is stored in a memory array in step 37. In step 38, a filtered data stream P_filter(t) is generated by averaging the data, for example, using a suitable filter function, for example, P_filter(t) = (P t-N +...+ P t-2 + Pt-1 + P t ) / N. The data stream thus generated is stored in a memory array at step 39. At step 40, the rate of change, i.e., the change in concentration per time, Δ P_filter(t) = P_filter(t) - P_filter(t-1), is calculated. At step 41, a check is made as to whether the calculated rate of change exceeds a threshold value. If this is not the case, the calculated particulate matter concentration P_filter(t) is output, in particular displayed, at step 42. The process then continues at step 33.

[0033] If the rate of change in step 41 is greater than a specified threshold, the affected value is marked with a counter (Counter = Counter + 1) in step 43 and, if necessary, locked. The value is saved. If an error is detected in step 36, an error indication for calculating counters (CounterCalN) is initiated in step 44, and the process then continues with step 43. In step 45, the previously averaged concentration value is locked, P_latch = P_filter(t-1).

[0034] In the following, steps 46, 49, 52, 55 and 58 are carried out individually or in any combination. This can occur simultaneously or in any order. In step 46, a check is made to see whether the air conditioning system has switched from recirculated air to fresh air supply. In addition, a check is made to see whether the counter is less than a first counter calculated in step 44 (Counter < CounterCal1?). If there is no change in the air conditioning system from recirculated air to fresh air, a value P_display to be displayed is output in step 47, which is equal to the locked value P_latch (P_display = P_latch). If there is a change in the operation of the air conditioning system from recirculated air to fresh air, a first error value P_Error1 is output in step 48 (P_display = P_error1).

[0035] In step 49, a check is performed to determine whether a vehicle occupant is smoking. A check is also performed to determine whether the counter is less than a second counter calculated in step 44 (Counter < CounterCal2?). If no vehicle occupant is smoking, a display value P_display is output in step 50 that is equal to the locked value P_latch (P_display = P_latch). If it is determined in step 49 that a vehicle occupant is smoking, a second error value P_Error2 is output in step 51 (P_display = P_error2).

[0036] In step 52, a check is made to determine whether the fan speed has been increased. A check is also made to determine whether the counter is less than a third counter calculated in step 44 (Counter < CounterCal3?). If the fan speed has not been increased, a display value P_display is output in step 53 that is equal to the locked value P_latch (P_display = P_latch). If the fan speed has been increased, a third error value P_error3 is output in step 54 (P_display = P_error3).

[0037] In step 55, a check is made to determine whether a door is ajar. A check is also made to determine whether the counter is less than a fourth counter calculated in step 44 (Counter < CounterCal4?). If no door is ajar, a value P_display is output in step 56 that is equal to the locked value P_latch (P_display = P_latch). If step 55 determines that a door is ajar, a fourth error value P_error4 is output in step 57 (P_display = P_error4).

[0038] In step 58, a check is made to determine whether a window is open. A check is also made to determine whether the counter is less than a fifth counter calculated in step 44 (Counter < CounterCal5?). If no window is open, a display value P_display is output in step 59, which is equal to the locked value P_latch (P_display = P_latch). If it was determined in step 58 that a window is open, a fifth error value P_error5 is output in step 60 (P_display = P_error5).

[0039] In step 61, a check is performed to determine whether one of the values ​​P-display to be output is equal to an error value P_errorN or whether the counter is greater than a maximum counter value. If this is the case, the counter is set to 0 in step 62, and the process then continues with step 33. If the conditions checked in step 61 are not met, the process continues directly with step 33.

[0040] The Fig. 3 schematically shows a device according to the invention for adapting particulate matter measured values ​​recorded by a sensor for detecting particulate matter within a motor vehicle. The device 12 according to the invention comprises a sensor 13 for detecting particulate matter measured values, in particular for detecting the particulate matter concentration. The device 12 also comprises a device 14 for detecting at least one condition parameter of the motor vehicle. Furthermore, the device 13 comprises a control device 15 designed to carry out a method according to the invention described above. The sensor 13 and the device 14 are connected to the control device in such a way that the measured values ​​recorded by the sensor 13 can be transmitted to the control device 15 and the condition parameters recorded by the device 14 can be transmitted to the control device 15. The device 12 according to the invention can optionally also comprise a display 16.The display 16 is designed to output the particulate matter measurement values ​​output by the control device 15, which may have been adjusted according to the method according to the invention.

[0041] The Fig. Figure 4 schematically shows a motor vehicle according to the invention. The motor vehicle 30 comprises a device 12 according to the invention for adjusting particulate matter measured values ​​recorded by a particulate matter sensor. List of reference symbols 1 Start 2 Recording / measuring particulate matter values 3 Does the rate of change of the recorded particulate matter measurements exceed a specified threshold? 4 Output measured value 5 Display (corrected if necessary) value for particulate matter concentration 6 Marking of affected measured values ​​and recording status parameters 7 Adjusting the measured values ​​depending on at least one of the recorded condition parameters using a correction factor 8 Continue monitoring with regard to the rate of change of measured values 9 Does the rate of change exceed the specified threshold? 10 Update of the estimate of particulate matter concentration 11 End 12 Device for adjusting particulate matter measurements 13 Sensor for recording particulate matter measurements 14 Device for recording at least one condition parameter of the motor vehicle 15 Control device 16 Advertisement 30 motor vehicles 31 Start 32 particulate matter sensors in operation 33 Fine dust sensor in operating mode 34 Outputting signals 35 Entering particulate matter sensor data 36 Is there an error? 37 Save raw data stream 38 generate a filtered data stream by averaging 39 save filtered data stream 40 Calculate rate of change 41 Does the rate of change exceed a threshold? 42 output / display filtered data stream 43 Mark value with a counter 44 Display error message for meter calculation 45 lock previous value 46 Changing the air conditioning system from recirculated air to fresh air? 47 output locked value 48 first error message 49 Is smoking permitted in the vehicle? 50 output locked value 51 display second error message 52 Fan speed increased? 53 output locked value 54 display third error message 55 Is a door ajar? 56 output locked value 57 fourth error message 58 Is a window open? 59 output locked value 60 fifth error message 61 Was an error message displayed or is the counter above a maximum? 62 Set counter to zero Y Yes N No

Claims

[1] Method for adapting particulate matter measured values ​​detected by a sensor (13) for detecting particulate matter within a motor vehicle (30), which comprises the following steps: - Recording of fine dust measured values ​​using the sensor (13), - detecting at least one condition parameter of the motor vehicle (30), - Adjusting the recorded particulate matter measurement values ​​using a correction factor depending on the at least one recorded condition parameter. [2] Method according to claim 1, characterized by that the rate of change of the recorded particulate matter measurements is determined and the recorded particulate matter measurements are adjusted if the rate of change exceeds a specified threshold. [3] Method according to claim 1 or claim 2, characterized by that the adjusted particulate matter measurements are output to a human-machine interface. [4] Method according to one of claims 1 to 3, characterized by that the motor vehicle (30) comprises an air conditioning system and at least one parameter of the operating state of the air conditioning system is detected as a state parameter of the motor vehicle (30). [5] Method according to one of claims 1 to 4, characterized by that the temperature and / or the air humidity and / or the current position of the motor vehicle (30) and / or the operating state of the vehicle doors and / or the windows and / or the operating state of the fan is detected. [6] Method according to one of claims 1 to 5, characterized by that the status parameter recorded is whether smoking is currently taking place in the motor vehicle (30). [7] Method according to one of claims 1 to 6, characterized bythat the vehicle interior and / or the surroundings of the motor vehicle (30) are at least partially recorded by means of a camera, the recorded data are evaluated with regard to possible causes of increased particulate matter pollution and the recorded particulate matter measured values ​​are adjusted depending on the result of the evaluation. [8] Method according to one of claims 1 to 7, characterized by that the correction factor is adjusted depending on the at least one recorded state parameter. [9] Device (12) for adjusting particulate matter measurement values ​​recorded by a sensor (13) for detecting particulate matter within a motor vehicle (30), characterized by that the device (12) comprises a sensor (13) for detecting particulate matter measurement values ​​and a device (14) for detecting at least one condition parameter of the motor vehicle (30), and is designed to carry out a method according to one of the preceding claims. [10] Motor vehicle (30) comprising a sensor (13) for detecting fine dust within the motor vehicle (30) and designed to carry out a method according to one of claims 1 to 8 and / or comprising a device (12) according to claim 9.

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